JP2012100064A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus that can realize an optimal color bleeding reduction processing by reducing achromatization of an edge and unprocessed color bleeding due to an erroneous determination by color bleeding reduction means.SOLUTION: Information about how an appearance of color bleeding changes by a magnification chromatic aberration correction processing in the preceding stage is obtained to switch on/off the color bleeding reduction processing in response to a value in the information. Therefore, a color bleeding reduction processing can be controlled to be available at only an area where there is no negative effect of the color bleeding reduction processing. As a result, a better color bleeding reduction can be realized. Furthermore, additional information is given to an optical DB to obtain information for determining appearance of color bleeding and for switching on/off the color bleeding reduction processing in response to a value in the information. Therefore, the color bleeding reduction processing can be controlled to be available at only an area where there is no negative effect of the color bleeding reduction processing. As a result, a better color bleeding reduction processing can be realized.

Description

  The present invention relates to an imaging apparatus, and more particularly to an apparatus having a lateral chromatic aberration correction and color blur suppression function.

  Conventionally, an optical system of an imaging apparatus has chromatic aberration in which an imaging position is different for each color. This occurs because the refractive index of the lens differs for each wavelength of light, and is a factor that degrades image quality, particularly due to color blurring around the edge.

  Therefore, the conventional image pickup apparatus detects color edges from the luminance signal and calculates a suppression coefficient from the amplitude of the edge signal, thereby suppressing color fringing with reduced achromatic color at the contour portion where no color fringing occurs. Some perform processing. This technique is described in Patent Document 1.

  Further, it is known that the shift amount of the imaging position changes according to the focal length, the aperture, the object distance (hereinafter referred to as an optical parameter) and the distance from the center of the optical axis (hereinafter referred to as an image height). ing.

  Therefore, in the conventional imaging apparatus, the deviation amount of the imaging position between the reference color signal and the correction target color signal is stored in advance for each optical parameter and image height, and the correction target signal is based on the stored data. In some cases, the chromatic aberration of magnification is corrected by interpolating this data with neighboring data. This technique is described in Patent Document 2.

JP 2004-040546 A JP 2001-186533 A

  However, when edge detection is performed from the luminance signal and the color blur suppression coefficient is calculated from the amplitude of the edge signal, the luminance signal changes greatly at the high contrast color edge, so the color blur is determined and color blur suppression processing is performed. Will occur, resulting in achromatic edges. Further, although the change in the luminance signal is small in the low-contrast portion, there is a possibility that color blur may occur. Therefore, color blur suppression processing is not performed, and color blur suppression remains.

  As described above, in the color blur suppression process in which the edge is detected from the luminance signal and the suppression coefficient is calculated from the amplitude of the edge signal, there is a possibility that the achromatic color of the edge and the suppression of the color blur remain.

  Further, when the magnification chromatic aberration correction process by the interpolation process is performed, the edge waveform response deteriorates depending on the correction amount. Therefore, the color blur suppression process causes unevenness of the edge achromatic color or the suppression residue. There is a problem.

In order to achieve the above object, the imaging apparatus of the present invention provides:
An optical system, an image sensor that converts and outputs a subject image projected by the optical system into an image signal, an optical database that holds a table of magnification chromatic aberration correction amounts, and a magnification chromatic aberration correction amount based on information in the optical database. An interpolation coefficient generating means for generating, a magnification chromatic aberration correcting means for correcting a chromatic aberration of magnification according to a correction amount from the interpolation coefficient generating means, and a color blur suppressing means for processing an output signal of the magnification chromatic aberration correcting means; An imaging device comprising: a chromatic aberration evaluation unit that detects an interpolation phase from an output signal of the interpolation coefficient generation unit; and a selector that selects and outputs one of the output of the magnification chromatic aberration correction unit or the output of the color blur suppression unit. In the device
The output signal of the magnification chromatic aberration correction unit and the output signal of the color blur suppression unit are selected and output according to the output signal of the chromatic aberration evaluation unit.

The imaging device of the present invention is
An optical system, an image sensor that converts and outputs a subject image projected by the optical system into an image signal, an optical database that holds a table of magnification chromatic aberration correction amounts, and a magnification chromatic aberration correction amount based on information in the optical database. An interpolation coefficient generating means for generating, a magnification chromatic aberration correcting means for correcting a chromatic aberration of magnification according to a correction amount from the interpolation coefficient generating means, and a color blur suppressing means for processing an output signal of the magnification chromatic aberration correcting means; An image pickup apparatus including a chromatic aberration evaluation unit that detects an interpolation phase from an output signal of the interpolation coefficient generation unit, and controls the operation of the color blur suppression unit in accordance with the output signal of the chromatic aberration evaluation unit. It is a feature.

The imaging device of the present invention is
An optical system, an image sensor that converts and outputs a subject image projected by the optical system into an image signal, a table of magnification chromatic aberration correction amounts, and an optical database that holds information about the inclination of an image edge due to magnification chromatic aberration, Interpolation coefficient generation means for generating a magnification chromatic aberration correction amount from information in the optical database, magnification chromatic aberration correction means for correcting magnification chromatic aberration according to the correction amount from the interpolation coefficient generation means, and output signal of the magnification chromatic aberration correction means Color blur suppression means for processing the image, chromatic aberration evaluation means for determining an edge shape by magnification chromatic aberration correction from information on the inclination of the edge of the image due to magnification chromatic aberration in the optical database, and the output of the magnification chromatic aberration correction means or the An image pickup apparatus including a selector that selects and outputs one of the outputs of the color blur suppression unit. Te, an output signal of the magnification chromatic aberration correction means, an output signal of the suppressing means blurring the color, it is characterized in that selects and outputs according to the output signal of the aberration evaluation unit.

The imaging device of the present invention is
An optical system, an image sensor that converts and outputs a subject image projected by the optical system into an image signal, a table of magnification chromatic aberration correction amounts, and an optical database that holds information about the inclination of an image edge due to magnification chromatic aberration, Interpolation coefficient generation means for generating a magnification chromatic aberration correction amount from information in the optical database, magnification chromatic aberration correction means for correcting magnification chromatic aberration according to the correction amount from the interpolation coefficient generation means, and output signal of the magnification chromatic aberration correction means In the imaging apparatus, the chromatic aberration evaluation unit includes: The operation of the color blur suppression unit is controlled according to the output of the unit.

The imaging device of the present invention is
An optical system, an image sensor that converts and outputs a subject image projected by the optical system into an image signal, a table of magnification chromatic aberration correction amounts, and an optical database that holds information about the inclination of an image edge due to magnification chromatic aberration, Interpolation coefficient generation means for generating a magnification chromatic aberration correction amount from information in the optical database, magnification chromatic aberration correction means for correcting magnification chromatic aberration according to the correction amount from the interpolation coefficient generation means, and output signal of the magnification chromatic aberration correction means Color blur suppression means for performing processing on the image, chromatic aberration evaluation means for determining edge shape by correction of chromatic aberration of magnification from information on the inclination of the edge of the image due to chromatic aberration of magnification in the optical database, and output of the interpolation coefficient generation means, and Selecting one of the output of the magnification chromatic aberration correcting unit or the output of the color blur suppressing unit. In the imaging apparatus including the selector, the output signal of the magnification chromatic aberration correction unit and the output signal of the color blur suppression unit are selected and output according to the output signal of the chromatic aberration evaluation unit. .

