JP4860914B2 - Image projection apparatus, image projection method, and program - Google Patents

Description

The present invention relates to an image projection technique in an image projection apparatus that projects an image on a predetermined display surface, such as an image projection apparatus that projects an image on a screen such as a projector, or a color image projection apparatus such as a color display (color monitor). is there.

  An image display device such as a projector is for viewing an image projected on a screen. Generally, the appearance of a projected image varies greatly depending on the brightness of the surrounding environment and the characteristics of the screen. For this reason, in the color design of a projector that is an image display device, a typical peripheral environment and screen characteristics are set, and gradation conversion parameters and color conversion parameters are created as the peripheral environment and screen characteristics in an ideal state. The created parameters are used for gradation conversion and color conversion processing of an image at the time of display. In addition, if the surrounding environment and screen characteristics are different from the ideal state, use a sensor, etc., and change the conversion parameters for the brightness and color temperature of the low brightness area based on the environmental information (light quantity and color temperature) from the projection surface. I was going to change it.

  As a technique for changing a conversion parameter regarding the brightness and color temperature of the low brightness portion using a sensor or the like based on environmental information (light quantity and color temperature) from the projection surface, for example, Japanese Patent Laid-Open No. 2002-125125 and Japanese Patent Laid-Open No. 2002-2002 No. -74349.

  The image display device described in Japanese Patent Application Laid-Open No. 2002-125125 determines whether there is an influence of environmental light based on the environmental information and determines that there is an influence of environmental light in order to provide an environment-adaptive image display. In such a case, the input / output characteristic data for display used by the display means for displaying the image is corrected so that at least the output of the low brightness portion is increased.

On the other hand, the image display device described in Japanese Patent Application Laid-Open No. 2002-74349 provides brightness of an image in a visual environment based on visual environment information (brightness information and color information) in order to provide environment-adaptive image display. The brightness information included in the visual environment information is adapted to the brightness of the ideal environment. An image to be displayed is calculated based on the calculated color difference between the color information included in the visual environment information obtained by correcting and correcting the brightness information and the color information of the image in the ideal environment. Is going to be corrected.
JP 2002-125125 A JP 2002-74349 A

  However, when the surrounding environment and the screen characteristics are different, not only the environmental information from the projection surface (display surface) is different, but also the human visual characteristics are changed. For this reason, although the appearance of contrast and saturation also changes, the above two inventions (Patent Document 1 and Patent Document 2) do not consider human visual characteristics that change according to the surrounding environment. Therefore, when the surrounding environment is dark, there is a problem that the contrast of the projected image appears lower than when the surrounding environment is bright. Thus, since the actual surrounding environment and the characteristics of the screen to be used are usually different from the ideal state, a correction process suitable for the change in the visual characteristics is desired.

The present invention has been made in view of the above problems, and an object thereof is to realize highly accurate color reproduction by correcting gradation and saturation in consideration of changes in human visual characteristics in an image projection apparatus. And

In order to achieve the above object, an image projection apparatus according to the present invention comprises the following arrangement. That is,
An image projection apparatus that projects an image on a predetermined display surface,
A measurement result obtained by measuring the amount of light for each color when a pattern image composed of a plurality of colors is displayed on the display surface , and an acquisition means for acquiring a predetermined value held in advance with respect to the amount of light ;
A gradation adjustment curve is selected from a plurality of gradation adjustment curves having different linearities according to the relationship between the measurement result and the predetermined value, and the image is based on the selected gradation adjustment curve. Gradation correction means for correcting the gradation of
A saturation adjustment curve is selected from a plurality of saturation adjustment curves having different linearities according to the relationship between the measurement result and the predetermined value, and the image is based on the selected saturation adjustment curve. Saturation correction means for correcting the saturation of the image.

According to the present invention, it is possible to realize highly accurate color reproduction by correcting gradation and saturation in consideration of changes in human visual characteristics in an image projection apparatus .

  The image display apparatus according to each embodiment of the present invention measures the amount of reflected light from the projection surface using a sensor under the surrounding environment and screen characteristics that are actually used, and uses the measurement results to measure the image scale. Tone correction and saturation correction are performed. This is because human visual characteristics with respect to color change depending on the surrounding environment and screen characteristics that are actually used. Therefore, the gradation (brightness) and saturation that determine the color are determined based on the measurement results. By direct correction, an image reflecting human visual characteristics is realized. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
<Configuration of image display device>
FIG. 1 is a block diagram showing a configuration of an image display apparatus according to an embodiment of the present invention. 101 is an image display device according to an embodiment of the present invention, 102 is an I / F unit for exchanging data with other devices such as a computer, and 103 is a screen surface (projection target) reflecting the surrounding environment and screen characteristics. 1 is a data acquisition unit that acquires measurement results from (not shown in FIG. 1), 104 is a sensor that performs measurement, 105 is a color coordinate conversion unit that performs color coordinate conversion in the image display apparatus 101, and 106 is the surrounding environment and screen characteristics. Saturation correction unit that performs saturation correction considering image quality, 107 is a gradation correction unit that performs gradation correction considering the surrounding environment and screen characteristics, and 108 temporarily holds image data and measurement results for image data processing A data buffer 109, an image projection unit 109 that projects the processed image onto a screen, and a user 110 performs an image processing operation using the image display device 101. UI unit 111 for measuring, a pattern storage unit for measurement for storing pattern images for characteristic measurement such as white, black, red, green, and blue, and 112 for correcting images according to the dynamic range of the projected image A range-specific correction parameter storage unit 113 for storing parameters, and a design time measurement result storage unit 113 for storing measurement results when color design is performed in an ideal state.

<Overall processing>
FIG. 2 is a flowchart showing the flow of image processing in the image display apparatus 101. Details of the image processing in the image display apparatus 101 will be described using the flowchart of FIG. In step S201, it is determined whether or not to adjust the projection image. If adjustment is to be performed, the process proceeds to step S202. If not, the process proceeds to step S206. In step S202, a pattern image for characteristic measurement such as white, black, red, green, and blue is projected on the screen surface, and the screen surface that reflects the surrounding environment and screen characteristics is measured. In step S203, a gradation characteristic adjustment parameter (hereinafter referred to as “gradation adjustment parameter”) is set based on the measurement result in step S202. In step S204, a saturation characteristic adjustment parameter (hereinafter referred to as "saturation adjustment parameter") is set based on the measurement result in step S202. In step S205, it is determined whether or not the adjustment is completed. If completed, the process proceeds to step S206. If not completed, the process returns to step S202.

  In step S206, an image to be projected onto a screen surface (not shown) is input to the image display apparatus 101. In step S207, gradation correction is performed using the gradation adjustment parameter set in step S203. In step S208, saturation correction is performed using the saturation adjustment parameter set in step S204. In step S209, the corrected image is projected from the image projection unit 109 onto the screen, and the process ends.

<Measurement process>
FIG. 3 is a flowchart for explaining the details of the measurement process (step S202) in the image display apparatus 101. Details of the measurement process will be described with reference to the flowchart of FIG. In step S <b> 301, a pattern image for characteristic measurement such as white, black, red, green, and blue is read from the measurement pattern storage unit 111. The characteristic measurement pattern image is a single-color image for each color, and is composed of a total of 10 colors of 7 gray scales from black to white and 3 colors of red, green and blue. . In step S302, the pattern image for characteristic measurement read in step S301 is projected on the screen surface. In step S303, the pattern image for characteristic measurement projected on the screen surface in step S302 is measured using the sensor 104. Here, the measurement by the sensor 104 is to measure XYZ values of 10 colors of the projected pattern image for characteristic measurement, and the measurement results are the following data.

Black: XM1, YM1, ZM1
Gray A: XM2, YM2, ZM2
Gray B: XM3, YM3, ZM3
Gray C: XM4, YM4, ZM4
Gray D: XM5, YM5, ZM5
Gray E: XM6, YM6, ZM6
White: XM7, YM7, ZM7
Red: XM8, YM8, ZM8
Green: XM9, YM9, ZM9
Blue: XM10, YM10, ZM10
In step S304, the measurement result of each color measured in step S303 is stored in the data buffer 108. In step S305, it is determined whether or not the measurement has been completed for all characteristic measurement pattern images. If the measurement has been completed, the measurement process is terminated. If not, the process returns to step S301.

