JP2011254214A - Outline emphasis apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform edge enhancement for a luminance signal while preventing rough surface and black crushing.SOLUTION: A noise elimination unit 33 generates a noise elimination signal F1 in which noise is eliminated from an input luminance signal Y0 using a 3×3 filter. An edge extraction unit 35 extracts an edge of the input luminance signal Y0 to obtain wide range edge component E2 of each pixel using a 5×5 filter. A first adjustment unit 38 in a gain adjustment unit 45 sets initial gain K1 of each pixel in accordance with a luminance value of an input luminance signal Y0. A second adjustment unit 39 adjusts the initial gain K1 to obtain correction gain K2 in accordance with a value of the wide range edge component E2 of each pixel. A multiplier 37 multiplies the wide range edge component E2 by the correction gain K2 to obtain the adjusted edge component F2. An adder 36 adds a noise elimination signal F1 and the adjusted edge component F2 to generate a processed luminance signal Y' of each pixel.

Description

  The present invention relates to a contour enhancement device for performing contour enhancement on an image obtained by an imaging device such as an endoscope scope.

  In general, an image signal obtained by an imaging element in an endoscope apparatus is displayed on a monitor or the like after being subjected to contour enhancement in order to enhance the feature of the image. In the contour enhancement, for example, a luminance signal of a pixel having a relatively large luminance difference from the surrounding pixels is relatively greatly enhanced, thereby clearly displaying the contour of the photographing object.

  In an endoscope apparatus, the inside of a lumen that hardly reflects illumination light or a portion where water that reflects a large amount of illumination light is collected, for example, a dark portion, a high-intensity portion, and a low-intensity portion on one captured image. May be displayed. In these dark portions, high luminance portions, and low luminance portions, noise is amplified by edge enhancement, and roughness may be displayed on the screen. Further, blackout may occur in the peripheral portion of the high luminance portion due to edge enhancement.

  For example, Patent Literature 1 discloses a contour enhancement device for performing contour enhancement while suppressing noise amplification. In this contour emphasizing apparatus, an edge component is extracted from the luminance signal by edge enhancement in which a relatively wide pixel area (for example, 5 × 5) is referred to, and a relatively narrow pixel area (3 × 3) is referred to. Thus, noise is removed from the luminance signal to obtain a noise removal signal. Then, the edge component and the noise removal signal are added to generate a processed luminance signal.

JP 2008-288742 A

  However, just adding the noise removal signal to the edge component as in Patent Document 1 cannot sufficiently prevent roughness and blackout that occur on the captured image.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a contour emphasizing device that can effectively prevent roughness, blackout, and the like that occur in a captured image obtained by an endoscope scope or the like.

  An outline emphasizing device according to the present invention includes a noise removal unit that generates a noise removal signal of a pixel of interest using a luminance signal of the pixel of interest and a first peripheral pixel located around the pixel of interest in a minute region, Edge extraction means for detecting the wide edge component of the pixel of interest using the luminance signal of the second peripheral pixel located around the pixel of interest in the wide area larger than the pixel and the minute area, and adjusting the gain of the wide edge component A gain adjusting means; and an adding means for adding the noise removal signal and the gain-adjusted wide-range edge component to generate a processed luminance signal of the pixel of interest. Set the gain of the wide-range edge component of the pixel to a relatively large value, and relatively reduce the gain of the wide-range edge component of the pixel of interest that has relatively low or high luminance. Characterized in that it constant.

  The gain of the wide-range edge component of the target pixel with relatively low luminance is set to be larger as the luminance value of the target pixel is higher, and the gain of the wide-range edge component of the target pixel with relatively high luminance is the target pixel. It is preferable that the luminance value is set to be smaller as the luminance value is higher.

  In addition, the range of the luminance value determined to be relatively low luminance by the gain adjusting unit is preferably wider than the range of the luminance value determined to be relatively high luminance. Furthermore, the range of the luminance value determined to be relatively medium luminance by the gain adjusting means should be wider than the range of luminance values determined to be relatively low luminance.