The imaging device of the present invention is
An optical system, an image sensor that converts and outputs a subject image projected by the optical system into an image signal, a table of magnification chromatic aberration correction amounts, and an optical database that holds information about the inclination of an image edge due to magnification chromatic aberration, Interpolation coefficient generation means for generating a magnification chromatic aberration correction amount from information in the optical database, magnification chromatic aberration correction means for correcting magnification chromatic aberration according to the correction amount from the interpolation coefficient generation means, and output signal of the magnification chromatic aberration correction means Color blur suppression means for performing processing on the image, chromatic aberration evaluation means for determining edge shape by correction of chromatic aberration of magnification from information on the inclination of the edge of the image due to chromatic aberration of magnification in the optical database, and output of the interpolation coefficient generation means, and In the image pickup apparatus, the color blur suppression unit according to the output of the chromatic aberration evaluation unit It is characterized by controlling the operation.

Another feature of the present invention is that
The color blur suppression unit according to the present invention is characterized in that a suppression gain is adjusted by an output signal of the chromatic aberration evaluation unit.

Another feature of the present invention is that
The chromatic aberration evaluation means according to the present invention is characterized in that, from the output signal of the interpolation coefficient calculation means, a smaller value is output as the value of the decimal part of the correction coefficient is closer to 0.5.

Another feature of the present invention is that
The optical database in the present invention is:
The information regarding the inclination of the edge of the image due to the lateral chromatic aberration is image information when a predetermined subject is photographed.

Another feature of the present invention is that
The chromatic aberration evaluating means according to the present invention is characterized in that a large value is output when the value of the information regarding the inclination of the edge of the image due to the chromatic aberration of magnification in the optical database is large.

Another feature of the present invention is that
In the chromatic aberration evaluation means in the present invention, the value of the information related to the inclination of the edge of the image due to the chromatic aberration of magnification in the optical database is large, and the value of the decimal part of the correction coefficient of the output signal of the interpolation coefficient calculation means is greater than 0.5. It is characterized by outputting a larger value as it is farther away.

  According to the present invention, the operation of the color blur suppression unit is switched according to the correction information of the magnification chromatic aberration correction or the edge information stored in advance in the optical database, thereby eliminating the edge caused by the erroneous determination of the color blur suppression unit. It is possible to realize the optimal color blur suppression process by reducing the remaining color saturation and suppression of color blur.

The block diagram which shows the imaging device of 1st Example Graph showing the relationship between image height and correction amount Conceptual diagram of lateral chromatic aberration correction Block diagram showing color blur suppression processing Setting diagram of suppression gain for color blur suppression processing Relationship between the amount of correction for chromatic aberration of magnification and frequency characteristics The block diagram which shows the imaging device of 2nd Example Block diagram showing color blur suppression processing Setting diagram of suppression gain for color blur suppression processing Relationship diagram between chromatic aberration correction value and chromatic aberration evaluation value Block diagram showing an image pickup apparatus of a third embodiment Illustration of edge evaluation value The block diagram which shows the imaging device of 4th Example Relationship diagram between edge evaluation value and chromatic aberration evaluation value The block diagram which shows the imaging device of 5th Example Block diagram showing an imaging apparatus of a sixth embodiment Frequency characteristics and select signal characteristics of the first embodiment Edge shape evaluation value and select signal characteristic diagram of the third embodiment Characteristic diagram of edge shape evaluation value, chromatic aberration evaluation value and select signal of the fifth embodiment

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Example 1]
FIG. 1 shows a block diagram of an imaging apparatus according to the first embodiment of the present invention.

  In FIG. 1, 1 is an optical system including a zoom lens, a focus lens, and a diaphragm, 2 is an optical system driving means for driving the optical system 1, 3 is an image sensor, 4 is an image sensor driving means for driving the image sensor 3, 5 is an analog front end unit (AFE) including CDS means and an A / D converter, 6 is a system control unit, and 7 is a table of magnification chromatic aberration correction amounts previously calculated from a plurality of image heights and optical parameters. 8 is an image height calculation means for calculating the distance from the optical center, and 9 is a correction amount corresponding to the image height acquired from the image height calculation means 8 from a table of magnification chromatic aberration correction amounts acquired from the optical database 7. 10 is a magnification chromatic aberration correction unit that performs magnification chromatic aberration correction processing using the generated correction amount, and 11 is an image signal that has been subjected to magnification chromatic aberration correction processing. Color blur suppression means for performing color blur suppression processing for the color blur, 12 is a chromatic aberration evaluation means for evaluating the state of chromatic aberration from the correction amount generated by the correction amount generation means 9, 13 is an output image signal of the magnification chromatic aberration correction means 10, and This is a selector that selects and outputs the output image signal of the color blur suppression unit 11 according to the output signal of the chromatic aberration evaluation unit 12.

  Hereinafter, a photographing operation in the imaging apparatus configured as described above will be described.

  First, the optical system 1 drives a diaphragm and a lens according to a control signal from the system control unit 6 to form a subject image controlled to an appropriate brightness on the image sensor 3. The image sensor 3 is driven by a drive pulse controlled by the system control unit 6, converts the subject image into an electrical signal by photoelectric conversion, and outputs it as an analog image signal. The analog image signal output from the image pickup device 3 is removed from the clock synchronization noise by the CDS means inside the AFE 5 by the drive pulse controlled by the system control unit 6, and the digital image signal by the A / D converter inside the AFE 5. Is converted to

  The image height calculation means 8 acquires the coordinate position of the pixel of interest and the coordinate position of the optical center by the system control unit 6, and obtains the image height hgt using the calculation shown in [Equation 1], for example.

  Here, xadr represents the horizontal coordinate of the pixel of interest, and yadr represents the vertical coordinate of the pixel of interest. Hc represents the horizontal coordinate of the optical center, and Vc represents the vertical coordinate of the optical center.

  The correction amount generation unit 9 calculates a correction amount corresponding to the image height acquired from the image height calculation unit 8 from the magnification chromatic aberration correction amount table acquired by the system control unit 6.

  The magnification chromatic aberration correction amount table acquired from the optical database shows the number of pixels that are shifted from the correct pixel position in decimal units. When the value is positive, the table is shifted outward from the optical center and negative. When it is a value, it indicates that it is shifted inward with respect to the optical center. The optical database stores a correction amount with respect to the image height for each predetermined section, and the data between the stored image heights is obtained by linear approximation or quadratic curve approximation. .

  The lateral chromatic aberration correction unit 10 performs lateral chromatic aberration correction processing on the input image signal based on the correction amount acquired from the correction amount generation unit 9.

  The optical correction amount for correcting the lateral chromatic aberration is a phase shift amount obtained by separating the distortion amount at the target pixel position as a phase shift component in the horizontal and vertical directions.

  FIGS. 3A to 3C are conceptual diagrams for correcting this phase shift.

  The black pixel in FIG. 3 (a) indicates the phase that the target pixel S should be originally, and the gray pixel is a virtual pixel that indicates the position where the target pixel S was photographed with a phase shift due to the influence of lateral chromatic aberration. S ′.

  In order to correct the lateral chromatic aberration, a virtual pixel S ′ whose phase is shifted by Hp in the horizontal direction and Vp in the vertical direction may be obtained and rearranged at the position of the pixel of interest S.

