JP2006086788A - Picture correction method, picture correction apparatus, projection type picture display device and brightness unevenness and/or color unevenness correction program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve with less correction processing, effective luminance unevenness and/or color unevenness correction in displaying a picture by means of a projection type picture display device. <P>SOLUTION: A picture correction method allows the brightness unevenness and/or color unevenness correction generated on the displayed picture and comprises: calculating a luminance and/or chromaticity space variation at each divided region by dividing each pixel of the displayed picture or the displayed picture (Steps S1-S3); calculating the luminance and/or chromaticity correction requirement for the each pixel or the each divided region based on the calculated luminance and/or chromaticity space variation (Step S4); and correcting the luminance and/or the chromaticity based on the brightness and/or chromaticity correction requirement (Steps S5, S6). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image correction method, an image correction apparatus, a projection image display apparatus, and an image correction program that enable correction of luminance unevenness and color unevenness of a display image by a projection image display apparatus.

  Projection-type image display devices such as projectors cause unevenness in brightness and color in the displayed image due to some causes such as the quality of display devices (liquid crystal light valves, color foils, etc.) and light source lamps, and deterioration over time due to long-term use. There are things to do. The luminance unevenness and the color unevenness are also a major factor that deteriorates the image quality, and the suppression of the luminance unevenness and the color unevenness is a big problem for improving the quality of the display image. Various methods have been proposed to improve the luminance unevenness and color unevenness (see, for example, Patent Documents 1 to 7).

Patent Document 1 generates correction data from a luminance difference or luminance ratio between a predetermined luminance distribution characteristic set in advance and the luminance distribution characteristic of a display image. The correction data is stored in the memory in association with the horizontal position and the vertical position of the image to be displayed.
Further, Patent Document 2 sets a circular adjustment range, stores correction data having a correction amount that increases as it approaches the center of the circular range for pixels included in the adjustment range, and stores the lookup table as a lookup table. It is used to perform correction.

  Further, in Patent Document 3, one representative point is set for each divided region divided into a plurality of areas, and correction data at this representative point is set. Correction data for each pixel is obtained by interpolation from correction data at nearby representative points.

Further, Patent Document 4 stores correction parameters for each gradation for the entire display image, and determines and applies the correction parameters for each divided region obtained by dividing the display image.
Further, Patent Document 5 divides a projection area into triangular elements, and generates correction data at each vertex of the triangular elements. Then, the correction data inside the triangular element is interpolated from the correction data of each vertex of the triangular element.

Further, Patent Document 6 considers a quadrilateral element in a projection area, and generates correction data at each vertex of the quadrilateral element.
Further, Patent Document 7 performs the same processing as Patent Document 4 in that a correction parameter is determined and applied for each divided region obtained by dividing a display image. The correction process is applied to a multi-projection system.

JP-A-5-197357 JP-A-8-146922 JP-A-8-171371 JP 2000-284773 A JP 2000-316170 A JP 2001-134252 A JP 2003-46751 A

  As can be seen from the above patent documents, most of the above patent documents correct the display image using the brightness and chromaticity of the image data to be displayed, that is, the image data itself and the correction parameters. It is.

  As described above, the conventional luminance unevenness / color unevenness correction processing method has a problem that the amount of correction processing is extremely large because the display image is corrected using the image data itself and the correction parameters. Many of the above-mentioned patent documents divide the display screen, calculate correction parameters for each divided area obtained by the division, and perform correction processing using the correction parameters obtained in all the divided areas. However, since correction processing is performed using correction parameters obtained in all the divided regions, there is a problem that the amount of correction processing also increases in this case.

  In particular, recently, a display image in a projection type image display device such as a projector tends to have a higher resolution. When performing luminance unevenness / color unevenness correction for such a high-resolution display image, the conventional correction method as described above inevitably requires a large number of correction processes. Therefore, when performing luminance unevenness / color unevenness correction on a high-resolution display image displayed by a projection-type image display device such as a projector, it is required to perform effective correction processing with a small processing amount. It is done.

  The present invention provides an image correction method, an image correction apparatus, and a projection type capable of effectively correcting luminance unevenness and color unevenness generated in a high-resolution display image displayed by a projection display apparatus with a small correction processing amount. An object is to provide an image display device and an image correction program.

  (1) The image correction method of the present invention is an image correction method that enables correction of luminance unevenness and / or color unevenness occurring in a display image, and is obtained by dividing each pixel of the display image or the display image. A step of calculating a spatial change amount of the luminance and / or chromaticity of each divided region, and a luminance and a luminance for each of the pixels or the divided regions based on the calculated luminance and / or chromaticity spatial change amount And / or calculating the necessity of correction of chromaticity and correcting the luminance and / or chromaticity based on the necessity of correction of luminance and / or chromaticity.

  Since the display image is corrected using the correction necessity calculated based on the magnitude of the spatial change amount of the display image in this way, a high-resolution display image displayed by the projection display device Can be effectively corrected with a small amount of correction processing. In the present invention, the difference between the luminance of the pixel of interest or the divided region of interest and the luminance of the pixel or divided region existing in the vicinity thereof is used as the amount of spatial change in luminance, and the pixel of interest or the divided region of interest The difference between the chromaticity and the chromaticity of the pixels or divided areas existing in the vicinity thereof is used as the spatial change amount of the chromaticity.

(2) In the image correction method according to (1), it is preferable that the luminance is a luminance component or a brightness component in a color system taking into account three attributes of color.
As a result, the amount of spatial change in luminance can be calculated appropriately.

(3) In the image correction method according to (1) or (2), it is preferable that the chromaticity is a hue component, a saturation component, or a color difference component in a color system that takes into account three attributes of color.
As a result, the amount of spatial change in chromaticity can be calculated appropriately.

(4) In the image correction method according to any one of (1) to (3), the luminance correction necessity degree is negatively correlated with the magnitude of the spatial change amount of the luminance. It is preferable that the chromaticity correction necessity is modeled so as to have a negative correlation with the amount of spatial change in the chromaticity.
As a result, the smaller the luminance spatial change amount, the larger the necessity of correcting the luminance, and the optimum luminance correction necessity according to the magnitude of the luminance spatial change amount. In addition, the smaller the chromaticity spatial change amount, the larger the chromaticity correction necessity can be obtained, and the optimum chromaticity correction necessity according to the magnitude of the chromaticity spatial change amount is obtained. Can do.

(5) In the image correction method according to any one of (1) to (4), a threshold value is set for each of the luminance and / or chromaticity correction necessity levels, and correction is performed based on the threshold value. It is possible to determine whether or not.
As a result, it is possible to perform correction on pixels or divided areas that need to be corrected for luminance unevenness and / or color unevenness, and thus effective correction can be performed while reducing the amount of correction processing.

(6) In the image correction method according to (5), the luminance and / or chromaticity correction necessity level is expressed as binary information indicating whether or not to correct based on the respective threshold values. It is preferred that
The binary information is, for example, information such as “1” (corrected) or “0” (not corrected), and the luminance and / or chromaticity correction necessity is represented by such binary information. Thus, it is possible to simplify the determination process of whether or not to perform correction.

(7) In the image correction method according to (6), binary information indicating whether or not to correct the luminance and / or chromaticity correction necessity with respect to the divided areas in the divided areas. It is preferable to set any value.
This represents the degree of necessity of correction of each divided area by information such as “1” (corrected) and “0” (not corrected). In this way, for each divided region, the luminance and / or chromaticity correction necessity level is expressed by binary information, so that a determination process for determining whether or not to correct each pixel in each divided region is performed. It can be simplified.