  The gain adjusting means preferably sets the gain of the wide-range edge component of the pixel of interest having a relatively low luminance and a luminance value lower than a predetermined value to zero. On the other hand, the gain of the wide-range edge component of the pixel of interest having relatively medium luminance is set to 1, and the gain of the wide-range edge component of the pixel of interest having relatively low luminance or high luminance is set to less than 1.

  The gain adjusting means reduces the gain of the pixel of interest by multiplying the gain of the pixel of interest by a coefficient less than 1, for example, when the pixel of interest has a lower luminance than the luminance of surrounding pixels located around the pixel of interest. It is also preferable to perform gain adjustment. In this case, it is preferable to determine whether or not the target pixel is lower than the luminance of the surrounding pixels using a wide-range edge component. That is, it is preferable that the gain adjusting means reduce the gain of the target pixel when the wide-range edge component is less than zero.

  The contour emphasizing device according to another aspect of the present invention uses a luminance signal of a pixel of interest and a first peripheral pixel located around the pixel of interest in a minute area to generate a noise removal signal of the pixel of interest. Means for detecting the wide edge component of the pixel of interest using the luminance signal of the second peripheral pixel located around the pixel of interest in the wide area of the target pixel and the micro area, Gain adjustment means for performing gain adjustment; and addition means for adding the noise removal signal and the gain-adjusted wide-range edge component to generate a processed luminance signal of the pixel of interest. The gain of the target pixel having a lower brightness than the brightness of the peripheral pixels located in the periphery is relatively reduced, and the gain of the target pixel having a higher brightness than the brightness of the peripheral pixels is reduced. Wherein the relatively larger that the.

  The contour emphasizing method according to the present invention includes a noise removal step for generating a noise removal signal of a target pixel using a luminance signal of the target pixel and a first peripheral pixel located around the target pixel in a minute region, An edge extraction step for detecting the wide edge component of the target pixel using the luminance signal of the second peripheral pixel located around the target pixel in the wide area wider than the pixel and the minute area, and adjusting the gain of the wide edge component A gain adjustment step, and an addition step of adding the noise removal signal and the gain-adjusted wide-range edge component to generate a processed luminance signal of the pixel of interest. The wide edge component of the pixel of interest is set to a relatively large luminance and the gain of the wide edge component of the pixel is relatively low or high. Wherein the gain is set relatively small.

  According to another aspect of the present invention, there is provided a contour emphasizing method that uses a luminance signal of a pixel of interest and a first peripheral pixel located around the pixel of interest in a minute region to generate a noise removal signal of the pixel of interest. An edge extraction step for detecting a wide edge component of the target pixel using a luminance signal of the second peripheral pixel located around the target pixel in a wide area larger than the target pixel and the micro area, and A gain adjustment step for performing gain adjustment, and an addition step for generating a processed luminance signal of the pixel of interest by adding the noise removal signal and the gain-adjusted wide-range edge component. The gain of the target pixel whose brightness is lower than the brightness of the surrounding pixels located in is relatively reduced, and the brightness is higher than the brightness of the surrounding pixels. Wherein the gain of the high target pixel is relatively large.

  In the present invention, by removing the noise of the luminance signal and adjusting the gain of the edge component according to the luminance value of each pixel of interest, it is possible to prevent roughness and blackout on the captured image.

It is a block diagram of an endoscope system in one embodiment of the present invention. It is a block diagram which shows an outline emphasis block further in detail. It is a figure for showing the pixel in a micro field. It is a figure for showing the operator of the 1st filter. It is a figure for showing the pixel in a wide area | region. It is a figure for showing the operator of the 2nd filter. It is a graph which shows a look-up table.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows an endoscope system including an image contour emphasizing apparatus according to an embodiment of the present invention. The endoscope system includes a scope 10 and a processor 20. The scope 10 is an imaging device for obtaining an image signal from a subject, and the processor 20 is an image processing device for processing the image signal obtained by the scope 10 and outputting it as an observation image.

