JP2006109168A - Image display system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform multi-screen display in which a variation in colors and brightness between projectors is corrected while assuring a wide dynamic range of an image signal to be input. <P>SOLUTION: An image display system 1 has: a plurality of projectors 12, 13 for image display each of which projects part of an image based on an image signal 20 and displays each projected image simultaneously thereby providing the whole image; and a projector 11 for correction which generates an image signal for correction for correcting a variation in colors in each part of the whole image and projects an image for correction based on the image signal for correction by superposing it onto the whole image. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image display system, and more particularly to an image display system capable of multi-screen display.

  In projectors, the color, brightness, and the like in the projection screen may be uneven for each projector due to variations in components. For this reason, the latest projector includes an image detection device such as a camera that can monitor the state of the projection screen, and a circuit that corrects color, brightness, and the like based on the detection result of the image detection device (hereinafter referred to as color correction, respectively). Often referred to as a brightness correction unit), and the color and brightness are adjusted using these before use of the projector. In many cases, the projector is also provided with a circuit (hereinafter referred to as a geometric shape correction unit) that performs screen division / enlargement display, trapezoidal distortion correction, and the like.

  Recently, an image display system capable of so-called multi-screen display has been developed, in which one image signal is divided and each divided image signal is displayed on each of a plurality of projectors to obtain an entire image. FIG. 9 shows an example of such an image display system (see Patent Document 1). The projectors 111, 112, 113, and 114 are arranged on the screen 116 so that the maximum image projection ranges 151, 152, 153, and 154 slightly overlap each other.

A video signal control device 110 is provided outside the projector. The video signal control device 110 is composed of a personal computer or the like. The video signal control device 110 processes the image signal supplied from the external video input device 118 and supplies it to the projectors 111, 112, 113 and 114. Further, the video signal control device 110 includes a geometric shape correction unit, a color correction unit, and a brightness correction unit, and corrects each image so that the projection image looks uniform and natural as a whole, and the corrected image signal To the individual projectors. This is to prevent the color and brightness from differing between projection screens when these projectors are projected simultaneously. The video signal control device 110 is connected to a screen state monitoring camera 130 that reads the state of the image projected on the screen 116, and performs correction based on the video signal from the screen state monitoring camera 130. The image signal has a uniform projection image when the magnitudes of the three primary colors of red, green, and blue (hereinafter referred to as R, G, and B) are the minimum level (hereinafter referred to as the all black level). It is corrected to look like. Each projector is normally corrected to the full black level of the brightest projected image. For this reason, in other projectors, correction for raising the signal level is performed in advance, and the signal level is handled as the full black level of the projector.
WO99 / 031877 pamphlet JP 2004-70257 A

  However, in a projector that has been corrected to increase the signal level in advance, the R, G, and B3 primary color signals cannot be reduced below the full black level of the projector obtained by the correction, and the signal magnitude It can be corrected only in the direction of increasing the height. As a result, there is a problem that the gradation expression range (hereinafter referred to as dynamic range) of the image signal becomes narrow.

  Further, in the conventional technique, since a dedicated correction device is required, there is a problem in that it affects the cost of the entire system or requires a complicated operation each time and affects the operability.

  The object of the present invention is that there is a variation in the color and brightness of all black levels in the projection screen between projectors due to individual differences of individual projectors, screen reflection characteristics, and ambient ambient light (for example, fluorescent lamps). Even in such a case, an object is to provide an image display system capable of multi-screen display while ensuring a wide dynamic range of an input image signal without requiring a dedicated correction device.

  The image display system according to the present invention includes a plurality of image display projectors that each project a part of an image based on an image signal and display each projection image simultaneously to obtain an entire image, and in each part of the entire image And a correction projector that generates a correction image signal for correcting the color variation and projects the correction image based on the correction image signal on the entire image.

  Therefore, even if the color or brightness of the image displayed by each image display projector varies due to individual differences among individual projectors, screen reflection characteristics, or ambient ambient light, the correction projector can change the image. These variations can be corrected by superimposing and projecting on the correction image.