  (8) The image correction method of the present invention is an image correction method that enables correction of luminance unevenness and / or color unevenness occurring in a display image, and is obtained by dividing each pixel of the display image or the display image. A step of calculating a spatial change amount of the luminance and / or chromaticity of each divided region, and a luminance and a luminance for each of the pixels or the divided regions based on the calculated luminance and / or chromaticity spatial change amount Calculating a degree of necessity for correction of chromaticity, and setting a correction order of luminance and / or chromaticity for each pixel or the divided region based on the degree of necessity for correction of luminance and / or chromaticity; And correcting the luminance and / or chromaticity based on the correction order of the luminance and / or chromaticity.

As described above, since the display image is corrected using the correction necessity calculated based on the magnitude of the space change amount, the effective luminance unevenness / color with respect to the display image by the projection type image display device. Unevenness correction can be realized with a small correction processing amount. Further, in the present invention, the correction order of luminance and / or chromaticity for each pixel or the divided area is set, so that a pixel or a divided area having a high degree of correction can be preferentially corrected. More efficient correction is possible.
The image correction method described in (8) preferably has the characteristics described in (2) to (4). Further, in the image correction apparatus described in (8), the luminance and / or chromaticity correction necessity level for each divided area can be assigned a representative value in each divided area.

(9) In the image correction method according to (8), the correction order of the luminance and / or chromaticity is set in order of the necessity of correction of the luminance and / or chromaticity, and the luminance and / or color is set. It is preferable that the correction of the degree is performed on pixels to be processed in a predetermined order from the pixel or the divided region having a high necessity for correcting the luminance and / or chromaticity in order.
As a result, the correction processing amount can be reduced by making correction targets up to a predetermined order in descending order of necessity of correction. Although correction of pixels or divided regions lower than a predetermined order is omitted, since the necessity for correction is low, there is little influence on image quality due to omission of correction.

(10) An image correction apparatus according to the present invention is an image correction apparatus capable of correcting luminance unevenness and / or color unevenness generated in a display image, and is obtained by dividing each pixel of the display image or the display image. A spatial change amount calculating means for calculating a spatial change amount of the luminance and / or chromaticity of each divided region, and each pixel or the divided region based on the calculated spatial change amount of the luminance and / or chromaticity Correction necessity calculation means for calculating the necessity for correction of luminance and / or chromaticity with respect to the image, and correction means for correcting the luminance and / or chromaticity based on the necessity for correction of luminance and / or chromaticity It is characterized by that.
As a result, the same effect as the effect of the image correction method described in (1) can be obtained. In addition, the image correction apparatus described in (10) preferably has the characteristics of the image correction methods described in (2) to (7).

  (11) An image correction apparatus according to the present invention is an image correction apparatus capable of correcting luminance unevenness and / or color unevenness generated in a display image, and is obtained by dividing each pixel of the display image or the display image. A spatial change amount calculating means for calculating a spatial change amount of the luminance and / or chromaticity of each divided region, and each pixel or the divided region based on the calculated spatial change amount of the luminance and / or chromaticity A correction necessity calculation means for calculating a necessity for correction of luminance and / or chromaticity with respect to the luminance and / or luminance for each pixel or the divided region based on the magnitude of the necessity for correction of luminance and / or chromaticity A correction order for setting a correction order of chromaticity is provided, and a correction means for correcting the luminance and / or chromaticity based on the correction order of the luminance and / or chromaticity is provided.

  As a result, the same effect as the effect of the image correction method described in (8) can be obtained. Also in (11), it is preferable that the image correction method described in (2) to (4) and the image correction method described in (9) have the same characteristics. Also, in the image correction apparatus described in (11), the luminance and / or chromaticity correction necessity level for each divided area can be assigned a representative value in each divided area.

(12) A projection-type image display apparatus according to the present invention is a projection-type image display apparatus including an image correction apparatus that can correct luminance unevenness and / or color unevenness generated in a display image. The image correction apparatus according to (10) or (11) is provided.
By having such an image correction apparatus, effective luminance unevenness and / or color unevenness correction for a display image can be realized with a small correction processing amount, and a high-quality image with less luminance unevenness and / or chromaticity unevenness can be realized. It can be displayed.

(13) The image correction program of the present invention is an image correction program that enables correction of luminance unevenness and / or color unevenness generated in a display image, and is obtained by dividing each pixel of the display image or the display image. A step of calculating a spatial change amount of the luminance and / or chromaticity of each divided region, and a luminance and a luminance for each of the pixels or the divided regions based on the calculated luminance and / or chromaticity spatial change amount And / or calculating the necessity of correction of chromaticity and correcting the luminance and / or chromaticity based on the necessity of correction of luminance and / or chromaticity.
Also by this, the same effect as the effect of the image correction method described in (1) can be obtained. In addition, the image correction apparatus described in (13) preferably has the characteristics of the image correction methods described in (2) to (7).

  (14) The image correction program of the present invention is an image correction program that enables correction of luminance unevenness and / or color unevenness occurring in a display image, and is obtained by dividing each pixel of the display image or the display image. A step of calculating a spatial change amount of the luminance and / or chromaticity of each divided region, and a luminance and a luminance for each of the pixels or the divided regions based on the calculated luminance and / or chromaticity spatial change amount Calculating a degree of necessity for correction of chromaticity, and setting a correction order of luminance and / or chromaticity for each pixel or the divided region based on the degree of necessity for correction of luminance and / or chromaticity; And correcting the luminance and / or chromaticity based on the correction order of the luminance and / or chromaticity.

  As a result, the same effect as the effect of the image correction method described in (8) can be obtained. Also, (14) preferably has the same characteristic features as the image correction methods described in (2) to (4) and the image correction method described in (9). Also in the image correction program described in (14), the luminance and / or chromaticity correction necessity level for each divided area can be assigned a representative value in each divided area.

Hereinafter, embodiments of the present invention will be described. Before describing the embodiment, first, the outline of the present invention will be described.
In the present invention, as in a projection image display device (hereinafter referred to as a projector), image data to be displayed and image display means for displaying the image data are separately prepared, and a display image displayed by the image display means The luminance unevenness and / or color unevenness that occurs in the image is to be corrected.

  As described above, the present invention corrects the luminance unevenness and / or color unevenness generated in the display image displayed by the projector. When correcting the luminance unevenness and / or color unevenness, the entire display screen is corrected. Instead of correcting the display image, luminance unevenness and / or color unevenness correction processing is performed on a region where luminance unevenness and / or color unevenness is conspicuous. This realizes effective luminance unevenness and / or color unevenness correction with a small correction processing amount.

  In the present invention, “brightness unevenness and / or color unevenness” is hereinafter referred to as “brightness unevenness / color unevenness” for simplification of description, and similarly “brightness and / or color unevenness”. “Chromaticity” is also expressed as “luminance / chromaticity”, but “luminance irregularity / color irregularity” means “luminance irregularity and / or color irregularity”, and “luminance / chromaticity” is “luminance”. And / or chromaticity ”. Therefore, in the following description, for example, “brightness / chromaticity space change amount” means “brightness and / or chromaticity space change amount”. It refers to both or either of “the amount of spatial change in chromaticity”.

  Here, it is assumed that the region where the luminance unevenness / color unevenness is conspicuous is a region where the amount of spatial change in the luminance / chromaticity of the display image is small. Therefore, the luminance / chromaticity space change amount of the display image is calculated based on the image data corresponding to the display image (referred to as image data to be displayed), and based on the calculated luminance / chromaticity space change amount. Make corrections.

  Therefore, in the present invention, the luminance / chromaticity space change amount of the display image is calculated based on the image data. Then, based on the calculated luminance / chromaticity space change amount, the luminance / chromaticity correction necessity degree is calculated for each area obtained by dividing each pixel or display image (referred to as a divided area). Luminance unevenness / color unevenness correction is performed based on the necessity of brightness / chromaticity correction. Hereinafter, the embodiment of the present invention will be described in two parts, Embodiment 1 and Embodiment 2. The first embodiment is referred to as “first luminance unevenness / color unevenness correction processing”, and the second embodiment is referred to as “second luminance unevenness / color unevenness correction processing”.