<Tone adjustment parameter setting process>
FIG. 4 is a flowchart for explaining the details of the gradation adjustment parameter setting process (step S203) in the image display apparatus 101. Details of the gradation adjustment parameter setting process will be described with reference to the flowchart of FIG.

  In step S401, the measurement result stored in step S304 is read from the data buffer 108. In step S402, the measured gradation range YML is calculated using equation (1). For the calculation, Y values (YM1, YM7) of the black image and the white image are used.

  In step S403, the gradation range YDL in the ideal state is read from the design-time measurement result storage unit 113 that stores the measurement result measured in the ideal state at the time of color design in advance. The design-time measurement result storage unit 113 stores data having the contents shown in FIG. The stored data items include XYZ values that are the colorimetric results of the pattern image for characteristic measurement, gradation range values, saturation ranges of red, green, and blue, and RGB values that are internal signals of the image display device. And an XYZ value conversion matrix. A conversion matrix is a coefficient of Formula (2) and Formula (3).

  In step S404, the gradation index GB is calculated using equation (4). Here, the gradation index GB is a value indicating how much gradation reproduction efficiency is obtained under the currently used surrounding environment and screen characteristics with respect to the gradation range in the ideal state. is there.

  In step S405, a gradation adjustment curve is selected based on the correspondence shown in FIG. 6 using the result of the gradation index GB calculated in step S404. The gradation adjustment curve is stored in the correction parameter storage unit 112 for each range.

  As shown in FIG. 6, the gradation adjustment curve number is associated with each gradation index, and the gradation adjustment curve has a higher linearity as the gradation index is larger, and a stronger nonlinearity as the gradation index is smaller. It has become a curve. An example of the tone adjustment curve is shown in FIG. The gradation adjustment curve GB1 in FIG. 6 corresponds to the curve 701 in FIG. 7, the gradation adjustment curve GB2 is the curve 702, the gradation adjustment curve GB3 is the curve 703, the gradation adjustment curve GB4 is the curve 704, The gradation adjustment curve GB5 corresponds to the curve 705, and the gradation adjustment curve GB6 corresponds to the curve 706, respectively.

  In step S406, the tone adjustment parameter is calculated by multiplying the tone adjustment curve selected in step S405 by the reciprocal of the tone index GB and normalizing the curve so that the maximum value becomes 100. This gradation adjustment parameter indicates an output value with respect to an input value used for gradation correction. A curve 707 in FIG. 7 is an example when the gradation adjustment parameter is calculated with the gradation index GB = 0.5 in the gradation adjustment curve 706. In step S407, the gradation adjustment parameter calculated in step S406 is stored in the correction parameter storage unit 112 for each range, and the gradation adjustment parameter setting process ends.

<Saturation adjustment parameter setting process>
FIG. 8 is a flowchart for explaining the details of the saturation adjustment parameter setting process (step S204) in the image display apparatus 101. Details of the saturation adjustment parameter setting process will be described with reference to the flowchart of FIG.

  In step S801, the measurement result stored in step S304 is read from the data buffer 108. In step S802, the measured saturation ranges CMR, CMG, and CMB are calculated using Expressions (5) to (6). For the calculation, XYZ values of a white image, a red image, a green image, and a blue image are used.

  For X, Y, and Z, XM8, YM8, and ZM8 that are red XYZ values, XM9, YM9, and ZM9 that are green XYZ values, and XM10, YM10, and ZM10 that are blue XYZ values are substituted. , Lm8, am8, and bm8 that are red Lab values, Lm9, am9, and bm9 that are blue Lab values, and Lm10, am10, and bm10 that are green Lab values. As Xn, Yn, and Zn, XM7, YM7, and ZM7 that are white XYZ values are used.

  In step S803, the saturation ranges CDR, CDG, and CDB in the ideal state are read from the design-time measurement result storage unit 113 that stores the measurement results measured in the ideal state in advance during color design (see FIG. 5). In step S804, saturation indexes CR, CG, and CB are calculated using equation (7). Here, the saturation indexes CR, CG, and CB indicate how much saturation reproduction efficiency is obtained with respect to the saturation range in the ideal state under the currently used ambient environment and screen characteristics. Is a value indicating

  In step S805, a saturation adjustment curve is selected based on the correspondence shown in FIG. 9 using the results of the saturation indexes CR, CG, and CB calculated in step S804. The saturation adjustment curve is stored in the correction parameter storage unit 112 for each range.

  As shown in FIG. 9, the saturation adjustment curve number is associated with each saturation index, and the saturation adjustment curve is more linear as the saturation index is larger, and is more nonlinear as the saturation index is smaller. It is a curve. An example of the saturation adjustment curve is shown in FIG. The saturation adjustment curve CB1 in FIG. 9 corresponds to the curve 1001 in FIG. 10, the saturation adjustment curve CB2 is the curve 1002, the saturation adjustment curve CB3 is the curve 1003, and the saturation adjustment curve CB4 is the curve 1004. The saturation adjustment curve CB5 corresponds to the curve 1005, and the saturation adjustment curve CB6 corresponds to the curve 1006, respectively.

  In step S806, the saturation adjustment parameter is calculated by multiplying the saturation adjustment curve selected in step S805 by the reciprocal of the saturation indexes CR, CG, and CB, and further normalizing to a maximum value of 100. To do. This saturation adjustment parameter indicates an output value with respect to an input value used for saturation correction. A curve 1007 in FIG. 10 is an example in the case where the saturation adjustment parameter is calculated by setting the saturation index CR = CG = CB = 0.5 in the saturation adjustment curve 1006. In step S807, the saturation adjustment parameter calculated in step S806 is stored in the correction parameter storage unit 112 for each range, and the saturation adjustment parameter setting process ends.

<Tone correction processing>
FIG. 11 is a flowchart for explaining the details of the gradation correction processing (step S207) in the image display apparatus 101. Details of the gradation correction processing will be described with reference to the flowchart of FIG.

  In step S1101, the gradation adjustment parameter stored in step S407 is read from the correction parameter storage unit 112 for each range. In step S1102, the conversion matrix coefficient between the RGB value and the XYZ value obtained in advance at the time of design is read from the design time measurement result storage unit 113.

  In step S1103, the matrix coefficient used for conversion from the RGB value read in step S1102 to the XYZ value is used (expression (2)) to calculate the XYZ value of each pixel. In step S1104, only the Y value is corrected using the gradation adjustment parameter read in step S1101. In step S1105, it is determined whether or not gradation correction of the projected image has been completed for all pixels. If completed, the process proceeds to step S1106. If not completed, the process returns to step S1104. In step S1106, the matrix coefficient used for conversion from the XYZ value read in step S1102 to the RGB value is used (formula (3)), the RGB value of each pixel is calculated, and the tone correction process is completed.

<Saturation correction processing>
FIG. 12 is a flowchart for explaining the details of the saturation correction process (step S208) in the image display apparatus 101. Details of the saturation correction processing will be described using the flowchart of FIG.

  In step S1201, the saturation adjustment parameter stored in step S807 is read from the correction parameter storage unit 112 for each range. In step S1202, each of the RGB values is corrected using the saturation adjustment parameter read in step S1201. In step S1203, it is determined whether or not the saturation correction of the projection image has been completed for all pixels. If it has been completed, the saturation correction process is terminated, and if not, the process returns to step S1202.

  As described above, according to the image display apparatus of the present embodiment, the amount of reflected light from the projection surface is measured using a sensor under the surrounding environment and screen characteristics that are actually used, and the gradation and saturation are measured. By performing correction processing in consideration of changes in visual characteristics with respect to the dynamic range, it is possible to realize more accurate color reproduction.

[Second Embodiment]
Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

<Configuration of image display device>
FIG. 13 is a block diagram showing a configuration of an image display apparatus 1301 according to the second embodiment of the present invention. Since names and functions of the respective parts are the same as those in the first embodiment, description thereof is omitted. The difference from the first embodiment is that, instead of the range-specific correction parameter storage unit 112, a brightness-specific correction parameter storage unit 1314 for storing parameters for correcting images according to the brightness of the surrounding environment is added. It is a point.

<Overall processing>
The overall processing is the same as that of the first embodiment, and is as shown in the flowchart of the image processing shown in FIG. Detailed description is omitted.

<Measurement process>
The measurement process is the same as that of the first embodiment, and is as shown in the flowchart of the measurement process shown in FIG. Detailed description is omitted.