  The scope 10 includes an image sensor 11. The image sensor 11 forms an image with light from a subject, and an analog image signal is generated from the formed image. In the image sensor 11, the timing generator 16 controls the reading / reading timing of the image signal.

  The analog image signal is converted into a digital signal by an AFE (analog front end) 12, and then color interpolation is performed by a color interpolation block 13. The analog image signal subjected to the color interpolation is subjected to matrix conversion in the matrix conversion block 14 and input to the YC conversion block 15 as an RGB signal. The RGB signal is converted into a luminance signal Y and color difference signals Cb and Cr in the YC conversion block 15. The luminance signal Y and the color difference signals Cb and Cr are sent to the processor 20.

  The processor 20 has a CPU 21, and the operation of each block in the processor 20 is controlled by the CPU 21. The luminance signal Y and the color difference signals Cb and Cr sent to the processor 20 are subjected to removal of color noise by an LPF (low-pass filter) or the like in the noise removal block 22, and then the luminance signal Y is described later in the contour enhancement block 23. Edge enhancement is applied. The color difference signals Cb and Cr are not subjected to edge enhancement in the edge enhancement block 23.

  The color difference signals Cb and Cr and the luminance signal Y subjected to edge enhancement are converted into RGB signals by the RGB conversion block 24. The RGB signal is adjusted in color according to the output device in the color management block 26 after the image size is adjusted in the scale adjustment block 25 and is output as an observation image to the monitor 27 or the printer 28.

  FIG. 2 is a block diagram showing details of the contour emphasis block 23. The contour enhancement block 23 includes a noise removing unit 33, an edge extracting unit 35, a gain adjusting unit 45, and an adder 36. In the following description, the luminance signal Y input to the contour enhancement block 23 is the input luminance signal Y0, and the luminance signal Y subjected to edge enhancement in the contour enhancement block 23 is processed luminance signal Y ′. Will be described.

  The noise removing unit 33 includes a first line memory block 41, a first filter 31, and a subtracter 32. The input luminance signal Y0 is sequentially input to the first line memory block 41 and the subtracter 32 for each pixel in the noise removing unit 33. The first line memory block 41 temporarily stores the input luminance signal Y0 for at least three lines so that the input luminance signal Y0 in the 3 × 3 region can be input to the first filter 31 at the same time.

  As shown in FIG. 3, the input luminance signal Y0 in the 3 × 3 region (small region) R1 centered on each pixel (target pixel P0) is sequentially input from the first line memory block 41 to the first filter 31. Is done. That is, the input luminance signal Y0 of each pixel of interest P0 and peripheral pixels located around the pixel of interest P0 in the minute region R1 is input to the first filter 31 at the same timing.

  The first filter 31 performs edge enhancement using the input luminance signal Y0 related to the input target pixel P0 and its surrounding pixels, and extracts an edge component (a minute range edge component E1) of the target pixel P0. As shown in FIGS. 3 and 4, the first filter 31 uses the input luminance signal Y0 of the first specific peripheral pixel P1 located in the vertical direction and the vertical direction of the target pixel P0 among the input peripheral pixels as an edge. A Laplacian filter that performs enhancement, and detects a minute range edge component E1 of the pixel of interest P0 by secondary differentiation.

  The minute range edge component E1 is input to the subtractor 32, and the subtractor 32 subtracts the minute range edge component E1 from the input luminance signal Y0 for each pixel of interest P0, and generates a noise removal signal F1 for each pixel of interest P0. Generated.

  The edge extraction unit 35 includes a second line memory block 42 and a second filter 34. The input luminance signal Y0 input to the edge extraction unit 35 is sequentially input to the second line memory block 42 for each pixel and temporarily stored in the second line memory block 42. The second line memory block 42 stores the input luminance signal Y0 for at least five lines so that the input luminance signal Y0 in the 5 × 5 region can be input to the second filter 34 at the same time.

