JP3933145B2 - Image display device and image display method - Google Patents

Description

  The present invention relates to an image display device and an image display method for easily displaying a personal computer input image even under illumination.

  When a presentation is performed using a projector, it is often difficult to reproduce a chart created by a presenter like a personal computer screen due to the effects of room lighting or a screen. In response to this problem, efforts are being made to achieve more faithful color reproduction by performing color management that takes into account the input / output characteristics of the device and the surrounding lighting environment. Furthermore, in order to recognize changes in the surrounding lighting environment and projection plane, color measurement is performed with a light sensor, correction data is stored in a table, input video signals are converted in a table, and output, so that faithful color is achieved. It is disclosed to improve the reproduction (see Patent Document 1).

It is also disclosed that a color correction table for performing faithful color reproduction and a table for performing color correction with priority on brightness are prepared, and color correction is performed with a table with priority on brightness at the time of PC input ( Patent Document 2).
JP 2002-94822 A JP 2002-290759 A

  However, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-94822), as is apparent from FIG. 6 (FIG. 12 of the present application) published in the publication, the color components of the surrounding environment are subtracted when the color is reproduced faithfully. Since a correction curve is created and an image is output as a result, the brightness of the entire screen becomes dark, and as a result, the visibility of the displayed image is reduced.

  Further, Patent Document 2 (Japanese Patent Application Laid-Open No. 2002-290759) discloses that a color correction table with brightness priority is provided in addition to a color correction table for performing faithful color reproduction so as to cope with the above-described problems. However, in the brightness priority mode, in order to maintain the same brightness as the input level for the signal that has been darkened in order to reproduce faithful color, the signal is displayed in a color correction table in which a white component is added. As a result, as the white component is added, the color becomes an achromatic color, and there is a problem that the visibility of the color deteriorates.

  The present invention has been made in consideration of the above-described problems, and an object of the present invention is to provide an image display device and an image display method for improving visibility even under illumination when a personal computer input signal is image-displayed by a projector. Is.

The first aspect of the present invention is a means (53) for multiplying each RGB video signal by a predetermined ratio based on the maximum value of the luminance signal of the entire screen, and a means for detecting a color component from the multiplied video signal (56). ), Means (51) for detecting the RGB minimum value from the multiplied video signal, and means for subtracting from the multiplied video signal at a predetermined ratio based on the color component detection result and the minimum value detection result (52), the white component is reduced, the complementary color and the primary color component are increased without lowering the brightness of the entire screen, and the color visibility is increased.

According to a second aspect of the present invention, means (57) for adding a predetermined value to each of the RGB video signals based on the maximum value of the luminance signal of the entire screen, and means for detecting a color component from the video signal after the addition (57) 56), means (51) for detecting the RGB minimum value from the video signal after addition, and subtracting from the video signal after addition at a predetermined ratio based on the color component detection result and the minimum value detection result Since the image display device is provided with the means (52), it has the effect of increasing the color visibility without reducing the brightness with a simpler circuit configuration.

The third of the present invention, means for detecting the color components (56), by each of RGB differences of claim 1 or claim 2, wherein the dividing into six color components of the primary color component and the complementary color component Since it is an image display device, it has the effect of increasing the visibility of all the primary color components and complementary color components.

According to a fourth aspect of the present invention, a step of multiplying each RGB video signal by a predetermined ratio based on the maximum value of the luminance signal of the entire screen , a step of detecting a color component from the multiplied video signal, and the post-multiplication An image display comprising: detecting an RGB minimum value from the video signal; and subtracting the color component detection result and the minimum value detection result at a predetermined ratio from the multiplied video signal. Since this method is the same as the first aspect of the present invention, the white component is reduced and the complementary color and primary color components are increased without lowering the brightness of the entire screen, so that the color visibility is improved.

