JP6855131B2 - Map screen display device, brightness adjustment parameter calculation device, and map screen display method - Google Patents

Description

The present invention relates to a map screen display device, a parameter calculation device for brightness adjustment, and a map screen display method. In particular, a map screen display device that enables three-dimensional visibility of terrain by shading, and the map screen display device draws It is suitable for use in a brightness adjustment parameter calculation device for calculating parameters used for image brightness adjustment and a map screen display method.

Conventionally, on a map screen displayed by a map screen display device (for example, a navigation device), it is assumed that the background image of the mountains constituting the map screen when viewed from directly above the sky is irradiated with light from a predetermined direction. Then, by displaying an image in which a shadow is added to the shadowed portion at that time, the surrounding terrain can be visually recognized in three dimensions.

The background image is displayed based on the image data in which the background image is recorded, but the average brightness value of the image data (original image) is calculated based on the Y value of each pixel in the YUV color gamut. When the average brightness value is darker than the reference value, there is known a technique for adjusting the brightness of a dark portion of image data to increase the recognition rate of the original image (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-146246

FIG. 10 is a diagram showing a display example of a conventional map screen. The map screen 1000 shown in FIGS. 10A and 10B is a map screen when the area around the vehicle's own vehicle position is viewed from directly above the sky, and is the position of the own vehicle on which the vehicle's own vehicle position mark 1001 is located. It is generated by superimposing a map image of the surrounding area and a background image 1020 representing the terrain. FIG. 10A shows a state in which the traveling direction of the vehicle is north when the map screen 1000 is displayed in the heading-up mode. That is, the upper side of the map screen 1000 is north. Further, FIG. 10B shows a state when the traveling direction of the vehicle is south when the map screen 1000 is displayed in the heading-up mode. That is, the upper side of the map screen 1000 is south. The area on the map displayed in FIG. 10 (a) and the area on the map displayed in FIG. 10 (b) are the same.

In this map screen 1000, it is assumed that the background image 1020 is illuminated from the northwest direction when the north is on the upper side, and the background image 1020 is shaded on the shadowed portion at that time. Is created by adding. That is, the background image 1020 is shaded so that the terrain can be correctly recognized when the north side of the map screen 1000 is on the upper side.

For example, in the background image 1020, the valley bottom 1021, the ridge line 1022, and the ridge line 1023 are shown. Further, a western slope 1031 is shown between the valley bottom 1021 and the ridge line 1022. Further, an eastern slope 1032 is shown between the valley bottom 1021 and the ridge line 1023. Then, a shadow is added to the part that becomes a shadow when the light is irradiated from the northwest direction. As a result, most of the western slope 1031 is shaded. In FIG. 10, each shadow is shown with the same density on the map screen 1000, but each shadow actually has a shade.

The map screen 1000 in which most of the western slope 1031 is shaded in this way correctly corrects the topography of the valley bottom 1021, the ridge line 1022, and the ridge line 1023 when the north is on the upper side as shown in FIG. 10 (a). It is visible. That is, it is possible to intuitively grasp that the vehicle is traveling on the road along the valley bottom 1021.

However, on the map screen 1000, when the south is on the upper side as shown in FIG. 10 (b), a shadow is added to a portion that becomes a shadow when light is irradiated from the northwest direction on a general map screen. Considering that, the terrain of the valley bottom 1021 is mistakenly visually recognized as a ridgeline. In addition, the terrain of the ridges 1022 and 1123 is mistakenly visually recognized as the valley bottom. That is, although the vehicle is actually traveling on the road along the valley bottom 1021, there arises a problem that the vehicle is mistakenly recognized as traveling on the road along the ridgeline.

In order to solve this problem, when the traveling direction of the vehicle is south (= when the direction to the upper side of the map screen is south in the heading up mode), the brightness of each pixel of the background image is inverted. Can be considered. By doing so, when the direction to the upper side of the map screen is south, it is possible to make it a state in which a shadow is added to the part that becomes a shadow when light is irradiated from the southeast direction. Can be solved.

FIG. 11 shows a state in which the light and darkness of each pixel is inverted with respect to the background image of FIG. 10B. As is clear from the comparison between FIGS. 11 and 10 (b), the light and darkness of each pixel in the background image 1020 is inverted, so that it is as if the light was emitted from the southeast direction located on the upper left side at that time. Is shaded. Therefore, the map screen 1000 can correctly see the topography of the valley bottom 1021, the ridge line 1022, and the ridge line 1023 even when the south is on the upper side. That is, it becomes possible to intuitively grasp that the vehicle is traveling on the road along the valley bottom 1021.

However, when the map screen is displayed in the heading-up mode, the following problems occur when the light and darkness of each pixel of the background image is inverted according to the traveling direction of the vehicle. That is, the brightness of the background image before inversion and the brightness of the background image after inversion may deviate from each other. In this case, even if a common area on the map is displayed on the map screen, the traveling direction of the vehicle. As a result, the brightness of the map screen changes drastically, causing a problem that the user feels uncomfortable. The above problems are not limited to the devices mounted on the vehicle (including not only the devices fixed to the vehicle but also the devices brought into the vehicle), and the terrain can be visually recognized three-dimensionally by shading. This is a problem common to devices capable of displaying a map screen including a drawn image and displaying the map screen in a heading-up mode in which the map screen is displayed upside down depending on the traveling direction of the user.

The present invention has been made to solve such a problem, and has prevented the terrain around the user's position from being erroneously visually recognized when the map screen is displayed in the heading-up mode. The purpose of the above is to prevent the user who refers to the map screen from feeling uncomfortable.

In order to solve the above-mentioned problems, the map screen display device of the present invention assumes that the drawn image of the mountain range constituting the map screen when viewed from directly above the sky is irradiated with light from a predetermined direction. When displaying a map screen containing a drawn image that allows the mountain range to be visually recognized three-dimensionally by displaying a drawn image with shadows added to the shadowed part , the user's direction of travel is detected and the map screen is displayed. Is displayed in the heading-up mode, the direction of travel of the user is the range of directions in which the light and darkness of each pixel in the drawn image is not reversed (the direction in which the light hits when it is assumed that the light is emitted from a predetermined direction). The non-reversal range (range) and the reversal range that is the range of the direction in which the light and darkness of each pixel in the drawn image is reversed (the range of the direction in which the light does not hit when it is assumed that the light is irradiated from a predetermined direction). When the user's traveling direction belongs to the inversion range, the brightness of each pixel of the drawn image is inverted and the brightness is adjusted so as to approach the brightness of the drawn image before inversion. Generate an adjusted image and display a map screen containing the adjusted image.