  Further, according to the present invention, the calculation of the amount of spatial change, the calculation of the necessity of correction, the image correction process, and the like can be performed for each pixel unit or divided region unit, but in the following embodiments, the process is performed for each pixel unit. An example of performing is described.

[Embodiment 1]
The first embodiment describes the “first luminance unevenness / color unevenness correction process”, and this “first luminance unevenness / color unevenness correction process” is based on the magnitude of the luminance / chromaticity space change amount. The brightness / chromaticity correction necessity is set, and the correction (brightness unevenness / color unevenness correction) based on the brightness / chromaticity correction necessity is performed. This luminance / chromaticity correction necessity level indicates the high necessity of luminance / chromaticity correction for a certain pixel, and is used to determine whether to perform luminance / chromaticity correction for a certain pixel. It is an indicator.

  Hereinafter, the “first luminance unevenness / color unevenness correction process” will be described with reference to three correction processing methods. These three correction processing methods are referred to as “first luminance unevenness / color unevenness correction process (part 1)”, “first luminance unevenness / color unevenness correction process (part 2)”, and “first luminance unevenness / color unevenness”. This will be referred to as “correction processing (part 3)”. First, “first luminance unevenness / color unevenness correction process (part 1)” will be described.

  As a rough processing procedure of the “first luminance unevenness / color unevenness correction process (part 1)”, first, the luminance / chromaticity space change amount of each pixel or each divided region of the display image is calculated. Then, the brightness / chromaticity correction necessity for each pixel is calculated based on the calculated luminance / chromaticity space change amount, and the luminance / chromaticity correction processing is performed according to the calculated brightness / chromaticity correction necessity. Decide whether or not to perform.

Hereinafter, the “first luminance unevenness / color unevenness correction process (part 1)” will be described in detail.
FIG. 1 is a diagram showing a configuration of an image correction apparatus for realizing “first luminance unevenness / color unevenness correction processing (part 1)”.

  The image correcting apparatus shown in FIG. 1 calculates luminance / chromaticity data D2 for calculating luminance / chromaticity data D2 of each pixel based on image data D1 (assuming R, G, B color system data) to be displayed. Calculation means 1, luminance / chromaticity space change amount calculation means 2 for calculating luminance / chromaticity space change amount D3 based on luminance / chromaticity data D2 of each pixel, luminance based on luminance / chromaticity space change amount D3 The luminance / chromaticity correction necessity calculation means 3 for calculating the chromaticity correction necessity degree D4, the luminance / chromaticity correction necessity degree D4, the luminance / chromaticity correction parameter D5, and the threshold value D6 of the luminance / chromaticity correction necessity degree Luminance / chromaticity data D2 is corrected based on the luminance / chromaticity correction means 4 for generating corrected luminance / chromaticity data D7, and luminance for converting the corrected luminance / chromaticity data D7 into corrected image data D8. .Has chromaticity data / image data conversion means 5 And it has a configuration. The corrected image data D8 converted by the luminance / chromaticity data / image data conversion means 5 is given to each pixel of the display device.

FIG. 2 is a flowchart for explaining the processing procedure of “first luminance unevenness / color unevenness correction process (part 1)”.
In FIG. 2, first, the pixel number k is initialized (step S1). Then, from the image data (R, G, B color system data) D1 to be displayed, the luminance / chromaticity data D2 of the pixel (pixel of interest) with the pixel number at that time is calculated (step S2).

  The luminance / chromaticity data D2 is calculated by calculating the luminance / chromaticity data from a color system (color model) in which normal image data and three attributes of color (hue, lightness, and saturation) are modeled. The conversion formula for calculating the luminance / chromaticity data differs depending on what color system is used and the difference in the reference. Examples of the color specification include XYZ, YCbCr, Lab and the like in addition to RGB. Here, the XYZ color system is used.

In this case, if the image data D1 at the pixel i, j of interest (representing the position of the pixel of interest by coordinates i, j) is R _{i, j} , G _{i, j} , B _{i, j} , the pixel i, The luminance / chromaticity data D2 at j (represented by luminance / chromaticity data X _{i, j} , Y _{i, j} , Z _{i, j} )
X _{i, j} = X (R _{i, j} , G _{i, j} , B _{i, j} ) (1)
Y _{i, j} = Y (R _{i, j} , G _{i, j} , B _{i, j} ) (2)
Z _{i, j} = Z (R _{i, j} , G _{i, j} , B _{i, j} ) (3)
It is represented by

Using the luminance / chromaticity data X _{i, j} , Y _{i, j} , Z _{i, j} of the XYZ color system, the luminance / chromaticity space change amount D3 of the pixel of interest is calculated (step S3). It is assumed that the luminance / chromaticity space change amount D3 of the pixel of interest is represented by the magnitude of the difference between the pixel of interest and the luminance / chromaticity data of the pixels existing around it.

If the luminance / chromaticity space change amount D3 is represented by the luminance / chromaticity space change amounts Φ _X , Φ _Y , Φ _Z , Φ _X , Φ _Y , Φ _Z are
It is represented by In the equations (4) to (6), n is the size of the filter, and w is the weight (w becomes a smaller value as n increases).

FIG. 3 is a diagram showing the luminance / chromaticity data X _{i, j} , Y _{i, j} , Z _{i, j of} the pixel i, j of interest and the surrounding pixels. In FIG. 3, since n = 1, i takes one of i and i ± 1, and j takes j and j ± 1. In the case of FIG. 3, the equations (4) to (6) are expressed as follows. In FIG. 3, since n = 1, w = 1.

As described above, the luminance / chromaticity space variation amounts Φ _X , Φ _Y , and Φ _Z can be obtained. Note that the luminance / chromaticity space variation of the pixel i, j of interest is represented by Φx | _{i, j} , Φy | _{i, j} , Φz | _{i, j} .

Subsequently, based on the luminance / chromaticity space change amount Φx | _{i, j} , Φy | _{i, j} , Φz | _{i, j} of the pixel of interest, the luminance / chromaticity correction necessity level D4 of the pixel of interest (this is The pixel luminance / chromaticity correction necessity Wx | _{i, j} , Wy | _{i, j} , Wz | _{i, j} ) is calculated (step S4). The luminance / chromaticity correction necessity is modeled so as to have a negative correlation with the magnitude of the luminance / chromaticity space change amount. Therefore, the larger the luminance / chromaticity space change amount is, the smaller the luminance / chromaticity correction necessity becomes.

  FIG. 4 is a diagram showing the relationship between the luminance / chromaticity space change amount and the luminance / chromaticity correction necessity. FIG. 4A shows an example in which the luminance / chromaticity correction necessity of the pixel with respect to the luminance / chromaticity space change amount can be acquired as a continuous value, and FIG. 4B shows the luminance with respect to the luminance / chromaticity space change amount. An example in which the degree of chromaticity correction necessity can be acquired as a discontinuous value (stepwise value in this example) is shown.

  In the example of FIG. 4A, that is, an example in which the luminance / chromaticity correction necessity level can be acquired as a continuous value, as can be seen from FIG. As the relationship with the luminance / chromaticity correction necessity, for example, the relationship shown by curves A1, A2, A3 can be considered. An example of a conversion equation for obtaining the luminance / chromaticity correction necessity from the spatial change amount of the luminance / chromaticity is shown below.

In this equation (10), W is the luminance / chromaticity correction necessity to be obtained, Φ is the luminance / chromaticity space variation of the pixel of interest, Φmax is the maximum value of luminance / chromaticity space variation, Φmin is the luminance This is the minimum value of the chromaticity space change amount.