  The correction projector includes a color information detection unit that detects color information of an image signal, and a partial conversion unit that generates a correction image signal for performing color correction on a predetermined color. The partial conversion correction value storage unit that stores the correction value used for correction for the specified hue, and the correction value stored in the partial conversion correction value storage unit are used as the color information detection result in the color information detection unit. Accordingly, a correction value to be used for correction is selected, and a partial conversion correction value calculation unit for obtaining a partial conversion intensity according to the color information detection result in the color information detection unit, and the selected correction value are calculated. A partial conversion calculation unit that uses a value obtained by multiplying the partial conversion intensity as a correction image signal can be provided.

  The partial conversion unit can perform partial conversion by using, as a correction image signal, a value obtained by adding a predetermined color image signal to the correction image signal.

  In addition, the color correction unit of the correction projector has an overall conversion unit that performs overall conversion, which is a collective color correction for all colors, and the overall conversion unit saves matrix coefficients used for overall conversion. You may comprise so that a value preservation | save part and the whole conversion calculating part which performs whole conversion by making the value which multiplied the matrix coefficient and the correction image signal into a new correction image signal may be provided.

  Further, each of the image display projectors is assigned to the image display projector based on the detection result detected by the color information detection unit that detects the color information of the image signal and the color information detection unit of the image display projector. You may comprise so that it may have a color correction part which correct | amends the dispersion | variation in the color of the projector for an image display with respect to an image signal.

  In addition, the correction projector is configured to detect the variation in the brightness of the projection image displayed by the image display projector, and to correct the brightness of the image display projector based on the detection result of the image detection device. And a brightness correction unit that calculates the α blend correction value for each image display projector and transmits the calculated α blend correction value to the image display projector.

  Further, the brightness correction unit of the correction projector calculates an α blend correction value for correcting the brightness of the overlapping portion of the projected image of the image display projector, and the calculated α blend correction value is an image related to the overlapping portion. It can be transmitted to a display projector.

  The image display method of the present invention is an original image in which a plurality of image display projectors each share a part of an image based on an image signal and project simultaneously, and display each projection image to display an entire image. The projection step and the correction projector generate a correction image signal for correcting the color variation in each part of the entire image, and the correction image based on the correction image signal is projected on the entire image to be corrected. And a correction projection step for displaying the entire image.

  The correction projection step includes a partial conversion step for correcting a color with respect to a predetermined color, and the partial conversion step detects a color value of an image signal and stores a correction value used for correction in advance for a specified hue. Selecting a correction value used for correction from the stored correction values according to the detected color information, obtaining a partial conversion intensity according to the detected color information, selecting A correction image signal generation step using a value obtained by multiplying the calculated correction value and the calculated partial conversion intensity as a correction image signal.

  The correction image signal generation step may include setting a value obtained by adding an image signal of a predetermined color to the correction image signal as the correction image signal.

  Further, the correction projection step has a total conversion step for correcting all colors in a lump after the partial conversion step, and the total conversion step stores in advance matrix coefficients used for the total conversion. And a step of performing total conversion by using a value obtained by multiplying the matrix coefficient and the correction image signal as a new correction image signal.

  In the original image projecting step, the image display projector detects the color information of each image signal shared by the image display projector, and the image display projector shares the image shared by the image display projector according to the detected color information. And correcting a color variation of the image display projector for the signal.

  Further, the original image projection step includes a step of detecting in advance a brightness variation of the projection image displayed by the image display projector, and a brightness of the image display projector based on the detected brightness variation of the projection image. A step of calculating an α blend correction value for performing correction for each image display projector and a step of correcting the image signal based on the calculated α blend correction value can be provided.

  As described above, according to the image display system and the image display method of the present invention, even when the color and brightness of the image displayed by each image display projector vary, the correction projector applies correction to those images. These variations can be corrected by superimposing and projecting on the image. Therefore, multi-screen display can be performed while ensuring a wide dynamic range of the input image signal without requiring a dedicated correction device.

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

  The present invention is an image display system for projecting one image using a plurality of projectors, for image correction provided with a device for detecting a newly projected image (hereinafter referred to as “image detection device”). A projector for correcting and generating and projecting a corrected image that alleviates the difference in color and brightness uniformity of images projected from other projectors, screen reflection characteristics, ambient light, etc. Then, the correction image is superimposed on an image projected from another projector, thereby performing adjustment for making the color and brightness appear uniform.

  FIG. 1 shows an overall configuration diagram of an image display system of the present invention. The image display system 1 includes projectors 11, 12 and 13, an image signal distributor 17, an image signal generator 18, and a control signal distributor 19.