According to the present invention configured as described above, when the map screen is displayed in the heading-up mode, the traveling direction of the user is predetermined as a range of directions for reversing the brightness of each pixel in the drawn image. When it belongs to the inversion range, the brightness of each pixel of the drawn image is inverted. Therefore, regardless of the traveling direction of the user, that is, the upper direction of the map screen, the state of the shadow in the drawn image is the state in which the shadow is added to the portion that becomes a shadow when the light is irradiated from a predetermined direction. It is possible to prevent the terrain around the user position from being erroneously visually recognized. Then, according to the present invention configured as described above, when displaying a drawn image in which light and dark are inverted, the brightness of the drawn image after inversion is adjusted so as to approach the brightness of the drawn image before inversion. Will be done. As a result, when the brightness of the drawn image is inverted and displayed according to the change in the traveling direction of the user, it is possible to prevent the brightness of the drawn image before the inversion and the brightness of the drawn image after the inversion from deviating from each other. It is possible to prevent the brightness of the map screen from changing drastically, and it is possible to prevent the user from feeling uncomfortable.

It is a block diagram which shows the functional structure example of the map screen display device which concerns on 1st Embodiment of this invention. It is a figure which shows typically the contents of the background image database. It is a figure which shows the background image data and the inverted image data. It is a figure which shows an example of the determination condition stored in the determination condition storage part which concerns on 1st Embodiment of this invention. It is a figure which shows the area on the map which was displayed as a map screen on the display. It is a figure which shows an example of the background image displayed on the display. It is a figure which shows an example of the processing of the parameter calculation part which concerns on 1st Embodiment of this invention. It is a figure which shows an example of the processing of the map screen display device which concerns on 1st Embodiment of this invention. It is a block diagram which shows the functional structure example of the parameter calculation apparatus for brightness adjustment which concerns on 2nd Embodiment of this invention. It is a figure which shows the display example of the conventional map screen. It is a figure which shows the display example of a map screen.

<First Embodiment>
Hereinafter, the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a functional configuration example of the map screen display device 100 according to the first embodiment of the present invention. The map screen display device 100 according to the present embodiment is a navigation device provided in the vehicle, such as a function of displaying a map screen around the current position of the vehicle, a function of searching for a route to a destination, and the like. Has. In the present embodiment, the map screen display device 100 will be described as a navigation device provided in the vehicle, but the map screen display device 100 does not have to be a device provided in the vehicle, and is mounted on the vehicle, for example. It may be a mobile terminal (smartphone, tablet PC, notebook PC). Further, the map screen display device 100 does not have to have a navigation function. That is, the present invention described below displays a map screen including a background image (corresponding to a "drawing image" in the claims) that can be visually recognized three-dimensionally by adding a shadow in a heading-up mode. It is widely applicable to possible devices. Therefore, for example, the present invention can be applied to a mobile terminal carried by a user who moves on foot, by train, or by other means. The "background image" includes all images in which the terrain can be visually recognized three-dimensionally by shading.

As shown in FIG. 1, the own vehicle position detection device 12 and the display 13 are connected to the map screen display device 100 of the first embodiment. Further, the map screen display device 100 includes a parameter calculation unit 20, a traveling direction detection unit 21, a direction range determination unit 22, an image generation unit 23, a map screen generation unit 24, and a map screen display unit 25 as functional configurations thereof. There is. The parameter calculation unit 20 includes a partition background image brightness value calculation unit 201 (corresponding to the “compartment drawing image brightness value calculation unit” in the claims), a comparison target image data generation unit 202, and a comparison target image brightness value calculation. A unit 203, a brightness difference calculation unit 204, and a parameter determination unit 205 are provided. Further, the map screen display device 100 includes a map data storage unit 30 and a determination condition storage unit 31. In the first embodiment, the invention will be described by exemplifying a case where the map screen display device 100 for displaying the map screen has a function of calculating adjustment parameters (described later). In this regard, the map screen display device 100 that displays the map screen does not have a function of calculating the adjustment parameters, and is not the map screen display device 100 (calculation of the brightness adjustment parameters of the second embodiment). The device corresponding to the device 100A) may calculate the adjustment parameters, and the map screen display device 100 may execute various processes related to the map screen display using the adjustment parameters calculated by the other device. A configuration in which a device independent of the map screen display device 100 calculates adjustment parameters will be described in the second embodiment.

Each of the above functional blocks 20 to 25 and 201 to 205 can be configured by any of hardware, DSP (Digital Signal Processor), and software. For example, when configured by software, each of the above functional blocks 20 to 25 and 201 to 205 is actually configured to include a computer CPU, RAM, ROM, etc., and may be used as a recording medium such as RAM, ROM, hard disk, or semiconductor memory. It is realized by operating the stored program. This also applies to the functional block included in the brightness adjustment parameter calculation device 100A according to the second embodiment.

The map data storage unit 30 stores the map data 301. The map data 301 includes node information and road link information. Node information and road link information are used for route search and the like. Further, the map data 301 includes road data used for drawing roads on a map screen, facility data related to facilities existing on the map, place name data used for drawing character strings such as place names and road names on the map screen, and the like. include. Further, the map data 301 has a background image database. The background image database stores background image data in which a section background image (described later) representing the terrain is recorded.

FIG. 2 is a diagram schematically showing the contents of the background image database. Here, the map is divided in advance into a mesh shape based on longitude and latitude, and is managed by dividing it into rectangular areas having the same size. Hereinafter, a rectangular area formed by being divided into a mesh shape on a map is referred to as a "mesh area". In the background image database, background image data (corresponding to the "compartment drawing image" of the claims) in which the partition background image representing the topography of the mesh area is recorded for each mesh area (the "drawing image" of the claims) is recorded. (Equivalent to "data") is stored.

More specifically, as shown in FIG. 2, the background image database has a record for each mesh area. Each record in the background image database contains at least a background image ID, background image data (actual file of background image data, which may be information indicating the address of a storage area in which the actual file is stored), and adjustment parameters. And the section background image area information. The background image ID is identification information that identifies the background image data. The adjustment parameters will be described later. The partition background image area information is information indicating an area in the map of the corresponding mesh area (for example, information indicating the coordinates of the four corners of the rectangular mesh area). In the present embodiment, the background image data (actual file) and the adjustment parameters are stored in each record of the background image database. In this regard, the background image data and the adjustment parameters may be managed in different databases in association with the background image ID. In this case, the association between the background image data and the adjustment parameter is performed based on the background image ID.

The compartment background image recorded in the background image data is assumed to have been irradiated with light from the northwest direction located in the upper left when the north is on the upper side, and shadows are added to the shadowed part at that time. .. As will be described later, the map screen displays a background image showing the terrain, information about the road, the current position of the vehicle, information about the facility (facility icon, name, etc.), and information about the place name for the area on the map to be displayed. It is a screen in which a map image including, etc. is superimposed. The background image is composed of a combination of a plurality of compartment background images.

The map screen display device 100 can display a map screen at a plurality of different levels of scale, and has a background image database for each level of scale. Then, when displaying the background image, the background image database corresponding to the current scale ratio level is used to display the background image. However, in the following, for convenience of explanation, the processing when changing the scale rate level is omitted, and the background image is displayed using the background image database of a specific level of scale rate. To do.