<Tone adjustment parameter setting process>
FIG. 14 is a flowchart for explaining the details of the tone adjustment parameter setting process (step S203) in the image display apparatus 1301. Details of the gradation adjustment parameter setting process will be described with reference to the flowchart of FIG.

  Steps S1401 to S1404 are the same as steps S401 to S404 in the first embodiment. In step S1405, the gradation index-specific gradation adjustment curve correspondence table is selected according to the measurement result read from the data buffer 1308 in step S1401. Specifically, the YM1 value, which is the Y value of the pattern image (black image) for characteristic measurement, is used as a measurement result reflecting the surrounding environment and screen characteristics, and the relationship between the YM1 value and a preset threshold value is used. Accordingly, a table is selected by distinguishing a bright environment, an intermediate environment, and a dark environment.

  If the determination result in step S1405 is a bright environment, the gradation index-specific gradation adjustment curve correspondence table shown in FIG. 15A is selected, and if it is an intermediate environment, the floor shown in FIG. 15B is selected. A gradation adjustment curve correspondence table by key index is selected, and in a dark environment, the gradation adjustment curve correspondence table by gradation index shown in FIG. 15C is selected.

  In FIGS. 15A, 15B, and 15C, tone adjustment curve numbers are associated with the brightness of the surrounding environment and the tone index. Is a curve in which the linearity increases as the gradation index increases and the nonlinearity increases as the gradation index decreases. Further, the curve is such that the contrast is lower in a bright environment and the contrast is higher in a dark environment.

  Examples of gradation adjustment curves shown in FIGS. 15A, 15B, and 15C are shown in FIGS. The gradation adjustment curve GB1a in FIG. 15A corresponds to the curve 701 in FIG. 7, the gradation adjustment curve GB2a is the curve 702, the gradation adjustment curve GB3a is the curve 703, and the gradation adjustment curve GB4a is The curve 704, the gradation adjustment curve GB5a correspond to the curve 705, and the gradation adjustment curve GB6a corresponds to the curve 706, respectively.

  Also, the tone adjustment curve GB1b in FIG. 15B corresponds to the curve 1601 in FIG. 16, the tone adjustment curve GB2b is the curve 1602, the tone adjustment curve GB3b is the curve 1603, and the tone adjustment curve. GB4b corresponds to the curve 1604, the gradation adjustment curve GB5b corresponds to the curve 1605, and the gradation adjustment curve GB6b corresponds to the curve 1606, respectively.

  Further, the tone adjustment curve GB1c in FIG. 15C corresponds to the curve 1701 in FIG. 17, the tone adjustment curve GB2c is the curve 1702, the tone adjustment curve GB3c is the curve 1703, and the tone adjustment curve. GB4c corresponds to curve 1704, tone adjustment curve GB5c corresponds to curve 1705, and tone adjustment curve GB6c corresponds to curve 1706, respectively.

  In step S1406, the result of the gradation index GB calculated in step S1404 is used, and based on any one of the correspondence relationships shown in FIGS. 15A, 15B, and 15C selected in step S1405. Select a curve for gradation adjustment. The tone adjustment curve is stored in the brightness-specific correction parameter storage unit 1314. In step S1407, the gradation adjustment parameter is calculated by multiplying the gradation adjustment curve selected in step S1406 by the reciprocal of the gradation index GB and normalizing the curve so that the maximum value becomes 100. This gradation adjustment parameter indicates an output value with respect to an input value used for gradation correction. In step S1408, the gradation adjustment parameter calculated in step S1407 is stored in the brightness-specific correction parameter storage unit 1314, and the gradation adjustment parameter setting process ends.

<Saturation adjustment parameter setting process>
FIG. 18 is a flowchart for explaining the details of the saturation adjustment parameter setting process (step S1404) in the image display apparatus 1301. Details of the saturation adjustment parameter setting process will be described with reference to the flowchart of FIG.

  Steps S1801 to S1804 are the same as steps S801 to S804 in the first embodiment. In step S1805, a saturation correspondence curve for each saturation index is selected according to the measurement result read from the data buffer 1308 in step S1801. Specifically, the YM1 value, which is the Y value of the pattern image (black image) for characteristic measurement, is used as a measurement result reflecting the surrounding environment and screen characteristics, and the relationship between the YM1 value and a preset threshold value is used. Accordingly, a table is selected by distinguishing a bright environment, an intermediate environment, and a dark environment.

  If the determination result in step S1805 is a bright environment, the saturation index-specific saturation adjustment curve correspondence table shown in FIG. 19A is selected, and if it is an intermediate environment, the saturation shown in FIG. 19B is selected. The saturation correspondence curve for each degree index is selected. If the environment is dark, the saturation correspondence curve for each saturation index shown in FIG. 19C is selected.

  19 (a), 19 (b), and 19 (c), the saturation adjustment curve number is associated with the brightness of the surrounding environment and the saturation index. The curve is such that the greater the saturation index, the stronger the linearity, and the smaller the saturation index, the stronger the nonlinearity. In addition, the curve is a curve in which the saturation enhancement is weakened in a bright environment and the saturation enhancement is enhanced in a dark environment. Examples of the saturation adjustment curves shown in FIGS. 19A, 19B, and 19C are shown in FIGS. 10, 20, and 21. FIG.

  The saturation adjustment curve CB1a in FIG. 19A corresponds to the curve 1001 in FIG. 10, the saturation adjustment curve CB2a is the curve 1002, the saturation adjustment curve CB3a is the curve 1003, and the saturation adjustment curve CB4a is. A curve 1004, a saturation adjustment curve CB5a correspond to the curve 1005, and a saturation adjustment curve CB6a corresponds to the curve 1006, respectively.

  Further, the tone adjustment curve GB1b in FIG. 19B corresponds to the curve 2001 in FIG. 20, the saturation adjustment curve CB2b is the curve 2002, the saturation adjustment curve CB3b is the curve 2003, and the saturation adjustment curve. CB4b corresponds to the curve 2004, the saturation adjustment curve CB5b corresponds to the curve 2005, and the saturation adjustment curve CB6b corresponds to the curve 2006, respectively.

  Further, the tone adjustment curve GB1c in FIG. 19C corresponds to the curve 2101 in FIG. 21, the saturation adjustment curve CB2c is the curve 2102, the saturation adjustment curve CB3c is the curve 2103, and the saturation adjustment curve. CB4c corresponds to curve 2104, saturation adjustment curve CB5c corresponds to curve 2105, and saturation adjustment curve CB6c corresponds to curve 2106, respectively.

  In step S1806, any one of FIG. 19 (a), FIG. 19 (b), and FIG. 19 (c) selected in step S1805 is used, using the results of the saturation indexes CR, CG, and CB calculated in step S1804. Select a saturation adjustment curve based on the correspondence. The saturation adjustment curve is stored in the brightness-specific correction parameter storage unit 1314.

  In step S1807, the saturation adjustment parameter is calculated by multiplying the saturation adjustment curve selected in step S1806 by the reciprocal of the saturation indices CR, CG, and CB, and further normalizing to a maximum value of 100. To do. This saturation adjustment parameter indicates an output value with respect to an input value used for saturation correction. In step S1808, the saturation adjustment parameter calculated in step S1807 is stored in the brightness-specific correction parameter storage unit 1314, and the saturation adjustment parameter setting process ends.

<Tone correction processing>
The gradation correction process is the same as that of the first embodiment and is as shown in the flowchart of the measurement process shown in FIG. Detailed description is omitted.

<Saturation correction processing>
The saturation correction process is the same as that of the first embodiment, and is as shown in the flowchart of the measurement process shown in FIG. Detailed description is omitted.

  As described above, according to the image display apparatus according to the present embodiment, the amount of reflected light from the projection surface is measured using a sensor under the surrounding environment and screen characteristics that are actually used, and gradation and saturation are measured. By performing correction processing in consideration of changes in visual characteristics with respect to the brightness of the image, it is possible to realize more accurate color reproduction.