  The projector 11 is an image correction projector provided with an image detection device 28 (see FIG. 2). The projectors 12 and 13 are image display projectors that project the divided image signals each of which is assigned to the screen 16. The projectors 11, 12, and 13 are connected to an image signal distributor 17 via a signal cable, and the image signal distributor 17 is further connected to an image signal generator 18. In the present embodiment, the viewer H views the screen 16 from the same direction as the projectors 11, 12, and 13.

  The image signal generator 18 generates an original image signal 20 which is an image signal composed of a video signal or the like, and outputs it to the image signal distributor 17. The image signal distributor 17 distributes the original image signal 20 to the projectors 11, 12, and 13. The projectors 12 and 13 receive the original image signal 20 from the image signal distributor 17 and display an image of the display range of the original image signal 20 assigned to each on a display device (not shown) such as a liquid crystal panel. . The display range of the display device is determined by the display start position and the display end position in the horizontal and vertical directions. The projectors 12 and 13 perform geometric shape correction (image enlargement, trapezoid correction, etc.) on the display image on the display device, and project the image onto the screen 16. The projector 11 detects a portion where the colors and brightness of the images projected from the projectors 12 and 13 are non-uniform by the image detection device 28, creates an optimal corrected image, and projects it on the screen 16.

  The projector 11 and each of the projectors 12 and 13 are connected to each other by a high-speed data transfer interface such as USB or LAN via a control signal distributor 19 which is a relay for the control signal 15. The projector 11 transmits to the projectors 12 and 13 a control signal 15 for changing the setting value of the brightness correction unit in the projectors 12 and 13 based on the brightness distribution of the projection image detected by the image detection device. Correct the brightness of the entire projected image.

  FIG. 2 shows an internal configuration diagram of each projector shown in FIG. The CPU 21 calculates correction data based on the detected brightness distribution data. The A / D converter 22 converts the original image signal 20 from an analog signal to a digital signal.

  The geometric shape correction unit 23 enlarges / reduces the digital image signal from the A / D conversion unit 22 to an arbitrary screen size, and corrects the trapezoidal distortion of the projection screen. The image storage unit 221 holds the digital image signal from the A / D conversion unit 22 and data necessary for each correction process for the processing of the geometric shape correction unit 23. A still image may be directly input from the CPU 21 to the geometric shape correction unit 23 via the system bus 211.

  As shown in an example of the configuration in FIG. 3, the color correction unit 24 includes a color information detection unit 248 that obtains color information such as a hue for each pixel of an image from the digital image signal input from the geometric shape correction unit 23, The partial conversion unit 241 that performs color correction by changing parameters for correction calculation for each range of the color information, the overall conversion unit 242 that collectively performs color correction of each RGB color, and the data of the system bus 211 And an interface 249 for performing exchange.

  The partial conversion unit 241 performs color adjustment of a specific hue such as skin color or red. The partial conversion unit 241 selects a partial conversion calculation unit 243 that performs partial conversion and correction values a1, a2, and a3 used for partial conversion according to the designated hue, and detects color information in the color information detection unit 248. A partial conversion correction value calculation unit 244 that obtains a partial conversion strength hx (described later) according to the result, and a partial conversion correction value storage unit 245 that stores correction values a1, a2, and a3 are provided. Furthermore, the partial conversion unit 241 of the projector 11 can also set offset coefficients Br1, Bg1, and Bb1 of the sizes of the RGB image signals. The offset coefficients Br1, Bg1, and Bb1 are used to correct the influence of the screen color when projecting onto a screen with a specific color. The offset coefficients Br1, Bg1, and Bb1 are stored in the partial conversion correction value storage unit 245.

  The overall conversion unit 242 corrects the difference in hue based on the individual difference between the projectors. That is, in the liquid crystal panel projector, the RGB single color and white projection images may not be uniform, and the color directionality can be adjusted by this correction. The overall conversion unit 242 stores the overall conversion calculation unit 246 that collectively performs color correction of each color of RGB using 3 × 3 matrix conversion on the image signal, and matrix coefficients C11 to C33 used for the overall conversion. And an overall conversion correction value storage unit 247. The total conversion calculation unit 246 can also set offset coefficients Br2, Bg2, and Bb2 of the sizes of the RGB image signals. The offset coefficients Br2, Bg2, Bb2 are used to match the hues of the projectors by adding them to the image signal. The offset coefficients Br2, Bg2, and Bb2 are stored in the overall conversion correction value storage unit 247.