The own vehicle position detecting device 12 detects the current position of the vehicle (hereinafter, referred to as “own vehicle position”). The own vehicle position detection device 12 is configured to include, for example, a GPS (Global Positioning System) and an autonomous navigation unit. The own vehicle position corresponds to the user position.

The display 13 displays various display screens (for example, a map screen). For the display 13, for example, a liquid crystal display, an organic EL display, or the like is used.

The parameter calculation unit 20 calculates adjustment parameters for adjusting the brightness of the compartment background image for each background image data and registers them in each record of the background image database. Hereinafter, regarding the processing of the parameter calculation unit 20, the section background image brightness value calculation unit 201, the comparison target image data generation unit 202, the comparison target image brightness value calculation unit 203, and the brightness difference calculation unit 204 included in the parameter calculation unit 20. And will be described in detail through the description of the parameter determination unit 205.

The parameter calculation unit 20 reads the background image data stored in the background image database one by one from the map data storage unit 30 and sets it as a processing target according to the user's instruction, and adjusts based on the background image data to be processed. The parameters for adjustment are calculated, and the calculated adjustment parameters are registered in the corresponding record of the background image database. The user instructs, for example, to start the above-described processing when the map data 301 is newly stored in the map data storage unit 30 or when the map data 301 is updated.

Hereinafter, the processing of the parameter calculation unit 20 when calculating the adjustment parameter based on the background image data to be processed will be described. In the present embodiment, the image data (including the background image data, the inverted image data described later, and the adjusted image data) is the 256th floor of each color component of R (red), G (green), and B (blue). This is bitmap data in which the pixels held as the gradation value of the tone are arranged in a dot matrix. Further, in the following description, in the pixels constituting the image data, the value of the color component of R is referred to as "R value" (however, 0 ≦ R value ≦ 255), and the value of the color component of G is referred to as “G value”. (However, 0 ≦ G value ≦ 255), and the value of the color component of B is called “B value” (however, 0 ≦ B value ≦ 255). Further, in the following description, the variable in which the adjustment parameter is stored is referred to as "variable L". The initial value of the variable L (= initial value of the adjustment parameter) is "0". In the present embodiment, the "variable" conceptually represents a variable in which the values of various information are stored (for example, a variable defined in a program that realizes the function of the parameter calculation unit 20).

First, the parameter calculation unit 20 reads and acquires the background image data to be processed from the background image database. In the following description of the processing of the parameter calculation unit 20, when simply expressed as "background image data", unless otherwise specified, it means the background image data for which the parameter calculation unit 20 calculates the adjustment parameter.

FIG. 3A is an example of background image data acquired by the parameter calculation unit 20. It is a figure which simplifies the background image data D1 in consideration of convenience of explanation. In the background image data D1 of FIG. 3A, the upper side in the figure is north. Further, in the compartment background image recorded in the background image data D1, the reference numeral R1 represents a ridgeline and the reference numeral T1 represents a valley bottom. Between the ridge line R1 and the valley bottom T1, a slope S1 that slopes downward as a whole toward the east is shown. Since the slope S1 is a portion that becomes a shadow when light is irradiated from the northwest direction, a shadow is added. Most of the compartment background image recorded in the background image data D1 is occupied by the slope S1, and therefore, the image is dark as a whole.

After acquiring the background image data, the partition background image brightness value calculation unit 201 uses the following formula S1 to obtain the partition background image brightness value (corresponding to the "compartment drawing image brightness value" in the claims). calculate. Hereinafter, the variable in which the partition background image brightness value is stored is referred to as “variable ALp”.
(Equation S1) Variable ALp = ((total of R values of all pixels of background image data) + (total of G values of all pixels of background image data) + (B value of all pixels of background image data) Total)) / 3

The partition background image brightness value obtained by the formula S1 is the average of the "total R value", the "total G value", and the "total B value", and is the partition background recorded in the background image data. It can be used as an index of image brightness.

Next, the comparison target image data generation unit 202 inverts the brightness of each pixel of the background image data based on the background image data, and sets the pixel value of each pixel after the inversion of brightness to the current adjustment parameter (current time). The image data to be compared is generated by adjusting with the value of the variable L of. Specifically, the comparison target image data generation unit 202 generates the comparison target image data by converting the color components of each color of all the pixels of the background image data by the following formulas S2 to S4.
(Equation S2) R value of pixels of image data to be compared = 255- (R value of pixels of background image data) + variable L
(Equation S3) G value of pixels of image data to be compared = 255- (G value of pixels of background image data) + variable L
(Equation S4) B value of pixel of image data to be compared = 255- (B value of pixel of background image data) + variable L

In the formula S2, the portion of "255- (R value of the pixel of the background image data)" on the right side means that the lightness and darkness of the R color component of the pixel are reversed. Further, in the equation S2, the portion of "+ variable L" on the right side means that the pixel value is adjusted based on the adjustment parameter. The same applies to the formula S3 and the formula S4.

When the R value of the pixel of the image data to be compared is obtained by the formula S2, the R value exceeds 255 (R value> 255) and the R value falls below 0 (R value <0). obtain. The comparison target image data generation unit 202 sets the R value to 255 when the R value exceeds 255, and sets the R value to 0 when the R value is less than 0. The same applies to the G value of the pixel of the comparison target image data calculated by the formula S3 and the B value of the pixel of the comparison target image data calculated by the formula S4.

As described above, the initial value of the variable L (initial value of the adjustment parameter) is "0", and the stage where the adjustment parameter described later is not updated (= the stage where the adjustment parameter is the initial value). The comparison target image data generated in is the image data in which the light and darkness of the background image data is inverted. Hereinafter, for convenience of explanation, the comparison target image data generated when the adjustment parameter is the initial value is particularly referred to as "inverted image data".

FIG. 3B shows inverted image data D2 generated based on the background image data D1 of FIG. 3A. As described above, the inverted image data is generated by inverting the brightness of the background image data. Therefore, the brighter the compartment background image recorded in the background image data, the darker the image recorded in the inverted image data (hereinafter, referred to as "compartment inverted image"), and conversely, the more the compartment background image is recorded in the background image data. The darker the compartment background image, the brighter the compartment inverted image recorded in the inverted image data. As described above, the section background image recorded in the background image data D1 of FIG. 3A is mostly dark with the shaded slope S1. Therefore, as shown in FIG. 3B, the section inverted image recorded in the inverted image data D2 generated by inverting the brightness of the background image data D1 becomes bright as a whole.

Next, the comparison target image brightness value calculation unit 203 calculates the comparison target image brightness value using the following formula S5. Hereinafter, the variable in which the brightness value of the image to be compared is stored is referred to as “variable ALn”.
(Equation S5) Variable ALn = ((total of R values of all pixels of comparison target image data) + (total of G values of all pixels of comparison target image data) + (total of all pixels of comparison target image data) B value total)) / 3

The comparison target image brightness value obtained by the formula S5 is the average of the "total R value", the "total G value", and the "total B value", and is an image recorded in the comparison target image data. It can be used as an index of the brightness of.

