JP4241813B2 - Coefficient data generation apparatus, coefficient data generation method, program for executing the method, and computer-readable medium storing the program - Google Patents

Description

  The present invention relates to a coefficient data generation device, a coefficient data generation method, a program for executing the method, and a computer-readable medium storing the program.

  Specifically, the present invention obtains a student signal corresponding to the first image signal by subjecting the teacher signal corresponding to the second image signal to image quality deterioration processing based on the class information indicating the stage of image quality deterioration. By generating coefficient data based on this student signal and the like, the first image signal to be inputted is converted into the second image signal, so that the present image quality deterioration of the display can be appropriately corrected. The present invention relates to an image display device or the like that improves the quality of an image displayed on the display when the display is deteriorated with time.

  Conventionally, the image quality of the display is adjusted at the time of shipment from the factory, but the user can also adjust the brightness, hue, and the like with a GUI (Graphical User Interface) or the like of the display control unit.

  In a display such as an LCD, the image quality deteriorates as compared with the time of shipment from the factory due to the deterioration of the display device over time. At that time, the user can adjust so as to correct the image quality deterioration using the GUI of the display control unit described above. If the adjustment for correcting the image quality deterioration is automatically performed, it is convenient for the user.

  Therefore, in a display such as an LCD, in order to suppress deterioration in image quality due to deterioration of the display device over time, a predetermined signal is directly collected from an element on the display device, and the display control unit uses this predetermined signal to obtain image quality. Various proposals such as correction of deterioration have been made.

  As described above, when a predetermined signal is acquired from an element on the display device of the display to correct image quality deterioration, a predetermined measurement image is displayed on the display when the predetermined signal is acquired. It is necessary to collect the predetermined signal at predetermined time intervals.

  In this case, depending on the elapsed time after collecting the predetermined signal, the deterioration of the display device with time progresses further. In that case, image quality deterioration cannot be corrected appropriately depending on the collected predetermined signal, and it is impossible to improve the quality of the image displayed on the display.

  An object of the present invention is to obtain a second image signal capable of appropriately correcting the current image quality deterioration of the display, and to improve the quality of an image displayed on the display when the display deteriorates with time. There is.

A coefficient data generation device according to the present invention generates coefficient data used in an estimation formula used when converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data. An input unit to which a teacher signal corresponding to the second image signal is input, and the teacher signal input to the input unit is subjected to image quality deterioration processing based on class information indicating a stage of image quality deterioration. And a signal processing means for obtaining a student signal corresponding to the first image signal, and a plurality of first pixel data located around the position of interest in the teacher signal based on the student signal output from the signal processing means. a first data selection means for selecting a second based on the student signal output from the signal processing means, for selecting a plurality of second pixel data located around the target position in the teacher signal Based on the data selection means, a plurality of second pixel data selected by the second data selection means, a class detection means for detecting the class to which the pixel data at the target position belongs, and detected by the class detection means Class generation means for generating new class information by combining the class information and the class information indicating the stage of image quality degradation, the new class information generated by the class generation means, and the first data selection means. Using the plurality of first pixel data and the pixel data of the target position in the teacher signal, a calculation means for obtaining coefficient data for each class is provided.

The coefficient data generation method according to the present invention is a coefficient data used in an estimation formula used when converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data. In order to generate the image signal, the first step of inputting a teacher signal corresponding to the second image signal, and the teacher signal input in the first step are converted into image quality based on class information indicating the stage of image quality degradation. A second step of performing a deterioration process to obtain a student signal corresponding to the first image signal, and a plurality of positions located around the target position in the teacher signal based on the student signal obtained in the second step a third step of selecting a first pixel data, based on the student signal obtained in this second step, the selecting a plurality of second pixel data located around the target position in the teacher signal , A fifth step for detecting a class to which the pixel data at the target position belongs based on the plurality of second pixel data selected in the fourth step, and a detection in the fifth step. Sixth step of generating new class information by combining class information and class information indicating the stage of image quality deterioration, and new class information generated in the sixth step, selected in the third step And a seventh step of obtaining the coefficient data for each class using the plurality of first pixel data and the pixel data of the target position in the teacher signal.

  A program according to the present invention is for causing a computer to execute the above-described image signal processing method. A computer-readable medium according to the present invention records the above-described program.

  In the present invention, a teacher signal corresponding to the second image signal is input. The teacher signal is subjected to image quality deterioration processing based on class information indicating the stage of image quality deterioration, and a student signal corresponding to the first image signal is obtained.

  Based on this student signal, a plurality of pixel data located around the target position in the teacher signal are selected. The class information indicating the stage of image quality deterioration is sequentially changed, and coefficient data is generated for each class using the selected pixel data, the class information indicating the image quality deterioration, and the pixel data of the target position in the teacher signal. Is required.

  By using the coefficient data of each class thus obtained, it is possible to obtain a second image signal that can appropriately correct the current image quality degradation of the display from the first image signal.

  According to the present invention, the current image quality deterioration information is obtained based on the feature amount corresponding to the image quality of the measurement image detected by displaying the measurement image on a display at a plurality of past points in time, and the image quality deterioration information is obtained. Based on this, the input first image signal is converted into a second image signal, and a second image signal that can appropriately correct the current image quality deterioration of the display can be obtained. When degradation occurs, the quality of the image displayed on the display can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of an image display apparatus 100 as an embodiment. The image display apparatus 100 includes a microcomputer, and includes a control unit 101 for controlling the operation of the entire apparatus, and a remote control signal receiving circuit 102 that receives a remote control signal. The remote control signal receiving circuit 102 is connected to the control unit 101, receives, for example, an infrared remote control signal output in response to a user operation from the remote control transmitter 200, and sends an operation signal corresponding to the remote control signal to the control unit. 101 is provided.

  Further, the image display apparatus 100 uses the input terminal 103 to which red, green, and blue color signals Ri, Gi, Bi as input image signals are input, and these color signals Ri, Gi, Bi as output image signals. And a signal processing unit 104 that converts and outputs red, green, and blue color signals Ro, Go, and Bo.

  The image display apparatus 100 also includes a display 105 and a display control unit 106 that causes the display 105 to display images based on the color signals Ro, Go, and Bo output from the signal processing unit 104 in the normal mode. The display control unit 106 displays the measurement image on the display 105 in the measurement mode. In the present embodiment, 24 single-color images constituting a Gretag Macbeth Color Checker are sequentially displayed. The color signal for displaying the monochromatic image is generated based on data stored in advance in a memory (not shown) in the control unit 101, for example.