  As shown in FIG. 3 (b), the virtual pixel S ′ is a pixel between the pixels s1, s2, s3, s4 and the virtual pixel S ′ from the actually captured pixels s1, s2, s3, s4 that exist in the vicinity. It can be generated by performing a weighted interpolation calculation with the distances c1, c2, c3, and c4.

  The generated virtual pixel S ′ is replaced with the position of the pixel of interest S as shown in FIG. 3C, and the lateral chromatic aberration is corrected.

  The color blur suppression unit 11 performs color blur suppression processing on the image signal on which the magnification chromatic aberration correction processing has been performed.

  FIG. 4 shows a configuration diagram of the color blur suppression unit 11.

  In this embodiment, the description will be made assuming that all pixel positions have RGB values.

  The contrast detection unit 1101 performs a filter operation using a first-order differential filter such as a Sobel filter, and outputs the output as a contrast value.

  The suppression coefficient calculation unit 1104 calculates the suppression coefficient according to the R contrast signal from the contrast detection unit 1101.

  The suppression process 1107 suppresses color blur in accordance with the R image plane and the suppression coefficient from the suppression coefficient calculation unit 1104.

  The contrast detection unit 1102 performs a filter operation using a first-order differential filter such as a Soble filter, and outputs the output as a contrast value.

  The suppression coefficient calculation unit 1105 calculates a suppression coefficient according to the G contrast signal from the contrast detection unit 1102.

  The suppression process 1108 suppresses color blur according to the G image plane and the suppression coefficient from the suppression coefficient calculation unit 1105.

  The contrast detection unit 1103 performs a filter operation using a first-order differential filter such as a Sobel filter and outputs the output as a contrast value.

  The suppression coefficient calculation unit 1106 calculates a suppression coefficient according to the B contrast signal from the contrast detection unit 1103.

  The suppression processing 1109 suppresses color blur according to the B image plane and the suppression coefficient from the suppression coefficient calculation unit 1106.

Next, the operation of the suppression coefficient calculation means 1104 to 1106 will be described in detail.
The suppression function of the suppression coefficient calculation means 1104 to 1106 determines a function shape as shown in FIG. 5 using, for example, the calculation shown in [Equation 2].

  In [Equation 2], kr represents a suppression coefficient, A represents the amplitude of the contrast signal detected by the contrast detection means 1101 to 1103, and Th1 and Th2 were determined in advance according to the contrast range in which color blur suppression is performed. Indicates the value.

  The chromatic aberration evaluation unit 12 evaluates the state of chromatic aberration from the correction amount generated by the correction amount generation unit 9.

  FIG. 6 shows the relationship between the fractional part of the correction amount, which is the output of the correction amount generation means 9, and the frequency characteristics. A correction amount of 1 means that the correction position is an adjacent pixel position. The frequency characteristic is lowest at the center of the pixel position.

  FIG. 17 shows the relationship between this frequency characteristic and the output signal of the chromatic aberration evaluating means 12.

  In the chromatic aberration evaluating means 12, when the frequency characteristic is smaller than the predetermined value α, it means that the frequency characteristic is low and the edge is dull due to the correction of the chromatic aberration of magnification. 1 is used as an output signal. If the frequency characteristic is larger than α, it means that the frequency characteristic is high, and the dullness of the edge due to magnification chromatic aberration correction has little influence. Therefore, 0 is output so that data with color blur suppression is output. Signal.

  The selector 13 selects and outputs the output image signal of the magnification chromatic aberration correction unit 10 and the output image signal of the color blur suppression unit 11 according to the output signal of the chromatic aberration evaluation unit 12.

  When the output signal of the chromatic aberration evaluation means 12 is 1, there is a high possibility that the color edge will be achromatic due to the color blur suppression process. Therefore, the output image signal of the magnification chromatic aberration correction means 10 that does not perform the color blur suppression process is used. If the output signal of the chromatic aberration evaluation means 12 is 0, the desired color blur suppression process can be performed. Therefore, the output image signal of the color blur suppression means 11 subjected to the color blur suppression process is output.

  As described above, according to the output signal of the chromatic aberration evaluation means, the output image of the magnification chromatic aberration correction process and the output image obtained by performing the color blur suppression process on the output image of the magnification chromatic aberration correction process are selected and output. As a result, it is possible to output an image in which the achromatic color of the edge due to erroneous determination of the color blur suppression process is reduced.

[Example 2]
(Multi-value control with correction amount control)
FIG. 7 shows a block diagram of the image pickup apparatus of the present invention of the second embodiment.

  The second embodiment is substantially the same as the first embodiment, and the same members are denoted by the same reference numerals, and description thereof is omitted. The difference is that the operation of the color blur suppression unit 112 is controlled in accordance with the output signal of the chromatic aberration evaluation unit 122.

  FIG. 8 shows a configuration diagram of the color blur suppression unit 112.

  Since the operations of the contrast detection units 1101 to 1103 and the suppression units 1107 to 1109 are the same as those in the first embodiment, a description thereof will be omitted, and the suppression coefficient calculation units 1124 to 1126 that are features of the present invention will be described.

  The suppression function of the suppression coefficient calculation means 1124 to 1126 determines the function shape as shown in FIG. 9 by using the calculation shown in [Equation 3], for example.

  In [Equation 3], kr represents a suppression coefficient, A represents the amplitude of the contrast signal detected by the contrast detection means 1101 to 1103, and Th1 and Th2 are predetermined according to the contrast range in which color fringing suppression is performed. Β represents a chromatic aberration evaluation value that is an output signal of the chromatic aberration evaluation means 122.

  Since β, which is an output signal of the chromatic aberration evaluating means 122, has a small value, the maximum value of the suppression gain of color blur suppression is small, so that the degree of suppression is small, and if the value is large, the maximum value of the suppression gain of color blur suppression is Since it increases, the degree of suppression increases.

  The chromatic aberration evaluation unit 122 evaluates the state of chromatic aberration from the correction amount generated by the correction amount generation unit 9.

  FIG. 6 shows the relationship between the fractional part of the correction amount, which is the output of the correction amount generation means 9, and the frequency characteristics. A correction amount of 1 means that the correction position is an adjacent pixel position. The frequency characteristic is lowest at the center of the pixel position.

  FIG. 10 shows the relationship between the decimal part of the correction amount and the chromatic aberration evaluation value. When the frequency characteristic is high, it means that the edge dullness due to the correction of the chromatic aberration of magnification has little influence. Therefore, a value close to 1 is output so that the maximum value of the suppression gain of the color blur suppression process is not lowered. . When the frequency characteristic is low, it means that the influence of the edge dullness due to the magnification chromatic aberration correction is large. Therefore, a value close to 0 is output, and the maximum value of the suppression gain of the color blur suppression process is reduced, The effect of color blur suppression processing is made difficult.

  This graph is merely an example, and it is only necessary to have a characteristic that outputs a large value when the frequency characteristic is high and outputs a small value when the frequency characteristic is low.

  As described above, by adjusting the degree of suppression of the color blur suppression process performed on the output image of the magnification chromatic aberration correction process according to the output signal of the chromatic aberration evaluation means, it is possible to make an erroneous determination of the color blur suppression process. It is possible to output an image with reduced achromatic edges.

[Example 3]
(Binary control determined by additional information in optical DB)
FIG. 11 shows a block diagram of the image pickup apparatus of the present invention of the third embodiment.