Next, the brightness difference calculation unit 204 calculates the brightness difference using the following formula S6. Hereinafter, the variable in which the value of the brightness difference is stored is referred to as “variable ΔAL”.
(Equation S6) Variable ΔAL = variable ALp-variable ALn

However, when the partition background image brightness value (value of the variable ALp) is larger than the threshold value ALh, the brightness difference calculation unit 204 calculates the brightness difference using the following formula S7 instead of the formula S6. To do.
(Equation S7) Variable ΔAL = Threshold ALh-Variable ALn

When the brightness value of the compartment background image is larger than the threshold value ALh, the brightness of the compartment background image recorded in the background image data is very bright. The brightness difference calculation unit 204 uses the formula when the brightness value of the partition background image is larger than the threshold value ALh in order to prevent the brightness of the partition adjustment image recorded in the adjustment image data described later from becoming too bright. The brightness difference is calculated using the formula S7 instead of S6.

The brightness difference calculated by the formula S6 or the formula S7 is the brightness between the compartment background image recorded in the background image data and the image recorded in the comparison target image data (hereinafter, referred to as “comparison target image”). It can be used as an index showing the difference between. The smaller the absolute value of the brightness difference value (the value of the variable ΔAL), the smaller the difference in brightness of these images, and the larger the absolute value of the value of the brightness difference, the larger the difference in brightness of these images. Further, the value of the brightness difference becomes a positive value when the compartment background image is brighter than the comparison target image, and becomes a negative value when it is dark.

Next, the parameter determination unit 205 determines whether or not the condition J1 is satisfied.
(Condition J1) | Variable ΔAL | <Threshold E

When the | variable ΔAL | is smaller than the threshold value E, the threshold value E is set to a value such that the brightness of the compartment background image and the comparison target image can be regarded as equivalent. For example, the value of the threshold value E is "1". Therefore, when the condition J1 is satisfied, the brightness of the compartment background image and the comparison target image are the same.

When the condition J1 is satisfied, the parameter determination unit 205 determines the value of the variable L at the present time as the value of the adjustment parameter associated with the background image data in the background image database. Since the value of the adjustment parameter is determined as described above, the brightness of each pixel of the background image data is inverted, and the pixel value of each pixel after the inversion of brightness is adjusted with the adjustment parameter to generate the data. The brightness of the image (compartment adjustment image as described later) recorded in the image data (adjusted image data as described later) is equivalent to the brightness of the compartment background image recorded in the background image data.

On the other hand, when the condition J1 is not satisfied, the comparison target image data generation unit 202 updates the adjustment parameter by the following equation S8. In the equation S8, the variable L on the left side indicates the value of the adjustment parameter after the update, and the variable L on the right side indicates the value of the adjustment parameter before the update.
(Equation S8) Variable L = Variable L + Correction value Q

The comparison target image data generation unit 202 obtains the correction value Q by the following formula S9.
(Equation S9) Modified value Q = coefficient ω * variable ΔAL (where 0 <coefficient ω << threshold E)

In the formula S9, the coefficient ω is a coefficient that sufficiently reduces the absolute value of the variable ΔAL, and is, for example, “0.1”. For the adjustment parameter updated by the equation S8, the value obtained by sufficiently reducing the absolute value of the variable ΔAL is added (when the value of the variable ΔAL is positive) or subtracted (the value of the variable ΔAL is positive) to the adjustment parameter before the update. If it is negative), it is the value.

After that, the parameter calculation unit 20 uses "update of adjustment parameters using formula S8", "generation of comparison target image data using formula S2 to formula S4", and "comparison target image brightness value using formula S5". "Calculation of", "Calculation of brightness difference using equation S6" and "Determination of whether or not condition J1 is satisfied" are repeatedly executed until the condition J1 is satisfied. The value of the variable L in is determined as the value of the adjustment parameter associated with the background image data in the background image database.

As described above, the partition background image brightness value calculation unit 201 is a partition background image brightness value indicating the brightness of the partition background image recorded in the background image data based on the pixel value of each pixel of the background image data. Is calculated. Next, the comparison target image data generation unit 202 changes the adjustment parameter stepwise, inverts the brightness of each pixel of the background image data at each step, and determines each pixel based on the adjustment parameter. The image data to be compared is generated by adjusting the pixel value. The comparison target image brightness value calculation unit 203 calculates the comparison target image brightness value indicating the brightness of the image recorded in the comparison target image data based on the pixel value of each pixel of the comparison target image data. The brightness difference calculation unit 204 calculates the difference between the partition background image brightness value and the comparison target image brightness value. The parameter determination unit 205 determines the adjustment parameter at the stage when the brightness difference becomes smaller than the threshold value as the adjustment parameter associated with the background image data. Since the final adjustment parameter value is determined in this way, when the background image data is inverted and the brightness is adjusted by the adjustment parameter, the adjusted image data and the background image data The brightness can be made equal.

By the way, the traveling direction detection unit 21 detects the traveling direction of the vehicle. For example, the traveling direction detection unit 21 detects the traveling direction of the vehicle by the signal acquired from the autonomous navigation unit of the own vehicle position detecting device 12. In the present embodiment, the traveling direction of the vehicle means the direction in which the vehicle is traveling.

When the map screen is displayed in the heading-up mode (hereinafter, simply referred to as "in the case of the heading-up mode"), the direction range determining unit 22 uses the traveling direction of the vehicle detected by the traveling direction detecting unit 21 as the background. It is determined whether the image belongs to a non-inverted range, which is a range in which the light and darkness of the image is not inverted, and a reverse range, which is a range in which the light and darkness of the background image is inverted. Hereinafter, the processing of the direction range determination unit 22 will be described in detail.

Here, the determination condition storage unit 31 stores the determination conditions that define the non-reversal range and the inversion range. FIG. 4 is a diagram showing the contents of an example of the determination conditions according to the present embodiment. As shown in FIG. 4, the non-reversing range is the range of the direction including the north. The reversal range is a range of directions outside the non-reversal range, including the south. The boundaries between the non-reversal range and the reversal range are defined in the northeast and southwest.

The direction range determination unit 22 refers to the determination condition stored in the determination condition storage unit 31, and includes the traveling direction of the vehicle detected by the traveling direction detecting unit 21 and the direction range and the inversion range included in the non-reversing range. It is determined whether the traveling direction of the vehicle belongs to the non-reversing range or the reversing range by comparing with the range of the directions. The direction range determination unit 22 considers the northeast, which is the boundary between the reversal range and the non-reversal range, to be within the non-reversal range. On the contrary, the direction range determination unit 22 considers the southwest, which is the boundary between the inversion range and the non-inversion range, to be within the inversion range.