In the present embodiment, as described above, L ^* a ^* as a feature amount corresponding to the image quality of the measurement image is displayed by the remote control transmitter 200 while the measurement image is displayed on the display 105 as the measurement mode ^. A b ^* signal is detected. Details of the remote control transmitter 200 will be described later. In this case, the L ^* a ^* b ^* signal is detected corresponding to each pixel of the display device of the display 105 for each single-color image and for each single-color image.

The above-described detection of the L ^* a ^* b ^* signal by the remote control transmitter 200 is performed at a time immediately after purchase of the device and at a time after each predetermined operating time. In this case, detection at each time point needs to be performed in the same optical environment. For example, it is performed at night with the room light turned off.

In addition, the image display apparatus 100 receives the L ^* a ^* b ^* signal at each time point detected by the remote control transmitter 200 and wirelessly transmitted as described above, via the reception antenna 107, and the reception unit 108. It has a memory 109 for storing L ^* a ^* b ^* signals at each time point received by the receiving unit 108, and a W / R control circuit 110 that controls writing and reading of the memory 109.

When the L ^* a ^* b ^* signal at each time point received by the receiving unit 108 is stored in the memory 109, the display output from the operating time calculation unit 162 present in a degradation information output circuit 154 (described later) of the signal processing unit 104 The data of the operation accumulated time TM of 105 is stored as a pair with the L ^* a ^* b ^* signal. Thereby, it becomes possible to know which operation accumulated time each L ^* a ^* b ^* signal at each time point corresponds to. Thus, the L ^* a ^* b ^* signals at each time stored in the memory 109 are supplied to the signal processing unit 104. The signal processing unit 104 performs signal conversion processing based on the L ^* a ^* b ^* signals at each time point.

  Here, details of the remote control transmitter 200 will be described. FIG. 2 shows the configuration of the remote control transmitter 200. The remote control transmitter 200 includes a central processing unit (CPU) 201 that controls the entire operation, a read only memory (ROM) 202 that stores an operation program of the CPU 201, and a RAM ( random access memory) 203. The CPU 201, ROM 202, and RAM 203 are each connected to a bus 204.

  The remote control transmitter 200 also has a key operation unit 205 as a user interface unit. The key operation unit 205 is connected to the bus 204 via the interface 206. Similarly, the remote control transmitter 200 has a display 207 as a user interface unit. This display 207 is connected to the bus 204 via an interface 208. The display 207 is composed of an LCD or the like.

  The remote control transmitter 200 has a remote control signal transmission circuit 209 that transmits, for example, an infrared remote control signal. The transmission circuit 209 is connected to the bus 204 via the interface 210.

Further, the remote control transmitter 200 captures an image for measurement displayed on the display 105, and 3 of the XYX coordinate system corresponding to each pixel of the display device of the display 105 output from the imaging unit 211. And a signal processing unit 212 that converts the stimulus value XYZ into an L ^* a ^* b ^* signal in a CIE1967 (L ^* a ^* b ^* ) space.

  The imaging unit 211 is configured using, for example, a CCD solid-state imaging device as an imaging device. The imaging signals (red, green, and blue color signals) obtained by the imaging unit 211 are supplied to the display unit 207, and the captured image is displayed on the display unit 207. An image frame is provided on the screen of the display 207, and imaging is performed so that the measurement image displayed on the display 105 matches the image frame, whereby each pixel of the display device of the display 105 and each of the image sensor A pixel can be associated. Thereby, as described above, it is possible to obtain the tristimulus values XYZ in the XYX coordinate system corresponding to each pixel of the display device of the display 105 from the imaging unit 211.

The signal processing unit 212 is connected to the bus 204 via the interface 213. The L ^* a ^* b ^* signal corresponding to each pixel of the display 105 obtained by the signal processing unit 212 is temporarily stored in the RAM 203 via the interface 213.

The remote control transmitter 200 also has a transmission unit 215 for wirelessly transmitting the L ^* a ^* b ^* signal temporarily stored in the RAM 203 via the transmission antenna 214. The transmission unit 215 is connected to the bus 204 via the interface 216.

  The operation of the remote control transmitter 200 shown in FIG. 2 will be described. First, the operation for transmitting a remote control signal will be described. In this case, when the user performs a key operation for causing the image display apparatus 100 to perform a predetermined operation using the key operation unit 205, the CPU 201 controls the remote control signal transmission circuit 209 via the interface 210 in accordance with the operation. Data is sent. As a result, a remote control signal corresponding to the operation is output from the remote control signal transmission circuit 209.

Next, an operation when a measurement image displayed on the display 105 is captured and an L ^* a ^* b ^* signal corresponding to each pixel of the display device of the display 105 is transmitted to the image display device 100 will be described.

  When the user performs an imaging preparation operation using the key operation unit 205, the CPU 201 puts the imaging unit 211 and the signal processing unit 212 into an operation state via the interface 213. At this time, since the captured image is displayed on the display device 207, the user can adjust the measurement image displayed on the display 105 to match the image frame provided on the display device 207.

After the adjustment, when the user performs an imaging operation with the key operation unit 205, the L ^* a ^* b ^* signal corresponding to each pixel of the display device of the display 105 obtained from the signal processing unit 212 at the operation timing is the interface 213. Are temporarily stored in the RAM 203. Thereafter, the L ^* a ^* b ^* signal is read from the RAM 203, supplied to the transmission unit 215 through the interface 216, and transmitted from the transmission unit 215 to the image display apparatus 100 via the transmission antenna 214.

  Next, the signal processing unit 104 will be further described. FIG. 3 shows the configuration of the signal processing unit 104. The signal processing unit 104 uses the input terminal 141 to which the red, green, and blue color signals Ri, Gi, and Bi are input and the color signals Ri, Gi, and Bi to the image quality deterioration due to the temporal deterioration of the display 105 described above. And a signal processing circuit 142 that converts and outputs red, green, and blue color signals Rop, Gop, and Bop to be compensated.

  Further, the signal processing unit 104 converts the scanning line structure of the color signals Rop, Gop, and Bop output from the signal processing circuit 142 into one corresponding to the display structure of the display 105, and this scanning. A gamma correction circuit 144 that performs gamma correction in accordance with the gradation characteristics of the display 105 for the red, green, and blue color signals output from the line conversion circuit 143, and the red, green that is output from the gamma correction circuit 144 And an output terminal 145 for outputting blue color signals Ro, Go, Bo. In the scanning line conversion circuit 143, for example, conversion from an interlace method to a progressive method is performed.

  Details of the signal processing circuit 142 will be described. The signal processing circuit 142 individually processes the color signals Ri, Gi, Bi to obtain the color signals Rop, Gop, Bop, respectively. In the following, only the processing system for obtaining the red color signal Rop from the red color signal Ri will be described in order to avoid complicated description. However, in practice, processing for obtaining the green color signal Gop from the green color signal Gi and processing for obtaining the blue color signal Bop from the blue color signal Bi are performed in parallel by the same processing system.