  In the case of the example in FIG. 4B, for example, depending on which range the value of the spatial change amount Φ of luminance / chromaticity of the pixel of interest is, luminance / chromaticity correction is required to correspond to the range. The degree W is obtained. As an example, the degree W can be obtained as follows.

In this equation (11), if Φ is Φmin ≦ Φ <Φ1, the brightness / chromaticity correction necessity W is obtained as W = 1, and if Φ is Φ1 ≦ Φ <Φ2, the brightness / color is calculated. The degree of necessity correction W is obtained as W = a, and if Φ is Φ2 ≦ Φ <Φ3, the luminance / chromaticity correction degree W is obtained as W = b, and if Φ is Φ3 ≦ Φ <Φmax. The brightness / chromaticity correction necessity W is obtained as W = 0.

As described above, the luminance / chromaticity correction necessity Wx | _{i, j} , Wy | _{i, j} , Wz | _{i, j} of the pixel of interest can be calculated. Whether or not the luminance / chromaticity of the pixel of interest is to be corrected is determined based on the luminance / chromaticity correction necessity Wx | _{i, j} , Wy | _{i, j} , Wz | _{i, j} (step S5). .

Determining whether to correct the brightness and chromaticity of the pixel to be the target is preset luminance and chromaticity correction required degree threshold D6 (which luminance and chromaticity correction required degree threshold W _{MX of,} W _MY , W _MZ ). In this case, the calculated luminance and chromaticity correction required degree _{Wx | i, j, Wy |} i, j, Wz | i, the threshold value _W MX of _j luminance and chromaticity correction _necessity, W _MY, than _{W MZ} If it is larger, correction is performed.

If it is determined that the luminance / chromaticity of the pixel of interest is to be corrected as a result of this determination, the luminance / chromaticity correction means 4 uses the luminance / chromaticity correction parameter D5 to determine the luminance / chromaticity of the pixel of interest. Correction processing is performed (step S6). As a result, corrected luminance / chromaticity data D7 (represented by corrected luminance / chromaticity data X ′ _{i, j} , Y ′ _{i, j} , Z ′ _{i, j} ) is obtained.

Then, the corrected luminance / chromaticity data X ′ _{i, j} , Y ′ _{i, j} , Z ′ _{i, j} subjected to the luminance / chromaticity correction processing for the pixel of interest is converted into image data (R, G, B table). Color system data) and transferred to the pixels of the display device as corrected image data D8 (step S7).

  If it is determined in step S5 whether or not the luminance / chromaticity of the pixel of interest is to be corrected, it is determined that the luminance / chromaticity of the pixel of interest is not to be corrected. Step S7 is entered.

  Then, it is determined whether or not correction processing has been considered for all pixels (step S8). If correction processing has been considered for all pixels, the processing ends, and correction processing has to be considered for all pixels. For example, the pixel number k is shifted (k = k + 1) (step S9), the process returns to step S2, and the processes after step S2 are performed.

FIG. 5 is a diagram for explaining a specific example of the spatial change amount of luminance / chromaticity in an image to be displayed and the necessity of luminance / chromaticity correction based on the spatial variation amount.
FIG. 5A shows an image to be displayed. The luminance / chromaticity space change amount is calculated for the image to be displayed, and the calculated luminance / chromaticity space change amount is expressed by the density of the monochrome color. The thing is FIG.5 (b).
FIG. 5B shows that the higher the degree of black, the smaller the amount of spatial change in luminance and chromaticity. In the example of FIG. 5, since the sky and the road are almost black, it can be said that the amount of spatial change in luminance and chromaticity is extremely small.

  FIG. 5C shows an example in which the luminance / chromaticity correction necessity is obtained by the above-described equation (10) based on the obtained spatial change amount of the luminance / chromaticity. In FIG. 5C, the luminance / chromaticity correction necessity is represented by a continuous amount of 0.0 to 1.0. In the example of FIG. 5C, it can be seen that the sky and road have a particularly high necessity for luminance / chromaticity correction.

  As described above, according to the “first luminance unevenness / color unevenness correction process (part 1)”, the luminance / chromaticity space variation amount of the pixel of interest is calculated, and the luminance / chromaticity space variation amount is calculated. The luminance / chromaticity correction necessity based on the size is obtained, and when the luminance / chromaticity correction necessity is larger than a preset threshold value, the luminance / chromaticity correction is performed on the pixel of interest. ing. As described above, the correction process is performed only for the portions where the luminance / chromaticity correction is necessary, so that effective luminance unevenness / color unevenness correction can be performed with a small correction processing amount.

Next, the “first luminance unevenness / color unevenness correction process (2)” will be described.
As a rough processing procedure of the “first luminance unevenness / color unevenness correction process (2)”, brightness / chromaticity data is obtained for each pixel of one screen (one frame) of image data to be displayed. The luminance / chromaticity space variation is calculated from the calculated luminance / chromaticity data of each pixel, and the luminance / chromaticity correction necessity is calculated based on the luminance / chromaticity space variation. Then, a threshold value of the luminance / chromaticity correction necessity of each pixel is obtained from the luminance / chromaticity correction necessity of the pixel for one screen, and the luminance / chromaticity correction necessity of each pixel is binary with the obtained threshold value. Then, using the binarized luminance / chromaticity correction necessity (referred to as binarized luminance / chromaticity correction necessity), it is determined whether to perform luminance / chromaticity correction of a certain pixel.

FIG. 6 is a diagram showing a configuration of an image correction apparatus for realizing the first luminance unevenness / color unevenness correction process (No. 2).
The components of the image correction apparatus shown in FIG. 6 are, as in the image correction apparatus shown in FIG. 1, luminance / chromaticity data calculation means 1, luminance / chromaticity space change amount calculation means 2, luminance / chromaticity. The correction necessity degree calculation means 3, the luminance / chromaticity correction means 4, and the luminance / chromaticity data / image data conversion means 5 are provided. Furthermore, in addition to these components, the luminance / chromaticity correction necessity threshold D6 is set based on the luminance / chromaticity correction necessity D4 calculated by the luminance / chromaticity correction necessity calculation means 3. Luminance for obtaining binarized luminance / chromaticity correction necessity D9 by binarizing luminance / chromaticity correction necessity D4 based on threshold value D6 for luminance / chromaticity correction necessity threshold 6 The chromaticity correction necessity degree binarization means 7 is provided.

FIG. 7 is a flowchart for explaining the processing procedure of “first luminance unevenness / color unevenness correction processing procedure (2)”.
In FIG. 7, first, luminance / chromaticity data X, Y, Z for each pixel is calculated from image data (R, G, B color system data) corresponding to one screen of image data to be displayed. (Step S11), and from the calculated luminance / chromaticity data X, Y, Z for each pixel, the luminance / chromaticity spatial variation Φ _X , Φ _Y , Φ _Z for each pixel is calculated (Step S12). ). Then, the brightness / chromaticity correction necessity levels W _X , W _Y , W _Z are calculated based on the calculated spatial variation amounts Φ _X , Φ _Y , Φ _Z of the brightness / chromaticity (step S13).

Next, based on the calculated luminance / chromaticity correction necessity levels W _X , W _Y , W _Z , the luminance / chromaticity correction necessity threshold setting means 6 performs the luminance / chromaticity correction necessity threshold value D 6 (this A threshold value of brightness / chromaticity correction necessity level W _MX , W _MY , and W _MZ is set (step S14).

Note that the threshold values W _MX , W _MY , and W _MZ of the luminance / chromaticity correction necessity level are threshold values for binarizing the luminance / chromaticity correction necessity level. _These will be referred to as _MX , W _MY and W _MZ . A method for setting the binarization thresholds W _MX , W _MY , and W _MZ will be described later.