[Third Embodiment]
<About measurement processing>
In the first and second embodiments, the pattern image for characteristic measurement in the measurement process has been described as 10 single colors, but is not limited to 10 colors. Gray steps may be increased, and colors may be increased in the hue direction such as cyan, magenta, and yellow. Furthermore, a color in the saturation direction such as increasing the gradation pattern of red, green, and blue may be added. Further, the present invention is not limited to monochromatic projection. The same color may be projected onto a plurality of locations on the screen surface to absorb variations in the screen surface. Of course, it may be configured to project a plurality of colors simultaneously. That is, any data that is effective for gradation correction and saturation correction may be used.

<About measurement results>
In the first and second embodiments, the XYZ value is used as the measurement result in the sensor 104 (or 1304). However, the present invention is not limited to this, and spectral data, RGB data, Lab data, etc. It does not matter. The data format is not limited as long as the data can calculate the difference between the measurement result at the time of design and the measurement result under the ambient environment and screen characteristics currently used. In addition, although the number of measurements was not mentioned, it may be a method of averaging by measuring multiple times in order to reduce variation in measurement results and increase reliability, or it may be based on a single measurement. Is not limited.

<Tone adjustment parameter setting process>
In the first and second embodiments, the Y value difference between the black image and the white image is used in calculating the measurement gradation range, but the present invention is not limited to this. You may use the value which shows brightness, such as L value of Lab space.

<Conversion matrix>
In the first and second embodiments, the 3 × 3 conversion matrix is used in the expressions (2) and (3), but the present invention is not limited to this. Color conversion may be performed using a 3 × 9 or 3 × 20 conversion matrix including a nonlinear term. Further, color conversion may be performed using an LUT using previously measured grid point data.

<Correspondence between index and adjustment curve>
In the first and second embodiments, the correspondence between the gradation index and the gradation adjustment curve, the saturation index and the saturation adjustment curve, using FIGS. 6, 9, 15, and 19. Although the respective indices have been explained for each 0.1 step, the step width is not limited.

<About the adjustment curve shape>
In the first and second embodiments, the gradation adjustment curve and the saturation adjustment curve are combined as straight lines using FIGS. 7, 10, 16, 17, 20, and 21. Although described, the curve shape is not limited. It may be a curve, or may be a curve shape combining a straight line and a curve.

<Selecting the saturation adjustment curve>
In the first and second embodiments, the example in which the saturation adjustment curves are selected as the common curves for red, green, and blue has been described. A saturation adjustment curve may be selected according to the individual saturation indexes of red, green, blue, and may not be shared.

<Calculation of saturation measurement range>
In the first and second embodiments, the calculation of the saturation measurement range has been described using Expression (5) and Expression (6), but the saturation is not limited to the Lab space. Any space where saturation is required, such as YCC space, Luv space, CIECAM97s space, and CIECAM02 space, may be used.

<About gradation correction>
In the first and second embodiments, it has been described that the Y value is used for gradation correction. However, the present invention is not limited to the Y value. Any value can be used as long as brightness information is required, such as Lab space, Luv space, CIECAM97s space, CIECAM02 space, and the like.

<About saturation correction>
In the first and second embodiments, the RGB value is corrected for the saturation correction. However, the saturation correction may be performed after the RGB value is converted into a color signal indicating the saturation. . The color space in that case is not particularly limited as long as it is a space where saturation information is required, such as Lab space, Luv space, YCC space, CIECAM97s space, and CIECAM02 space.

<Brightness environment>
In the first and second embodiments, the brightness environment has been described as being classified into three brightness environments using FIGS. 15 and 19, but the present invention is not limited to this. What is necessary is just to comprise so that a correction process can be switched according to an environment, and the number of classifications is not limited.

<Environment types>
In the first and second embodiments, brightness has been described as an environment for classification, but the present invention is not limited to this. The environment may be classified according to the image size, the projection distance to the screen, the observation distance, and the like. Furthermore, a plurality of environmental classifications may be held for each purpose of use of the image display device such as a presentation or a meeting.

<Storage medium>
Note that the present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, and a printer), and a device (for example, a copying machine and a facsimile device) including a single device. You may apply to.

  Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described first to third embodiments to a system or apparatus, and to provide a computer (or CPU) of the system or apparatus. Needless to say, this can also be achieved by reading and executing the program code stored in the storage medium by the MPU).

  In this case, the program code itself read from the storage medium realizes the functions of the first to third embodiments described above, and the storage medium storing the program code constitutes the present invention. .

  As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like is used. I can do it.

  Further, by executing the program code read by the computer, not only the functions of the first to third embodiments described above are realized, but also an OS running on the computer based on the instruction of the program code. It goes without saying that the case where (operating system) or the like performs part of the actual processing and the functions of the first to third embodiments described above are realized by the processing.

  Further, after the program code read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the first to third embodiments described above are realized by the processing.

[Fourth Embodiment]
In the first to third embodiments, image processing for an image projected by one image projection unit (109 or 1309) has been described. However, the present invention is not limited to this, and an image having a plurality of image projection units. You may apply to the image process with respect to the image projected by a display apparatus or the system provided with a several image display apparatus.

  When applied to an image display apparatus having a plurality of image projection units or a system including a plurality of image display apparatuses, the image display apparatus and the system are used according to the surrounding environment and screen characteristics actually used. In addition to the effect that the projection of the image reflecting the human visual characteristics with respect to the color can be realized, the variation in the color between the plurality of image projection units or between the plurality of image display devices is suppressed, and the color matching is simplified and performed. The effect that it can carry out with high precision will also be produced. Hereinafter, in a fourth embodiment of the present invention, an image display device including a plurality of image projection units will be described in detail with reference to the drawings.

  FIG. 22 is a block diagram showing a configuration of an image display apparatus according to the fourth embodiment of the present invention. 2201 is an image display device according to the present embodiment, 2202 is an I / F unit for exchanging data with other devices such as a computer, and 2203 is a measurement from a screen surface (not shown) reflecting the surrounding environment and screen characteristics. A data acquisition unit for acquiring a result, 2204 is a first sensor for measuring an image projected from the first image projection unit, 2205 is a second sensor for measuring an image projected from the second image projection unit, and 2206 is A color coordinate conversion unit that performs color coordinate conversion inside the image display device 2201, 2207 is a saturation correction unit that performs saturation correction considering the surrounding environment and screen characteristics, and 2208 is a gradation correction that considers the surrounding environment and screen characteristics. A gradation correction unit 2209 for performing image data processing, a data buffer for temporarily storing image data and measurement results for image data processing, and 2210 for processed image data A first image projection unit that projects the image onto the screen, 2211 a second image projection unit that projects the processed image onto the screen, and 2212 a UI unit that allows the user to perform image processing operations using the image display device 2201. Reference numeral 2213 denotes a measurement pattern storage unit for storing pattern images for characteristic measurement such as white, black, red, green, and blue. Reference numeral 2214 denotes a measurement result at design time for storing measurement results when colors are designed in an ideal state. A storage unit 2215 is a correction parameter storage unit that stores correction parameters for performing gradation correction and saturation correction.

<Overall processing>
FIG. 23 is a flowchart showing the flow of image processing in the image display apparatus 2201. Details of image processing in the image display device 2201 will be described with reference to the flowchart of FIG. In step S2301, it is determined whether or not to adjust the projection image. If adjustment is to be performed, the process proceeds to step S2302, and if not, the process proceeds to step S2306. In step S2302, a pattern image for measuring characteristics such as white, black, red, green, and blue is projected on the screen surface from the first image projection unit 2210 or the second image projection unit 2211, and the first sensor 2204 or the second sensor. 2205 is used to measure each screen surface reflecting the surrounding environment and screen characteristics. In step S2303, a gradation adjustment parameter is set for each image projection unit based on the measurement result in step S2302. In step S2304, a saturation adjustment parameter is set for each image projection unit based on the measurement result in step S2302. In step S2305, it is determined whether or not the adjustment is completed. If completed, the process proceeds to step S2306, and if not completed, the process returns to step S2302.

  In step S2306, an image to be projected onto a screen surface (not shown) is input to the image display device 2201. In step S2307, tone correction is performed for each image projection unit using the tone adjustment parameter set in step S2303. In step S2308, saturation correction is performed for each image projection unit using the saturation adjustment parameter set in step S2304. In step S2309, the corrected image is projected onto the respective screens from the first image projection unit 2210 and the second image projection unit 2211, and the process ends.