  The signal processing circuit 142 includes first and second tap selection circuits 151 and 152 that selectively extract and output a plurality of pixel data located around the target position in the color signal Rop based on the color signal Ri. is doing. The first tap selection circuit 151 selectively extracts a plurality of pixel data of prediction taps used for prediction. The second tap selection circuit 152 selectively extracts a plurality of pixel data of class taps used for class classification. Here, the periphery of the target position means a position that is spatially (horizontal and vertical) and temporal (frame direction) close to the target position.

  FIG. 4A shows an example of the arrangement of prediction taps, and FIG. 4B shows an example of the arrangement of class taps. 4A and 4B, “◯” indicates the position of the tap, and “X” indicates the position of interest. In the present embodiment, seven pixel data in the current field (shown by a solid line) and the previous field (shown by a broken line) are extracted as pixel data of a prediction tap, and the current field (shown by a solid line) and the previous field (shown by a broken line). 13 pixel data are extracted as pixel data of the class tap.

  The signal processing circuit 142 includes a space class information generation circuit 153 that generates space class information from the pixel data of the class tap selectively extracted by the second tap selection circuit 152. The space class information generation circuit 153 generates an ADRC code as space class information by performing processing such as 1-bit ADRC (Adaptive Dynamic Range Coding) on each of the plurality of pixel data of the class tap.

  ADRC calculates the maximum value and minimum value of a plurality of pixel data of a class tap, calculates a dynamic range that is the difference between the maximum value and the minimum value, and requantizes each pixel value in accordance with the dynamic range. . In the case of 1-bit ADRC, the pixel value is converted to 1 bit depending on whether it is larger or smaller than the average value of the plurality of pixel values of the class tap. The ADRC process is a process for making the number of classes representing the level distribution of pixel values relatively small. Therefore, not only ADRC but encoding which compresses the bit number of pixel values, such as VQ (vector quantization), may be used.

  In addition, the signal processing circuit 142 includes a deterioration information output circuit 154. FIG. 5 shows the configuration of the deterioration information output circuit 154. The deterioration information output circuit 154 includes an operation time counter 161, an operation time calculation unit 162, and a deterioration information output unit 163.

  The operating time counter 161 performs a count-up operation based on a count clock (not shown) while the display 105 is operating. The count value of the operation time counter 161 corresponds to the accumulated operation time of the display 105. Based on the count value of the operation time counter 161, the operation time calculation unit 162 obtains an operation accumulation time TM that is an operation accumulation time of the display 105. The data of the operation accumulated time TM is supplied to the deterioration feature amount output unit 163 and also supplied to the memory 109 as described above.

In the memory 109 (see the figure), L ^* detected corresponding to each pixel of the display device of the display 105 for each of the 24 color images as the measurement images displayed on the display 105 at a plurality of times ^. The a ^* b ^* signal is stored in pairs with the data of the operation accumulation time TM at each time point. In the deterioration information output unit 163 of the deterioration information output circuit 154, for example, every time the L ^* a ^* b ^* signal at a new time is stored in the memory 109, the L ^* a at each time stored in the memory 109 is stored. ^{A *} b ^* signal is supplied along with data of the operation accumulated time TM.

Degradation information output unit 163, when the L ^* a ^* b ^* signal at each time point from the memory 109 is supplied, for each 24-color monochromatic image, corresponding to each pixel of the display device of the display 105, L ^*, For each of a ^* and b ^* , a calculation formula (for example, a cubic formula) having an operation cumulative time TM as a parameter for obtaining a change amount based on the time immediately after purchase is generated, and the information is stored in the internal memory. Store it. In this case, the coefficient of the calculation formula is determined by, for example, the least square method from the relationship between the accumulated operation time at each time point and the amount of change in L ^* , a ^* , and b ^* .

For example, FIG. 6 shows an example of the relationship between the operation cumulative time TM and the amount of change in L ^* . Time t ₀ indicates a detection time immediately after purchase, and L ^* = L ₀ . Time points t _i and t _{i + 1} indicate subsequent detection time points, and L ^* = L _i and L ^* = L _{i + 1} , respectively. Therefore, the amount of change in time t _i is [Delta] L _i, the variation in time t _{i + 1} was ΔL i _{+ 1.} The above-described calculation formula is obtained based on the amount of change at each time point, and has the operation accumulated time TM as a parameter. Therefore, it is possible to obtain the change amount ΔL _n at the present time (accumulated operation time t _n ) by the calculation formula. The same applies to a ^* and b ^* , and the current changes Δa _n and Δb _n can be obtained by the calculation formula obtained as described above.

Further, the deterioration information output unit 163 uses a calculation formula for the amount of change in L ^* , a ^* , and b ^* in each of the 24-color monochrome images for the pixel corresponding to the target position in the color signal Rop to be created. , the amount of change [Delta] L _n of the current (operating accumulated time t _n) in the pixel portion corresponding to the target position, generates .DELTA.a _n, [Delta] b _n, and outputs the image quality deterioration information in the pixel portion corresponding to the target position described above.

  Returning to FIG. 3, the signal processing circuit 142 also includes a degradation class information generation circuit 155 for generating degradation class information. The degradation class information generation circuit 155 is based on the image quality degradation information in the pixel portion corresponding to the target position in the color signal Rop to be generated, which is output from the degradation information output circuit 154. Is generated. In this case, the image quality deterioration information may be used as it is as the deterioration class information, or the number of bits indicating the amount of change constituting the image quality deterioration information may be used after being compressed by ADRC processing.

  Further, the signal processing circuit 142 generates a class code CL indicating the result of class classification based on the space class information generated by the space class information generation circuit 153 and the deterioration class information generated by the deterioration class information generation circuit 155. A class code generation circuit 156 that performs the processing. The class code CL indicates a class to which the pixel data y at the target position in the color signal Rop belongs.

  The signal processing circuit 142 has a coefficient memory 157. The coefficient memory 157 stores, for each class, a plurality of coefficient data Wi (i = 1 to n) used in an estimation formula used in an estimation prediction calculation circuit 158 described later. The coefficient data Wi is information for converting the color signal Ri into the color signal Rop. The class code CL output from the above-described class code generation circuit 156 is supplied to the coefficient memory 157 as read address information. From this coefficient memory 157, the coefficient data Wi of the estimation formula corresponding to the class code CL is read and supplied to the estimated prediction calculation circuit 158. A method for generating the coefficient data Wi will be described later.