  As shown in FIG. 5, the input luminance signal Y0 in the 5 × 5 area (wide area) R2 centered on each pixel (target pixel P0) is sequentially input from the second line memory block 42 to the second filter 34. Is done. That is, the input luminance signal Y0 of each pixel of interest P0 and peripheral pixels located around the pixel of interest P0 in the wide area R2 is input to the second filter 34 at the same timing.

  The second filter 34 performs edge enhancement using the input pixel of interest P0 and the input luminance signal Y0 of the surrounding pixels, and extracts an edge component (wide-range edge component E2) of the pixel of interest P0. In the present embodiment, the second filter 34 is a 5 × 5 Laplacian filter shown in FIG. 6, and detects a wide-range edge component E2 by secondary differentiation. As described above, the edge enhancement unit 35 performs edge enhancement using the second peripheral pixel located around the target pixel P0 in the wide area R2 wider than the minute area R1.

  Here, the second filter 34 performs edge enhancement using the input luminance signal Y0 of a specific pixel (second specific peripheral pixel P2) among peripheral pixels in the wide area R2. As is apparent from FIGS. 5 and 6, the second specific peripheral pixel P2 is a pixel located in the vertical and horizontal directions with respect to the target pixel P0, and the target pixel P0 in a 3 × 3 region centered on the target pixel P0. The pixels are located in the four diagonal directions. As is apparent from FIG. 6, the second filter 34 is a peripheral pixel P2 closer to the target pixel P0 than the other peripheral pixels P2 (pixels positioned in the vertical and horizontal directions within the 3 × 3 region). The luminance value of is referred to more strongly.

  The gain adjustment unit 45 includes first and second adjustment units 38 and 39, a multiplier 37, and a memory 40 that stores a lookup table (hereinafter referred to as LUT), and performs gain adjustment of the wide-range edge component E2.

  FIG. 7 is a graph showing the LUT, where the horizontal axis represents the luminance value of the input luminance signal Y0 and the vertical axis represents the initial gain K1. As shown in FIG. 7, the LUT indicates the relationship between each luminance value and the value of the initial gain K1 corresponding to each luminance value. In FIG. 7, the input luminance signal Y0 is indicated by 10 bits, and the initial gain K1 is indicated by 0 to 1.

  As shown in FIG. 2, the input luminance signal Y <b> 0 of each target pixel is sequentially input to the first adjustment unit 38. The first adjustment unit 38 reads a value corresponding to the luminance value of the input luminance signal Y0 from the LUT, and outputs the value to the second adjustment unit 39 as the initial gain K1 of each target pixel.

  As shown in FIG. 7, in the LUT, the initial gain K1 is set to 0 for luminance values 1 to 20. When the luminance value exceeds 20, the initial gain K1 is determined to be gradually larger than 0 each time the luminance value increases, and increases to 1 at the luminance value 200, and the initial gain K1 is maintained at 1 at the luminance values 200 to 1000. The When the luminance value exceeds 1000, the initial gain K1 gradually decreases from 1 each time the luminance value increases, and the initial gain K1 becomes about 0.6 at the luminance value (maximum value) 1024.

  Therefore, in the first adjustment unit 38, when the luminance value is 199 or less and the pixel of interest P0 is determined to be relatively low in luminance, the initial gain K1 of the pixel of interest P0 is set to 0 or more and less than 1. . At this time, when the target pixel P0 is further set to a luminance value of 20 or less and is substantially regarded as a dark part, the initial gain K1 is set to zero. Further, when the luminance value of the target pixel P0 is larger than 20, the higher the luminance value, the larger the initial gain K1 is set.