<Measurement process>
FIG. 24 is a flowchart illustrating details of the measurement process (step S2302) in the image display apparatus 2201. Details of the measurement process will be described with reference to the flowchart of FIG. In step S2401, an image projection unit to be adjusted is selected. In step S2402, a pattern image for characteristic measurement such as white, black, red, green, and blue is read from the measurement pattern storage unit 2213. The pattern image for characteristic measurement is a single color image for each color, and consists of 7 gray scale levels from black to white and a total of 10 colors of 3 colors, red, green and blue. To do.

  In step S2403, the pattern image for characteristic measurement read in step S2402 is projected on the screen surface from the image projection unit selected in step S2401. In step S2404, the pattern image for characteristic measurement projected on the screen surface in step S2403 is measured using the first sensor 2204 or the second sensor 2205 corresponding to the image projection unit selected in step S2401, and then measured. The result is stored in the data buffer 2209. Here, the measurement by the first sensor 2204 or the second sensor 2205 is to measure XYZ values of 10 colors of each projected pattern image for characteristic measurement. In the case of the first image projection unit, the measurement result is as follows. It is data.

Black: XM11, YM11, ZM11
Gray A: XM12, YM12, ZM12
Gray B: XM13, YM13, ZM13
Gray C: XM14, YM14, ZM14
Gray D: XM15, YM15, ZM15
Gray E: XM16, YM16, ZM16
White: XM17, YM17, ZM17
Red: XM18, YM18, ZM18
Green: XM19, YM19, ZM19
Blue: XM110, YM110, ZM110
In the case of the second image projection unit, the measurement result is the following data.

Black: XM21, YM21, ZM21
Gray A: XM22, YM22, ZM22
Gray B: XM23, YM23, ZM23
Gray C: XM24, YM24, ZM24
Gray D: XM25, YM25, ZM25
Gray E: XM26, YM26, ZM26
White: XM27, YM27, ZM27
Red: XM28, YM28, ZM28
Green: XM29, YM29, ZM29
Blue: XM210, YM210, ZM210
In step S2405, the measurement result of each color measured in step S2404 is stored in the data buffer 2209. In step S2406, it is determined whether or not the measurement has been completed for all characteristic measurement pattern images. If completed, the process proceeds to step S2407, and if not completed, the process returns to step S2402. In step S2407, it is determined whether or not the measurement using all the image projection units has been completed. If the measurement has been completed, the measurement process is terminated. If not, the process returns to step S2401.

<Tone adjustment parameter setting process>
FIG. 25 is a flowchart for explaining the details of the tone adjustment parameter setting process (step S2303) in the image display apparatus 2201. Now, the details of the gradation adjustment parameter setting process will be described with reference to the flowchart of FIG.

  In step S2501, an image projection unit that performs gradation adjustment parameter setting processing is selected. In step S2502, among the measurement results stored in step S2405, black, gray A, gray B, gray C, gray D, gray E, and white are the measurement results YM11, YM12, YM13, YM14, YM15, YM16, YM17 (in the case of the first image projection unit. In the case of the second image projection unit, YM21, YM22, YM23, YM24, YM25, YM26, YM27) are read from the data buffer 2209.

  In step S2503, black, gray A, and gray among the pattern images for characteristic measurement in the ideal state are stored from the design time measurement result storage unit 2214 that stores the measurement results measured in the ideal state in advance during color design. YD1, YD2, YD3, YD4, YD5, YD6, and YD7, which are measurement results for the seven colors B, Gray C, Gray D, Gray E, and White, are read.

  In step S2404, the measured result of each pattern image for characteristic measurement is associated with each pattern. The association results based on the measurement results of the first image projection unit 2210 and the second image projection unit 2211 are shown in FIGS. 27A and 27B, respectively. This associated relationship is a tone adjustment parameter. FIG. 28 shows an example in which this correspondence is interpolated and graphed. The horizontal axis represents the measurement results (after normalization) of the first image projection unit 2210 or the second image projection unit 2211, and the vertical axis represents an example of the measurement results in the ideal state (after normalization). .

  The graph 2801 is an example in which the measurement result in the actual environment and the measurement result in the ideal environment match, and the graph 2802 is darker in the measurement result in the actual environment than the measurement result in the ideal environment. This is an example of the result, and the graph 2803 is an example in which the measurement result in the actual environment is brighter than the measurement result in the ideal environment. In other words, if the measurement result in the actual environment is darker than the measurement result in the ideal environment, the graph is convex upward, and the measurement result in the actual environment is better than the ideal environment. When the result is brighter than the measurement result at, a downwardly convex graph shape is obtained.

  The gradation adjustment parameter shown in FIG. 28 indicates an output value with respect to an input value used for gradation correction. The gradation adjustment parameters shown in FIG. 28 are stored in the correction parameter storage unit 2215. In step S2504, it is determined whether or not the gradation adjustment parameter setting process has been completed for all image projection units. If the gradation adjustment parameter setting process has been completed, the gradation adjustment parameter setting process has been completed. The process returns to S2501.

  The design-time measurement result storage unit 2214 stores data having the contents shown in FIG. The stored data items are a conversion matrix of RGB values and XYZ values, which are internal signals of the image display device, in addition to the XYZ values that are the measurement results of the pattern image for characteristic measurement. The conversion matrix is a coefficient of Expression (8) and Expression (9).

<Saturation adjustment parameter setting process>
FIG. 29 is a flowchart for explaining the details of the saturation adjustment parameter setting process (step S2304) in the image display apparatus 2201. Details of the saturation adjustment parameter setting process will be described with reference to the flowchart of FIG.

  In step S2901, an image projection unit that performs saturation adjustment parameter setting processing is selected. In step S2902, YM18, YM19, and YM110 (in the case of the first image projection unit; in the case of the second image projection unit) that are the measurement results for three colors of red, green, and blue among the measurement results stored in step S2405. In this case, YM28, YM29, and YM210) are read from the data buffer 2209.

  In step S2903, red, green, and blue of the pattern images for characteristic measurement in the ideal state are stored from the design-time measurement result storage unit 2214 that stores the measurement results measured in the ideal state in advance during color design. YD8, YD9, and YD10, which are measurement results for the three colors, are read.

  In step S2404, the saturation adjustment parameters CR1, CG1, and CB1 (first image) are calculated for each pattern according to Expression (10) or Expression (11) based on the measurement results of the measured characteristic measurement pattern images. In the case of the projection unit, in the case of the second image projection unit, CR2, CG2, and CB2) are calculated and stored in the correction parameter storage unit 2215.

  In step S2904, it is determined whether or not the saturation adjustment parameter setting process has been completed for all image projection units. If the saturation adjustment parameter setting process has been completed, the saturation adjustment parameter setting process has been completed. The process returns to S2901.

<Tone correction processing>
FIG. 30 is a flowchart for explaining the details of the gradation correction processing (step S2307) in the image display apparatus 2201. Details of the tone correction processing will be described with reference to the flowchart of FIG.

  In step S3001, an image projection unit that performs gradation correction processing is selected. In step S3002, the gradation adjustment parameter corresponding to each image projection unit stored in step S2303 is read from the correction parameter storage unit 2215.

  In step S3003, the RGB value is corrected using the gradation adjustment parameter read in step S3002 (the corrected value is indicated as R'G'B '). In step S3004, it is determined whether or not the gradation correction of the projected image has been completed for all pixels. If completed, the process proceeds to step S3005. If not completed, the process returns to step S3003. In step S3005, it is determined whether or not gradation correction processing has been completed for all image projection units. If completed, the gradation correction processing is terminated. If not completed, the process returns to step S3001.

<Saturation correction processing>
FIG. 31 is a flowchart for explaining the details of the saturation correction process (step S2308) in the image display apparatus 2201. Details of the saturation correction processing will be described using the flowchart of FIG.

  In step S3101, an image projection unit that performs saturation correction processing is selected. In step S3102, the saturation adjustment parameter corresponding to each image projection unit stored in step S2304 is read from the correction parameter storage unit 2215. In step S3103, using the saturation adjustment parameter read in step S3102, equation (12) (during saturation correction for the first image projection unit) or equation (13) (saturation correction for the second image projection unit). To correct RGB values.

  In step S3104, it is determined whether or not the saturation correction of the projection image has been completed for all pixels. If completed, the process proceeds to step S3105, and if not completed, the process returns to step S3103. In step S3105, it is determined whether or not the saturation correction has been completed for all the image projection units. If the saturation correction has been completed, the saturation correction process is terminated. If not, the process returns to step S3101.