  Further, the signal processing circuit 142 uses the plurality of pixel data xi of the prediction tap selectively extracted by the first tap selection circuit 151 and the coefficient data Wi read from the coefficient memory 157 in the color signal Rop to be generated. An estimated prediction calculation circuit 158 that calculates pixel data y of the target position is provided.

  The estimated prediction calculation circuit 158 is supplied with a plurality of pixel data xi of the prediction tap corresponding to the target position from the first tap selection circuit 151, and coefficient data Wi corresponding to the target position from the coefficient memory 157, The pixel data y at the target position is calculated using the estimation formula (1).

  Next, the operation of the signal processing circuit 142 will be described. From the color signal Ri input to the input terminal 141, the second tap selection circuit 152 selectively extracts a plurality of pixel data of class taps located around the target position in the color signal Rop to be created. The plurality of pixel data of the class tap is supplied to the space class information generation circuit 153. In this space class information generation circuit 153, processing such as 1-bit ADRC is performed on the pixel data of the class tap to generate space class information.

Further, the deterioration information output circuit 154 outputs image quality deterioration information in the pixel portion corresponding to the target position in the color signal Rop to be created. The image quality deterioration information, in pixel portions corresponding to the target position, for each of the 24 colors of the monochrome images L ^*, a ^*, b ^* of the variation of the current (operating time _{t n) ΔL n, Δa n} , Δb _n . The image quality deterioration information is supplied to the deterioration class information generation circuit 155. The deterioration class information generation circuit 155 generates deterioration class information based on the image quality deterioration information.

  Then, the space class information generated by the space class information generation circuit 153 and the deterioration class information generated by the deterioration class information generation circuit 155 are supplied to the class code generation circuit 156. The class code generation circuit 156 generates a class code CL indicating the result of class classification based on the space class information and the degradation class information.

  This class code CL represents the detection result of the class to which the pixel data at the target position in the color signal Rop to be created belongs. This class code CL is supplied to the coefficient memory 157 as read address information.

  Further, based on the color signal Ri inputted to the input terminal 141, the first tap selection circuit 151 selectively selects a plurality of pixel data xi of the prediction tap located around the target position in the color signal Rop to be created. To be taken out. The plurality of pixel data xi of the prediction tap is supplied to the estimated prediction calculation circuit 158. The estimated prediction calculation circuit 158 uses a plurality of pixel data xi of the prediction tap and coefficient data Wi corresponding to the position of interest read from the coefficient memory 157 based on the estimation formula (see formula (1)). Pixel data y at the target position in the color signal Rop to be obtained is obtained.

  As described above, the signal processing circuit 142 generates the degradation class information based on the image quality degradation information in the pixel portion corresponding to the target position in the color signal Rop to be generated, and further, the class code CL is generated based on the degradation class information. Generated. The coefficient data Wi (i = 1 to n) corresponding to the class code CL is used to calculate the pixel data y. Therefore, it is possible to obtain a color signal Rop that can individually compensate for image quality degradation in each pixel portion of the display device of the display 105.

  Although the processing for obtaining the red color signal Rop from the red color signal Ri has been described above, the signal processing circuit 142 performs the same processing for the green and blue color signals Gi and Bi. Similarly, it is possible to obtain green and blue color signals Gop and Bop that can individually compensate for image quality deterioration in each pixel portion of the display device of the display 105.

  In the signal processing unit 104 shown in FIG. 3, the color signals Rop, Gop, Bop output from the signal processing circuit 142 are supplied to the scanning line conversion circuit 143, and the scanning line structure corresponds to the display structure of the display 105. Is converted to For example, the scanning line conversion circuit 143 performs conversion from the interlace method to the progressive method. Further, the red, green, and blue color signals output from the scanning line conversion circuit 143 are supplied to the gamma correction circuit 144 to perform gamma correction in accordance with the gradation characteristics of the display 105. The red, green and blue color signals Ro, Go and Bo output from the gamma correction circuit 144 are output to the output terminal 145 as output image signals.

Next, the operation of the image display apparatus 100 shown in FIG. 1 will be described. In the measurement mode, the display control unit 106 displays a measurement image on the display 105. In the present embodiment, 24-color single-color images constituting a Gretag / Macbeth / color checker are sequentially displayed. With the measurement image displayed on the display 105 as described above, the remote control transmitter 200 (see FIG. 2) detects an L ^* a ^* b ^* signal as a feature amount corresponding to the image quality of the measurement image. The In this case, the L ^* a ^* b ^* signal is detected corresponding to each pixel of the display device of the display 105 for each single-color image and for each single-color image.

Detection of the L ^* a ^* b ^* signal by the remote control transmitter 200 is performed immediately after the purchase of the device and at a point in time after each predetermined operating time. In this case, detection at each time point is performed in the same optical environment. Thus, the L ^* a ^* b ^* signal at each time point detected by the remote control transmitter 200 is wirelessly transmitted from the remote control transmitter 200.

Thus, the L ^* a ^* b ^* signal at each time point transmitted wirelessly from the remote control transmitter 200 is received by the receiving unit 108. Then, the L ^* a ^* b ^* signal at each time point is supplied from the receiving unit 108 to the memory 109 and stored therein. In this case, the data of the accumulated operation time TM of the display 105 output from the operation time calculation unit 162 (see FIGS. 3 and 5) existing in the deterioration information output circuit 154 of the signal processing unit 104 is the L ^* a ^* b. ^* Stored in pairs with signals.

For example, every time the L ^* a ^* b ^* signal at a new time point is stored in the memory 109, the L ^* a ^* b ^* signal at each time point stored in the memory 109 is the data of the operation accumulated time TM. At the same time, it is supplied to the deterioration information output unit 163 (see FIGS. 3 and 5) existing in the deterioration information output circuit 154 of the signal processing unit 104, and as described above, for obtaining the amount of change based on the time immediately after purchase. A calculation formula having the operation accumulated time TM as a parameter is generated.

  In the normal mode, red, green, and blue color signals Ri, Gi, and Bi input to the input terminal 103 are supplied to the signal processing unit 104. As described above, the signal processing unit 104 obtains red, green, and blue color signals Ro, Go, and Bo that can individually compensate for image quality deterioration in each pixel portion of the display device of the display 105 (see FIG. 3 and its description). Then, the display control unit 106 displays an image based on the color signals Ro, Go, Bo output from the signal processing unit 104 on the display 105. Thereby, even if each pixel portion of the display device of the display 105 is deteriorated with time, the display 105 can obtain an image with a good image quality.