  In FIG. 11, 1 is an optical system including a zoom lens, a focus lens, and a diaphragm, 2 is an optical system driving means for driving the optical system 1, 3 is an image sensor, 4 is an image sensor driving means for driving the image sensor 3, 5 is an analog front end unit (shown as AFE) including CDS means and an A / D converter, 6 is a system control unit, 73 is a table of magnification chromatic aberration correction amounts calculated in advance from a plurality of image heights and optical parameters, and An optical database that holds information about the inclination of the edge of the image due to chromatic aberration of magnification, 8 is an image height calculation means for calculating the distance from the optical center, and 9 is an image height calculation from a table of magnification chromatic aberration correction amounts acquired from the optical database 73. Correction amount generation means for generating a correction amount according to the image height acquired from the means 8, 10 is a magnification for performing magnification chromatic aberration correction processing by the generated correction amount Chromatic aberration correction means 11, color blur suppression means 11 that performs color blur suppression processing on an image signal that has been subjected to magnification chromatic aberration correction processing, and 123 is a magnification based on information about the inclination of the edge of the image due to magnification chromatic aberration obtained from the optical database 73 Chromatic aberration evaluation means 13 for evaluating the edge shape after chromatic aberration correction, 13 selects the output image signal of the magnification chromatic aberration correction means 10 and the output image signal of the color blur suppression means 11 according to the output signal of the chromatic aberration evaluation means 123. It is a selector that outputs.

  Hereinafter, a photographing operation in the imaging apparatus configured as described above will be described.

  First, the optical system 1 drives a diaphragm and a lens according to a control signal from the system control unit 6 to form a subject image controlled to an appropriate brightness on the image sensor 3. The image sensor 3 is driven by a drive pulse controlled by the system control unit 6, converts the subject image into an electrical signal by photoelectric conversion, and outputs it as an analog image signal. The analog image signal output from the image pickup device 3 is removed from the clock synchronization noise by the CDS means inside the AFE 5 by the drive pulse controlled by the system control unit 6, and the digital image signal by the A / D converter inside the AFE 5. Is converted to

  The image height calculation means 8 acquires the coordinate position of the pixel of interest and the coordinate position of the optical center by the system control unit 6, and obtains the image height hgt using the calculation shown in [Equation 4], for example.

  Here, xadr represents the horizontal coordinate of the pixel of interest, and yadr represents the vertical coordinate of the pixel of interest. Hc represents the horizontal coordinate of the optical center, and Vc represents the vertical coordinate of the optical center.

  The correction amount generation unit 9 calculates a correction amount according to the image height acquired from the image height calculation unit 8 from the table of the magnification chromatic aberration correction amount acquired by the system control unit 6.

  The magnification chromatic aberration correction amount table acquired from the optical database shows the number of pixels that are shifted from the correct pixel position in decimal units. When the value is positive, the table is shifted outward from the optical center and negative. When it is a value, it indicates that it is shifted inward with respect to the optical center. The optical database stores a correction amount with respect to the image height for each predetermined section, and the data between the stored image heights is obtained by linear approximation or quadratic curve approximation. .

  The lateral chromatic aberration correction unit 10 performs lateral chromatic aberration correction processing on the input image signal based on the correction amount acquired from the correction amount generation unit 9.

  The optical correction amount for correcting the lateral chromatic aberration is a phase shift amount obtained by separating the distortion amount at the target pixel position as a phase shift component in the horizontal and vertical directions.

  FIGS. 3A to 3C are conceptual diagrams for correcting this phase shift.

  The black pixel in FIG. 3 (a) indicates the phase that the target pixel S should be originally, and the gray pixel is a virtual pixel that indicates the position where the target pixel S was photographed with a phase shift due to the influence of lateral chromatic aberration. S ′.

  In order to correct the lateral chromatic aberration, a virtual pixel S ′ whose phase is shifted by Hp in the horizontal direction and Vp in the vertical direction may be obtained and rearranged at the position of the pixel of interest S.

  As shown in FIG. 3B, the virtual pixel S ′ is a pixel between the pixels s1, s2, s3, s4 and the virtual pixel S ′ from the actually photographed pixels s1, s2, s3, s4 that exist in the vicinity. It can be generated by performing a weighted interpolation calculation with the distances c1, c2, c3, and c4.

  The generated virtual pixel S ′ is replaced with the position of the pixel of interest S as shown in FIG. 3C, and the lateral chromatic aberration is corrected.

  The color blur suppression unit 11 performs color blur suppression processing on the image signal on which the magnification chromatic aberration correction processing has been performed.

  FIG. 4 shows a configuration diagram of the color blur suppression unit 11.

  In this embodiment, the description will be made assuming that all pixel positions have RGB values.

  The contrast detection unit 1101 performs a filter operation using a first-order differential filter such as a Sobel filter, and outputs the output as a contrast value.

  The suppression coefficient calculation unit 1104 calculates the suppression coefficient according to the R contrast signal from the contrast detection unit 1101.

  The suppression process 1107 suppresses color blur in accordance with the R image plane and the suppression coefficient from the suppression coefficient calculation unit 1104.

  The contrast detection unit 1102 performs a filter operation using a first-order differential filter such as a Sobel filter and outputs the output as a contrast value.

  The suppression coefficient calculation unit 1105 calculates a suppression coefficient according to the G contrast signal from the contrast detection unit 1102.

  The suppression process 1108 suppresses color blur according to the G image plane and the suppression coefficient from the suppression coefficient calculation unit 1105.

  The contrast detection unit 1103 performs a filter operation using a first-order differential filter such as a Sobel filter and outputs the output as a contrast value.

  The suppression coefficient calculation unit 1106 calculates a suppression coefficient according to the B contrast signal from the contrast detection unit 1103.

  The suppression processing 1109 suppresses color blur according to the B image plane and the suppression coefficient from the suppression coefficient calculation unit 1106.

  Next, the operation of the suppression coefficient calculation means 1104 to 1106 will be described in detail.

  The suppression function of the suppression coefficient calculation means 1104 to 1106 determines a function shape as shown in FIG. 5 using, for example, the calculation shown in [Equation 5].

  In [Equation 5], kr represents a suppression coefficient, A represents the amplitude of the contrast signal detected by the contrast detection means 1101 to 1103, and Th1 and Th2 are determined in advance according to the contrast range in which color blur suppression is performed. Indicates the value.

  The chromatic aberration evaluation means 123 obtains an edge shape evaluation value after chromatic aberration correction from the information regarding the inclination of the edge of the image due to the chromatic aberration of magnification in the optical database 73, and outputs a control signal of the selector 13.

  The edge shape evaluation value is obtained by the following method.

  First, from the optical database 73, information on the inclination of the edge of the image due to the lateral chromatic aberration of RGB is acquired.

  FIGS. 12A, 12C and 12E show the relationship between the G edge and the R or B edge inclination.

  FIGS. 12 (b), (d), and (f) are graphs showing the shift amount when the edge is shifted and the PSNR value at that time with respect to the edge that has shifted due to lateral chromatic aberration. Is.

  The difference between the maximum value and the minimum value of PSNR is obtained as an edge shape evaluation value.

In FIG. 12 (a), the slope of G and the edge of R or B are the same, meaning that they are standing upright. The shift amount and the PSNR at this time are as shown in FIG. 12 (b). The PSNR output at the completely coincident portion is large, and the PSNR output when it does not coincide is small.
Therefore, the edge shape evaluation value is a large value.