On the other hand, when the luminance value is 200 to 1000 and the target pixel P0 is determined to be relatively medium luminance, the initial gain K1 of the target pixel P0 is set to 1. Further, when the luminance value is 1001 or more and the pixel of interest P0 is determined to have a relatively high luminance, the initial gain K1 of the pixel of interest P0 is set to less than 1. At this time, the initial gain K1 is set to a smaller value as the luminance value of the target pixel is higher.

  In the LUT of the present embodiment, the range defined as low luminance (low luminance range) is 1 to 199, which is wider than the range defined as high luminance (high luminance range: 1001 to 1024). . Furthermore, the range determined to be medium luminance is 200 to 1000, which is wider than the low luminance range. The increase amount (increase rate) of the initial gain K1 with respect to the increase amount of the luminance value in the low luminance range (21 to 199) having the luminance value 21 or more is the decrease amount of the initial gain with respect to the increase amount of the luminance value in the high luminance range. It becomes smaller than (decrease rate).

  An initial gain K1 and a wide range edge component E2 for each target pixel P0 are sequentially input to the second adjustment unit 39. In the second adjustment unit 39, the initial gain K1 is further adjusted according to the value of the wide-range edge component E2 of each pixel of interest P0, and is output as the correction gain K2.

  Specifically, for a pixel of interest whose wide-range edge component E2 is less than 0, a value obtained by multiplying the initial gain K1 by a coefficient 1/2 is output as the correction gain K2. On the other hand, for the pixel of interest having a wide edge component of 0 or more, the initial gain K1 is not adjusted, and the initial gain K1 is output as it is as the correction gain K2.

  The wide-range edge component E2 is a parameter indicating whether the pixel of interest P0 has a luminance value larger than that of its peripheral pixels (second specific peripheral pixel P2 in this embodiment), and the edge component E2 is less than 0. In this case, the luminance of the target pixel P0 is smaller than the luminance of the peripheral pixels. On the other hand, when the edge component E2 is greater than or equal to 0, the luminance of the pixel of interest P0 is greater than or equal to the luminance of surrounding pixels. That is, in the second adjustment unit 39, when the luminance of the target pixel P0 is lower than that of the surrounding pixels, the gain of the target pixel P0 is relatively reduced, and when the luminance of the target pixel P0 is higher than that of the peripheral pixels, The gain of the pixel P0 is relatively increased.

  Note that, as described above, the wide-range edge component E2 is a pixel that strongly refers to a pixel that is close to the target pixel and is weakly referred to a pixel that is not close to the second specific peripheral pixel P2. Therefore, the wide-range edge component E2 indicates whether or not the weighted average value of the luminance values of the second specific peripheral pixel P2 is larger than the luminance value of the target pixel P0.

  The correction gain K2 is input to the multiplier 37 at the same timing as the wide-range edge component E2 regarding the same target pixel P0. In the multiplier 37, for each pixel of interest P0, the wide-range edge component E2 is multiplied by the correction gain K2, and the adjusted edge component F2 (= E2 × K2) is obtained.

  The adder 36 receives the adjusted edge component F2 and the noise removal signal F1 related to the same target pixel P0 at the same timing, and adds them to generate a processed luminance signal Y ′ for each target pixel P0. . The color difference signals Cb and Cr are not processed in the edge emphasis block 23 but are input to the RGB conversion block 24 (see FIG. 1). The RGB conversion block 24 uses the processed luminance signal Y ′ and the color difference signals Cb and Cr. An RGB signal is generated.

  As described above, in the present embodiment, in the first adjustment unit 38, the gains for the relatively high luminance and low luminance pixels are relatively reduced, and edge enhancement of these pixels is suppressed. When edge enhancement is suppressed in this way, the noise removal unit 33 removes noise from the luminance signal Y0, and the roughness in the high luminance part and the low luminance part is suppressed. On the other hand, with respect to the medium luminance pixels in which the characteristics of the shooting target are often expressed, the gain is relatively increased, so that the shooting target is clearly displayed with sufficient outline enhancement.

