JP2013162188A - Camera with panorama photographing function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus that exerts appropriate exposure control to a change in brightness of a subject, by making exposure control simpler in a photographing method in which a panorama photograph is formed by joining images while consecutively photographing images at a high speed.SOLUTION: A camera with a panorama photographing function which obtains a panorama image by joining a plurality of images consecutively obtained in a series of photographing comprises: pre-photographing photometric means, exposure average value calculating means, and exposure control means. The pre-photographing photometric means performs continuous photometry within a photographing range while panning the camera. The exposure average value calculating means calculates an exposure average value within the photographing range on the basis of photometry output from the pre-photographing photometric means. The exposure control means reflects the exposure average value on exposure conditions for panorama main photographing, and exerts exposure control in the panorama main photographing.

Description

  The present invention relates to a panorama shooting technique in an imaging apparatus such as a digital camera, and more particularly to an exposure control technique during panorama shooting.

  Conventionally, when using an imaging device to obtain an image of a subject with a wide field of view, such as landscapes, panoramic photography is performed by shooting multiple images and controlling exposure while moving the camera. Some have the function of forming. For example, in Patent Document 1, a panoramic photograph is formed by connecting a plurality of images. At that time, the photometric information of the region near the stitched portion of the images is acquired for each photographing with respect to the luminance change of the plurality of photographed images. An imaging apparatus characterized by exposure control for the next shooting using the obtained photometric information is disclosed.

Japanese Unexamined Patent Publication No. 8-136963

  However, in the conventional technique disclosed in Patent Document 1 described above, when a plurality of images are captured, the camera is shaken at a predetermined angle until the next capturing, and then the photometry and capturing are performed. Therefore, in an imaging method in which images are joined together while continuously shooting at a high speed to form a panoramic photo, exposure control processing for each shooting becomes complicated.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to simplify exposure control during panoramic shooting and to perform average exposure control with respect to a change in luminance of a subject.

  In a camera with a panoramic shooting function that obtains a panoramic image by connecting a plurality of images continuously acquired in a series of shooting, a pre-photometry metering means, an exposure average value calculating means, and an exposure control means, The pre-photometry unit measures the light continuously in the shooting range while panning the camera, and the exposure average value calculation unit calculates the average exposure value in the shooting range based on the photometric output from the pre-photometry unit. The camera with panorama shooting function is characterized in that the exposure control means reflects the exposure average value in the exposure condition of the main panorama shooting and executes exposure control in the main panorama shooting.

  According to the present invention, it is possible to provide a function of photographing under appropriate exposure conditions in the panorama photographing range by performing pre-photometry in accordance with the whole photographing range before starting the panoramic main photographing.

Shooting start position guide display explanatory diagram in panoramic shooting in the first embodiment Example 2 Panning speed guide display explanatory diagram in panoramic shooting System configuration diagram of digital camera of embodiment External view of digital camera of embodiment Example 1 showing a panoramic shooting operation for pre-photometry Flowchart in Example 2 for performing pre-photometry and performing panning speed guide display control of the camera during panoramic shooting operation

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 3 shows a block diagram of a digital camera to which the present invention can be applied.

  The subject image passes through the optical lens (10) and is then formed on the image sensor (11). The imaging control circuit (12) performs drive control of the image sensor (11), and converts an image signal from the image sensor (11) from analog to digital and sends it to the system control circuit (18). The image sensor (11) is composed of a CCD or a CMOS, and converts a subject image into an image signal and outputs it.

  Further, the image sensor (11) has a photometric function for measuring the luminance of the object, measures the luminance of the photographing range by a known AE technique, performs average photometry, and sends a photometric signal to the system control circuit (18). The system control circuit (18) that has received the photometric signal performs photometric data accumulation and averaging processing as necessary, and sends the photometric data to the exposure control circuit (13). The exposure control circuit (13) determines a diaphragm and a shutter speed (not shown) for adjusting the exposure amount based on the received photometry data and the camera shake correction amount that can be set by the camera shake correction control circuit (23).

  The posture detection circuit (14) detects the horizontal and vertical swing angles of the camera using an azimuth sensor, an angular velocity sensor, and the like, and sends the acquired data to the system control circuit (18).

  The memory control circuit (19) is controlled by the system control circuit (18), the volatile memory (24), the image sensor (11), the exposure control circuit (13), the posture detection circuit (14), and the image processing circuit. (20) Controls data transmission / reception in the recording memory (21) and the display unit (22). The system control circuit (18) is a circuit that controls the entire camera, and also an arithmetic circuit that performs various arithmetic operations.