According to a fifth aspect of the present invention, a step of adding a predetermined value to each of the RGB video signals based on the maximum value of the luminance signal of the entire screen, a step of detecting a color component from the video signal after the addition, and the addition An image comprising: detecting a minimum RGB value from a subsequent video signal; and subtracting the color component detection result and the minimum value detection result from the added video signal at a predetermined ratio. Since it is a display method, it has the effect of increasing the visibility of the color without reducing the brightness with simple processing steps, as in the second aspect of the present invention.

  As described above, since the colors to be displayed are emphasized with respect to the input signals of the personal computer RGB, the image visibility can be improved even in an illumination environment.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

(Embodiment 1)
First, the image display apparatus according to the first embodiment of the present invention will be described with reference to FIG.

  The projector 100 processes the input video signal and presses the POWER button 150 to output an enlarged projected video from the projection lens 190 using an internal light source and ride valve not shown. As an input, it has a Video input 170 and an RGB input 160, and each connects an external device. In addition, a mouse port such as USB is provided, and the mouse 130 is connected to operate as a setting state of the projector 100 or a pointer that can move on the screen. This also realizes the same function with the operation button 140.

  Next, a detailed block diagram of the projector 100 is shown in FIG. The VIDEO terminal 11 is a terminal for inputting an NTSC composite video signal.

  The S-VIDEO terminal 12 is a terminal for inputting an S video signal.

  The RGB / YPbPr terminal 13 is a terminal for inputting an RGB signal or a YPbPr signal.

  The input selector 21 is a selector for selecting one of the composite video signal input from the VIDEO terminal 11 and the S video signal input from the S-VIDEO terminal 12.

  The Y / C separation circuit 23 is a circuit for separating the composite video signal input by the color decoder 22 into a Y signal and a C signal.

  The color decoder 22 is a decoder for color-decoding a Y / C separated signal or an inputted Y / C signal into a YPbPr signal.

  The matrix circuit 24 is a circuit for performing matrix processing when converting a YPbPr signal input from the RGB / YPbPr terminal 13 into an RGB signal.

  The input selector 25 is a selector for selecting one of the RGB signals input from the RGB / YPbPr terminal 13 and the RGB signals generated by the matrix circuit 24.

  The input selector 26 is a selector for selecting any analog signal from the YPbPr signal generated by the color decoder 22 and the RGB signal input by the input selector 25.

  The A / D converter 30 is a converter for A / D converting the analog signal selected by the input selector 26 into an 8-bit digital signal.

  The resizing / freezing / on-screen generation circuit 40 resizes the digital signal A / D converted by the A / D converter 30 in accordance with the number of pixels of the LCD (Liquid Crystal Panel) panels 91 to 93, and superimposes the on-screen. It is a circuit for making it.

  The color conversion circuit 50 is a circuit that converts RGB data output from the resize / freeze / on-screen generation circuit 40 into a predetermined color.

  The main microcomputer 70 performs all kinds of control of the entire apparatus such as power supply (not shown) control, fan (not shown) control, temperature control, input switching control and the like, and sends color to the color conversion circuit 50 based on data from the external interface 71. Coordinate data is transferred and freeze control is performed on the resizing / freezing / on-screen generation circuit 40.

  The digital phase expansion circuits 81 to 83 are circuits for phase expansion of the digital signal color-corrected by the color conversion circuit 50 in consideration of the operation speed of the drive drivers (not shown) of the LCD panels 91 to 93.

  A panel driving IC (Integrated Circuit) 90 is a circuit for driving the LCD panels 91 to 93.

  The LCD panels 91 to 93 are panels for color-displaying digital signals color-corrected by the color conversion circuit 50 and phase-developed by the digital phase development circuits 81 to 83.

  A detailed block diagram of the color conversion circuit 50 shown in FIG. 9 is shown in FIG. A screen MAX detector 54 and a multiplier 53 for detecting the maximum value of the RGB signal output from the resize / freeze / on-screen generating circuit 40 within one frame of the screen are provided, and the signal level of the screen MAX detector 54 is set to a predetermined level. Based on the result of the division unit 55 that divides from the value, the multiplication amount of the multiplication unit 53 is determined, and the signal level of the video signal is amplified. Next, since the 6-axis detection unit 56 detects the RGBY (Yellow) C (Cyan) M (Magenta) of the color and the MIN detection unit 51, that is, the minimum of RGB, with respect to the output of the multiplication unit 53, the white component is Color conversion is performed by changing the subtraction amount of the subtraction unit 52 from the result of the detection unit to be detected.