  Further, the roughness in the low luminance part increases as the luminance value decreases, and particularly increases in a part where the luminance value is equal to or less than a predetermined value and is regarded as a dark part. Therefore, in the present embodiment, edge enhancement is suppressed as the luminance value is small in the low luminance part, and edge enhancement is not applied in the dark part, so that roughness in the low luminance part is appropriately suppressed.

  In addition, the roughness occurs over a relatively wide luminance value range (for example, about 0 to 200) in the case of low luminance, while it occurs only in the vicinity of the saturation value (1024) in the case of high luminance. Therefore, in the present embodiment, edge enhancement is suppressed over a wide luminance range (luminance value: 0 to 200) in the low luminance portion, while edge enhancement is performed only in a narrow luminance range (luminance value: 1000 to 1024) in the high luminance portion. It is suppressed.

  Further, in the second adjustment unit 39, when the target pixel P0 has lower luminance than the surrounding pixels, the gain of the target pixel P0 is reduced. When the gain is reduced in this way, black noise is less likely to occur around the high-luminance portion, coupled with the noise removal unit 33 removing the noise of the luminance signal Y0.

  In the case where blackout is unlikely to occur on the captured image, the second adjustment unit 39 is omitted, and the initial gain K1 output from the first adjustment unit 38 is directly multiplied by the wide-range edge component E2. good. In addition, when the roughness is difficult to occur, the first adjustment unit 38 may be omitted, and all the gains K1 input to the second adjustment unit 39 may be set to 1.

  Moreover, the numerical ranges of the high luminance range, the medium luminance range, and the low luminance range are examples, and may be set to other numerical ranges. Furthermore, although the gains K1 and K2 are set to 0 to 1 in the above description, they may be set as integer parameters. In this case, the gains K1 and K2 are set as, for example, parameters of 8 pits (0 to 256), and the values divided by 256 are input to the multiplier 37.

  In the present embodiment, a filter other than a Laplacian filter may be used as the first and second filters 31 and 34, for example, a filter for performing first-order differentiation may be used. Further, the noise removal performed by the noise removal unit is not particularly limited as long as noise can be removed using the luminance signal of the minute region R. For example, the noise may be removed by obtaining an average of the luminance signals of the target pixel P0 and the peripheral pixel P1 in the minute region R1. Alternatively, other LPFs may be used.

33 noise removal unit 35 edge extraction unit 38 first adjustment unit 39 second adjustment unit 45 gain adjustment unit E1 minute range edge component E2 wide range edge component F1 noise removal signal F2 processed edge component P0 target pixel P1 first specific peripheral pixel P2 Second specific peripheral pixel R1 Small area R2 Wide area Y0 Input luminance signal Y ′ Processed luminance signal

Claims (13)