  As described above, according to the present embodiment, in an image display device including a plurality of image projection units, the amount of light reflected from the projection surface under the surrounding environment and screen characteristics actually used in each image projection unit. By using a sensor and performing correction processing based on the measurement results, the variation between multiple image projection units can be suppressed, and color matching for color reproduction results in an ideal environment can be realized easily and with high accuracy. Is possible.

[Fifth Embodiment]
In the fourth embodiment, the case where each projected image from each image projection unit is matched with color reproduction in an ideal environment at the time of design has been described. In the fifth embodiment, from each image projection unit, A case where the projected images are directly matched will be described. Hereinafter, a fifth embodiment of the present invention will be described in detail with reference to the drawings.

  The configuration of the image display apparatus realizing the fifth embodiment is the same as the block diagram shown in FIG. 22, the entire processing flow is the same as the flowchart shown in FIG. 23, and other detailed explanations are also provided. Except for the following three points (the relationship between the input value and the output value in the gradation adjustment parameter setting process, the parameter calculation formula in the saturation adjustment parameter setting process, and the correction formula in the saturation correction process), the same as in the fourth embodiment Therefore, explanation is omitted.

<Tone adjustment parameter setting process>
In the gradation adjustment parameter setting processing in step S2503, the measurement results of the first image projection unit 2210 and the second image projection unit 2211 and the measurement results in the ideal state shown in FIGS. 27A and 27B, respectively. Is the correspondence shown in FIG.

  FIG. 32 shows the correspondence when matching the first image projection unit 2210 with the second image projection unit 2211. When matching the second image projection unit 2211 with the first image projection unit 2210, the correspondence in FIG. 32 is reversed. This associated relationship is a tone adjustment parameter. The gradation adjustment parameter shown in FIG. 32 indicates an output value with respect to an input value used for gradation correction.

<Saturation adjustment parameter setting process>
In step S2903, the saturation adjustment parameter calculation is performed using Expression (14) (when the first image projection unit is matched with the second image projection unit) or Expression (15) (Second image projection unit is projected to the first image). Part).

<Saturation correction processing>
The correction formula for saturation correction in step S3103 uses the saturation adjustment parameter read out in step S3102 and uses equation (16) (when the first image projection unit is matched with the second image projection unit) or equation ( 17) The RGB values are corrected using (when the second image projection unit is matched with the first image projection unit).

  As described above, according to the present embodiment, in an image table value device including a plurality of image projection units, reflection from the projection surface under the surrounding environment and screen characteristics actually used in each image projection unit. By measuring the amount of light using a sensor and performing correction processing in association with each measurement result, it is possible to suppress variations between multiple image projection units and to achieve color matching simply and with high accuracy. Become.

[Sixth Embodiment]
In the fourth and fifth embodiments, the color matching in the image display apparatus including a plurality of image projection units has been described. In the present embodiment, the color matching in a system including a plurality of image display apparatuses will be described. Hereinafter, a sixth embodiment according to the present invention will be described in detail with reference to the drawings.

  FIG. 33 is a block diagram showing a configuration of a system including an image display device 3301A and an image display device 3301B according to the sixth embodiment of the present invention. The names and functions of the respective parts are almost the same as in the fourth embodiment, and the difference from the fourth embodiment is that an image display device is configured for each image projection unit.

  3301A is an image display device according to the present embodiment, 3302A is an I / F unit for exchanging data with other devices such as a computer, and 3303A is a measurement from a screen surface (not shown) reflecting the surrounding environment and screen characteristics. A data acquisition unit that acquires results, a sensor 3304A that measures the data projected from the image projection unit, 3306A a color coordinate conversion unit that performs color coordinate conversion inside the image display device 3301A, and 3307A a peripheral environment and screen characteristics Saturation correction unit that performs saturation correction considering image quality, 3308A is a gradation correction unit that performs gradation correction considering the surrounding environment and screen characteristics, and 3309A temporarily holds image data and measurement results for image data processing A data buffer 3311A is an image projection unit that projects the processed image onto the screen surface, and 3312A is a user. A UI unit 3313A for performing image processing operations using the image display device 3301A, a measurement pattern storage unit 3314A for storing pattern images for characteristic measurement such as white, black, red, green, and blue Is a design-time measurement result storage unit that stores measurement results when colors are designed in an ideal state, and 3315A is a correction parameter storage unit that stores correction parameters for performing gradation correction and saturation correction. .

  3301B is an image display device according to the present embodiment, 3302B is an I / F unit for exchanging data with other devices such as a computer, and 3303B is a measurement from a screen surface (not shown) reflecting the surrounding environment and screen characteristics. A data acquisition unit for acquiring a result, a sensor 3304B for measuring data projected from the image projection unit, 3306B for a color coordinate conversion unit for color coordinate conversion in the image display device 3301B, and 3307B for a surrounding environment and screen characteristics 3308B is a gradation correction unit that performs gradation correction considering the surrounding environment and screen characteristics, and 3309B temporarily holds image data and measurement results for image data processing. The data buffer 3311B is an image projection unit for projecting the processed image onto the screen, and 3312B is a user. Is a UI unit for performing image processing operations using the image display device 3301B, 3313B is a measurement pattern storage unit that stores pattern images for characteristic measurement such as white, black, red, green, and blue, and 3314B is A design-time measurement result storage unit that stores measurement results when the color is designed in an ideal state, and 3315B is a correction parameter storage unit that stores correction parameters for performing gradation correction and saturation correction.

<Overall processing>
FIG. 34 is a flowchart showing a flow of image processing in the image display device 3301B and the image display device 3301B. Details of the image processing in the image display device 3301A will be described using the flowchart of FIG. In step S3401, it is determined whether or not to adjust the projection image. If adjustment is to be performed, the process proceeds to step S3402, and if not, the process proceeds to step S3406. In step S3402, white, black, red, green, blue, and the like are displayed on the screen surface from the image projection unit 3311A (in the case of processing by the image display device 3301A. In the case of processing by the image display device 3301B, image projection unit 3311B). A pattern image for characteristic measurement is projected, and a sensor 3304A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, sensor 3304B) is used to reflect the surrounding environment and screen characteristics. Measure the screen surface.

  In step S3403, a tone adjustment parameter is set based on the measurement result in step S3402. In step S3404, a saturation adjustment parameter is set based on the measurement result in step S3402. In step S3405, it is determined whether or not the adjustment is completed. If completed, the process proceeds to step S3406. If not completed, the process returns to step S3402.

  In step S3406, an image to be projected onto a screen surface (not shown) is input to the image display device 3301A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, the image display device 3301B). In step S3407, gradation correction is performed using the gradation adjustment parameter set in step S3403. In step S3408, saturation correction is performed using the saturation adjustment parameter set in step S3404. In step S3409, the corrected image is projected onto the screen from the image projection unit 3311A (in the case of processing by the image display device 3301A. In the case of processing by the image display device 3301B), the processing is finished.

<Measurement process>
FIG. 35 is a flowchart for explaining the details of the measurement processing (step S3402) in the image display device 3301A and the image display device 3301B. Details of the measurement process will be described with reference to the flowchart of FIG. In step S3501, a pattern image for characteristic measurement such as white, black, red, green, and blue is measured with a measurement pattern storage unit 3313A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, measurement is performed. Read out from the pattern storage unit 3313B). The pattern image for characteristic measurement is the same as that in the fourth embodiment.

  In step S3502, the pattern image for characteristic measurement read in step S3501 is transferred from the image projection unit 3311A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B), the screen is displayed. Project onto a surface.

  In step S3503, the pattern image for characteristic measurement projected on the screen surface in step S3502 is a sensor 3304A corresponding to the image projection unit 3311A (in the case of processing in the image display device 3301A. Processing in the image display device 3301B) In this case, measurement is performed using the sensor 3304B corresponding to the image projection unit 3311B, and the measurement result is obtained in the data buffer 3309A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, the data buffer 3309B). ). Here, the measurement by the sensor 3304A or the sensor 3304B is to measure XYZ values of 10 colors of each projected pattern image for characteristic measurement. In the case of processing in the image display device 3301A, the measurement result is the following data. is there.