In FIG. 12 (c), the slopes of the G edge and the R or B edge are the same, but both edges are dull. The shift amount and the PSNR at this time are as shown in FIG. 12 (d), and the PSNR output at the completely coincident portion is maximized, but the PSNR output is increased as a whole.
Therefore, the edge shape evaluation value is a small value.

  FIG. 12 (e) means a state in which the slope of the G edge and the R or B edge are different. The shift amount and the PSNR at this time are as shown in FIG. 12 (f), and since there is no complete coincidence, the PSNR output is reduced as a whole.

  Therefore, the edge shape evaluation value is a small value.

  The relationship between the edge shape evaluation value and the output signal of the chromatic aberration evaluation means 123 is shown in FIG.

  When the output of the edge shape evaluation value is smaller than the predetermined value γ, it means that the edge is dulled by correcting the chromatic aberration of magnification. Therefore, 1 is output so that data that does not suppress color blurring is output. Signal. When the output of the edge shape evaluation value is large, it means that the edge is still standing after the correction of the chromatic aberration of magnification. Therefore, 0 is used as the output signal so that the data subjected to the color blur suppression is output.

  The selector 13 selects and outputs the output image signal of the magnification chromatic aberration correction unit 10 and the output signal of the color blur suppression unit 11 according to the output signal of the chromatic aberration evaluation unit 123.

  When the output signal of the chromatic aberration evaluation unit 123 is 1, there is a high possibility that the color edge is achromatic due to the color blur suppression process. Therefore, the output image signal of the magnification chromatic aberration correction unit 10 that does not perform the color blur suppression process is used. If the output signal is 0 and the output signal of the chromatic aberration evaluation means 123 is 0, it means that the desired color blur suppression process can be performed. Therefore, the output image signal of the color blur suppression means 11 subjected to the color blur suppression process is output.

  As described above, according to the output signal of the chromatic aberration evaluation means, the output image of the magnification chromatic aberration correction process and the output image obtained by performing the color blur suppression process on the output image of the magnification chromatic aberration correction process are selected and output. As a result, it is possible to output an image in which the achromatic color of the edge due to erroneous determination of the color blur suppression process is reduced.

[Example 4]
(Multi-valued control determined by additional information in optical DB)
FIG. 13 shows a block diagram of the image pickup apparatus of the present invention of the fourth embodiment.

  The fourth embodiment is substantially the same as the third embodiment, and the same members are denoted by the same reference numerals, and the description thereof is omitted. The difference is that the operation of the color blur suppression unit 114 is controlled in accordance with the output signal of the chromatic aberration evaluation unit 124.

  FIG. 8 shows a configuration diagram of the color blur suppression unit 114.

  Since the operations of the contrast detection units 1101 to 1103 and the suppression units 1107 to 1109 are the same as those in the third embodiment, the description thereof will be omitted, and the suppression coefficient calculation units 1124 to 1126 which are features of the present invention will be described.

  The suppression function of the suppression coefficient calculation means 1124 to 1126 determines a function shape as shown in FIG. 9, for example, using the calculation shown in [Equation 6].

  In [Equation 6], kr indicates a suppression coefficient, A indicates the amplitude of the contrast signal detected by the contrast detection means 1101 to 1103, and Th1 and Th2 are predetermined according to the contrast range in which color blur suppression is performed. Β represents a chromatic aberration evaluation value that is an output signal of the chromatic aberration evaluation means 124.

  Since β, which is an output signal of the chromatic aberration evaluating means 124, is small, the maximum value of the suppression effect of color blur suppression is small, so the degree of suppression is small, and if the value is large, the maximum value of suppression gain of color blur suppression is large. Since it increases, the degree of suppression increases.

  The chromatic aberration evaluation means 124 obtains an edge shape evaluation value after chromatic aberration correction from the information regarding the inclination of the edge of the image due to the chromatic aberration of magnification in the optical database 73, and obtains a chromatic aberration evaluation value from the edge shape evaluation value.

  The edge shape evaluation value is obtained by the following method.

  First, from the optical database 73, information on the inclination of the edge of the image due to the lateral chromatic aberration of RGB is acquired.

  FIGS. 12A, 12C and 12E show the relationship between the G edge and the R or B edge inclination.

  FIGS. 12 (b), (d), and (f) are graphs showing the shift amount when the edge is shifted and the PSNR value at that time with respect to the edge that has shifted due to lateral chromatic aberration. Is.

  The difference between the maximum value and the minimum value of PSNR is obtained as an edge shape evaluation value.

  In FIG. 12 (a), the slope of G and the edge of R or B are the same, meaning that they are standing upright. The shift amount and the PSNR at this time are as shown in FIG. 12 (b). The PSNR output at the completely coincident portion is large, and the PSNR output when it does not coincide is small. Therefore, the edge shape evaluation value is a large value.

In FIG. 12 (c), the slopes of the G edge and the R or B edge are the same, but both edges are dull. The shift amount and the PSNR at this time are as shown in FIG. 12 (d), and the PSNR output at the completely coincident portion is maximized, but the PSNR output is increased as a whole.
Therefore, the edge shape evaluation value is a small value.

  FIG. 12 (e) means a state in which the slope of the G edge and the R or B edge are different. The shift amount and the PSNR at this time are as shown in FIG. 12 (f), and since there is no complete coincidence, the PSNR output is reduced as a whole.

  Therefore, the edge shape evaluation value is a small value.

  FIG. 14 shows the relationship between the edge shape evaluation value and the chromatic aberration evaluation value.

  The larger the edge shape evaluation value, the smaller the dullness of the edge due to the correction of the chromatic aberration of magnification. Therefore, a larger chromatic aberration evaluation value is output. This graph is merely an example, and it is sufficient that the chromatic aberration evaluation value increases as the edge shape evaluation value increases.

  As described above, by adjusting the degree of suppression of the color blur suppression process performed on the output image of the magnification chromatic aberration correction process according to the output signal of the chromatic aberration evaluation unit, the edge caused by the erroneous determination of the color blur suppression process An image with reduced achromatic color can be output.

[Example 5]
(Control when combining two actions, binary control)
FIG. 15 shows a block diagram of an image pickup apparatus according to the fifth embodiment of the present invention.

  In FIG. 15, 1 is an optical system including a zoom lens, a focus lens, and a diaphragm, 2 is an optical system driving means for driving the optical system 1, 3 is an image sensor, 4 is an image sensor driving means for driving the image sensor 3, 5 is an analog front end unit (shown as AFE) including CDS means and an A / D converter, 6 is a system control unit, 73 is a table of magnification chromatic aberration correction amounts calculated in advance from a plurality of image heights and optical parameters, and An optical database that holds information about the inclination of the edge of the image due to chromatic aberration of magnification, 8 is an image height calculation means for calculating the distance from the optical center, and 9 is an image height calculation from a table of magnification chromatic aberration correction amounts acquired from the optical database 73. Correction amount generation means for generating a correction amount according to the image height acquired from the means 8, 10 is a magnification for performing magnification chromatic aberration correction processing by the generated correction amount Chromatic aberration correction means 11, color blur suppression means for performing color blur suppression processing on an image signal subjected to magnification chromatic aberration correction processing, and 125 a correction amount generated by the correction amount generation means 9 and a magnification obtained from the optical database 73. Chromatic aberration evaluating means for evaluating the edge shape after correcting the chromatic aberration of magnification from information on the inclination of the edge of the image due to chromatic aberration. It is a selector that selects and outputs in accordance with the output signal of the evaluation means 125.