  The volatile memory (24) is a high-speed accessible memory such as SDRAM. The nonvolatile memory (25) is a memory for recording constants, variables, and programs for the operation of the system control circuit (18).

  The recording memory (21) is a memory that can be detached from the digital camera. If the memory capacity is insufficient, it can be replaced.

  The operation of the system control circuit (18) is determined by instruction signals from the release operation button (15), the MENU operation button (16), and the main subject selection button (17). The MENU operation button (16) displays a screen for setting various cameras and is used for setting each mode.

  There are two shooting modes: a panoramic shooting mode and a normal shooting mode for shooting only one image. The panorama shooting mode is a shooting sequence mode in which a plurality of images are continuously acquired in a series of shooting to obtain a panorama image.

  The normal shooting mode is a normal shooting sequence in which panoramic shooting is not performed. The description is omitted because it is not directly related to the present invention.

  There are two panoramic shooting modes: a pre-photometry metering mode in which photometry of the entire shooting area is acquired by panning before shooting, and a simple photometry mode in which the photometry value of the entire panorama shooting is determined only by photometry at the start of shooting.

  Furthermore, in the pre-photometry mode, if you select the main subject area during shooting, the pre-photographing area whole metering mode that can change the weighting of the photometric value, and the pre-photographing area whole metering mode that performs photometry over the entire shooting area It has.

  FIG. 4 shows an external view of the digital camera. An LCD (113) corresponding to the display unit (22) in FIG. 3 is provided on the back of the digital camera.

  Also, the release SW (110) corresponding to the release operation button (15) in FIG. 3, the MENU_SW (111) corresponding to the MENU operation button (16), and the main subject selection SW (112) corresponding to the main subject selection button (17). ) Is provided.

  The release SW (110) performs two-step detection by pressing a button, and outputs a SW-1 signal when the first step is pressed, and outputs a SW-2 signal when the first step is pressed.

  FIG. 5 illustrates a shooting sequence according to this embodiment with reference to a flowchart. This flowchart is a shooting sequence mode for performing preliminary photometry operation in the pre-photographing range whole photometry mode and the main subject area photometry mode.

  When shooting is started, a sequence according to the flowchart is started.

  It is determined from the MENU_SW (111) whether or not the panorama shooting mode has been selected (S101). If the panoramic shooting mode is selected, the next pre-photometry mode selection state is determined (S102). If the pre-photometry mode is selected, the process proceeds to S103, and the live view image is displayed on the LCD (113). If the pre-photometry mode is not selected, the process proceeds to S123.

  If the process proceeds to S103, the system control circuit (18) next determines the state of the SW-1 signal of the release SW (110) (S104). If the SW-1 state is set to the ON state, the posture detection circuit (14) detects the horizontal and vertical swing angles of the camera at the pre-photometry metering start position. Based on this detection, the system control circuit (18) stores it in the volatile memory (24) as photographing start reference position data (S105).

  Next, it is determined whether or not a pre-photographing range entire photometry mode for metering the entire pre-photographing range is selected (S106). If the pre-photographing area whole photometry mode is selected, the process proceeds to S107.

  If not selected, the process proceeds to S119.

  In S107, the image sensor (11) performs photometry of the shooting range while panning the camera to obtain photometric data. Next, the system control circuit (18) determines the state of the SW-1 signal of the release SW (110) (S108). If the SW-1 state is set to OFF, the process proceeds to (S109).

  On the other hand, if the state of SW-1 is set to ON in (S108), the process returns to (S107).

  If the pre-shooting range entire photometry mode is not selected and the main subject area photometry mode is selected and the process proceeds to S119, the process proceeds to the main subject area photometry mode.

  Next, the system control circuit (18) determines the signal state of the main subject selection SW (112) (S120). If the main subject selection SW (112) is set to the OFF state during the panning of the camera, the system control circuit (18) determines the state of the SW-1 signal of the release SW (110) (S121). If the SW-1 state is set to OFF, the process proceeds to (S109).

  On the other hand, when the system control circuit (18) detects the ON state of the main subject selection SW (112) in (S120), the detected predetermined area is set as the main subject area, and photometric data of the area is acquired.

  Next, the process returns to the sequence of (S120) again to determine the state of the signal of the main subject selection SW (112).

  On the other hand, when the state of SW-1 is set to ON in (S121), the process returns to the sequence of (S120) again to determine the state of the signal of the main subject selection SW (112).

  When the series of sequences (S120) to (S122) is repeated a plurality of times, the system control circuit (18) accumulates the photometric data of the main subject area for the number of times in the volatile memory (24).