  FIG. 3 shows the multiplier 53, the MAX detector 54, and the divider 55. The RGB signal is converted by the MTX (matrix) 541 and the Y signals of the Y, Pb, and Pr signals are stored in the memory 543. Thereafter, the result of the comparator 542 is established only when there are more Y signals in one frame, and the signal level in the memory 543 is updated. The result is divided by a dividing unit 55 from a predetermined value, and the coefficient is multiplied by a multiplying unit 53.

  FIG. 5 shows an RGBYCM six-axis detector, and the difference between RG, RB, GR, GB, BR, and BG is set to 561 from the multiplied RGB signals. Ys (Yellow component) is obtained by selecting a value having a smaller difference amount between RB and GB. Similarly, by selecting a small value from each difference amount, each component of RGBYCM is obtained.

  FIG. 6 is a diagram illustrating the MIN detection unit 51, and the smallest signal level is obtained by performing two comparisons 511 and 512 of the multiplied RGB signals.

  FIG. 7 is a block diagram showing the final color calculation. The RGBYCM signal components are multiplied by the levels of the MIN detection unit 51 by the multipliers 59a to 59f, and finally, the RGB signals are subtracted from the RGB signal to the subtraction unit 52. To determine the amount to be subtracted.

  The operation of the image display apparatus of the present invention in the projector 100 as described above will be described.

  The RGB signal of the personal computer input from the RGB / YPbPr terminal 13 is A / D converted and resized, and then input to the color conversion circuit 50. The input RGB signal calculates the luminance (Y) signal level in the MTX 541 of the screen MAX detection 54. Next, the comparator 542 determines that only the largest value in the screen is updated by storing the Y signal level in the memory 543 to be reset in one frame. At this time, when the 8-bit input level (maximum 255 level) is smaller than 255, for example, when the maximum level is 200 in the screen, the division unit 55 obtains a multiplication coefficient of 255/200 = 1.275. At 53, the RGB signal is multiplied by 1.275 with respect to all pixels of one frame of data (see FIG. 8B). Further, when the signal level of the RGB signal multiplied by 1.275 is recognized as R: 200 levels / 256 gradations, G: 150 levels / 256 gradations, and B: 50 levels / 256 gradations, FIG. 8 shows. As described above, since the white component that can be detected by the MIN detection unit 51 is the minimum value of RGB, the white component has 50 levels. Further, the 6-axis detector 56 obtains each component of the 6 axes. In the case of the pixel level as described above, the Rs component and the Ys component can be detected as 50 and 100, respectively. Accordingly, the multiplier 59a multiplies the Ys component 100 and the MIN component (white component) 50, and the multiplier 59d multiplies the Rs component 50 and the MIN component (white component) 50. The subtracting unit 52 first subtracts 20 levels equivalent to 1/256 from B corresponding to the opposite color of yellow in the additive color mixture by the bit shift (not shown) of the multiplication result described above to the YCM of the complementary color component. Further, 10 levels corresponding to 1/2 of the above multiplication result are subtracted from G and B for the primary color component RGB.

  As described above, the input of the color conversion circuit 50 increases the brightness by 1.275 times, G is −10, B is −20−10 = −30, and the R and Y components become larger. In the image finally projected on the screen, the R and Y components are dark and the white component is reduced, which is not faithful color reproduction, but improves the color visibility in PC images under illumination. An image can be displayed (see FIG. 8C). In addition, since the coefficient to be multiplied in the multiplication unit 53 is determined from the whole of one frame, the video can be multiplied at an optimum ratio without being crushed white.

  In this embodiment, only R and Y can improve color visibility. However, since 6-axis detection is performed and color calculation is performed, the visibility of all colors of the primary color component and the complementary color component can be improved. it can. Further, when performing color calculation, processing according to the minimum value, that is, the amount of white level, is performed, so that an RGB input signal having a higher white level can exhibit the effect.