Based on the set binarization thresholds W _MX , W _MY and W _MZ , the luminance / chromaticity correction necessity is binarized (step S 15). As a result, the binarized luminance / chromaticity correction necessity D9 (represented by the binarized luminance / chromaticity correction necessity W ′ _X , W ′ _Y , W ′ _Z ) is obtained. Here, a method for setting the binarization thresholds W _MX , W _MY , and W _MZ will be described.

FIG. 8 is a diagram illustrating a method for setting binarization thresholds W _MX , W _MY , and W _MZ . In FIG. 8, the luminance / chromaticity correction necessity levels W _X , W _Y , and W _Z are the luminance / chromaticity correction necessity levels calculated in step S13 in FIG. The brightness / chromaticity correction necessity levels W _X , W _Y , and W _Z are obtained by, for example, equation (10).

Then, a histogram f (w) as shown in FIG. 8 is created using the luminance / chromaticity correction necessity levels W _X , W _Y , W _Z (step S151), and based on the histogram f (w). A threshold value for binarization is set (step S152). The binarization threshold is such that, in the histogram f (w), the sum of the number of pixels in the section W _M ≦ W ≦ 1.0 is equal to or less than the allowable correction processing amount Sum as shown in the following equation (12). It is set to a W _M by the binarization threshold value.

When the binarization threshold value W _M , that is, the binarization threshold values W _MX , W _MY , and W _{MZ in} the luminance / chromaticity data X, Y, and Z are set in this way, the binarization threshold value W _M is set. Using the threshold values W _MX , W _MY and W _MZ , the luminance / chromaticity correction necessity is binarized.

FIG. 9 is a diagram for explaining a process of binarizing the luminance / chromaticity correction necessity using the binarization thresholds W _MX , W _MY , and W _MZ .
In FIG. 9, the horizontal axis represents the luminance / chromaticity correction necessity W _X , W _Y , W _Z obtained in step S13 of FIG. 7 (this is represented as luminance / chromaticity correction necessity (1) in FIG. 9). ), and, _{W M} is a binary threshold value. Also, the vertical axis represents the binarized luminance / chromaticity correction necessity D9 (this is represented by the binarized luminance / chromaticity correction necessity W ′ _X , W ′ _Y , W ′ _Z ). Note that the binarized luminance / chromaticity correction necessity W ′ _X , W ′ _Y , W ′ _Z is represented as luminance / chromaticity correction necessity (2) in FIG.

As can be seen from FIG. 9, the luminance and chromaticity correction required degree (1) of the luminance and chromaticity correction required degree depending on whether the binarization threshold W or larger than _M (2) "1" (to correct ) Or “0” (not corrected).

Thus, for example, if the luminance and chromaticity correction required degree (1) at least a binarization threshold W _M, brightness and chromaticity correction required degree (2) is "1", in this case, Indicates that luminance / chromaticity correction is performed. Further, if the luminance and chromaticity correction required degree (1) is less than the binarization threshold value W _M, brightness and chromaticity correction required degree (2) is "0", in this case, the luminance and color Indicates that no degree correction is performed.

  Of the two images (a) and (b) shown in FIG. 9, (a) shows that the luminance / chromaticity correction necessity is luminance / chromaticity correction necessity (1), that is, luminance / color. The degree of necessity correction is an image represented by a continuous amount of 0.0 to 1.0, which is the same image as (c) of FIG. Further, (b) is an image in which the luminance / chromaticity correction necessity is represented by the luminance / chromaticity correction necessity (2), that is, the binarized luminance / chromaticity correction necessity.

  As can be seen from FIG. 9 (b), the black portion indicates the necessity of luminance / chromaticity correction “0”, that is, the portion where luminance / chromaticity correction is not performed, and the white portion requires luminance / chromaticity correction. The degree is “1”, that is, a portion where luminance / chromaticity correction is performed.

When the luminance / chromaticity correction necessity (2), that is, the binarized luminance / chromaticity correction necessity W ′ _X , W ′ _Y , W ′ _Z is obtained as described above, the binarized luminance is obtained. Using the chromaticity correction necessity levels W ′ _X , W ′ _Y , and W ′ _Z , it is determined whether or not to perform luminance / chromaticity correction processing for each pixel of image data to be displayed.

The luminance / chromaticity correction processing will be described from step S16 onward in FIG. First, the pixel number k is initialized (k = 0) (step S16), and the luminance / chromaticity data X, Y, Z of the pixel to be processed (the pixel of interest) are acquired (step S17). . Then, the binarized luminance / chromaticity correction necessity levels W ′ _X , W ′ _Y , and W ′ _Z for the pixel of interest are acquired (step S18).

Based on the binarized luminance / chromaticity correction necessity W ′ _X , W ′ _Y , W ′ _Z , it is determined whether or not the luminance / chromaticity of the pixel of interest is to be corrected (step S19). As described above, whether or not the luminance / chromaticity correction of the pixel of interest is to be performed is determined when the binarized luminance / chromaticity correction necessity levels W ′ _X , W ′ _Y , and W ′ _Z are “1”. In some cases, luminance / chromaticity correction is performed, and in the case where the binarized luminance / chromaticity correction necessity W ′ _X , W ′ _Y , W ′ _Z is “0”, luminance / chromaticity correction is performed. Suppose not.

  If it is determined in step S19 that the luminance / chromaticity correction of the pixel of interest is to be performed, the luminance / chromaticity correction means 4 uses the luminance / chromaticity correction parameter D5 to determine the luminance / chromaticity of the pixel of interest. A chromaticity correction process is performed (step S20).

  Then, the corrected luminance / chromaticity data subjected to the luminance / chromaticity correction processing for the pixel of interest is converted into image data (R, G, B color system data) and transferred to the pixel of the display device ( Step S21). If it is determined in step S19 that the luminance / chromaticity of the pixel of interest is to be corrected, and it is determined that the luminance / chromaticity of the pixel of interest is not to be corrected, the correction is not performed directly. Step S21 is entered.

  Then, it is determined whether or not correction processing has been considered for all pixels (step S22). If correction processing has been considered for all pixels, the processing ends, and correction processing has to be considered for all pixels. For example, the pixel number k is shifted (k = k + 1) (step S23), the process returns to step S2, and the processes after step S17 are performed.

  As described above, according to the “first luminance unevenness / color unevenness correction process (2)”, the spatial change amount of the luminance / chromaticity of pixels for one screen is calculated, and the luminance / chromaticity of the luminance / chromaticity is calculated. A luminance / chromaticity correction necessity (1) is obtained based on the magnitude of the space change amount, and a threshold is set for the luminance / chromaticity correction necessity (1). Based on this threshold, the luminance / chromaticity correction necessity (2), that is, the binarized luminance / chromaticity correction necessity is obtained, and the image data of the image data is obtained by the binarized luminance / chromaticity correction necessity. It is determined whether correction is performed for each pixel.

  As described above, the “first luminance unevenness / color unevenness correction process (2)” determines whether or not to perform the luminance / chromaticity correction depending on the necessity of binarized luminance / chromaticity correction. Since it is determined to be “corrected” or “0” (not corrected), it is possible to determine whether or not to correct at high speed and accurately.

  Next, the “first luminance unevenness / color unevenness correction process (3)” will be described. This “first luminance unevenness / color unevenness correction process (part 3)” is performed for each divided area obtained by dividing the display screen. The binarized luminance / chromaticity correction necessity (“1”: correct, “0”: do not correct) described in “.” Is assigned.