When the map screen is displayed in the north-up mode instead of the heading-up mode, the direction range determination unit 22 does not perform the above determination.

When the map screen is displayed in the north-up mode, the image generation unit 23 generates display background image data in which the background image of the area on the map around the position of the own vehicle is recorded. More specifically, the image generation unit 23 accesses the background image database of the map data storage unit 30 and acquires a plurality of background image data used for displaying the background image. That is, the image generation unit 23 acquires background image data corresponding to each of the mesh areas included in the area on the map around the position of the own vehicle to be displayed on the display 13 as a map screen. Next, the image generation unit 23 combines the acquired plurality of background image data and performs necessary image processing (size adjustment, resolution adjustment, etc.) to generate display background image data. The display background image data is image data in which a background image representing the terrain of the area on the map around the position of the own vehicle to be displayed on the display 13 is recorded. The background image is an image composed of a combination of a plurality of compartment background images. The image generation unit 23 outputs the generated background image data for display to the map screen generation unit 24.

On the other hand, in the case of the heading-up mode, the image generation unit 23 determines that the traveling direction of the vehicle belongs to the non-reversing range by the direction range determining unit 22 described above, and that it belongs to the reversing range. Perform different processing. Hereinafter, each process will be described in order.

<When the traveling direction of the vehicle belongs to the non-reversing range>
When the direction range determination unit 22 determines that the traveling direction of the vehicle belongs to the non-reversing range, the image generation unit 23 is included in the area on the map displayed as a map screen on the display 13 based on the traveling direction of the vehicle. The background image data corresponding to each of the mesh areas to be obtained is acquired. Next, the image generation unit 23 combines the acquired plurality of background image data, converts the inclination of the image data according to the traveling direction of the vehicle, and adjusts the size according to the display area of the display 13. Necessary image processing such as resolution adjustment processing is performed to generate display background image data, which is output to the map screen generation unit 24.

<When the traveling direction of the vehicle belongs to the reversal range>
When the direction range determination unit 22 determines that the traveling direction of the vehicle belongs to the inversion range, the image generation unit 23 has a background corresponding to each of the mesh areas included in the area on the map displayed as the map screen on the display 13. Get image data.

FIG. 5 is suitable for explaining the mesh area included in the area on the map displayed as the map screen on the display 13 when the direction range determination unit 22 determines that the traveling direction of the vehicle belongs to the inversion range. It is a figure which shows in an aspect. In FIG. 5, the upper side is the south on the map screen, and the lower side is the north on the map screen. In FIG. 5, the area on the map is composed of nine mesh areas of mesh area MA1 to mesh area MA9. The background image data corresponding to the mesh area MA1 has a background image ID of "# 1", and the value of the adjustment parameter associated with the background image data in the background image database is "73". The background image ID related to the background image data corresponding to the mesh area MA2 is "# 2", and the value of the adjustment parameter related to the data is "36". The background image ID related to the background image data corresponding to the mesh area MA3 is "# 3", and the value of the adjustment parameter related to the data is "46". The background image ID related to the background image data corresponding to the mesh area MA4 is "# 4", and the value of the adjustment parameter related to the data is "49". The background image ID related to the background image data corresponding to the mesh area MA5 is "# 5", and the value of the adjustment parameter related to the data is "85". The background image ID related to the background image data corresponding to the mesh area MA6 is "# 6", and the value of the adjustment parameter related to the data is "83". The background image ID related to the background image data corresponding to the mesh area MA7 is "# 7", and the value of the adjustment parameter related to the data is "55". The background image ID related to the background image data corresponding to the mesh area MA8 is "# 8", and the value of the adjustment parameter related to the data is "109". The background image ID related to the background image data corresponding to the mesh area MA9 is "# 9", and the value of the adjustment parameter related to the data is "53".

When the area on the map displayed as the map screen on the display 13 has the aspect shown in FIG. 5, the image generation unit 23 acquires nine background image data having background image IDs # 1 to # 9.

Next, the image generation unit 23 acquires the adjustment parameters associated with each of the acquired plurality of background image data, and the average value of the acquired plurality of adjustment parameters (hereinafter referred to as "adjustment parameter average value"). ) Is calculated. In the case of the example of FIG. 5, the image generation unit 23 acquires each of the adjustment parameters associated with the nine background image data whose background image IDs are # 1 to # 9. Then, the image generation unit 23 calculates the adjustment parameter average value (in this case, “65”) based on the acquired nine adjustment parameters.

Next, the image generation unit 23 inverts the light and darkness of each pixel for each of the acquired plurality of background image data, and adjusts the pixel value of each pixel after the light and darkness is reversed by the adjustment parameter average value. Generate adjusted image data. In the case of the example of FIG. 5, the image generation unit 23 reverses the light and darkness of each pixel of the background image data for each of the nine background image data whose background image IDs are # 1 to # 9, and then reverses the light and darkness. Adjusted image data is generated by adjusting the pixel value of each pixel of the above with the average value of the adjustment parameters.

More specifically, the parameter calculation unit 20 adjusts one background image data by converting the color components of each color of all the pixels of the one background image data by the following equations S10 to S12. Generate image data.
(Equation S10) R value of the pixel of the adjusted image data = 255- (R value of the pixel of the background image data) + Average value of the parameters for adjustment (Equation S11) G value of the pixel of the adjusted image data = 255- (Background image data) (G value of the pixel of

In the adjusted image data generated as described above, the light and darkness of the compartment background image recorded in the background image data was reversed, and the pixel value of each pixel after the light and darkness was reversed was adjusted by the adjustment parameter average value. This is image data in which a parcel adjustment image is recorded.

Next, the image generation unit 23 combines a plurality of adjusted image data corresponding to the acquired plurality of background image data, performs a process of converting the inclination of the image data according to the traveling direction of the vehicle, and a display area of the display 13. The adjustment image data for display is generated by performing necessary image processing such as a process of adjusting the size and a process of adjusting the resolution accordingly. The display adjustment image data is image data in which a background image showing the terrain of the area on the map around the position of the own vehicle to be displayed on the display 13 is recorded. The background image recorded in the display adjustment image data is tilted in the vertical direction according to the traveling direction of the vehicle. For example, when the vehicle travels in the south direction, the vertical direction of the background image recorded in the display adjustment image data is such that the south in the background image is located on the upper side and the north in the background image is located on the lower side. It is in a tilted state. The background image displayed based on the display adjustment image data is an image composed of a combination of a plurality of section adjustment images. The image generation unit 23 outputs the generated display adjustment image data to the map screen generation unit 24.

As described above, the image generation unit 23 according to the present embodiment generates display adjustment image data by the method described above when the heading-up mode is used and the traveling direction of the vehicle belongs to the inversion range. Then, it is output to the map screen generation unit 24. As will be described later, the map screen display unit 25 displays the map screen on the display 13, but the background image of the map screen is displayed based on the display adjustment image data. Then, since the above processing is executed by the image generation unit 23, the following effects are obtained.