  Subsequently, the system control circuit (18) calculates an average value of exposure from the obtained photometric data of the pre-photographing photometric range, and sends the exposure average data to the exposure control circuit (13) (S109).

  Next, the exposure control circuit (13) calculates appropriate shooting conditions such as aperture, shutter speed, ISO, etc. for adjusting the exposure based on the received exposure average data (S110), and sets the shooting conditions for main panorama shooting (S111).

  Next, the system control circuit (18) determines the state of SW-1 of the release SW (110) (S112). If the SW-1 state is set to ON, the photographing start reference position data stored in the volatile memory (24) is read in (S105). Using the read photographing start reference position data, the pre-photographing metering start reference position shown in FIGS. 1A and 1B is displayed on the LCD 113 as a guide display (S113).

  Next, as shown in FIG. 1 (c), the position of the camera is guided and displayed on the LCD (113) by the attitude detection circuit (14) using the photographing start reference position data read in (S113). Next, the position of the camera moved by the photographer is determined (S114). If the camera has been moved to the shooting start reference position, the process proceeds to (S115).

  On the other hand, if the pre-photometry mode is not selected in (S102), the process proceeds to a normal panoramic shooting sequence, and the system control circuit (18) determines the state of the SW-1 signal of the release SW (110) ( S123). If the SW-1 state is set to ON, subject photometry is performed at the current angle of view (S124).

  Next, the photometric data is sent to the exposure control circuit (13) to calculate the photographing conditions (S125).

  Subsequently, the system control circuit (18) determines the state of the SW-2 of the release SW (110) (S115). If the SW-2 state is set to ON, panoramic main shooting is started (S116).

  Next, while the photographer performs continuous shooting while swinging the camera at a predetermined angle for panoramic shooting, the posture detection circuit (14) determines whether or not the camera is swung to a predetermined angle (S117). If the camera is shaken to a predetermined angle, or if the camera has timed out without being shaken to a predetermined angle within a predetermined time, panorama shooting is terminated.

  Next, the image processing circuit (20) arranges a plurality of photographed images obtained by continuously photographing through a series of operations in the order of photographing, and synthesizes overlapping portions between the photographed images. The horizontally long image synthesized in this way is stored in the recording memory (19) as one piece of image data (S118).

  On the other hand, if the panoramic shooting mode is not selected in (S101), the normal shooting sequence is advanced (S121). Since the normal photographing sequence is not directly related to the present invention, it will be omitted.

  FIG. 1 shows an example of guide display displayed in the present embodiment.

  FIG. 1 (a) shows an example of pre-photometry that performs preliminary photometry within the shooting range before the main panoramic shooting. (201) shows the horizontal swing angle of the camera at the reference position where pre-photometry is started, and (202) shows an example of the reference position of the vertical swing angle.

Further, (203) shows the pre-photometric photometric range in the horizontal direction, and (204) shows the detectable range of the swing angle position in the vertical direction of the camera. The horizontal and vertical swing angles of the camera are detected by an orientation sensor, an angular velocity sensor, or the like in the posture detection circuit (14).

  Fig. 1 (b) shows the detection position of the camera at the start of the main panorama shooting. (205) shows the horizontal swing angle of the camera, (206) shows the vertical swing angle, and each shows an example of a state in which each is shifted from the reference position of the pre-photometry metering start position.

  (205) shows a state in which the swing angle in the horizontal direction is shifted by a predetermined angle in the left direction, and (206) shows a state in which the swing angle in the vertical direction is shifted by a predetermined angle in the downward direction.

  FIG. 1 (c) shows the detection position of the camera at the start of the main panorama shooting, and shows an example of the state where it matches the reference position of the pre-photometry metering start position.

  (207) shows a state in which the horizontal swing angle of the camera at the start of the main panoramic image coincides with the reference position of the pre-photometry metering start position, and (208) shows the vertical swing angle of the pre-photometry metering start position. An example of a state that matches the reference position is shown. From this state, the camera is panned in the direction of the arrow to perform the main panorama shooting.

  As described above, by performing pre-photometry in accordance with the entire shooting range or the main subject before the start of panoramic shooting, it is possible to provide a function for shooting with appropriate exposure conditions in the panoramic shooting range.

  FIG. 6 illustrates a shooting sequence according to the present embodiment with reference to a flowchart. This flowchart is a panning speed guide display sequence mode in the preliminary photometry range total photometry mode and main subject area photometry mode.