FIG. 10 is a diagram illustrating a configuration of an image correction apparatus for realizing “first luminance unevenness / color unevenness correction processing (part 3)”.
The image correction apparatus of FIG. 10 differs from the image correction apparatus of FIG. 6 used in the description of “first luminance unevenness / color unevenness correction process (2)” with respect to each divided region. Binary correction luminance / chromaticity correction necessity level for assigning “1” or “0” as the chromaticity correction necessity degree D9 (binary luminance / chromaticity correction necessity level W ′ _X , W ′ _Y , W ′ _Z ) A divided area allocating means 8 is provided.

  The binarized luminance / chromaticity correction necessity division area assigning means 8 assigns information on the binary luminance / chromaticity correction necessity “1” or “0” assigned to each divided area in FIG. The binarized luminance / chromaticity correction necessity D10 is assumed.

  In this way, the binarized luminance / chromaticity correction necessity division area assigning means 8 sets the binarized luminance / chromaticity correction necessity degree “1” (corrected) or “0” (not corrected) in each divided area. As a result of the assignment, the binarized luminance / chromaticity correction necessity level of each divided region is set to either “1” (correction) or “0” (not correction).

  Therefore, in the “first luminance unevenness / color unevenness correction process (part 3)”, the luminance / chromaticity correction means 4 applies the divided area allocation binarized luminance / chromaticity correction necessity level D10 to each divided area. Acquire the corresponding binarized luminance / chromaticity correction necessity “1” (correct) or “0” (do not correct), perform luminance / chromaticity correction processing for each pixel in each divided area, corrected Luminance / chromaticity data D7 is generated.

  FIG. 11 is a flowchart for explaining the processing procedure of “first luminance unevenness / color unevenness correction process (3)”. Steps S31 to S35 in the flowchart shown in FIG. 11 are the same as steps S11 to S15 in the flowchart shown in FIG.

In the “first luminance unevenness / color unevenness correction process (part 3)”, the binarized luminance / chromaticity correction necessary degree division region is provided after the binarization process of the luminance / chromaticity correction necessary degree (step S35). There is an assignment process (step S36) of the luminance / chromaticity correction necessity level to the divided areas by the assignment means 8. Thereby, for each divided area, the divided area allocation binarized luminance / chromaticity correction necessity D10 (this is divided into divided area allocation binarized luminance / chromaticity correction necessity W ″ _X , W ″ _Y , W “1” or “0” is assigned as “ _Z ”.
Note that steps S37 to S44 in FIG. 11 are processes corresponding to steps S16 to S23 in FIG. 7, and therefore, description thereof is omitted here.

FIG. 12 is a diagram for explaining the process of assigning the binarized luminance / chromaticity correction necessary degree divided area assigning means 8 to the divided areas. The process of assigning the binarized luminance / chromaticity correction necessity level to the divided areas is performed by dividing the divided area assignment binarized luminance / chromaticity correction necessity levels W ″ _X , W ″ _Y , W “ _Z ” is assigned “1” or “0”.

The process of assigning the binarized luminance / chromaticity correction necessity level to the divided areas is performed by obtaining a series product of the binarized luminance / chromaticity correction necessity levels in each divided area. The series product of the binarized luminance / chromaticity correction necessity in each of the divided areas is
Represented by Note that n in the equation (13) represents the size of the filter. If n = 1, the equation (13) is
It can be expressed as.

  According to this, if all the luminance and chromaticity correction necessity levels of a plurality of pixels included in a certain divided area are “1”, the number product of the divided areas is 1, and the luminance / The chromaticity correction necessity level is set as “1” (correction). In addition, if the luminance / chromaticity correction necessity level of one of the plurality of pixels included in the divided area is “0”, the sequence product of the divided area is 0, The luminance / chromaticity correction necessity level of the divided area is set to “0” (not corrected).

  12A shows an image in which the binarized luminance / chromaticity correction necessity level D9 is set, and FIG. 12B shows the setting of the divided region allocation binarized luminance / chromaticity correction necessity level D10. This shows the image when it is broken. In FIG. 12B, the white part indicates an area assigned “1” as the necessity for luminance / chromaticity correction, and the black part indicates an area assigned “0” as the degree of necessity for luminance / chromaticity correction. ing. As is clear from FIGS. 12A and 12B, the luminance / chromaticity correction for the image data to be displayed is performed by adding the process of assigning the binarized luminance / chromaticity correction necessity level to the divided areas. Processing can be greatly reduced.

[Embodiment 2]
The second embodiment describes the “second luminance unevenness / color unevenness correction process”. The “second luminance unevenness / color unevenness correction process” is roughly performed by the obtained brightness / chromaticity correction. Based on the necessity, the luminance / chromaticity correction order is set, and the luminance / chromaticity correction is performed according to the luminance / chromaticity correction order.

  Note that the luminance / chromaticity correction order can be set for each pixel using the luminance / chromaticity correction necessity calculated for each pixel. It is also possible to assign the luminance / chromaticity correction necessity level to each divided area and set the luminance / chromaticity correction processing for each divided area. In the second embodiment, an example in which the luminance / chromaticity correction necessity level is assigned to each divided area and the luminance / chromaticity correction processing is performed for each divided area will be described.

  FIG. 13 is a diagram illustrating a configuration of an image correction apparatus for realizing the luminance unevenness / color unevenness correction process of the second embodiment, that is, the “second luminance unevenness / color unevenness correction process”.

  In FIG. 13, the same components as those of the image correction apparatus (for example, the image correction apparatus shown in FIG. 1) used in the description of the first embodiment are denoted by the same reference numerals. In the image correction apparatus shown in FIG. 13, the luminance / chromaticity correction necessity degree division area assigning means 11 assigns the luminance / chromaticity correction necessity degree D4 calculated by the luminance / chromaticity correction necessity degree calculation means 3 to each divided area. And a luminance / chromaticity correction order D13 for setting the luminance / chromaticity correction order D13 based on the luminance / chromaticity correction necessity D12 (divided region allocation luminance / chromaticity correction necessity D12) for each divided region assigned to each divided region. A chromaticity correction order setting unit 12 is provided. Then, the luminance / chromaticity correction means 4 performs luminance / chromaticity correction based on the luminance / chromaticity correction order D13 set by the luminance / chromaticity correction order setting means 12.

  Note that the representative values of the luminance / chromaticity correction necessity of each divided area are used for assigning the luminance / chromaticity correction necessity to the divided areas. As this representative value, for example, any one of the minimum value, the maximum value, the average value, the median value, and the like of the luminance / chromaticity correction necessity calculated for each pixel can be used.

  FIG. 14 is a flowchart for explaining a processing procedure of luminance unevenness / color unevenness correction processing, that is, “second luminance unevenness / color unevenness correction processing” in the second embodiment. The processes in step S51, step S52, and step S53 in FIG. 14 are the same as steps S11, S12, and S13 in FIG.

In FIG. 14, when the luminance / chromaticity correction necessity levels W _X , W _Y , W _Z are calculated in step S53, the luminance / chromaticity correction necessity levels W _X , W _Y , W _Z are used to calculate the luminance / chromaticity correction degrees W _X , W _Y , W _Z. The degree of chromaticity correction necessity is assigned to the divided areas (step S54). Next, the luminance / chromaticity correction order setting unit 12 sets the luminance / chromaticity correction order (step S55), and thereby the luminance / chromaticity correction order D13 (which is referred to as the luminance / chromaticity correction order S _X , S _Y and S _Z ) are set.

  FIG. 15 is a diagram for explaining setting of the luminance / chromaticity correction order performed by the luminance / chromaticity correction order setting means 12. As shown in FIG. 15, the luminance / chromaticity correction order setting unit 12 determines the luminance / chromaticity correction necessary degree D4 of each pixel or the divided area allocation luminance / chromaticity correction of each divided area as a pixel or a divided area of the display image. The brightness / chromaticity correction order D13 is set by rearranging the necessary degree D12 in descending order.