FIG. 6A is a simplified diagram showing an example of a background image displayed in the display area of the display 13 when the traveling direction of the vehicle is north in the heading-up mode. For convenience of explanation, in FIG. 6A and FIGS. 6B and 6C described later, in addition to the background image, a mark indicating the position of the own vehicle and a mark indicating north, south, east, and west are also displayed. Further, in FIG. 6A and FIGS. 6B and 6C described later, the mesh for partitioning the mesh region is represented by a dotted line. In FIG. 6A, reference numeral R2 indicates a ridgeline, and reference numerals T2 and T3 indicate valley bottoms, respectively. The west side of the valley bottom T2 and the east side of the ridgeline R2 are parts that become shadows when light is irradiated from the northwest direction, and shadows are added.

FIG. 6B shows a display when a region common to the region of FIG. 6A is displayed on the display 13 without applying the present invention when the traveling direction of the vehicle is south in the heading-up mode. The state of the background image displayed in No. 13 is shown. As shown in FIG. 6B, when the present invention is not applied, a background image that is simply upside down is displayed depending on whether the vehicle is traveling in the north direction or the south direction. In this case, no shadow is added to the eastern region A1 of the valley bottom T3, which should be a shadow when light is irradiated from the northwest direction, and the region A2 sandwiched between the ridgeline R2 and the valley bottom T2, and conversely, the northwest. A shadow is added to the region A3 sandwiched between the valley bottom T3 and the ridgeline R2, which does not become a shadow when light is irradiated from the direction of, and the region A4 on the west side of the valley bottom T2. Therefore, the user may not be able to correctly see the terrain represented by the background image.

FIG. 6 (c) shows the display 13 when the region common to the region of FIG. 6 (a) is displayed on the display 13 by applying the present invention when the traveling direction of the vehicle is south in the heading-up mode. Shows the state of the background image displayed in. As shown in FIG. 6C, when the present invention is applied, the image generation unit 23 executes the above-described processing, so that the light and darkness of the background image is reversed. Therefore, as shown in FIG. 6 (c), the area that should be a shadow when the light is irradiated from the northwest direction is appropriately shaded, and the user correctly corrects the terrain represented by the background image. It is visible.

Further, when the present invention is applied, since the image generation unit 23 executes the above-described processing, the brightness of the background image is adjusted by using the adjustment parameter average value in each of the mesh regions. As described above, the adjustment parameter associated with the one background image data is the compartment inversion image (see FIG. 3A) in which the light and darkness of the compartment background image (see FIG. 3A) recorded in the one background image data is inverted. It is a parameter for making the brightness of FIG. 3B) equal to the brightness of the compartment background image. The adjustment parameter average value is the average value of each adjustment parameter of the mesh area included in the area on the map displayed on the display 13. Therefore, when displaying the background image, the brightness of the compartment background image constituting the background image is adjusted by using the average value of the adjustment parameters, so that the overall brightness of the entire background image before the inversion of light and dark and the light and darkness are adjusted. It is possible to prevent the overall brightness of the background image displayed after reversing the image from deviating from the overall brightness, prevent the brightness of the map screen including the background image from changing drastically, and prevent the user from feeling uncomfortable. it can.

Further, in the present embodiment, when displaying a background image in which light and dark are reversed according to the traveling direction of the vehicle, the brightness of each of the compartment background images constituting the background image is associated with the corresponding background image data. Instead of adjusting using the adjustment parameters with different values, the adjustment is made using the average value of the adjustment parameters. Due to such a configuration, the brightness of each of the compartment background images displayed on the display 13 is adjusted by using the parameters of common values, and it is possible to prevent the brightness of the background image from becoming uneven. In this respect as well, it is possible to prevent the user who refers to the map screen from feeling uncomfortable.

By the way, the map screen generation unit 24 generates map screen data in which the map screen to be displayed on the display 13 is recorded. More specifically, the map screen generation unit 24 acquires information indicating the vehicle position detected by the vehicle position detection device 12 and information indicating the vehicle travel direction detected by the travel direction detection unit 21, and also maps. Access the map data 301 of the data storage unit 30 to acquire necessary information, and obtain information on the roads around the vehicle, marks indicating the current position of the vehicle, information on facilities (facility icons, names, etc.), and information on place names. Generates map image data in which a map image including the above is recorded.

Further, the map screen generation unit 24 generates map screen data by superimposing the generated map image data on the display background image data or the display adjustment image data input from the image generation unit 23. The map screen data is image data in which a map screen in which the above-mentioned map image is superimposed on a background image recorded in the display background image data or the display adjustment image data is recorded. The map screen generation unit 24 outputs the generated map screen data to the map screen display unit 25.

The map screen display unit 25 inputs map screen data from the map screen generation unit 24, and displays the map screen on the display 13 based on the map screen data.

FIG. 7 is a flowchart showing an example of processing of the parameter calculation unit 20 according to the present embodiment. The process shown in FIG. 7 is executed when the user gives an instruction to start the process. The user gives an instruction to start processing, for example, when the map data 301 is newly stored in the map data storage unit 30, or when the map data 301 is updated.

As shown in FIG. 7, the parameter calculation unit 20 acquires one background image data to be processed among the background image data registered in the background image database (step SA1). Next, the partition background image brightness value calculation unit 201 calculates the partition background image brightness value using the formula S1 based on the background image data (step SA2). Next, the comparison target image data generation unit 202 generates the comparison target image data using the formulas S2 to S4 (step SA3). Next, the comparison target image brightness value calculation unit 203 calculates the comparison target image brightness value using the formula S5 (step SA4).

Next, the brightness difference calculation unit 204 calculates the brightness difference using the formula S6 or the formula S7 (step SA5). Next, the parameter determination unit 205 determines whether or not the condition J1 is satisfied (step SA6). When the condition J1 is satisfied (step SA6: YES), the parameter determination unit 205 determines the current adjustment parameter (current variable L value) as the adjustment parameter value associated with the background image data in the background image database. (Step SA7). Next, the parameter calculation unit 20 determines whether or not the calculation of the adjustment parameters has been completed for all the background image data registered in the background image database (step SA8). When the calculation of the adjustment parameters for all the background image data is completed (step SA8: YES), the parameter calculation unit 20 ends the process. If there is background image data for which the calculation of the adjustment parameter has not been completed (step SA8: NO), the parameter calculation unit 20 returns the processing procedure to step SA1.

On the other hand, when the condition J1 is not satisfied (step SA6: NO), the comparison target image data generation unit 202 updates the adjustment parameters using the formulas S8 and S9 (step SA9). After that, the comparison target image data generation unit 202 returns the processing procedure to step SA3, and generates the comparison target image data using the adjustment parameters updated in step SA9.