  Hereinafter, a photographing operation in the imaging apparatus configured as described above will be described.

  First, the optical system 1 drives a diaphragm and a lens according to a control signal from the system control unit 6 to form a subject image controlled to an appropriate brightness on the image sensor 3. The image sensor 3 is driven by a drive pulse controlled by the system control unit 6, converts the subject image into an electrical signal by photoelectric conversion, and outputs it as an analog image signal. The analog image signal output from the image pickup device 3 is removed from the clock synchronization noise by the CDS means inside the AFE 5 by the drive pulse controlled by the system control unit 6, and the digital image signal by the A / D converter inside the AFE 5. Is converted to

  The image height calculation means 8 acquires the coordinate position of the pixel of interest and the coordinate position of the optical center by the system control unit 6, and obtains the image height hgt using the calculation shown in [Equation 7], for example.

  Here, xadr represents the horizontal coordinate of the pixel of interest, and yadr represents the vertical coordinate of the pixel of interest. Hc represents the horizontal coordinate of the optical center, and Vc represents the vertical coordinate of the optical center.

  The correction amount generation unit 9 calculates a correction amount according to the image height acquired from the image height calculation unit 8 from the table of the magnification chromatic aberration correction amount acquired by the system control unit 6.

  The magnification chromatic aberration correction amount table acquired from the optical database shows the number of pixels that are shifted from the correct pixel position in decimal units. When the value is positive, the table is shifted outward from the optical center and negative. When it is a value, it indicates that it is shifted inward with respect to the optical center. The optical database stores a correction amount with respect to the image height for each predetermined section, and the data between the stored image heights is obtained by linear approximation or quadratic curve approximation. .

  The lateral chromatic aberration correction unit 10 performs lateral chromatic aberration correction processing on the input image signal based on the correction amount acquired from the correction amount generation unit 9.

  The optical correction amount for correcting the lateral chromatic aberration is a phase shift amount obtained by separating the distortion amount at the target pixel position as a phase shift component in the horizontal and vertical directions.

  FIGS. 3A to 3C are conceptual diagrams for correcting this phase shift.

  The black pixel in FIG. 3 (a) indicates the phase that the target pixel S should be originally, and the gray pixel is a virtual pixel that indicates the position where the target pixel S was photographed with a phase shift due to the influence of lateral chromatic aberration. S ′.

  In order to correct the lateral chromatic aberration, a virtual pixel S ′ whose phase is shifted by Hp in the horizontal direction and Vp in the vertical direction may be obtained and rearranged at the position of the pixel of interest S.

  As shown in FIG. 3B, the virtual pixel S ′ is a pixel between the pixels s1, s2, s3, s4 and the virtual pixel S ′ from the actually photographed pixels s1, s2, s3, s4 that exist in the vicinity. It can be generated by performing a weighted interpolation calculation with the distances c1, c2, c3, and c4.

  The generated virtual pixel S ′ is replaced with the position of the pixel of interest S as shown in FIG. 3C, and the lateral chromatic aberration is corrected.

  The color blur suppression unit 11 performs color blur suppression processing on the image signal on which the magnification chromatic aberration correction processing has been performed.

  FIG. 4 shows a configuration diagram of the color blur suppression unit 11.

  In this embodiment, the description will be made assuming that all pixel positions have RGB values.

  The contrast detection unit 1101 performs a filter operation using a first-order differential filter such as a Sobel filter, and outputs the output as a contrast value.

  The suppression coefficient calculation unit 1104 calculates the suppression coefficient according to the R contrast signal from the contrast detection unit 1101.

  The suppression process 1107 suppresses color blur in accordance with the R image plane and the suppression coefficient from the suppression coefficient calculation unit 1104.

  The contrast detection unit 1102 performs a filter operation using a first-order differential filter such as a Sobel filter and outputs the output as a contrast value.

  The suppression coefficient calculation unit 1105 calculates a suppression coefficient according to the G contrast signal from the contrast detection unit 1102.

  The suppression process 1108 suppresses color blur according to the G image plane and the suppression coefficient from the suppression coefficient calculation unit 1105.

  The contrast detection unit 1103 performs a filter operation using a first-order differential filter such as a Sobel filter and outputs the output as a contrast value.

  The suppression coefficient calculation unit 1106 calculates a suppression coefficient according to the B contrast signal from the contrast detection unit 1103.

  The suppression processing 1109 suppresses color blur according to the B image plane and the suppression coefficient from the suppression coefficient calculation unit 1106.

  Next, the operation of the suppression coefficient calculation means 1104 to 1106 will be described in detail.

  The suppression function of the suppression coefficient calculation means 1104 to 1106 determines the function shape as shown in FIG. 5 by using the calculation shown in [Equation 8], for example.

  In [Equation 8], kr indicates a suppression coefficient, A indicates the amplitude of the contrast signal detected by the contrast detection units 1101 to 1103, and Th1 and Th2 are predetermined according to a contrast range in which color blur suppression is performed. Indicates the value.

  The chromatic aberration evaluation unit 125 obtains an edge shape evaluation value after chromatic aberration correction from the information regarding the inclination of the edge of the image due to the chromatic aberration of magnification in the optical database 73, and further obtains a chromatic aberration evaluation value from the output signal of the correction amount generation unit 9. A control signal of the selector 13 is output from the shape evaluation value and the chromatic aberration evaluation value.

  The edge shape evaluation value is obtained by the following method.

  First, from the optical database 73, information on the inclination of the edge of the image due to the lateral chromatic aberration of RGB is acquired.

  FIGS. 12A, 12C and 12E show the relationship between the G edge and the R or B edge inclination.

  FIGS. 12 (b), (d), and (f) are graphs showing the shift amount when the edge is shifted and the PSNR value at that time with respect to the edge that has shifted due to lateral chromatic aberration. Is.

  The difference between the maximum value and the minimum value of PSNR is obtained as an edge shape evaluation value.

  In FIG. 12 (a), the slope of G and the edge of R or B are the same, meaning that they are standing upright. The shift amount and the PSNR at this time are as shown in FIG. 12 (b). The PSNR output at the completely coincident portion is large, and the PSNR output when it does not coincide is small. Therefore, the edge shape evaluation value is a large value.

  In FIG. 12 (c), the slopes of the G edge and the R or B edge are the same, but both edges are dull. The shift amount and the PSNR at this time are as shown in FIG. 12 (d), and the PSNR output at the completely coincident portion is maximized, but the PSNR output is increased as a whole. Therefore, the edge shape evaluation value is a small value.

  FIG. 12 (e) means a state in which the slope of the G edge and the R or B edge are different. The shift amount and the PSNR at this time are as shown in FIG. 12 (f), and since there is no complete coincidence, the PSNR output is reduced as a whole. Therefore, the edge shape evaluation value is a small value.

  The chromatic aberration evaluation value is obtained by the following method.

  FIG. 6 shows the relationship between the fractional part of the correction amount, which is the output signal of the correction amount generating means 9, and the frequency characteristics. A correction amount of 1 means that the correction position is an adjacent pixel position. The frequency characteristic is lowest at the center of the pixel position.

  FIG. 10 shows the relationship between the decimal part of the correction amount and the chromatic aberration evaluation value. When the frequency characteristic is high, it means that the influence of the edge dullness due to the correction of the chromatic aberration of magnification is small, and a value close to 1 is output. When the frequency characteristic is low, it means that the influence of edge dullness due to magnification chromatic aberration correction is large, and thus a value close to 0 is output.