  It is determined whether or not the panorama shooting mode is selected from MENU_SW (111) for performing various camera settings by the photographer (S201). If the panoramic shooting mode is selected, the state of the next pre-photometry mode selection is discriminated (S202). If the pre-photometry mode is selected, a live view image is displayed on the LCD (113) (S203).

  Next, the system control circuit (18) determines the state of the SW-1 signal of the release SW (110) (S204). If the SW-1 state is set to the ON state, the posture detection circuit (14) detects the horizontal and vertical swing angles of the camera at the pre-photometry metering start position. Based on this detection, the system control circuit (18) stores it in the volatile memory (24) as photographing start reference position data (S205).

  Next, it is determined whether or not a pre-photographing range whole photometry mode for metering the entire pre-photographing range is selected (S206). If the pre-photographing range whole photometry mode is selected, photometry of the photographing range is performed by the image sensor (11) while panning the camera, and photometric data is acquired (S207).

  Next, the system control circuit (18) determines the state of the SW-1 signal of the release SW (110) (S208). If the SW-1 state is set to OFF, the process proceeds to (S209).

  On the other hand, if the state of SW-1 is set to ON in (S208), the process returns to (S207).

  On the other hand, if the pre-shooting range entire photometry mode is not selected in (S206) and the main subject area photometry mode is selected, the process proceeds to the main subject area photometry mode (S219).

  Next, the system control circuit (18) determines the signal state of the main subject selection SW (112) (S220). If the main subject selection SW (112) is set to OFF during camera panning, the system control circuit (18) determines the state of the SW-1 signal of the release SW (110) (S221). If the SW-1 state is set to OFF, the process proceeds to (S209).

  On the other hand, when the system control circuit (18) detects the ON state of the main subject selection SW (112) in (S220), the detected predetermined area is set as the main subject area, and photometric data of the area is acquired.

Next, returning to the sequence of (S220), the state of the signal of the main subject selection SW (112) is determined.
On the other hand, when the state of SW-1 is set to ON in (S221), the process returns to the sequence of (S220) again to determine the state of the signal of the main subject selection SW (112).

  When the series of sequences (S220) to (S222) is repeated a plurality of times, the system control circuit (18) accumulates the photometric data of the main subject area for the number of times in the volatile memory (24).

  Subsequently, the system control circuit (18) calculates an average value of exposure from the obtained photometric data of the pre-photometry photometric range, and sends the exposure average data to the exposure control circuit (13) (S209).

  Next, the exposure control circuit (13) calculates appropriate shooting conditions such as aperture, shutter speed, ISO, etc. for adjusting the exposure based on the received exposure average data (S210), and sets the shooting conditions for main panorama shooting (S211).

  Next, the panning speed thresholds (Pth1, Pth2) required for the panorama shooting by the camera are calculated from the combination of the shutter speed of the shooting conditions and the amount of camera shake correction that can be set by the camera shake correction control circuit (23) (S212). ).

  Next, the system control circuit (18) determines the state of SW-1 of the release SW (110) (S213). If the SW-1 state is set to ON, the photographing start reference position data stored in the volatile memory (24) is read in (S205). The pre-photographing metering start reference position shown in FIGS. 1 (a) and 1 (b) is displayed as a guide display on the LCD (113) using the read photographing start reference position data (S214).

  Next, as shown in FIG. 1C, the position of the camera is guided and displayed on the LCD (113) by the attitude detection circuit (14) using the photographing start reference position data read in (S213). Next, the position of the camera moved by the photographer is determined (S215). If the camera is moved to the shooting start reference position, the process proceeds to (S216).

  On the other hand, if the pre-photometry mode is not selected in (S202), the process proceeds to a normal panoramic shooting sequence, and the system control circuit (18) determines the state of the SW-1 signal of the release SW (110) ( S226). If the SW-1 state is set to ON, subject photometry is performed at the current angle of view (S227).

  Next, the photometry data is sent to the exposure control circuit (13) to calculate the photographing conditions (S228).

  Next, the panning speed threshold (Pth1, Pth2) data required when the camera takes a panoramic image is calculated from the combination of the shutter speed of the shooting conditions and the amount of camera shake correction that can be set by the image stabilization control circuit (23) ( S229).

  Subsequently, the system control circuit (18) determines the state of SW-2 of the release SW (110) (S216). If the SW-2 state is set to ON, panoramic main shooting is started (S217).

  Next, as shown in FIG. 2, the panning speed guide display that prompts the photographer to pan the camera panning speed using the panning speed threshold (Pth1, Pth2) data calculated in (S212) and the posture detection circuit (14) is displayed on the LCD ( 113) (S218).