(Embodiment 2)
An image display apparatus according to a second embodiment of the present invention will be described with reference to FIG.

  FIG. 11 shows an image display apparatus, that is, a display system using the projector 100. The image of the personal computer 61 connected to the input terminal 160 is projected onto the screen 110 using the projector 100. At this time, the remote controller 60 controls each function with respect to the projector 100. The optical sensor 94 is attached in the direction of the screen 110 and measures illuminance. Further, as is apparent from FIG. 4, the optical sensor 94 is input to the main microcomputer 70.

  The image display apparatus 100 in the present embodiment is almost the same as that in the first embodiment, but the difference is the processing contents of the color conversion circuit 50.

  The RGB signal input to the color conversion circuit 50 has a screen MAX detection unit 54 and an addition unit 57 for detecting the maximum value within one frame of the screen as shown in FIG. The amount to be added is calculated by the adder 57, and the signal level of the video signal is increased. Next, with respect to the output of the adder 57, the 6-axis detector 56 detects the color RGBYCM and the MIN detector 51 detects the white component, and the subtractor 52 subtracts the 6-axis detection result and the MIN detection value. Color conversion is performed by changing the amount.

  FIG. 4 shows the adder 57, the MAX detector 54, and the added amount calculator 58. The RGB signal is converted by the MTX (matrix) 541 and the Y signals of the Y, Pb, and Pr signals are stored in the memory 543. After the storage, the result of the comparator 542 is established only when there are more Y signals in one frame, and the signal level in the memory 543 is updated. After the difference is obtained by the subtractor 582 in the addition amount calculation unit 58, a predetermined RGB value is output by a look-up table (LUT) 581 having the numerical value as an input, and the addition unit 57 adds it to the input signal. .

  The operation of the image display apparatus of the present invention in the color conversion circuit 50 as described above will be described.

  When the output signal of the resize / freeze / on-screen generation circuit 40 is input to the color conversion circuit 50, the input RGB signal calculates the luminance (Y) signal level by the MTX 541 of the screen MAX detection unit 54. Next, the comparator 542 determines that only the largest value in the screen is updated by storing the Y signal level in the memory 543 to be reset in one frame. For example, in the case of a screen having a screen size of 1024 × 768 pixels, the MTX process is performed on all the pixels, and the maximum value is updated by comparison with the value in the memory 543. At this time, when the maximum value is 200 levels at the 8-bit input level (maximum 255 levels), the subtracter 582 inputs 255-200 = 55 levels to the LUT 581. In the LUT 581, the larger the input value, the larger the addition amount, and the different addition level or the same level addition amount for each RGB is calculated and added by the addition unit 57 according to the input value. In the present embodiment, when the result of the subtracter 582 is 30 to 60, 15 levels are added to the RGB input signals.

  Therefore, in the case of input signals of R: 200 levels / 256 gradations, G: 150 levels / 256 gradations, B: 50 levels / 256 gradations, R: 215 levels / 256 gradations, G: 165 levels / 256 gradations, B: 65 levels / 256 gradations, which are input to the 6-axis detection and MIN detection unit in the subsequent stage. The subsequent processing is performed in the same manner as in the first embodiment. The MIN detection unit 51 detects the 65 level, and the 6-axis detection unit 56 obtains the values of the Rs component 50 and the Ys component 100. Since the subtractor 52 is obtained from the 6-axis detection result and the MIN detection result, 25 levels that are 1/256 of 65 × 100 are subtracted from B, respectively, and 13 that is 1/25 of 65 × 50 is 13 Subtracted from B and G. Therefore, the output signals are R: 215 level, G: 152 level, and B: 27, the R component is 50 and 63, and the Y component 100 is 125. As a result, the color gain increases, resulting in color visibility. Is effective.

  Further, the light sensor 94 is used to measure the illuminance in the screen direction before the light source lamp (not shown) of the projector 100 is turned on, and the addition amount of the LUT is increased based on the illuminance measurement result. Although it is finally subtracted, a larger effect can be obtained by setting this to 1/128.