  This graph is merely an example, and it is only necessary to have a characteristic that outputs a large value when the frequency characteristic is high and outputs a small value when the frequency characteristic is low.

  FIG. 19 shows a relationship diagram for obtaining the output signal of the chromatic aberration evaluation means 125 from the edge shape evaluation value and the chromatic aberration evaluation value.

  When the value of the edge shape evaluation value is smaller than a predetermined value γ, it means that the dullness of the edge is increased by correcting the chromatic aberration of magnification, so that data that does not perform color blur suppression processing is output. 0 is output as an output signal of the chromatic aberration evaluating means 125.

  When the value of the edge shape evaluation value is larger than the predetermined value γ and the chromatic aberration evaluation value obtained from the frequency characteristics is smaller than the predetermined value α, the edge before magnification chromatic aberration correction is steep. This means that the edge is dull due to the correction of the chromatic aberration of magnification, and there is a possibility that the color blur is spread by the interpolation process of the correction of the chromatic aberration of magnification, so 0 is set so as to output data without performing the color blur suppression process. Output as an output signal of the chromatic aberration evaluation means 125.

  When the edge shape evaluation value is larger than the predetermined value γ and the chromatic aberration evaluation value obtained from the frequency characteristics is larger than the predetermined value α, the edge before correction of the chromatic aberration of magnification is cut off and the magnification is increased. Since there is little influence of edge dullness due to chromatic aberration correction, 1 is output as an output signal of the chromatic aberration evaluation means 125 so as to output data subjected to color blur suppression processing.

  The selector 13 selects and outputs the output image signal of the magnification chromatic aberration correction unit 10 and the output image signal of the color blur suppression unit 11 according to the output signal of the chromatic aberration evaluation unit 125.

  When the output signal of the chromatic aberration evaluation unit 125 is 1, there is a high possibility that the color edge is achromatic due to the color blur suppression process. Therefore, the output image signal of the magnification chromatic aberration correction unit 10 that does not perform the color blur suppression process is used. If the output signal of the chromatic aberration evaluation means 125 is 0, the desired color blur suppression process can be performed. Therefore, the output image signal of the color blur suppression means 11 subjected to the color blur suppression process is output.

  As described above, according to the output signal of the chromatic aberration evaluation means, the output image of the magnification chromatic aberration correction process and the output image obtained by performing the color blur suppression process on the output image of the magnification chromatic aberration correction process are selected and output. As a result, it is possible to output an image in which the achromatic color of the edge due to erroneous determination of the color blur suppression process is reduced.

[Example 6]
(Control when two operations are combined, multi-value control)
FIG. 16 is a block diagram of the image pickup apparatus of the present invention according to the sixth embodiment.

  The sixth embodiment is substantially the same as the fifth embodiment, and the same members are denoted by the same reference numerals, and description thereof is omitted. The difference is that the operation of the color blur suppression unit 116 is controlled in accordance with the output signal of the chromatic aberration evaluation unit 126.

  FIG. 8 shows a configuration diagram of the color blur suppression unit 116.

  Since the operations of the contrast detection means 1101 to 1103 and the suppression means 1107 to 1109 are the same as those in the fifth embodiment, description thereof will be omitted, and the suppression coefficient calculation means 1124 to 1126 which are features of the present invention will be described.

  The suppression function of the suppression coefficient calculation means 1124 to 1126 determines a function shape as shown in FIG. 9, for example, using the calculation shown in [Equation 9].

  In [Equation 9], kr indicates a suppression coefficient, A indicates the amplitude of the contrast signal detected by the contrast detection means 1101 to 1103, and Th1 and Th2 are determined in advance according to the contrast range in which color blur suppression is performed. Β represents a chromatic aberration evaluation value that is an output signal of the chromatic aberration evaluation means 126.

  Since β, which is an output signal of the chromatic aberration evaluating means 126, is small, the maximum value of the suppression gain for color blur suppression is small, so the degree of suppression is small, and if the value is large, the maximum value of the suppression gain for color blur suppression is Since it increases, the degree of suppression increases.

  The chromatic aberration evaluation unit 126 obtains an edge shape evaluation value after chromatic aberration correction from the information regarding the inclination of the edge of the image due to the chromatic aberration of magnification in the optical database 73, The state of chromatic aberration is evaluated, and the control signal of the color blur suppression means 116 is output.

  The edge shape evaluation value is obtained by the following method.

  First, from the optical database 73, information on the inclination of the edge of the image due to the lateral chromatic aberration of RGB is acquired.

  FIGS. 12A, 12C and 12E show the relationship between the G edge and the R or B edge inclination.

  FIGS. 12 (b), (d), and (f) are graphs showing the shift amount when the edge is shifted and the PSNR value at that time with respect to the edge that has shifted due to lateral chromatic aberration. Is.

  The difference between the maximum value and the minimum value of PSNR is obtained as an edge shape evaluation value.

  In FIG. 12 (a), the slope of G and the edge of R or B are the same, meaning that they are standing upright. The shift amount and the PSNR at this time are as shown in FIG. 12 (b). The PSNR output at the completely coincident portion is large, and the PSNR output when it does not coincide is small. Therefore, the edge shape evaluation value is a large value.

In FIG. 12 (c), the slopes of the G edge and the R or B edge are the same, but both edges are dull. The shift amount and the PSNR at this time are as shown in FIG. 12 (d), and the PSNR output at the completely coincident portion is maximized, but the PSNR output is increased as a whole.
Therefore, the edge shape evaluation value is a small value.

  FIG. 12 (e) means a state in which the slope of the G edge and the R or B edge are different. The shift amount and the PSNR at this time are as shown in FIG. 12 (f), and since there is no complete coincidence, the PSNR output is reduced as a whole.

  Therefore, the edge shape evaluation value is a small value.

  FIG. 14 shows the relationship between the edge shape evaluation value and the chromatic aberration evaluation value.

  The larger the edge shape evaluation value, the smaller the dullness of the edge due to the correction of the chromatic aberration of magnification. Therefore, a larger chromatic aberration evaluation value is output. This graph is merely an example, and it is sufficient that the chromatic aberration evaluation value increases as the edge shape evaluation value increases.

  FIG. 6 shows the relationship between the fractional part of the correction amount, which is the output signal of the correction amount generating means 9, and the frequency characteristics. A correction amount of 1 means that the correction position is an adjacent pixel position. The frequency characteristic is lowest at the center of the pixel position.

  FIG. 10 shows the relationship between the decimal part of the correction amount and the chromatic aberration evaluation value. When the frequency characteristic is high, it means that the influence of edge dullness due to magnification chromatic aberration correction is small, and a value close to 1 is set as a chromatic aberration evaluation value from the correction amount. If the frequency characteristic is low, it means that the influence of edge dullness due to magnification chromatic aberration correction is large, so a value close to 0 is used as the chromatic aberration evaluation value from the correction amount.

  This graph is merely an example, and it is only necessary to have a characteristic that outputs a large value when the frequency characteristic is high and outputs a small value when the frequency characteristic is low.

  The chromatic aberration evaluation value based on the edge shape evaluation value and the minimum value of the chromatic aberration evaluation value from the correction amount are output as an output signal of the chromatic aberration evaluation means 126.