Black: XM211, YM211, ZM211
Gray A: XM212, YM212, ZM212
Gray B: XM213, YM213, ZM213
Gray C: XM214, YM214, ZM214
Gray D: XM215, YM215, ZM215
Gray E: XM216, YM216, ZM216
White: XM217, YM217, ZM217
Red: XM218, YM218, ZM218
Green: XM219, YM219, ZM219
Blue: XM2110, YM2110, ZM2110
In the case of processing in the image display device 3301B, the measurement result is the following data.

Black: XM321, YM321, ZM321
Gray A: XM322, YM322, ZM322
Gray B: XM323, YM323, ZM323
Gray C: XM324, YM324, ZM324
Gray D: XM325, YM325, ZM325
Gray E: XM326, YM326, ZM326
White: XM327, YM327, ZM327
Red: XM328, YM328, ZM328
Green: XM329, YM329, ZM329
Blue: XM3210, YM3210, ZM3210
In step S3504, the measurement result of each color measured in step S3503 is stored in the data buffer 3309A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, it is stored in the data buffer 3309B). In step S3505, it is determined whether or not the measurement of all pattern images for characteristic measurement has been completed. If completed, the measurement process is terminated, and if not completed, the process returns to step S3501.

<Tone adjustment parameter setting process>
FIG. 36 is a flowchart for explaining the details of the tone adjustment parameter setting process (step S3403) in the image display device 3301A and the image display device 3301B. Details of the gradation adjustment parameter setting process will be described with reference to the flowchart of FIG.

  In step S3601, among the measurement results stored in step S3504, YM211, YM212, YM213, YM214, which are measurement results of seven colors of black, gray A, gray B, gray C, gray D, gray E, and white, YM215, YM216, YM217 (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, YM321, YM322, YM323, YM324, YM325, YM326, YM327) are stored in the data buffer 3309A (image display device 3301A). In the case of processing in the image display device 3301B, data is read from the data buffer 3309B).

  In step S3602, a design-time measurement result storage unit 3314A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, in which measurement results measured in an ideal state at the time of color design are stored in advance. From the design time measurement result storage unit 3314B), among the pattern images for characteristic measurement in the ideal state, the measurement results for seven colors of black, gray A, gray B, gray C, gray D, gray E, and white Read YD1, YD2, YD3, YD4, YD5, YD6, YD7.

  In step S3503, the measured result of each pattern image for characteristic measurement is associated with each pattern. FIG. 40 (a) and FIG. 40 (b) show the association results based on the respective measurement results in the case of the processing in the image display device 3301A and the case of the processing in the image display device 3301B. This associated relationship is a tone adjustment parameter. An example in which this correspondence is interpolated and graphed is as shown in FIG. 28 shown in the fourth embodiment. The gradation adjustment parameter shown in FIG. 28 indicates an output value with respect to an input value used for gradation correction. The gradation adjustment parameters shown in FIG. 28 are stored in the correction parameter storage unit 3315A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, the correction parameter storage unit 3315B). Finish the setting process.

<Saturation adjustment parameter setting process>
FIG. 37 is a flowchart for explaining the details of the saturation adjustment parameter setting processing (step S3404) in the image display device 3301A and the image display device 3301B. Details of the saturation adjustment parameter setting process will be described using the flowchart of FIG.

  In step S3701, YM218, YM219, YM2110 (in the case of processing in the image display device 3301A. In the image display device 3301B, which are the measurement results of three colors of red, green, and blue among the measurement results stored in step S3504. In the case of the above processing, YM328, YM329, and YM3210) are read from the data buffer 3309A (in the case of processing in the image display device 3301A, in the case of processing in the image display device 3301B).

  In step S3702, a measurement result storage unit 3314A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, in which measurement results measured in an ideal state at the time of color design are stored in advance. From the design-time measurement result storage unit 3314B), YD8, YD9, and YD10, which are measurement results for three colors of red, green, and blue, among the pattern images for characteristic measurement in the ideal state are read.

  Based on the measurement result of each pattern image for characteristic measurement measured in step S3503, saturation adjustment parameters CR21, CG21, and CB21 (image display device 21) are obtained for each pattern according to Expression (18) or Expression (19). In the case of processing in the image display device 31, CR32, CG32, CB32) is calculated, and in the case of processing in the correction parameter storage unit 3315A (image display device 3301A. Processing in the image display device 3301B) In this case, the correction parameter storage unit 3315B) is stored, and the saturation adjustment parameter setting process is completed.

<Tone correction processing>
FIG. 38 is a flowchart for explaining the details of the gradation correction processing (step S3407) in the image display device 3301A and the image display device 3301B. Details of the gradation correction processing will be described with reference to the flowchart of FIG.

  In step S3801, the gradation adjustment parameter stored in step S3403 is read from the correction parameter storage unit 3315A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, the correction parameter storage unit 3315B). .

  In step S3802, the RGB value is corrected using the gradation adjustment parameter read in step S3801 (the corrected value is indicated as R'G'B '). In step S3803, it is determined whether or not the gradation correction of the projected image has been completed for all pixels. If it has been completed, the gradation correction process is terminated. If not, the process returns to step S3802.

<Saturation correction processing>
FIG. 39 is a flowchart for explaining the details of the saturation correction processing (step S3408) in the image display device 3301A and the image display device 3301B. Details of the saturation correction processing will be described using the flowchart of FIG.

  In step S3901, the saturation adjustment parameter saved in step S3404 is read from the correction parameter storage unit 3315A (in the case of processing in the image display device 3301A. In the case of processing in the image display device 3301B, it is read out from the correction parameter storage unit 3315B). . In step S3902, using the saturation adjustment parameter read in step S3901, RGB values are calculated using equation (20) (during color correction of the image display device 3301A) or equation (21) (during color correction of the image display device 3301B). Make corrections.

  In step S3903, it is determined whether or not the saturation correction of the projected image has been completed for all pixels. If it has been completed, the saturation correction process is terminated. If not, the process returns to step S3902.

  As described above, according to the present embodiment, in the image processing for performing color matching in a plurality of image display devices, from the projection surface under the surrounding environment and screen characteristics actually used in each image display device. By measuring the amount of reflected light using a sensor and performing correction processing based on the measurement results, variations between multiple image display devices are suppressed, and color matching for color reproduction results in an ideal environment is simple and accurate. Can be realized.

[Seventh Embodiment]
<About measurement processing>
In each of the fourth to sixth embodiments, the pattern image for characteristic measurement in the measurement process has been described as 10 single colors, but is not limited to 10 colors. Gray steps may be increased, and colors may be increased in the hue direction such as cyan, magenta, and yellow. Furthermore, a color in the saturation direction such as increasing the gradation pattern of red, green, and blue may be added. Further, the present invention is not limited to monochromatic projection. The same color may be projected onto a plurality of locations on the screen surface to absorb variations in the screen surface. Of course, it may be configured to project a plurality of colors simultaneously. That is, any data that is effective for gradation correction and saturation correction may be used.

<About measurement results>
In each of the fourth to sixth embodiments, the XYZ value is used as the measurement result in the sensor. However, the present invention is not limited to this, and spectral data, RGB data, Lab data, etc. may be used. I do not care. The data format is not limited as long as the data can calculate the difference between the measurement result at the time of design and the measurement result under the ambient environment and screen characteristics currently used. In addition, although the number of measurements was not mentioned, it may be a method of averaging by measuring multiple times in order to reduce variation in measurement results and increase reliability, or it may be based on a single measurement. Is not limited.

<About the adjustment curve shape>
In each of the fourth to sixth embodiments, the example of the gradation adjustment curve is described as a table with reference to FIGS. 27 and 28, but the curve shape is not limited. Moreover, it is good also as an approximate expression instead of a table.

<About gradation correction>
In each of the fourth to sixth embodiments, it has been described that RGB values are used for gradation correction, but the present invention is not limited to RGB values. The Y value may be calculated using the equation (8) or the equation (9), and the tone correction may be performed using the Y value. At that time, the present invention is not limited to the 3 × 3 conversion matrix as shown in the equations (8) and (9). Color conversion may be performed using a 3 × 9 or 3 × 20 conversion matrix including a nonlinear term. Further, color conversion may be performed using an LUT using previously measured grid point data. Furthermore, it may be a space value for which brightness information is required, such as Lab space, Luv space, CIECAM97s space, CIECAM02 space, and is not limited.