  As shown in an example of the configuration in FIG. 4, the brightness correction unit 25 is a gain that can adjust the magnitude of a signal at an arbitrary position (horizontal coordinate x, vertical coordinate y) of an image signal. The system bus 211 exchanges data with a correction unit (hereinafter referred to as α blend correction unit 251), a γ correction unit 252 that corrects linearity of brightness change (hereinafter referred to as linearity), and the system bus 211. Interface 259.

  The α blend correction unit 251 corrects the image signal using the α blend correction value. Here, the α blend correction value is composed of contrast coefficients αr, αg, αb set for each color of RGB and bright coefficients Br, Bg, Bb set for each color of RGB. The contrast coefficients αr, αg, αb are used to enhance or suppress the vividness of the image signal. Bright coefficients Br, Bg, and Bb are used to increase or decrease the signal level of the entire image signal by adding it to the image signal, and to brighten or darken the projected image. The α blend correction unit 251 includes an α blend calculation unit 253 that performs an α blend calculation, an α blend correction value calculation unit 254 that calculates an α blend correction value used for the α blend correction, and an α that stores the calculated α blend correction value. And a blend correction value storage unit 255.

  The projector driving unit 26 converts the digital image signal from the brightness correction unit 25 into light (analog) projection image information and projects it onto the screen 16.

  The image detection device 28 is configured by a camera or the like, and detects the color and brightness distribution of the image projected on the screen 16.

  Next, the operation of the image display system of the present invention will be described using the flowchart shown in FIG.

  (Step 51) First, the image projection ranges of the projectors 12 and 13 are matched. If the image projection ranges do not become rectangular due to the arrangement of the projectors 12 and 13, first, the adjacent image projection ranges 41 and 42 are arranged so as to overlap in the overlapping region 43 as shown in FIG. 6A. Next, as shown in FIG. 6B, trapezoidal distortion correction is performed on the individual image projection ranges 41 and 42 by the geometric shape correction unit 23 of the projectors 12 and 13, and adjustment is performed so that the rectangular image projection ranges 44 and 45 are obtained. To do. At this time, the projection area 46 of the projector 13 overlapping the image projection range 44 of the projector 12, the projection area 47 of the projector 12 overlapping the image projection range 45 of the projector 13, and the non-display areas 48 and 49 are all black level. A signal is output. If the adjusted image projection ranges of the projectors 12 and 13 are not appropriate, the above operation is repeated again.

  (Step 52) Next, the image projection range of the projector 11 for image correction is matched with the image projection ranges 44 and 45 of the projectors 12 and 13. At this time, the image projection ranges of the two do not need to coincide with each other, but at least the maximum image projection range of the projector 11 for image correction is adjusted to include the image projection ranges 44 and 45 of the projectors 12 and 13.

  (Step 53A) Next, the still image signals of all black levels and RGB colors are input to the projector 12. At this time, an image is not projected from the projectors 11 and 13. The magnitudes of the RGB signals may be arbitrary but are at the same level. The projector 12 projects the input still image of all black level on the screen 16, and the image detection device 28 of the projector 11 detects the brightness distribution of the image projected on the screen 16. Similarly, the image detection device 28 also detects the distribution of brightness when a still image of each color of R, G, and B is projected. The brightness distribution of each color can be detected, for example, by determining the ratio between the brightness at the center position and the brightness at the peripheral position using the detected value at the center of the projection image as a reference value. This operation is performed to correct the brightness of the non-display area 48 and the portion other than the projection area 46 in the image projection range 44 projected by the projector 12 in the projected image of FIG. 6B.

  (Step 54A) Next, the CPU 21 of the projector 11 determines the α blend correction value (contrast coefficients αr, αg, αb, and the like) of the projector 12 based on the color and brightness distribution detected by the image detection device 28 of the projector 11. Bright coefficient Br, Bg, Bb) is calculated, and the calculated α blend correction value is stored in the α blend correction value storage unit 255 of the projector 12 via the interface 259 of the projector 12.