FIG. 8 is a flowchart showing an example of processing when the map screen display device 100 according to the present embodiment displays a map screen around the position of the own vehicle on the display 13. The process shown in FIG. 8 is started, for example, when the power of the map screen display device 100 is switched to ON, and is repeatedly executed until the power of the map screen display device 100 is switched to OFF. In FIG. 8, the operation mode of the map screen display device 100 is assumed to be a heading-up mode.

As shown in FIG. 8, the traveling direction detection unit 21 detects the traveling direction of the vehicle (step SB1). Next, the direction range determination unit 22 determines whether the traveling direction of the vehicle belongs to the non-reversal range or the reversal range (step SB2).

When the direction range determination unit 22 determines that the traveling direction of the vehicle belongs to the non-reversal range (step SB2: “non-reversal range”), the image generation unit 23 uses a plurality of image generation units 23 to display the background image from the background image database. The background image data of the above is acquired (step SB3). Next, the image generation unit 23 generates display background image data based on the plurality of background image data acquired in step SB3, and outputs the display background image data to the map screen generation unit 24 (step SB4). After the processing of step SB4, the map screen display device 100 shifts the processing procedure to step SB9.

On the other hand, when the direction range determination unit 22 determines that the traveling direction of the vehicle belongs to the inversion range (step SB2: "inversion range"), the image generation unit 23 uses a plurality of background image data used for displaying the background image. Acquire (step SB5). Next, the image generation unit 23 calculates the average value of the adjustment parameters (step SB6). Next, the image generation unit 23 uses the formulas S10 to S12 to generate adjusted image data corresponding to each of the plurality of background image data (step SB7). Next, the image generation unit 23 generates display adjustment image data based on the adjustment image data generated in step SB7, and outputs the display adjustment image data to the map screen generation unit 24 (step SB8). After the processing of step SB8, the map screen display device 100 shifts the processing procedure to step SB9.

In step SB9, the map screen generation unit 24 generates map image data, and superimposes the map image data on the display background image data or the display adjustment image data input from the image generation unit 23 to generate the map screen data. , Output to the map screen display unit 25. The map screen display unit 25 displays the map screen on the display based on the map screen data input from the map screen generation unit 24.

As described in detail above, the map screen display device 100 according to the present embodiment executes the following processing when displaying a map screen including a background image that can be three-dimensionally visually recognized by adding shadows. To do. That is, the map screen display device 100 detects the traveling direction of the vehicle, and when the map screen is displayed in the heading-up mode, the traveling direction of the vehicle is in a direction range in which the light and darkness of each pixel in the background image is not reversed. It is determined whether it belongs to a certain non-reversing range or a reversing range which is a range of directions for reversing the light and darkness of each pixel in the background image, and when the traveling direction of the vehicle belongs to the reversing range, each of the background images. The brightness of the pixel is inverted, an adjusted image whose brightness is adjusted so as to approach the brightness of the background image before the inversion is generated, and a map screen including the adjusted image is displayed.

According to this configuration, when the map screen is displayed in the heading-up mode, when the traveling direction of the vehicle belongs to a predetermined inversion range as a range of directions in which the light and darkness of each pixel in the background image is inverted. The brightness of each pixel in the background image is inverted. Therefore, regardless of the traveling direction of the vehicle, that is, the direction of the upper side of the map screen, the state of the shadow in the background image is the state in which the shadow is added to the portion that becomes a shadow when the light is irradiated from a predetermined direction. It is possible to prevent the terrain around the position of the own vehicle from being erroneously visually recognized. Then, according to the above configuration, when the brightness of each pixel of the background image is inverted, the brightness of the background image after the inversion is adjusted so as to approach the brightness of the background image before the inversion. , A map screen including the adjusted background image is displayed. As a result, when the brightness of the background image is inverted and displayed according to the change in the traveling direction of the vehicle, it is possible to prevent the brightness of the background image before the inversion and the brightness of the background image after the inversion from deviating from each other. It is possible to prevent the brightness of the map screen from changing drastically, and it is possible to prevent the user from feeling uncomfortable.

<Second Embodiment>
Next, the second embodiment will be described. FIG. 9 is a block diagram showing a functional configuration example of the brightness adjustment parameter calculation device 100A according to the present embodiment.

The brightness adjustment parameter calculation device 100A according to the present embodiment is a dedicated device for calculating adjustment parameters. The brightness adjustment parameter calculation device 100A stores, for example, a company that provides map data 301, a company that provides an application that uses map data 301 (for example, an application that is downloaded to a smartphone), and map data 301. It is provided in a company that provides a device (for example, a navigation device). The brightness adjustment parameter calculation device 100A accesses the background image database of the map data 301 stored in the map data storage device 200. Then, the brightness adjustment parameter calculation device 100A calculates the adjustment parameter and registers it in the background image database. The map data 301 having a background image database in which adjustment parameters are registered is provided, for example, via the Internet, and is recorded and provided on a recording medium such as a CD-ROM or a DVD, and is also provided, for example, a map. It is provided by providing a device in which the data 301 is stored (for example, the map screen display device 100 according to the first embodiment).

As shown in FIG. 9, the brightness adjustment parameter calculation device 100A includes a parameter calculation unit 20A. The parameter calculation unit 20A includes a section background image brightness value calculation unit 201A, a comparison target image data generation unit 202A, a comparison target image brightness value calculation unit 203A, a brightness difference calculation unit 204A, and a parameter determination unit 205A. , Equipped with. When calculating the adjustment parameter, the parameter calculation unit 20A executes the same processing as the parameter calculation unit 20 according to the first embodiment. Further, when calculating the adjustment parameters, the partition background image brightness value calculation unit 201A, the comparison target image data generation unit 202A, the comparison target image brightness value calculation unit 203A, the brightness difference calculation unit 204A, and the parameter determination unit 205A are used. The same processing as the section background image brightness value calculation unit 201, the comparison target image data generation unit 202, the comparison target image brightness value calculation unit 203, the brightness difference calculation unit 204, and the parameter determination unit 205, respectively, according to the first embodiment. To execute.

In each of the above embodiments, a shaded background image is used on the assumption that light is irradiated from the upper left direction, but the present invention is not limited to this. That is, a shaded background image may be used on the assumption that the light is irradiated from a direction other than the upper left direction.

Further, in the first embodiment, an example in which the boundary between the inversion range and the non-inversion range is set to the northeast and the southwest has been described, but the present invention is not limited to this.

Further, in the first embodiment, the average value of the adjustment parameters is calculated, and the brightness of each of the compartment background images constituting the background image is adjusted by using this average value. In this regard, the brightness of each of the compartment background images constituting the background image may be adjusted by using the adjustment parameters associated with the corresponding background image data. In this case, although the brightness of the compartment background image constituting the background image is adjusted by using different value adjustment parameters, the brightness of the background image before inversion and the brightness of the background image after inversion deviate from each other. Can be prevented.

Further, in the first embodiment, the calculation formulas for the partition background image brightness value and the comparison target image brightness value have been specifically specified, and the calculation method has been described. However, the method for calculating these values is not limited to the method exemplified in the first embodiment. These values may be values that are indicators of the brightness of the corresponding image and may be values calculated by a common calculation formula.