<About saturation calculation>
In each of the fourth to sixth embodiments, the correction parameters used in the saturation adjustment parameter setting process have been described using Expression (10) and Expression (11), but the values used for calculation are not limited to Y values. . Using equation (8), equation (9), equation (22), and equation (23), the saturation in the Lab space may be calculated, and the correction parameter may be calculated as the saturation ratio. Furthermore, it may be a space where saturation is required, such as YCC space, Luv space, CIECAM97s space, CIECAM02 space, and is not limited.

<About saturation correction>
In each of the fourth to sixth embodiments, with respect to saturation correction, the RGB value is corrected as in Expression (12) and Expression (13), but the RGB value is converted into a color signal indicating saturation. In addition, saturation correction may be performed. The color space in that case is not particularly limited as long as it is a space where saturation information is required, such as Lab space, Luv space, YCC space, CIECAM97s space, and CIECAM02 space.

<About adjustment target>
In the fourth to sixth embodiments, the image display apparatus that projects an image on a screen such as a projector has been described. However, the present invention can also be applied to a color image display apparatus such as a color display (color monitor). In the fourth to sixth embodiments, the adjustment of the two image projection units or the adjustment of the two image display devices has been described. However, the present invention is not limited to two. Furthermore, it may of course be applied between devices that are remote from each other.

<Storage medium>
Note that the present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, and a printer), and a device (for example, a copying machine and a facsimile device) including a single device. You may apply to.

  Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described fourth to sixth embodiments to a system or apparatus, and the computer (or CPU) of the system or apparatus. Needless to say, this can also be achieved when the MPU) reads and executes the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the fourth to sixth embodiments described above, and the storage medium storing the program code constitutes the present invention. .

  As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like is used. I can do it.

  Further, by executing the program code read by the computer, not only the functions of the fourth to sixth embodiments described above are realized, but also an OS running on the computer based on the instruction of the program code. It goes without saying that the case where the (operating system) or the like performs part of the actual processing and the functions of the fourth to sixth embodiments described above are realized by the processing.

  Further, after the program code read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the case where the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing and the functions of the fourth to sixth embodiments described above are realized by the processing.

1 is a block diagram illustrating a configuration of an image display device according to a first embodiment of the present invention. It is a flowchart which shows the flow of the image processing in an image display apparatus. It is a flowchart explaining the detail of the measurement process in an image display apparatus. 6 is a flowchart for explaining details of gradation adjustment parameter setting processing in the image display apparatus. It is a figure which shows an example explaining the measurement result at the time of an image display apparatus. It is a figure which shows an example of the correspondence with the curve for gradation adjustment for every gradation index | exponent in an image display apparatus. It is a figure which shows an example of the curve for gradation adjustment. It is a flowchart explaining the flow of the saturation adjustment parameter setting process in an image display apparatus. It is a figure which shows an example of a correspondence with the curve for saturation adjustment for every saturation index in an image display apparatus. It is a figure which shows an example of the curve for saturation adjustment. It is a flowchart explaining the detail of the gradation correction process in an image display apparatus. It is a flowchart explaining the detail of the saturation correction process in an image display apparatus. It is the block diagram which showed the structure of the image display apparatus concerning the 2nd Embodiment of this invention. It is a flowchart explaining the flow of the gradation adjustment parameter setting process in an image display apparatus. It is a figure which shows an example of the correspondence with the curve for gradation adjustment for every gradation index | exponent in an image display apparatus. It is a figure which shows an example of the curve for gradation adjustment. It is a figure which shows an example of the curve for gradation adjustment. It is a flowchart explaining the flow of the saturation adjustment parameter setting process in an image display apparatus. It is a figure which shows an example of a correspondence with the curve for saturation adjustment for every saturation index in an image display apparatus. It is a figure which shows an example of the curve for saturation adjustment. It is a figure which shows an example of the curve for saturation adjustment. It is a block diagram of the image display apparatus concerning the 4th, 5th embodiment of this invention. It is a flowchart which shows the flow of the image processing in an image display apparatus. It is a flowchart explaining the flow of the measurement process in an image display apparatus. It is a flowchart explaining the flow of the gradation adjustment parameter setting process in an image display apparatus. It is a figure for demonstrating an example of the measurement result at the time of an image display apparatus. It is a figure which shows an example of the gradation adjustment table for every image projection part in an image display apparatus. It is a figure which shows an example of the curve for gradation adjustment. It is a flowchart explaining the flow of the saturation adjustment parameter setting process in an image display apparatus. It is a flowchart explaining the flow of the gradation correction process in an image display apparatus. It is a flowchart explaining the flow of the saturation correction process in an image display apparatus. It is a figure which shows an example of the table for gradation adjustment in an image display apparatus. It is a block diagram of the image display apparatus concerning the 6th Embodiment of this invention. It is a flowchart explaining the flow of the image processing in an image display apparatus. It is a flowchart explaining the flow of the measurement process in an image display apparatus. It is a flowchart explaining the flow of the gradation adjustment parameter setting process in an image display apparatus. It is a flowchart explaining the flow of the saturation adjustment parameter setting process in an image display apparatus. It is a flowchart explaining the flow of the gradation correction process in an image display apparatus. It is a flowchart explaining the flow of the saturation correction process in an image display apparatus. It is a figure which shows an example of the gradation adjustment table for every image display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Image display apparatus 102 ... I / F part 103 ... Data acquisition part 104 ... Sensor 105 ... Color coordinate conversion part 106 ... Saturation correction part 107 ... Gradation correction Unit 108 ... data buffer 109 ... image projection unit 110 ... UI unit 111 ... measurement pattern storage unit 112 ... range-specific correction parameter storage unit 113 ... design time measurement result storage unit

Claims (8)

An image projection apparatus that projects an image on a predetermined display surface,
A measurement result obtained by measuring the amount of light for each color when a pattern image composed of a plurality of colors is displayed on the display surface , and an acquisition means for acquiring a predetermined value held in advance with respect to the amount of light ;
A gradation adjustment curve is selected from a plurality of gradation adjustment curves having different linearities according to the relationship between the measurement result and the predetermined value, and the image is based on the selected gradation adjustment curve. Gradation correction means for correcting the gradation of
A saturation adjustment curve is selected from a plurality of saturation adjustment curves having different linearities according to the relationship between the measurement result and the predetermined value, and the image is based on the selected saturation adjustment curve. An image projection apparatus comprising: a saturation correction unit that corrects the saturation of the image.   The image projection apparatus according to claim 1, wherein the pattern image includes white, black, red, green, and blue. The gradation correction means includes
A gradation range calculating means for calculating a gradation range using a white luminance value and a black luminance value among the measurement results;
A gradation range ratio calculating means for calculating a ratio between the calculated gradation range and a preset gradation range;
The image projection apparatus according to claim 2, wherein the gradation of the image is corrected from the calculated gradation range ratio. The saturation correction means includes
Range calculation means for calculating the saturation range of R, G, and B based on the measurement values of white, red, green, and blue among the measurement results;
Saturation range ratio calculating means for calculating a ratio between the calculated saturation range of R, G, B and a preset saturation range of R, G, B, and
The image projection apparatus according to claim 2, wherein the saturation of the image is corrected from the saturation range ratio calculated by the saturation range ratio calculation unit. The gradation correction means includes
The image projection apparatus according to claim 3, wherein the gradation of the image is corrected based on the gradation range ratio and a black luminance value in the measurement result. The saturation correction means includes
The image projection apparatus according to claim 4, wherein the saturation of the image is corrected based on a ratio of the saturation range and a black luminance value of the measurement result. An image projecting method in an image projecting apparatus that projects an image on a predetermined display surface,
A measurement result obtained by measuring the amount of light for each color when displaying a pattern image composed of a plurality of colors on the display surface , and an acquisition step of acquiring a predetermined value held in advance with respect to the amount of light ;
A gradation adjustment curve is selected from a plurality of gradation adjustment curves having different linearities according to the relationship between the measurement result and the predetermined value, and the image is based on the selected gradation adjustment curve. A gradation correction process for correcting the gradation of
A saturation adjustment curve is selected from a plurality of saturation adjustment curves having different linearities according to the relationship between the measurement result and the predetermined value, and the image is based on the selected saturation adjustment curve. An image projection method comprising: a saturation correction step of correcting the saturation of the image.   The program for functioning a computer as an image projection apparatus of any one of Claims 1 thru | or 6.

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