  The α blend correction value is calculated and stored for each horizontal dot and vertical line of the image signal input, but is calculated as information divided into horizontal m dots and vertical n lines (m and n are positive integers). May be saved. In other words, the α blend correction value of the area partitioned by horizontal m dots and vertical n lines can be represented by the values of the four corners of the area. FIG. 7 shows an example of a method for storing such an α blend correction value. The figure shows a portion corresponding to the upper left image area in the coordinates of the image signal, and one mesh in the figure corresponds to one coordinate of the image signal. If m = n = 32, the area surrounded by the coordinates (1, 1), (1, 32), (32, 1), (32, 32) constitutes the upper left corner area 71. Then, the α blend correction value at the coordinates (1, 1), (1, 32), (32, 1), (32, 32) of the four corners of the region 71 is the α blend correction value of each coordinate (x, y). Saved instead. If the number of signal pixels is, for example, 1024 × 768, the number of regions is 32 × 24, and it is only necessary to store the total number of corners 33 × 25 = 825 α blend correction values, and a huge amount of data can be stored. Can be prevented.

  (Step 53B) Next, still image signals of all black levels and RGB colors are input to the projector 13, and the same operation as in Step 53A is performed. At this time, an image is not projected from the projectors 11 and 12.

  (Step 54B) Next, similarly to step 54A, the CPU 21 of the projector 11 calculates the α blend correction value of the projector 13, and stores the calculated α blend correction value in the α blend correction value storage unit 255 of the projector 13. To do.

  (Step 53C) Next, all black level and RGB still image signals are simultaneously input to the projectors 12 and 13, and the same operation as in Step 53A is performed. At this time, an image is not projected from the projector 11. This operation is performed to correct the brightness of the region where the projection images of the projectors 12 and 13 overlap (projection regions 46 and 47 in FIG. 6B).

  (Step 54C) Next, as in step 54A, the CPU 21 of the projector 11 calculates the α blend correction value of the projectors 12 and 13, and stores the calculated α blend correction value of the projector 12 and 13 in the α blend correction value. The data is stored in the unit 255.

  (Step 53D) Next, the still image signals of all black levels and RGB colors are input to the projector 11, and the same operation as in Step 53A is performed. At this time, no image is projected from the projectors 12 and 13. This operation is performed for correcting the brightness of the projection image of the projector 11.

  (Step 54D) Next, the CPU 21 of the projector 11 calculates the α blend correction value of the projector 11 and stores the calculated α blend correction value in the α blend correction value storage unit 255 of the projector 11 as in step 54A. To do.

  (Step 55) Next, the original image signal 20 to be actually projected is inputted from the image signal generator 18 to the projectors 11, 12, 13 via the image signal distributor 17.

  (Step 56) Next, the color correction unit 24 of the projector 11, 12, 13 converts the image signal input from the A / D converter 22 into color information such as luminance and hue by the color information detection unit 248. . Luminance Yi is obtained by Equation 1. The hue Huei is obtained by, for example, Equations 2 and 3. In the following equations, R, G, and B represent the input signal level of each color.

  Next, the partial conversion correction value calculation unit 244 calculates a partial conversion intensity hx from 0 to 1 within the hue range m of the designated hue Hue from the luminance Yi and the hue Huei. Here, the designated hue Hue and the hue range m are stored in the partial conversion correction value storage unit 245 in advance. A formula for calculating the partial conversion strength hx is shown in Formula 4.

  The partial conversion correction value calculation unit 244 further selects the hue correction values a1 to a3 for each hue stored in advance in the partial conversion correction value storage unit 245 for each hue according to the hue Huei, and performs the partial conversion calculation. Send to part 243.

  (Step 57A) The partial conversion calculation unit 243 of the projectors 12 and 13 performs a hue correction calculation according to Formula 5 using the partial conversion strength hx obtained from the above calculation and the hue correction values a1 to a3. Here, Ro (x, y), Go (x, y), Bo (x, y) are the image signal output values of R, G, B at coordinates x, y, respectively, Ri (x, y), Gi (x, y) and Bi (x, y) represent R, G, and B image signal input values at coordinates x and y, respectively.

  (Step 57B) The partial conversion calculation unit 243 of the projector 11 calculates the corrected image using Equation 6 using the partial conversion intensity hx obtained from the above calculation and the hue correction values a1 to a3.

  (Step 58) Next, the total conversion calculation unit 246 of the total conversion unit 242 of the projector 11, 12, 13 receives the output signal from the partial conversion unit 241, and is stored in the total conversion correction value storage unit 247. The whole conversion is performed by Equation 7 using the coefficients C11 to C33 and the offset coefficients Br2, Bg2, and Bb2. Through the above steps, the hue adjustment of the image signal at one coordinate (x, y) is completed.