In addition, each of the above embodiments is merely an example of embodiment of the present invention, and the technical scope of the present invention should not be construed in a limited manner. That is, the present invention can be implemented in various forms without departing from its gist or its main features.

20, 20A Parameter calculation unit 21 Travel direction detection unit 22 Direction range determination unit 23 Image generation unit 24 Map screen generation unit 25 Map screen display unit 30 Map data storage unit 100 Map screen display device 201, 201A Section background image brightness value calculation Part (section drawing image brightness value calculation part)
202, 202A Comparison target image data generation unit 203, 203A Comparison target image brightness value calculation unit 204, 204A Brightness difference calculation unit 205, 205A Parameter determination unit

Claims (7)

By displaying a drawn image of the mountains that make up the map screen when viewed from directly above the sky, a shadow is added to the shadowed part assuming that light is emitted from a predetermined direction. A map screen display unit that displays a map screen including a drawn image that allows the mountain range to be visually recognized in three dimensions.
A traveling direction detection unit that detects the traveling direction of the user,
When the map screen is displayed in the heading-up mode, the direction in which the light hits when it is assumed that the traveling direction of the user detected by the traveling direction detecting unit is radiated from the predetermined direction. As a non-inverted range defined as a range of directions that do not invert the brightness of the drawn image, and as a range of directions that the light does not hit when it is assumed that light is irradiated from the predetermined direction. A map screen display device including a direction range determination unit for determining which range of the inversion range, which is a range of directions for reversing the brightness of the drawn image, is defined.
When the direction range determination unit determines that the traveling direction of the user belongs to the inversion range, the brightness of the drawn image is inverted and the brightness is adjusted so as to approach the brightness of the drawn image before the inversion. A map screen display device including an image generation unit that generates an adjusted image, wherein the map screen display unit displays the map screen including the adjusted image generated by the image generation unit. The drawn image is an image displayed by combining the section drawn images recorded in the drawn image data for each section divided in a mesh shape on the map.
A map data storage unit that stores the drawn image data of each section in association with a parameter for brightness adjustment is further provided.
The image generation unit
When the map screen is displayed in the heading-up mode and the direction range determination unit determines that the traveling direction of the user belongs to the inversion range, a plurality of the drawn image data used for displaying the drawn image. For each of the above, the brightness of the section drawing image is inverted, and the brightness is adjusted based on the parameters to generate a section adjustment image.
The map screen display unit
The map screen display device according to claim 1, wherein the map screen including a combination of the division adjustment images generated by the image generation unit is displayed. The image generation unit
When the map screen is displayed in the heading-up mode and the direction range determination unit determines that the user's traveling direction belongs to the inversion range.
The parameters associated with each of the plurality of drawn image data used for displaying the drawn image are acquired, and the average value of the acquired plurality of the parameters is calculated.
For each of the plurality of drawn image data used for displaying the drawn image, the brightness of the section drawn image is inverted, and the brightness is adjusted based on the calculated average value to generate the section adjusted image. The map screen display device according to claim 2. The map screen display device according to claim 2 or 3, further comprising a parameter calculation unit that calculates the parameters for each of the drawn image data of each section. The parameter calculation unit
A section drawing image brightness value calculation unit that calculates a section drawing image brightness value indicating the brightness of the section drawing image recorded in the drawing image data based on the pixel value of each pixel of the drawing image data.
The comparison target image data is obtained by changing the parameters step by step, inverting the brightness of each pixel of the drawn image data at each step, and adjusting the pixel value of each pixel based on the parameters. The comparison target image data generator to be generated and
A comparison target image brightness value calculation unit that calculates a comparison target image brightness value indicating the brightness of the image recorded in the comparison target image data based on the pixel value of each pixel of the comparison target image data.
A brightness difference calculation unit that calculates a brightness difference that is a difference between the partition drawing image brightness value and the comparison target image brightness value.
A parameter determination unit that determines the parameter at the stage when the brightness difference calculated by the brightness difference calculation unit becomes smaller than the threshold value with the parameter associated with the drawn image data.
The map screen display device according to claim 4, wherein the map screen display device is provided. A brightness adjustment parameter calculation device that calculates parameters stored in association with drawn image data in the map data storage unit of the map screen display device according to claim 2.
It is provided with a parameter calculation unit that calculates parameters for each of the drawn image data.
The parameter calculation unit
A section drawing image brightness value calculation unit that calculates a section drawing image brightness value indicating the brightness of the section drawing image recorded in the drawing image data based on the pixel value of each pixel of the drawing image data.
The comparison target image data is obtained by changing the parameters step by step, inverting the brightness of each pixel of the drawn image data at each step, and adjusting the pixel value of each pixel based on the parameters. The comparison target image data generator to be generated and
A comparison target image brightness value calculation unit that calculates a comparison target image brightness value indicating the brightness of the image recorded in the comparison target image data based on the pixel value of each pixel of the comparison target image data.
A brightness difference calculation unit that calculates a brightness difference that is a difference between the partition drawing image brightness value and the comparison target image brightness value.
It is characterized by having a parameter determining unit that determines the parameter at the stage where the brightness difference calculated by the brightness difference calculating unit becomes smaller than the threshold value with the parameter associated with the drawn image data. Parameter calculation device for brightness adjustment. By displaying a drawn image of the mountains that make up the map screen when viewed from directly above the sky, a shadow is added to the shadowed part assuming that light is emitted from a predetermined direction. It is a map screen display method by a map screen display device that displays a map screen including a drawn image so that the mountain range can be visually recognized three-dimensionally.
The first step in which the traveling direction detection unit of the map screen display device detects the traveling direction of the user,
When the direction range determination unit of the map screen display device displays the map screen in the heading-up mode, the traveling direction of the user detected by the traveling direction detecting unit irradiates light from the predetermined direction. It is assumed that the non-inverted range, which is the range of the direction in which the light and darkness of the drawn image is not inverted, which is defined as the range of the direction in which the light hits , and the light is irradiated from the predetermined direction. The second step of determining which range of the inversion range, which is the range of the direction in which the light and darkness of the drawn image is inverted, is defined as the range of the direction in which the light does not hit.
When the image generation unit of the map screen display device determines that the traveling direction of the user belongs to the inversion range when the map screen is displayed in the heading-up mode and the direction range determination unit determines the drawing. A third step of inverting the brightness of the image and adjusting the brightness so as to approach the brightness of the drawn image before inversion, and the third step of generating an adjusted image.
When the map screen display unit of the map screen display device determines that the traveling direction of the user belongs to the inversion range when the map screen is displayed in the heading-up mode and the direction range determination unit determines that the user's traveling direction belongs to the inversion range. A fourth step of displaying the map screen including the adjusted image generated by the image generation unit, and
A map screen display method characterized by including.

Images