  Next, while the photographer is performing panoramic shooting while continuously shooting while swinging the camera at a predetermined angle, the posture detection circuit (14) measures the camera panning speed, and the panning speed threshold calculated in (S212) A comparison is made with (Pth1, Pth2) (S219). If “Pth2 ≦ P ≦ Pth1” within the threshold, panorama shooting is continued, and it is determined whether or not the camera is swung to a predetermined angle (S220). If it is swung to a predetermined angle, or if it has not been swung to a predetermined angle within a predetermined time, panorama shooting is terminated.

  Next, the image processing circuit (20) arranges a plurality of photographed images obtained by continuously photographing through a series of operations in the order of photographing, and synthesizes overlapping portions between the photographed images. The horizontally long image synthesized in this way is stored in the recording memory (19) as one piece of image data (S221).

  On the other hand, if the panorama shooting mode is not selected in (S201), the normal shooting sequence is advanced (S230). Since the normal photographing sequence is not directly related to the present invention, it will be omitted.

  FIG. 2 shows an example of guide display displayed in the present embodiment.

  FIG. 2 shows the pan speed guide display (302) of the camera at the start of the main panorama shooting. The display guide of the horizontal swing angle detection position (301) of the camera is the movement of the pan speed guide display (302). Move the camera horizontally so that it overlaps with. The breadth of the pan speed guide display (302) indicates the panning speed threshold “Pth2 ≦ P ≦ Pth1”.

Further, (303) indicates a pre-photometric photometric range in the horizontal direction, and (304) indicates a detectable range of the swing angle position in the vertical direction of the camera. The horizontal and vertical swing angles of the camera are detected by an orientation sensor, an angular velocity sensor, or the like in the posture detection circuit (14).

  As described above, pre-photometry is performed for the entire shooting range or the main subject before the start of panoramic shooting, taking into account the optimal exposure conditions in the panoramic shooting range and the prevention of camera shake and the optimal exposure conditions during panoramic shooting. An excellent panoramic shooting function can be provided by displaying a guide for the panning speed.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  For example, the present invention shows an example of a panoramic photo in the horizontal direction, but a configuration of a panoramic photo in the vertical direction may be used. Alternatively, an EVF (Electric View Finder) may be used to display a panning speed guide display in the finder.

10 Optical lens
11 Image sensor
12 Imaging control circuit
13 Exposure control circuit
14 Attitude detection circuit
15 Release operation button
16 MENU operation buttons
17 Main subject selection button
18 System control circuit
19 Memory control circuit
20 Image processing circuit
21 Recording memory
22 Display
23 Image stabilization circuit
24 volatile memory
25 Nonvolatile memory

Claims (5)

  In a camera with a panoramic shooting function that obtains a panoramic image by joining a plurality of images continuously acquired during a series of shootings, pre-photometry means (11), exposure average value calculating means (18), and exposure Control means (13), the pre-photographing metering means (11) performs photometry continuously within the photographing range while panning the camera, the exposure average value calculating means (18) is the pre-photographing photometric means ( Based on the photometric output of 11), the exposure average value within the shooting range is calculated, and the exposure control means (13) reflects the exposure average value in the exposure conditions of the main panorama shooting, and controls the exposure in the main panorama shooting. A camera with panoramic shooting function, which is characterized by being executed.   The pre-photometry metering means (11) and the main subject area detection means (17), the pre-photometry metering means (11) performs photometry of the main subject area within the photographing range while panning the camera, and the pre-photometry metering Based on the photometric output from the means (11), the exposure average value of the main subject area in the shooting range is calculated, the exposure average value is reflected in the exposure conditions of the main panorama shooting, and the exposure control in the main panorama shooting is executed. The camera with a panoramic shooting function according to claim 1, wherein:   The camera with a panorama shooting function according to claim 2, wherein the main subject area detection means (17) is executed by a button operation of a photographer.   Based on the exposure condition calculated by the pre-photometry metering means (11), a panning speed calculating means (18) for calculating the panning speed of the camera required at the time of panoramic shooting, and a panning speed detecting means (14) of the camera 2. The camera with panorama shooting function according to claim 1, further comprising panning speed guide display means (20), wherein display control of the panning speed guide is executed from the panning speed calculation means (18). 5. The camera with a panoramic photographing function according to claim 4, wherein the panning speed calculating means (18) and the panning speed detecting means (14) of the camera detect the posture of the camera by an azimuth sensor or an angular velocity sensor.