  (Step 59) Next, the α blend correction value calculation unit 254 of the projector 11, 12, 13 sequentially reads out the α blend correction value stored in the α blend correction value storage unit 255 in synchronization with the image signal input. It sends out to the α blend calculation unit 253. In addition, when the α blend correction value is stored as information divided into horizontal m dots and vertical n lines, the α blend correction value calculation unit 254 matches the horizontal and vertical positions of the actual image signal input, It is obtained by interpolation calculation from the α blend correction values at the four surrounding points stored in the α blend correction value storage unit 255.

  Next, the α blend calculation unit 253 of the projectors 11, 12, and 13 performs calculation processing based on the α blend correction value. Formula 8 shows an example of a calculation formula processed by the α blend calculation unit 253. Here, Ro (x, y), Go (x, y), and Bo (x, y) are the image signal output values of R, G, and B at coordinates x and y, respectively, αr (x, y), αg (x, y) and αb (x, y) are the contrast coefficients of R, G, and B at coordinates x and y, respectively, Ri (x, y), Gi (x, y), Bo (x, y ) Is the R, G, B image signal input value at coordinates x, y, and Br (x, y), Bg (x, y), Bb (x, y) are R at coordinates x, y, respectively. , G, B bright coefficients.

  (Step 60) Next, the corrected image of the projector 11 is superimposed on the original image projected from the projectors 12 and 13.

  By the above procedure, adjustment for making the color and brightness appear uniform can be performed. By superimposing the corrected image of the projector 11 on the original image projected from the projectors 12 and 13, the projected image is based on the influence of the non-uniformity of the total black level of the projectors 12 and 13, the reflection characteristics of the screen, ambient light, and the like. It is possible to reduce the difference between the images of the respective parts.

  The first effect of the present invention is that the correction of the color and brightness (= darkness) of all black levels can be performed for each projector without restricting the dynamic range of the input image signal. It is to be able to call.

  The second effect is that, in multi-screen display using a plurality of projectors, it is possible to correct for all black level colors and uneven brightness of the entire projection screen due to individual differences among individual projectors. is there.

  The image display system of the present invention is not limited to the embodiment described above, and various modifications are possible. For example, all black levels are projected from the projectors 12 and 13, the color uniformity is detected by the image detection device 28 provided in the projector 11, and the entire conversion unit 242 of the color correction unit 24 is applied to each divided screen. The offset coefficients Br2, Bg2, and Bb2 are added to adjust the color of the entire divided screen first, and then the projector 11 adjusts the color and brightness of the details of the screen. It becomes possible.

  The projectors 12 and 13 for projecting the original image may be projected from the direction opposite to the viewer's viewpoint. FIG. 8 shows an example in which one projector is projected from the direction opposite to the viewpoint of the viewer H with four projectors.

1 is an overall configuration diagram of an image display system of the present invention. It is an internal block diagram of the projector which comprises the image display system shown in FIG. It is a block diagram of the color correction part of the projector shown in FIG. It is a block diagram of the brightness correction part of the projector shown in FIG. It is a flowchart which shows the procedure of the image projection method of this invention. It is explanatory drawing of the projection image before trapezoid distortion correction when two projectors are projected. It is explanatory drawing of the projection image after trapezoid distortion correction | amendment when projecting two projectors. It is explanatory drawing of the preservation | save method of (alpha) blend correction value. It is a conceptual diagram which shows the structural example of the image display system which projects from the direction opposite to a viewer's viewpoint with four projectors, and obtains one screen. It is a conceptual diagram which shows the structural example of the image display system of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image display system 11, 12, 13 Projector 17 Image signal distributor 18 Image signal generator 16 Screen 20 Original image signal 21 CPU
211 System bus 22 A / D conversion unit 221 Image storage unit 23 Geometric shape correction unit 24 Color correction unit 241 Partial conversion unit 242 Overall conversion unit 243 Partial conversion calculation unit 244 Partial conversion correction value calculation unit 245 Partial conversion correction value storage unit 246 Total conversion calculation unit 247 Total conversion correction value storage unit 248 Color information detection unit 249 Interface Brightness correction unit 25
251 α blend correction unit 252 γ correction unit 253 α blend calculation unit 254 α blend correction value calculation unit 255 α blend correction value storage unit 259 interface 26 projector drive unit 28 image detection device