  By using the minimum value of the chromatic aberration evaluation value as the output signal, when either one of the chromatic aberration evaluation values is small, the degree of suppression of the color blur suppression process can be reduced, that is, when both chromatic aberration evaluation values are large, that is, The degree of suppression of the color blur suppression process can be increased only when the edge before the lateral chromatic aberration correction is cut and the influence of the edge dullness due to the lateral chromatic aberration correction is small.

  As described above, by adjusting the degree of suppression of the color blur suppression process performed on the output image of the magnification chromatic aberration correction process according to the output signal of the chromatic aberration evaluation unit, the edge caused by the erroneous determination of the color blur suppression process An image with reduced achromatic color can be output.

1 Zoom lens, focus lens, optical system including aperture,
2 optical system driving means for driving the optical system 1;
3 Image sensor

Claims (11)

Optical system,
An image sensor that converts a subject image projected by the optical system into an image signal and outputs the image signal;
An optical database holding a table of chromatic aberration correction amounts;
Interpolation coefficient generating means for generating a chromatic aberration correction amount from the information in the optical database;
Magnification chromatic aberration correction means for correcting chromatic aberration of magnification according to the correction amount from the interpolation coefficient generation means;
Color blur suppression means for processing the output signal of the magnification chromatic aberration correction means;
Chromatic aberration evaluation means for evaluating the state of chromatic aberration correction in the pixel of interest from the output signal of the interpolation coefficient generation means;
In an imaging apparatus comprising: a selector that selects and outputs one of the output of the magnification chromatic aberration correction unit or the output of the color blur suppression unit;
An image pickup apparatus, wherein the output signal of the magnification chromatic aberration correction unit and the output signal of the color blur suppression unit are selected and output according to the output signal of the chromatic aberration evaluation unit. Optical system,
An image sensor that converts a subject image projected by the optical system into an image signal and outputs the image signal;
An optical database holding a table of chromatic aberration correction amounts;
Interpolation coefficient generating means for generating a chromatic aberration correction amount from the information in the optical database;
Magnification chromatic aberration correction means for correcting chromatic aberration of magnification according to the correction amount from the interpolation coefficient generation means;
Color blur suppression means for processing the output signal of the magnification chromatic aberration correction means;
In an imaging apparatus comprising chromatic aberration evaluation means for evaluating a state of chromatic aberration correction in a pixel of interest from an output signal of the interpolation coefficient generation means,
An image pickup apparatus that controls an operation of the color blur suppression unit in accordance with an output signal of the chromatic aberration evaluation unit. Optical system,
An image sensor that converts a subject image projected by the optical system into an image signal and outputs the image signal;
An optical database that holds a table of correction amounts of chromatic aberration of magnification and information about the inclination of the edge of the image due to chromatic aberration of magnification;
Interpolation coefficient generating means for generating a chromatic aberration correction amount from the information in the optical database;
Magnification chromatic aberration correction means for correcting chromatic aberration of magnification according to the correction amount from the interpolation coefficient generation means;
Color blur suppression means for processing the output signal of the magnification chromatic aberration correction means;
Chromatic aberration evaluation means for determining an edge shape by correcting the chromatic aberration of magnification from information on the inclination of the edge of the image due to chromatic aberration of magnification in the optical database;
In an imaging apparatus comprising: a selector that selects and outputs one of the output of the magnification chromatic aberration correction unit or the output of the color blur suppression unit;
An image pickup apparatus, wherein the output signal of the magnification chromatic aberration correction unit and the output signal of the color blur suppression unit are selected and output according to the output signal of the chromatic aberration evaluation unit. Optical system,
An image sensor that converts a subject image projected by the optical system into an image signal and outputs the image signal;
An optical database that holds a table of correction amounts of chromatic aberration of magnification and information about the inclination of the edge of the image due to chromatic aberration of magnification;
Interpolation coefficient generating means for generating a chromatic aberration correction amount from the information in the optical database;
Magnification chromatic aberration correction means for correcting chromatic aberration of magnification according to the correction amount from the interpolation coefficient generation means;
Color blur suppression means for processing the output signal of the magnification chromatic aberration correction means;
In an imaging apparatus comprising: chromatic aberration evaluating means for determining an edge shape by correcting chromatic aberration of magnification from information on an inclination of an edge of an image due to chromatic aberration of magnification of the optical database;
An image pickup apparatus that controls an operation of the color blur suppression unit in accordance with an output of the chromatic aberration evaluation unit. Optical system,
An image sensor that converts a subject image projected by the optical system into an image signal and outputs the image signal;
An optical database that holds a table of correction amounts of chromatic aberration of magnification and information about the inclination of the edge of the image due to chromatic aberration of magnification;
Interpolation coefficient generating means for generating a chromatic aberration correction amount from the information in the optical database;
Magnification chromatic aberration correction means for correcting chromatic aberration of magnification according to the correction amount from the interpolation coefficient generation means; Color blur suppression means for processing the output signal of the magnification chromatic aberration correction means;
Chromatic aberration evaluation means for determining edge shape by correction of chromatic aberration of magnification from the information on the inclination of the edge of the image due to chromatic aberration of magnification in the optical database and the output of the interpolation coefficient generation means;
In an imaging apparatus comprising: a selector that selects and outputs one of the output of the magnification chromatic aberration correction unit or the output of the color blur suppression unit;
An image pickup apparatus, wherein the output signal of the magnification chromatic aberration correction unit and the output signal of the color blur suppression unit are selected and output according to the output signal of the chromatic aberration evaluation unit. Optical system,
An image sensor that converts a subject image projected by the optical system into an image signal and outputs the image signal;
An optical database that holds a table of correction amounts of chromatic aberration of magnification and information about the inclination of the edge of the image due to chromatic aberration of magnification;
Interpolation coefficient generating means for generating a chromatic aberration correction amount from the information in the optical database;
Magnification chromatic aberration correction means for correcting chromatic aberration of magnification according to the correction amount from the interpolation coefficient generation means;
Color blur suppression means for processing the output signal of the magnification chromatic aberration correction means;
In an imaging apparatus comprising chromatic aberration evaluation means for determining edge shape by magnification chromatic aberration correction based on information on the inclination of an edge of an image due to magnification chromatic aberration in the optical database and an output of the interpolation coefficient generation means,
An image pickup apparatus that controls an operation of the color blur suppression unit in accordance with an output of the chromatic aberration evaluation unit. The image pickup apparatus according to claim 2, wherein the color blur suppression unit adjusts a suppression gain according to an output signal of the chromatic aberration evaluation unit. 5. The chromatic aberration evaluation unit outputs a smaller value from the output signal of the interpolation coefficient calculation unit as the value of the decimal part of the correction coefficient is closer to 0.5. The imaging device according to item. The optical database
The imaging apparatus according to claim 3, wherein the information related to the inclination of the edge of the image due to the lateral chromatic aberration is image information when a predetermined subject is photographed. 5. The image pickup apparatus according to claim 3, wherein the chromatic aberration evaluation unit outputs a large value when the value of the information related to the inclination of the edge of the image due to the chromatic aberration of magnification in the optical database is large. The chromatic aberration evaluation means has a large value of information regarding the inclination of the edge of the image due to the chromatic aberration of magnification in the optical database, and the value of the decimal part of the correction coefficient of the output signal of the interpolation coefficient calculation means is more than 0.5. The imaging apparatus according to claim 5, wherein a larger value is output as the value increases.