  In the above-described embodiment, the signal processing circuit 142 (see FIG. 3) is based on the space class information generated by the space class information generation circuit 153 and the deterioration class information generated by the deterioration class information generation circuit 155. Although the class code CL indicating the result of class classification is generated, the class code CL may be generated based only on the deteriorated class information generated by the deteriorated class information generating circuit 155.

In the above-described embodiment, the L ^* a ^* b ^* signal detected from all of the 24 monochrome images is shown. However, from some monochrome images important for determining the image quality degradation. The detected L ^* a ^* b ^* signal may be used.

In the above-described embodiment, the imaging unit 211 outputs tristimulus values XYZ of the XYX coordinate system corresponding to each pixel of the display device of the display 105, and the signal processing unit 212 outputs the tristimulus values XYZ. What is converted into an L ^* a ^* b ^* signal in the (L ^* a ^* b ^* ) space is shown. However, red, green, and blue color signals R, G, and B corresponding to each pixel of the display device of the display 105 may be output from the imaging unit 211. In this case, the signal processing unit 212 may be used. Thus, the color signals R, G, and B may be converted into tristimulus values XYZ in the XYX coordinate system, and the tristimulus values XYZ may be converted into L ^* a ^* b ^* signals.

Further, in the above-described embodiment, L ^* a ^* corresponding to each pixel of the display device of the display 105 by capturing a monochrome image displayed on the display 105 with the imaging unit 211 of the remote control transmitter 200 in the measurement mode ^. Although the detection of the b ^* signal is shown, for example, the L ^* a ^* b ^* signal corresponding to each pixel of the display device may be directly detected from the screen of the display 105 using a measurement sensor. it can.

In the above-described embodiment, the L ^* a ^* b ^* signal is detected as the feature quantity corresponding to the image quality of the measurement image, but other values corresponding to the image quality of the measurement image are used as the feature quantity. It may be used as

  Next, a method for generating coefficient data stored in the coefficient memory 157 in the signal processing circuit 142 in FIG. 3 will be described. This coefficient data is generated in advance by learning.

First, this learning method will be described. In the above equation (1), before learning, coefficient data W ₁ , W ₂ ,..., W _n are undetermined coefficients. Learning is performed on a plurality of signal data for each class. When the number of learning data is m, the following equation (2) is set according to the equation (1). n indicates the number of prediction taps.
y _k = W ₁ × x _k1 + W ₂ × x _k2 +... + W _n × x _kn (2)
(K = 1, 2,..., M)
When m> n, the coefficient data W ₁ , W ₂ ,..., W _n are not uniquely determined, so the element e _k of the error vector e is defined by the following equation (3), and (4) Coefficient data that minimizes e ² in the equation is obtained. Coefficient data is uniquely determined by a so-called least square method.
e _k = y _k − {W ₁ × x _k1 + W ₂ × x _k2 +... + W _n × x _kn } (3)
(K = 1, 2, ... m)

As a practical calculation method for obtaining coefficient data that minimizes e ² in equation (4), first, as shown in equation (5), e ² is expressed as coefficient data Wi (i = 1, 2,. .., N), and the coefficient data Wi may be obtained so that the partial differential value becomes 0 for each value of i.

  A specific procedure for obtaining the coefficient data Wi from the equation (5) will be described. If Xji and Yi are defined as in equations (6) and (7), equation (5) can be written in the form of a determinant of equation (8).

  Equation (8) is generally called a normal equation. Coefficient data Wi (i = 1, 2,..., N) can be obtained by solving this normal equation by a general solution method such as a sweep-out method (Gauss-Jordan elimination method).

  FIG. 7 shows the coefficient data generation device 170. The coefficient data generation apparatus 170 includes an input terminal 171 to which color signals Rt, Gt, and Bt as teacher signals corresponding to the red, green, and blue color signals Rop, Gop, and Bop are input. A student signal generation circuit 172 that generates color signals Rs, Gs, and Bs as student signals corresponding to the red, green, and blue color signals Ri, Gi, and Bi from the color signals Rt, Gt, and Bt. .

  The student signal generation circuit 172 is supplied with deterioration class information CLb corresponding to the deterioration class information output from the deterioration class information generation circuit 155 of the signal processing circuit 142 of FIG. The student signal generation circuit 172 includes a ROM table for obtaining the color signals Rs, Gs, Bs from the color signals Rt, Gt, Bt in each class indicated by the degradation class information CLb. The student signal generation circuit 172 generates color signals Rs, Gs, and Bs corresponding to the degradation class information CLb using the ROM table.

  This ROM table is generated in advance using, for example, the display 105 in which the operation accumulation time is short and each pixel portion of the display device hardly deteriorates with time. In this case, the signal processing unit 104 in FIG. 3 is disconnected from the signal processing circuit 142 and the scanning line conversion circuit 143, and the red, green, and blue color signals supplied to the scanning line conversion circuit 143 are Use 24 sets of red, green, and blue color signals to display the 24 single color images that make up the Macbeth Color Checker.

Then, the red, green, and blue color signals of each set are sequentially decreased at random from the reference values Rr, Gr, and Br. In this case, L ^* a ^* b ^* detected by the remote control transmitter 200 in a state where the respective red, green, and blue color signals supplied to the scanning line conversion circuit 143 are the reference values Rr, Gr, and Br, respectively ^. The signal is used as the first detection signal, and the levels of the red, green, and blue color signals of each set are sequentially and randomly changed to detect the L ^* a ^* b ^* signal to obtain the degradation class information CLb. The relationship between each class indicated by the class information CLb and the rate of change with respect to the reference values Rr, Gr, Br of the red, green, and blue color signals supplied to the scanning line conversion circuit 143 at that time is constructed.

In this case, as described above, 24 sets of red, green, and blue color signals are used. For example, there are 24 red color signals. Therefore, regarding the red signal, the change rate of a plurality of red color signals having a value other than 0 out of 24 color signals is averaged to obtain the change rate of the red color signal. The same applies to the green color signal and the blue color signal.
The ROM table stores the relationship between each class indicated by the degradation class information CLb and the rate of change of the red, green, and blue color signals with respect to the reference values Rr, Gr, Br. Therefore, when deterioration class information CLb indicating a certain class is given, information on the rate of change with respect to the reference values Rr, Gr, Br of the red, green, and blue color signals corresponding to the deterioration class information CLb is read from the ROM table, By multiplying this by the color signals Rt, Gt, Bt, the color signals Rs, Gs, Bs corresponding to the degradation class information CLb can be obtained.

  In the following, only the processing system for obtaining the coefficient data Wi used when generating the red color signal Rop from the red color signal Ri will be described in order to avoid complicated description. However, in practice, the same processing system is used to obtain coefficient data Wi used when generating the green color signal Go from the green color signal Gi, and the blue color signal Bi is generated from the blue color signal Bi. The processing for obtaining the coefficient data Wi used when performing the processing is also performed in parallel.