  Further, the display device of the present invention described above is described as a projector, but is not limited to the projector, and can be realized by a general display such as a plasma display or a liquid crystal display.

  Further, the processing of the present invention may be realized by software, and is not limited to the image display device, and it goes without saying that the display method itself is also effective.

  The image display apparatus and the image display method according to the present invention display the color to be displayed more emphasized with respect to the personal computer RGB input signal, so that the visibility of the image can be improved even in an illumination environment. It can be applied to the purpose of image display for displaying personal computer input images.

1 is a block diagram showing a color conversion circuit according to a first embodiment of the present invention. FIG. 3 is a block diagram showing a color conversion circuit according to a second embodiment of the present invention. The block diagram which shows amplification of the signal level of Embodiment 1 of this invention The block diagram which shows amplification of the signal level of Embodiment 2 of this invention Block diagram showing 6-axis detection of Embodiment 1 and Embodiment 2 of the present invention Block diagram showing minimum value detection in the first and second embodiments of the present invention The block diagram which shows the color calculation of Embodiment 1 and Embodiment 2 of this invention The figure which shows the signal level after the input signal level and color conversion process by Embodiment 1 and Embodiment 2 of this invention Detailed block diagram showing a projector according to an embodiment of the present invention 1 is an external view of a projector according to a first embodiment of the present invention. The image display system figure explaining Embodiment 2 of this invention Graph showing the correction curve in the conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 VIDEO terminal 12 S-VIDEO terminal 13 RGB / YPbPr terminal 21 Input selector 22 Color decoder 23 Y / C separation circuit 24 Matrix circuit 25 Input selector 26 Input selector 30 A / D converter 40 Resizing / Freezing / On-screen generation circuit 50 Color Conversion circuit 51 MIN (white) detection unit 52 Subtraction unit 53 Multiplication unit 54 Screen MAX detection unit 55 Division unit 56 6-axis detection unit 57 Addition unit 58 Addition amount calculation unit 60 Remote control 61 Personal computer 70 Main microcomputer 71 External interface 81-83 Digital Phase expansion circuit 90 Panel drive IC
91-93 LCD panel 100 Projector 110 Screen 130 Mouse 140 Operation button 150 POWER button 160 RGB input terminal 170 Video input terminal 190 Projection lens

Claims (5)

Means for multiplying each video signal of red (hereinafter R) green (hereinafter G) blue (hereinafter B) by a predetermined ratio based on the maximum value of the luminance signal of the entire screen ;
Means for detecting a color component from the multiplied video signal;
Means for detecting RGB minimum values from the multiplied video signal;
Means for subtracting a predetermined ratio based on the color component detection result and the minimum value detection result from the multiplied video signal;
An image display device comprising: Means for adding a predetermined value to each of the RGB video signals based on the maximum value of the luminance signal of the entire screen ;
Means for detecting a color component from the video signal after the addition;
Means for detecting a minimum value of RGB from the video signal after the addition;
Means for subtracting at a predetermined rate from the color component detection result and the minimum value detection result from the video signal after the addition;
An image display device comprising: Means for detecting the color components, the image display apparatus according to claim 1 or claim 2, wherein the dividing of RGB respective differences in 6 color components of primary color component and the complementary color component. Multiplying each RGB video signal by a predetermined ratio based on the maximum value of the luminance signal of the entire screen ;
Detecting a color component from the multiplied video signal;
Detecting a minimum value of RGB from the video signal after multiplication;
Subtracting a predetermined ratio based on the color component detection result and the minimum value detection result from the multiplied video signal;
An image display method comprising: Adding a predetermined value to each of the RGB video signals based on the maximum value of the luminance signal of the entire screen ;
Detecting a color component from the video signal after the addition;
Detecting a minimum value of RGB from the video signal after the addition;
Subtracting from the video signal after the addition at a predetermined ratio based on the color component detection result and the minimum value detection result ;
An image display method comprising:

Images