Claims (13)

A plurality of image display projectors that each project a part of an image based on an image signal and obtain an entire image by simultaneously displaying each projection image;
A correction projector that generates a correction image signal for correcting a color variation in each part of the entire image, and projects a correction image based on the correction image signal superimposed on the entire image. system. The correction projector includes a color information detection unit that detects color information of the image signal, and a partial conversion unit that generates the correction image signal for performing color correction on a predetermined color,
The partial converter is
A partial conversion correction value storage for storing correction values used for correction for a specified hue;
The correction value used for the correction is selected from the correction values stored in the partial conversion correction value storage unit according to the color information detection result in the color information detection unit, and the color information detection unit A partial conversion correction value calculation unit for obtaining a partial conversion intensity according to the color information detection result in
A partial conversion calculation unit that uses a value obtained by multiplying the selected correction value and the calculated partial conversion intensity as the correction image signal;
The image display system according to claim 1.   The image display system according to claim 2, wherein the partial conversion unit performs the partial conversion by using, as a correction image signal, a value obtained by adding an image signal of a predetermined color to the correction image signal. The color correction unit of the correction projector includes an overall conversion unit that performs overall conversion, which is correction of all colors for all colors.
The overall converter is
A global conversion correction value storage unit for storing matrix coefficients used for global conversion;
4. The apparatus according to claim 2, further comprising: an overall conversion calculation unit that performs the overall conversion by using a value obtained by multiplying the matrix coefficient and the correction image signal as a new correction image signal. 5. Image display system. Each of the image display projectors,
A color information detector for detecting color information of the image signal;
Color correction for correcting color variations of the image display projector for the image signal shared by the image display projector based on a detection result detected by the color information detection unit of the image display projector The image display system according to claim 2, further comprising a unit. The correction projector is
An image detection device for detecting variations in brightness of the projected image displayed by the image display projector;
An α blend correction value for correcting the brightness of the image display projector is calculated for each image display projector based on the detection result of the image detection device, and the calculated α blend correction value is used for the image display. A brightness correction unit that transmits to the projector,
The image display system according to any one of claims 2 to 5.   The brightness correction unit of the correction projector calculates an α blend correction value for correcting the brightness of the overlapping portion of the projected image of the image display projector, and the calculated α blend correction value is stored in the overlapping portion. The image display system according to claim 6, wherein the image display system transmits the image to the image display projector. A plurality of image display projectors, each sharing a part of an image based on an image signal and projecting it simultaneously, and displaying each projected image to display an entire image, and an original image projecting step,
The correction projector generates a correction image signal for correcting color variations in each part of the whole image, and the correction image based on the correction image signal is projected on the whole image so as to be corrected. And a correction projection step for displaying the entire image. The correction projection step includes a partial conversion step for correcting a color with respect to a predetermined color,
The partial conversion step includes
A step of preliminarily storing correction values used for correction for a specified hue;
Detecting color information of the image signal;
Selecting a correction value to be used for the correction from the stored correction values according to the detected color information;
Obtaining a partial conversion intensity according to the detected color information;
A correction image signal generation step in which a value obtained by multiplying the selected correction value and the calculated partial conversion intensity is used as the correction image signal.
The image display method according to claim 8.   The image display method according to claim 9, wherein the correction image signal generation step includes setting a value obtained by adding an image signal of a predetermined color to the correction image signal as a correction image signal. The correction projecting step has an overall conversion step for correcting the colors in a lump for all colors following the partial conversion step,
The whole conversion step includes
Pre-storing matrix coefficients for use in global transformation;
The image display method according to claim 9, further comprising: performing the entire conversion by using a value obtained by multiplying the matrix coefficient and the correction image signal as a new correction image signal. . The original image projecting step includes
The image display projector detecting color information of the image signal each of which is shared;
The image display projector includes a step of correcting a color variation of the image display projector with respect to the image signal shared by the image display projector according to the detected color information. Item 12. The image display method according to any one of Items 9 to 11. The original image projecting step includes
Detecting in advance brightness variations of the projected image displayed by the image display projector;
Calculating an α blend correction value for each of the image display projectors for performing brightness correction of the image display projector based on the detected brightness variation of the projection image;
The image display method according to claim 9, further comprising a step of correcting the image signal based on the calculated α blend correction value.

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