A noise removal unit that generates a noise removal signal of the pixel of interest using a luminance signal of the pixel of interest and a first peripheral pixel located around the pixel of interest in a minute region;
Edge extraction means for detecting a wide range edge component of the target pixel using a luminance signal of a second peripheral pixel located around the target pixel in the wide range area wider than the target pixel and the micro area;
Gain adjusting means for adjusting the gain of the wide-range edge component;
Adding means for adding the noise removal signal and the gain-adjusted wide-range edge component to generate a processed luminance signal of the pixel of interest;
The gain adjusting means sets the gain of the wide-range edge component of the pixel of interest having relatively medium luminance to be relatively large, and sets the gain of the wide-area edge component of the pixel of interest having relatively low luminance or high luminance. An outline emphasizing device characterized by being set relatively small.   2. The contour emphasizing apparatus according to claim 1, wherein the gain of the wide-range edge component of the target pixel having relatively low luminance is set to be larger as the luminance value of the target pixel is higher.   2. The contour emphasizing apparatus according to claim 1, wherein the gain of the wide-range edge component of the pixel of interest having relatively high luminance is set to be smaller as the luminance value of the pixel of interest is higher.   2. The contour according to claim 1, wherein a range of brightness values determined to be relatively low brightness by the gain adjusting means is wider than a range of brightness values determined to be relatively high brightness. Emphasis device.   2. The contour according to claim 1, wherein a range of luminance values determined to be relatively medium luminance by the gain adjusting means is wider than a range of luminance values determined to be relatively low luminance. Emphasis device.   The edge enhancement according to claim 1, wherein the gain adjusting unit sets a gain of a wide-range edge component of the pixel of interest having a relatively low luminance and a luminance value lower than a predetermined value to 0. apparatus.   The gain adjusting means sets the gain of the wide-range edge component of the target pixel having relatively medium luminance to 1, and sets the gain of the wide-range edge component of the target pixel having relatively low luminance or high luminance to less than 1. The contour emphasizing device according to claim 1, wherein the contour emphasizing device is set.   2. The gain adjusting unit also performs gain adjustment for reducing the gain of the target pixel when the target pixel has a luminance lower than that of a peripheral pixel located around the target pixel. The contour emphasizing device described in 1.   9. The gain adjusting means, when the target pixel has a luminance lower than that of a peripheral pixel located around the target pixel, the gain of the target pixel is multiplied by a coefficient less than one. The contour emphasizing device described in 1.   9. The contour emphasizing apparatus according to claim 8, wherein the gain adjusting unit reduces the gain of the target pixel when the wide-range edge component is less than zero. A noise removal unit that generates a noise removal signal of the pixel of interest using a luminance signal of the pixel of interest and a first peripheral pixel located around the pixel of interest in a minute region;
Edge extraction means for detecting a wide range edge component of the target pixel using a luminance signal of a second peripheral pixel located around the target pixel in the wide range area wider than the target pixel and the micro area;
Gain adjusting means for adjusting the gain of the wide-range edge component;
Adding means for adding the noise removal signal and the gain-adjusted wide-range edge component to generate a processed luminance signal of the pixel of interest;
The gain adjusting unit relatively reduces a gain of a target pixel having a lower luminance than that of a peripheral pixel located around the target pixel, and increases a gain of the target pixel having a higher luminance than the luminance of the peripheral pixel An outline emphasis device characterized by being relatively large. A noise removal step of generating a noise removal signal of the pixel of interest using a luminance signal of the pixel of interest and a first peripheral pixel located around the pixel of interest in a minute region;
An edge extraction step of detecting a wide range edge component of the target pixel using a luminance signal of a second peripheral pixel located around the target pixel in the wide range area wider than the target pixel and the micro area;
A gain adjusting step for adjusting the gain of the wide-range edge component;
Adding the noise removal signal and the gain-adjusted wide-range edge component to generate a processed luminance signal for the pixel of interest; and
In the gain adjustment step, the gain of the wide-range edge component of the pixel of interest having relatively medium luminance is set to be relatively large, and the gain of the wide-range edge component of the pixel of interest having relatively low luminance or high luminance is set. A contour emphasizing method characterized by being set relatively small. A noise removal step of generating a noise removal signal of the pixel of interest using a luminance signal of the pixel of interest and a first peripheral pixel located around the pixel of interest in a minute region;
An edge extraction step of detecting a wide range edge component of the target pixel using a luminance signal of a second peripheral pixel located around the target pixel in the wide range area wider than the target pixel and the micro area;
A gain adjustment step for adjusting the gain of the wide-range edge component;
Adding the noise removal signal and the gain-adjusted wide-range edge component to generate a processed luminance signal for the pixel of interest; and
In the gain adjustment step, the gain of the pixel of interest having a lower luminance than the luminance of the peripheral pixels located around the pixel of interest is relatively reduced, and the gain of the pixel of interest having a higher luminance than the luminance of the peripheral pixels An edge emphasizing method characterized in that is relatively increased.

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