  The coefficient data generation device 170 selectively extracts and outputs a plurality of pixel data located around the target position in the color signal Rt based on the color signal Rs output from the student signal generation circuit 172. One tap selection circuit 173 and a second tap selection circuit 174 are provided. The first and second tap selection circuits 173 and 174 are configured in the same manner as the first and second tap selection circuits 151 and 152 of the signal processing circuit 142 described above.

  In addition, the coefficient data generation apparatus 170 includes a space class information generation circuit 175 that generates space class information from a plurality of pixel data of class taps that are selectively extracted by the second tap selection circuit 173. The space class information generation circuit 175 is configured similarly to the space class information generation circuit 153 of the signal processing circuit 142 described above.

  Further, the coefficient data generation device 170 generates a class code CL indicating a class classification result based on the space class information CLa generated by the space class information generation circuit 175 and the above-described degradation class information CLb. 176. The class code generation circuit 176 is configured in the same manner as the class code generation circuit 156 of the signal processing circuit 142 described above. The class code CL indicates a class to which the pixel data y at the target position in the color signal Rt belongs.

  The coefficient data generation apparatus 170 includes a delay circuit 177 for adjusting the time of the color signal Rt supplied to the input terminal 171 and a normal equation generation unit 178. The normal equation generation unit 178 includes the pixel data y of each target position obtained from the color signal Rt time-adjusted by the delay circuit 177, and the first tap selection circuit 173 corresponding to the pixel data y of each target position. Coefficient data Wi for each class from the plurality of pixel data xi of the prediction tap that is selectively extracted in step S1 and the class code CL generated by the class code generation circuit 176 corresponding to the pixel data y of each target position. A normal equation (see equation (8)) for obtaining (i = 1 to n) is generated.

  In this case, one piece of learning data described above is generated by a combination of one piece of pixel data y and n pieces of pixel data xi (i = 1 to n) corresponding to n prediction taps. Therefore, the normal equation generation unit 178 generates a normal equation in which a lot of learning data is registered.

  The coefficient data generation device 170 is supplied with the data of the normal equation generated for each class by the normal equation generation unit 178, solves the normal equation generated for each class, and obtains coefficient data Wi for each class. A data determination unit 179 and a coefficient memory 180 that stores the obtained coefficient data Wi are provided. In the coefficient data determination unit 179, the normal equation is solved by, for example, a sweeping method, and the coefficient data Wi is obtained.

  The operation of the coefficient data generation device 170 shown in FIG. 7 will be described. The input terminal 171 receives a red color signal Rt as a teacher signal. The color signal Rt is supplied to the student signal generation circuit 172, and the color signal Rs as the student signal corresponding to the degradation class information CLb is generated.

  Based on the color signal Rs output from the student signal generation circuit 172, the second tap selection circuit 174 selectively extracts a plurality of pixel data of class taps located around the target position in the color signal Rt. The plurality of pixel data of the class tap is supplied to the space class information detection circuit 175. In the space class information generation circuit 175, processing such as 1-bit ADRC is performed on the pixel data of the class tap to generate space class information CLa.

  The space class information CLa and the degradation class information CLb generated by the space class information generation circuit 175 are supplied to the class code generation circuit 176. The class code generation circuit 176 generates a class code CL indicating the result of class classification based on the space class information CLa and the degradation class information CLb. This class code CL represents the detection result of the class to which the pixel data of the target position in the color signal Rt as the teacher signal belongs.

  Further, based on the color signal Rs output from the student signal generation circuit 172, the first tap selection circuit 173 selectively extracts a plurality of pixel data of prediction taps located around the target position in the color signal Rt. It is. The pixel data y at the target position sequentially obtained from the color signal Rt output from the delay circuit 177 and a plurality of prediction taps selectively extracted by the first tap selection circuit 173 corresponding to the pixel data y. From the pixel data xi and the class code CL generated by the class code generation circuit 176 corresponding to the pixel data y, the normal equation generation unit 178 generates a normal equation for generating coefficient data Wi for each class. Generated.

  Then, the coefficient data determination unit 179 solves the normal equation to obtain the coefficient data Wi of each class, and the coefficient data Wi is stored in the coefficient memory 180 that is divided into addresses for each class.

  In the above description, the processing for obtaining the coefficient data Wi used when generating the red color signal Rop from the red color signal Ri has been described. However, in the coefficient data generation device 170, the green and blue color signals are processed. A process for obtaining coefficient data Wi used when generating green and blue color signals Gop and Bop from Gi and Bi is similarly performed. As described above, the coefficient data generation device 170 shown in FIG. 7 can generate the coefficient data Wi of each class stored in the coefficient memory 157 of the signal processing circuit 142 of FIG.

  Note that the processing in the signal processing circuit 142 in FIG. 3 can be realized by software, for example, by an image signal processing apparatus 300 as shown in FIG. First, the image signal processing apparatus 300 shown in FIG. 8 will be described. The image signal processing apparatus 300 includes a CPU 301 that controls the operation of the entire apparatus, a ROM (read only memory) 302 that stores an operation program of the CPU 301, coefficient data, and the like, and a RAM (random) that forms a work area of the CPU 301. access memory) 303. These CPU 301, ROM 302, and RAM 303 are each connected to a bus 304.

  The image signal processing apparatus 300 also includes a hard disk drive (HDD) 305 as an external storage device and a drive (FDD) 307 that drives a floppy (registered trademark) disk 306. These drives 305 and 307 are each connected to a bus 304.

  In addition, the image signal processing apparatus 300 includes a communication unit 308 that is connected to a communication network 400 such as the Internet by wire or wirelessly. The communication unit 308 is connected to the bus 304 via the interface 309.

  In addition, the image signal processing device 300 includes a user interface unit. The user interface unit includes a remote control signal receiving circuit 310 that receives a remote control signal RM from the remote control transmitter 200, and a display 311 that includes an LCD (liquid crystal display) or the like. The receiving circuit 310 is connected to the bus 304 via the interface 312, and similarly the display 311 is connected to the bus 304 via the interface 313.

  The image signal processing apparatus 300 also has an input terminal 314 for inputting the color signals Ri, Gi, Bi, and an output terminal 315 for outputting the color signals Rop, Gop, Bop. The input terminal 314 is connected to the bus 304 via the interface 316, and similarly, the output terminal 315 is connected to the bus 304 via the interface 317.

  Here, instead of storing the processing program, coefficient data, and the like in advance in the ROM 302 as described above, for example, they are downloaded from the communication network 400 such as the Internet via the communication unit 308 and stored in the hard disk or RAM 303 for use. You can also Further, these processing programs, coefficient seed data, and the like may be provided on a floppy (registered trademark) disk 306.

  Further, instead of inputting the color signals Ri, Gi, Bi to be processed from the input terminal 314, they may be recorded in advance on a hard disk or downloaded from the communication network 400 such as the Internet via the communication unit 308. Further, instead of outputting the processed color signals Rop, Gop, and Bop to the output terminal 315 or in parallel therewith, they are supplied to the display 311 for image display, further stored in a hard disk, and the communication unit 308. It may be transmitted to a communication network 400 such as the Internet.

  A processing procedure for obtaining the color signals Rop, Gop, Bop from the color signals Ri, Gi, Bi in the image signal processing apparatus 300 shown in FIG. 8 will be described with reference to the flowchart of FIG.

  First, in step ST61, processing is started. In step S62, for example, color signals Ri, Gi, Bi for one frame or one field are input into the apparatus from the input terminal 314. Thus, the pixel data constituting the color signals Ri, Gi, Bi input from the input terminal 314 are temporarily stored in the RAM 303. When the color signals Ri, Gi, Bi are previously recorded in the hard disk drive 307 in the apparatus, the color signals Ri, Gi, Bi are read from the drive 307, and the color signals Ri, Gi, Bi are read out. Is temporarily stored in the RAM 303.

  In step ST63, it is determined whether or not the processing of all frames or all fields of the color signals Ri, Gi, Bi has been completed. When the process is finished, the process ends at step ST64. On the other hand, when the process is not finished, the process proceeds to step ST65.

In this step ST65, using the calculation formulas for the change amounts of L ^* , a ^* , and b ^* in each of the 24-color monochrome images for the pixel corresponding to the target position in the color signals Rop, Gop, and Bop to be created. The current image quality deterioration information in the pixel portion corresponding to the target position is obtained, and the deterioration class information is generated. The data of the calculation formula is stored in the RAM 303.

  Next, in step ST66, a plurality of pixel data of class taps and prediction taps are acquired from the color signals Ri, Gi, Bi input in step ST62, corresponding to the positions of interest in the color signals Rop, Gop, Bop. . In step ST67, is the processing for obtaining the pixel data of the color signals Rop, Gop, Bop completed in all areas of the pixel data of the color signals Ri, Gi, Bi for one frame or one field input in step ST62? Determine whether or not. If completed, the process returns to step ST62, and the process proceeds to input processing of color signals Ri, Gi, Bi for the next one frame or one field. On the other hand, when the process has not ended, the process proceeds to step ST68.

  In this step ST68, space class information is generated from a plurality of pixel data of the class tap acquired in step ST66, and based on this space class information and the degradation class information generated in step ST65 described above, the class code CL Is generated. In step ST69, the coefficient data Wi corresponding to the class code CL is read from the ROM 302 and temporarily stored in the RAM 303.

  Next, in step ST70, the coefficient data Wi and a plurality of pixel data of the prediction tap acquired in step ST66 are used to generate pixel data of the target position in the color signals Rop, Gop, and Bop using an estimation formula. Thereafter, the process returns to step ST66, and the same processing as described above is repeated.

  In this way, by performing processing according to the flowchart shown in FIG. 9, the pixel data of the input color signals Ri, Gi, Bi can be processed to obtain the pixel data of the color signals Rop, Gop, Bop. it can. As described above, the color signals Rop, Gop, and Bop obtained by processing in this way are output to the output terminal 315, supplied to the display 311 to display an image, and further to the hard disk drive 305. It is supplied and recorded on the hard disk. Although illustration of the processing device is omitted, the processing in the coefficient data generation device 170 in FIG. 7 can also be realized by software.

  A processing procedure for generating coefficient data will be described with reference to the flowchart of FIG. First, processing is started in step ST81, and a degradation class is selected in step ST82. In step ST83, it is determined whether learning has been completed for all the degraded classes. If learning has not been completed for all degradation classes, the process proceeds to step ST84.

  In this step ST84, the color signals Rt, Gt, Bt as teacher signals are inputted for one frame or one field. In step ST85, it is determined whether or not the processing of all the frames or fields of the color signals Rt, Gt, and Bt has been completed. If not finished, in step ST86, the color signals Rs, Gs, Bs as student signals are obtained from the color signals Rt, Gt, Bt input in step ST84 based on the degradation class selected in step ST82. Generate.

  In step ST87, a plurality of class taps and prediction taps corresponding to the target position in the color signals Rt, Gt, and Bt input in step ST84 from the color signals Rs, Gs, and Bs generated in step ST86. Obtain pixel data. In step ST88, it is determined whether or not the learning process has been completed in all regions of the color signals Rt, Gt, and Bt input in step ST84. When the learning process is finished, the process returns to step ST84, the color signals Rt, Gt, Bt for the next one frame or one field are input, and the same process as described above is repeated. On the other hand, when the learning process is not ended, the process proceeds to step ST89.

  In this step ST89, space class information is generated from the plurality of pixel data of the class tap acquired in step ST87, and based on this space class information and the information on the degradation class selected in step ST82 described above, the class code CL Is generated. In step ST90, a normal equation (see equation (8)) for obtaining coefficient data is generated for each class. Thereafter, the process returns to step ST87.

  When the processing is completed in step ST85 described above, in step ST91, the normal equation generated in step ST90 is solved by a sweeping method or the like, and coefficient data of each class corresponding to the degradation class selected in step ST82. Is calculated. Thereafter, the process returns to step ST82, the next degradation class is selected, the same processing as described above is repeated, and coefficient data of each class corresponding to the next degradation class is obtained.

  Further, when the calculation processing of the coefficient data of each class corresponding to all the degradation classes is completed in step ST83 described above, the coefficient data is stored in the memory in step ST92, and then the process is performed in step ST93. finish.

  In this way, by performing the processing according to the flowchart shown in FIG. 10, coefficient data can be obtained by the same method as that of the coefficient data generating apparatus 170 shown in FIG.

  In the above embodiment, the signal processing unit 104 (see FIG. 3) includes the scanning line conversion circuit 143 and the gamma correction circuit 144 in addition to the signal processing circuit 142, but the signal processing circuit 142 may be configured to include processing in the scanning line conversion circuit 143 and the gamma correction circuit 144.

  Also, the image display device 100 shown in FIG. 1 can be divided into a signal processing unit 100A and a display unit 100B as shown in FIG. In FIG. 11, portions corresponding to those in FIG.

  In this case, the signal processing unit 100A includes a control unit 101A, an input terminal 103, a signal processing unit 104A, an output terminal 111, a reception antenna 107, a reception unit 108, a memory 109, and a W / R control circuit 110. It is made up of. The signal processing unit 104A corresponds to, for example, the signal processing circuit 142 of the signal processing unit 104 illustrated in FIG. The control unit 101A controls the overall operation of the signal processing unit 100A.

  The display unit 100B includes a control unit 101B, a remote control signal receiving circuit 102, a signal processing unit 104B, a display 105, a display control unit 106, and an input terminal 112. The signal processing unit 104B corresponds to, for example, the scanning line conversion circuit 143 and the gamma correction circuit 144 of the signal processing unit 104 shown in FIG. The control unit 101B controls the overall operation of the display unit 100B.

It is a block diagram which shows the structure of the image display apparatus as embodiment. It is a block diagram which shows the structure of a remote control transmitter. It is a block diagram which shows the structure of a signal processing part. It is a figure which shows an example of a prediction tap and a class tap. It is a block diagram which shows the structure of a deterioration information output circuit. It is a figure which shows an example of the relationship between the operation | movement accumulation time TM and the variation | change_quantity of L ^* . It is a block diagram which shows the structure of a coefficient data generation apparatus. It is a block diagram which shows the structural example of the image signal processing apparatus for implement | achieving by software. It is a flowchart which shows an image signal process. It is a flowchart which shows coefficient data generation processing. It is a block diagram which shows the structure of the image display apparatus as other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Image display apparatus, 101 ... Control part, 102 ... Remote control signal receiving circuit, 103 ... Input terminal, 104 ... Signal processing part, 105 ... Display, 106 ... Display Control unit 107 ··· Reception antenna 108 ··· Reception unit 109 · · · Memory · 141 · · · input terminal 142 · · · signal processing circuit · 143 · · · scanning line conversion circuit · · · 144 · · · Gamma correction circuit, 145 ... output circuit, 151 ... first tap selection circuit, 152 ... second tap selection circuit, 153 ... space class information generation circuit, 154 ... degradation information Output circuit, 155... Degraded class information generation circuit, 156... Class code generation circuit, 157... Coefficient memory, 158. Operating time calculation unit, 163 ... deterioration information output unit, 170 ... coefficient data generation device, 171 ... input terminal, 172 ... student signal generation circuit, 173 ... first tap selection circuit, 174 ... second tap selection circuit, 175 ... space class information generation circuit, 176 ... class code generation circuit, 177 ... delay circuit, 178 ... normal equation generation unit, 179 ... Coefficient data determination unit, 180 ... Coefficient memory, 200 ... Remote control transmitter, 201 ... CPU, 205 ... Key operation unit, 209 ... Remote control signal transmission circuit, 211 ... Imaging unit, 212: Signal processing unit, 215: Transmission unit, 300: Image signal processing device

Claims (4)

An apparatus for generating coefficient data used in an estimation formula used when converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data,
Input means for inputting a teacher signal corresponding to the second image signal;
Signal processing means for subjecting the teacher signal input to the input means to image quality deterioration processing based on class information indicating a stage of image quality deterioration, and obtaining a student signal corresponding to the first image signal;
First data selection means for selecting a plurality of first pixel data located around a target position in the teacher signal based on a student signal output from the signal processing means;
Second data selection means for selecting a plurality of second pixel data located around the target position in the teacher signal based on the student signal output from the signal processing means;
Class detection means for detecting a class to which the pixel data of the target position belongs based on a plurality of second pixel data selected by the second data selection means;
Class generation means for generating new class information by combining the class information detected by the class detection means and the class information indicating the stage of image quality degradation;
Using the new class information generated by the class generation unit, the plurality of first pixel data selected by the first data selection unit, and the pixel data of the target position in the teacher signal, for each class, engaging the number of data generating device Ru and an arithmetic means for obtaining the coefficient data. In order to generate coefficient data used in an estimation formula used when converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data,
A first step of inputting a teacher signal corresponding to the second image signal;
A second step of subjecting the teacher signal input in the first step to image quality degradation processing based on class information indicating a stage of image quality degradation and obtaining a student signal corresponding to the first image signal;
A third step of selecting a plurality of first pixel data located around the target position in the teacher signal based on the student signal obtained in the second step;
A fourth step of selecting a plurality of second pixel data located around the target position in the teacher signal based on the student signal obtained in the second step;
A fifth step of detecting a class to which the pixel data of the target position belongs based on the plurality of second pixel data selected in the fourth step;
A sixth step of generating new class information by combining the class information detected in the fifth step and the class information indicating the stage of image quality degradation;
Using the new class information generated in the sixth step, the plurality of first pixel data selected in the third step, and the pixel data of the target position in the teacher signal, the coefficient for each class A coefficient data generation method comprising: a seventh step for obtaining data. In order to generate coefficient data used in an estimation formula used when converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data,
A first step of inputting a teacher signal corresponding to the second image signal;
A second step of subjecting the teacher signal input in the first step to image quality degradation processing based on class information indicating a stage of image quality degradation and obtaining a student signal corresponding to the first image signal;
A third step of selecting a plurality of first pixel data located around the target position in the teacher signal based on the student signal obtained in the second step;
A fourth step of selecting a plurality of second pixel data located around the target position in the teacher signal based on the student signal obtained in the second step;
A fifth step of detecting a class to which the pixel data of the target position belongs based on the plurality of second pixel data selected in the fourth step;
A sixth step of generating new class information by combining the class information detected in the fifth step and the class information indicating the stage of image quality degradation;
Using the new class information generated in the sixth step, the plurality of first pixel data selected in the third step, and the pixel data of the target position in the teacher signal, the coefficient for each class A computer-readable medium recording a program for causing a computer to execute a coefficient data generation method including a seventh step for obtaining data. In order to generate coefficient data used in an estimation formula used when converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data,
A first step of inputting a teacher signal corresponding to the second image signal;
A second step of subjecting the teacher signal input in the first step to image quality degradation processing based on class information indicating a stage of image quality degradation and obtaining a student signal corresponding to the first image signal;
A third step of selecting a plurality of first pixel data located around the target position in the teacher signal based on the student signal obtained in the second step;
A fourth step of selecting a plurality of second pixel data located around the target position in the teacher signal based on the student signal obtained in the second step;
A fifth step of detecting a class to which the pixel data of the target position belongs based on the plurality of second pixel data selected in the fourth step;
A sixth step of generating new class information by combining the class information detected in the fifth step and the class information indicating the stage of image quality degradation;
Using the new class information generated in the sixth step, the plurality of first pixel data selected in the third step, and the pixel data of the target position in the teacher signal, the coefficient for each class A program for causing a computer to execute a coefficient data generation method including a seventh step for obtaining data.

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