  As described above, in the example of the second embodiment, the luminance / chromaticity correction order is set for each divided region. However, FIG. 15, FIG. 16, FIG. 17, and FIG. 18 shows an example in which the luminance / chromaticity correction order is set for each divided region or pixel.

  FIG. 16 is a diagram for explaining a specific example of luminance / chromaticity correction order setting in 2 × 2 pixels or 2 × 2 divided regions of a display image. FIG. 16A shows the luminance / chromaticity correction necessity calculated for each 2 × 2 pixel or each 2 × 2 divided region, and the pixel number k of each pixel or each divided region is shown. The luminance / chromaticity correction necessity is calculated corresponding to the region number k (k = 1, 2, 3, 4). FIG. 16B shows the contents shown in FIG. 16A sorted so that the luminance / chromaticity correction needs are in descending order.

That is, in FIG. 16A, the number of the pixel or divided region having the highest luminance / chromaticity correction necessity (luminance / chromaticity correction necessity 0.4) is k = 3, and the second highest luminance. The number of pixels or divided regions having the chromaticity correction necessity (luminance / chromaticity correction necessity 0.3) is k = 2, and the third highest luminance / chromaticity correction necessity (luminance / chromaticity correction) The number of the pixel or divided region having the necessity 0.2) is k = 1, and the number of the pixel or divided region having the lowest luminance / chromaticity correction necessity (luminance / chromaticity correction necessity 0.1) is k. = 4.
When this is sorted so that the luminance / chromaticity correction necessity is in descending order, the result is as shown in FIG. 16B. As the luminance / chromaticity correction order, the pixel or divided region numbers k = 3 and k = 2. , K = 1, k = 4.

  FIG. 17 and FIG. 18 are diagrams for explaining two examples of the sorting method of luminance / chromaticity correction necessity level. FIG. 17 shows “Brightness / chromaticity correction necessity sorting method (Part 1)” and FIG. “Solution method of luminance / chromaticity correction necessity (part 2)”. In FIGS. 17 and 18, it is assumed that the pixels or divided regions to be sorted are eight pixels or divided regions with k = 1 to 8.

  The “sorting method for luminance / chromaticity correction necessity (part 1)” shown in FIG. 17 is an example of a sorting method by merge sort. As can be seen from FIG. 17, in this sorting method, a plurality of pixels or divided areas (in this example, pixels or divided areas of k = 1 to 8) to be sorted are recursively divided and merged again. In this way, the sorted arrangement is arranged in the descending order of the luminance / chromaticity correction necessity. In this example, the luminance / chromaticity correction order is the order of pixels or divided areas of k = 3, 6, 1, 2, 7, 4, 5, 8 as shown in the figure.

  FIG. 18 is a diagram for explaining a bucket-sorting sorting method as “sorting method for luminance / chromaticity correction necessity (part 2)”. This bucket-like sorting method is a bucket prepared in advance in order. The data is rearranged by throwing the data into the box.

  For example, the brightness / chromaticity correction necessity W is divided into three ranges (0.7 ≦ W ≦ 1.0, 0.3 ≦ W <0.7, 0.0 ≦ W <0.3), and buckets BK1, BK2, and BK3 are prepared for each range. Then, the pixels or divided areas having the luminance / chromaticity correction necessity corresponding to the range of the luminance / chromaticity correction necessity of the buckets BK1, BK2, BK3 are thrown into the corresponding buckets.

  Although this bucket-like sorting method does not necessarily have all the luminance / chromaticity correction necessity in an descending order, the luminance / chromaticity correction necessity contained in the bucket BK1 is the luminance contained in the bucket BK2. The luminance / chromaticity correction necessity higher than the chromaticity correction necessity and entered into the bucket BK2 is higher than the luminance / chromaticity correction necessity contained in the bucket BK3. Pixels or divided areas having the necessity for correction are not sorted in high order. As described above, the bucket sort-like sort method is an approximate sort method, but has an advantage of enabling high-speed processing.

  By the sorting method as described above, it is possible to arrange pixels or divided regions having a high necessity for luminance / chromaticity correction at positions having a high priority for luminance / chromaticity correction processing. When the luminance / chromaticity correction order is set in this manner, correction processing based on the luminance / chromaticity correction order is performed.

That is, in the flowchart of FIG. 14, first, luminance / chromaticity data X, Y, and Z for one screen (one frame) are acquired (step S56) and set by the luminance / chromaticity correction order setting means 12. The luminance / chromaticity correction order S _X , S _Y , S _Z for one screen is acquired (step S57). Then, according to the acquired luminance / chromaticity correction sequence for one screen, luminance / chromaticity correction processing is performed for a certain pixel (a pixel of interest) (step S58), and the luminance / chromaticity correction processing for the pixel of interest is performed. The corrected luminance / chromaticity is converted into image data and transferred to the pixels of the display device (step S59).

  Subsequently, it is determined whether or not an allowable correction processing amount has been reached (step S60). If the allowable correction processing amount has not been reached, the process returns to step S58, and the next pixel is set as a pixel of interest, and Correction processing is performed on the pixel of interest.

  Such processing is performed until the allowable correction processing amount is reached, and when the allowable correction processing amount is reached, if pixels still remain, correction processing for those pixels is omitted. Then, the luminance / chromaticity data relating to the pixels for which the luminance / chromaticity correction is omitted is converted into image data and transferred to the pixels of the display device (step S61).

  The allowable correction processing amount represents the number of correctable pixels, for example, up to how many pixels are to be corrected in the pixels for one screen. The number of pixels that can provide an effect is set in advance in consideration of the amount of correction processing.

  In the second embodiment, correction processing is performed in descending order of necessity of luminance / chromaticity correction based on the set luminance / chromaticity correction order, so that the luminance / chromaticity correction processing is temporarily omitted. Even if there is a pixel, the necessity for correcting the luminance and chromaticity of the pixel is not so high. Therefore, the influence on the image quality due to the omission of the luminance / chromaticity correction processing is extremely small.

  As described above, in the second embodiment, the luminance / chromaticity correction order is set for each pixel or each divided region, and correction is performed in the set luminance / chromaticity correction order. High pixel and divided areas can be preferentially corrected, and more effective correction is possible. Further, since the luminance and chromaticity correction is performed until the allowable correction processing amount is reached and the subsequent correction processing is omitted, the correction processing amount can be suppressed.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in each of the above-described embodiments, the example in which the calculation of the spatial change amount, the calculation of the necessity of correction, and the luminance / chromaticity correction processing are performed for each pixel has been described. However, these processing are performed for each divided region. Is also possible.
Further, in each of the above-described embodiments, the brightness / chromaticity correction processing is only a setting of whether or not to perform correction based on the luminance / chromaticity correction necessity level, and what kind of correction and how much correction is performed. Although the contents of correction are not mentioned, it is also possible to set the contents of correction.

  Further, the present invention may create an image correction program in which the processing procedure for realizing the present invention described above is described, and record the image correction program on a recording medium such as a floppy disk, an optical disk, or a hard disk. it can. Therefore, the present invention includes a recording medium on which the image correction program is recorded. Further, the image correction program may be obtained from the network.

FIG. 3 is a diagram illustrating a configuration of an image correction apparatus for realizing “first luminance unevenness / color unevenness correction processing (part 1)” according to the first embodiment of the present invention. 9 is a flowchart for explaining a processing procedure of “first luminance unevenness / color unevenness correction processing (part 1)”. FIG. 4 is a diagram illustrating luminance / chromaticity data X _{i, j} , Y _{i, j} , Z _{i, j of} pixels of interest _{i, j} and surrounding pixels. The figure which shows the relationship between the brightness | luminance and chromaticity correction | amendment necessity of the pixel to be paid with respect to the spatial variation | change_quantity of luminance and chromaticity. The figure explaining the specific example of the brightness | luminance and chromaticity spatial change amount in a certain image, and the brightness | luminance and chromaticity correction necessity based on it. FIG. 3 is a diagram illustrating a configuration of an image correction apparatus for realizing “first luminance unevenness / color unevenness correction processing (part 2)” according to the first embodiment of the present invention. 9 is a flowchart for explaining a processing procedure of “first luminance unevenness / color unevenness correction processing (part 1)”. Binarization threshold _{W MX, W MY, W} setting method with be described figure _MZ. Binarization threshold _{W MX, W MY,} diagram illustrating the binarization of luminance and chromaticity correction necessity with _{W MZ.} The figure which shows the structure of the image correction apparatus for implement | achieving "the 1st brightness | luminance nonuniformity / color nonuniformity correction process (the 3)" in Embodiment 1 of this invention. 9 is a flowchart for explaining a processing procedure of “first luminance unevenness / color unevenness correction processing (part 3)”. The figure explaining the allocation process to the division | segmentation area | region of the binarization brightness | luminance and chromaticity correction necessity. FIG. 9 is a diagram illustrating a configuration of an image correction apparatus for realizing luminance unevenness / color unevenness correction processing (“second luminance unevenness / color unevenness correction processing”) according to the second embodiment. 9 is a flowchart for explaining a processing procedure of luminance unevenness / color unevenness correction processing (“second luminance unevenness / color unevenness correction processing”) according to the second embodiment. The figure explaining the setting of the brightness | luminance and chromaticity correction | amendment order which a brightness | luminance and chromaticity correction necessity setting means performs. The figure explaining the specific example of the brightness | luminance and chromaticity correction | amendment order setting in a 2 * 2 pixel or 2 * 2 division area of a display screen. The figure explaining the sort method (the 1) of a brightness | luminance and chromaticity correction necessity degree. The figure explaining the sorting method (the 2) of luminance and chromaticity correction necessity.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Luminance / chromaticity calculation means, 2 ... Luminance / chromaticity space change amount calculation means, 3 ... Luminance / chromaticity correction necessity calculation means, 4 ... Luminance / chromaticity correction means, 5 ... Luminance / chromaticity data / image data conversion means, 6 ... Luminance / chromaticity correction necessity threshold setting means, 7 ... Luminance / chromaticity correction necessity binarization means, 8 ... Binary luminance / chromaticity correction necessity division area assigning means, 11... Luminance / chromaticity correction necessity divided area assignment means, 12... Luminance / chromaticity correction order setting means.

Claims (14)

An image correction method capable of correcting luminance unevenness and / or color unevenness occurring in a display image,
Calculating a spatial change amount of luminance and / or chromaticity of each pixel of the display image or each divided region obtained by dividing the display image;
Calculating a luminance and / or chromaticity correction necessity for each pixel or each divided region based on the calculated luminance and / or chromaticity spatial change amount;
Correcting the luminance and / or chromaticity based on the necessity of correcting the luminance and / or chromaticity;
An image correction method comprising: The image correction method according to claim 1,
An image correction method characterized in that the luminance is a luminance component or a brightness component in a color system taking into account three attributes of color. The image correction method according to claim 1 or 2,
An image correction method characterized in that the chromaticity is a hue component, a saturation component, or a color difference component in a color system that takes into account three attributes of color. The image correction method according to any one of claims 1 to 3,
The luminance correction necessity level is modeled so as to be negatively correlated with the magnitude of the luminance spatial change amount, and the chromaticity correction necessity level is determined by the spatial change amount of the chromaticity. An image correction method characterized by being modeled so as to have a negative correlation with the magnitude. The image correction method according to any one of claims 1 to 4,
An image correction method comprising: setting a threshold value for each of the luminance and / or chromaticity correction necessity levels, and determining whether to perform correction based on the threshold value. The image correction method according to claim 5,
The image correction method according to claim 1, wherein the luminance and / or chromaticity correction necessity level is expressed as binary information indicating whether or not to correct based on the respective threshold values. The image correction method according to claim 6,
An image correction method, wherein the luminance and / or chromaticity correction necessity level for the divided area is set to any one of binary information indicating whether or not the correction is performed in each divided area. An image correction method capable of correcting luminance unevenness and / or color unevenness occurring in a display image,
Calculating a spatial change amount of luminance and / or chromaticity of each pixel of the display image or each divided region obtained by dividing the display image;
Calculating a luminance and / or chromaticity correction necessity for each pixel or each divided region based on the calculated luminance and / or chromaticity spatial change amount;
Setting a correction order of luminance and / or chromaticity for each pixel or the divided region based on the necessity for correcting the luminance and / or chromaticity;
Correcting the luminance and / or chromaticity based on the correction order of the luminance and / or chromaticity;
An image correction method comprising: The image correction method according to claim 8,
The correction order of the luminance and / or chromaticity is set in the order of the necessity of correction of luminance and / or chromaticity, and the correction of the luminance and / or chromaticity is the necessity of correction of the luminance and / or chromaticity. An image correction method comprising performing processing from a pixel or a divided region having a higher order to a pixel or a divided region having a predetermined order in order. An image correction apparatus capable of correcting luminance unevenness and / or color unevenness generated in a display image,
A spatial change amount calculating means for calculating a spatial change amount of luminance and / or chromaticity of each pixel of the display image or each divided region obtained by dividing the display image;
Correction necessity calculation means for calculating a correction necessity degree of luminance and / or chromaticity for each pixel or the divided region based on the calculated spatial change amount of luminance and / or chromaticity;
Correction means for correcting the luminance and / or chromaticity based on the necessity for correcting the luminance and / or chromaticity;
An image correction apparatus comprising: An image correction apparatus capable of correcting luminance unevenness and / or color unevenness generated in a display image,
A spatial change amount calculating means for calculating a spatial change amount of luminance and / or chromaticity of each pixel of the display image or each divided region obtained by dividing the display image;
Correction necessity calculation means for calculating a correction necessity degree of luminance and / or chromaticity for each pixel or the divided region based on the calculated spatial change amount of luminance and / or chromaticity;
Correction order setting means for setting a correction order of luminance and / or chromaticity for each pixel or the divided region based on the degree of necessity of correction of the luminance and / or chromaticity;
Correction means for correcting the luminance and / or chromaticity based on the correction order of the luminance and / or chromaticity;
An image correction apparatus comprising: A projection-type image display device including an image correction device capable of correcting luminance unevenness and / or color unevenness generated in a display image,
A projection-type image display apparatus comprising the image correction apparatus according to claim 10 or 11 as the image correction apparatus. An image correction program capable of correcting luminance unevenness and / or color unevenness occurring in a display image,
Calculating a spatial change amount of luminance and / or chromaticity of each pixel of the display image or each divided region obtained by dividing the display image;
Calculating a luminance and / or chromaticity correction necessity for each pixel or each divided region based on the calculated luminance and / or chromaticity spatial change amount;
Correcting the luminance and / or chromaticity based on the necessity of correcting the luminance and / or chromaticity;
An image correction program characterized by comprising: An image correction program capable of correcting luminance unevenness and / or color unevenness occurring in a display image,
Calculating a spatial change amount of luminance and / or chromaticity of each pixel of the display image or each divided region obtained by dividing the display image;
Calculating a luminance and / or chromaticity correction necessity for each pixel or each divided region based on the calculated luminance and / or chromaticity spatial change amount;
Setting a correction order of luminance and / or chromaticity for each pixel or the divided region based on the necessity for correcting the luminance and / or chromaticity;
Correcting the luminance and / or chromaticity based on the correction order of the luminance and / or chromaticity;
An image correction program characterized by comprising: