JP2016051982A - Image processing system, camera, and image processing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing system which creates an image with high reproducibility of a light source such as a point light source.SOLUTION: The image processing system comprises: an area detection part which detects an area with a predetermined luminance or more from an image; and a reflection part which reflects the luminance and color tone of the area detected by the area detection part in the peripheral area of the area.SELECTED DRAWING: Figure 10

Description

  The present invention relates to an image processing apparatus, a camera, and an image processing program.

  Conventionally, image processing for improving the dynamic range and contrast of an image is known. For example, Patent Document 1 describes an imaging apparatus that extracts illumination components and reflectance components from an image and changes the dynamic range and contrast of the image based on those components.

JP 2007-28088 A

  In an image to which the conventional technology is applied, there is a problem in that the reproducibility of appearance is poor due to insufficient brightness of a light source such as a point light source.

The image processing apparatus according to claim 1, wherein an area detection unit that detects a high-brightness area having a predetermined luminance or more from an image, and a high-brightness area around the high-brightness area detected by the area detection unit. And a reflecting unit that reflects the luminance and color tone of the region.
The image processing apparatus according to claim 8, wherein a peripheral maximum luminance detecting unit that detects a peripheral maximum luminance near the target pixel, and a luminance of the target pixel as the peripheral maximum luminance detected by the peripheral maximum luminance detecting unit increases. A spatial filter that corrects the pixel of interest so that the
A camera according to a ninth aspect includes the image processing apparatus according to any one of the first to eighth aspects.
The image processing program according to claim 10, wherein an area detection step for detecting an area having a luminance of a predetermined level or more from an image, and the brightness and color tone of the area are set in a peripheral area detected by the area detection step. And causing the computer to execute a reflection step to be reflected.

  According to the present invention, an image with high reproducibility of a light source such as a point light source can be created.

It is sectional drawing which shows typically the structure of the camera which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows an example of the gradation curve G1. It is explanatory drawing which shows an example of the gradation curve G2. It is explanatory drawing which shows an example of the gradation curve G3. It is explanatory drawing which shows an example of the mixing coefficient W1. It is explanatory drawing which shows an example of the mixing coefficient W2. It is explanatory drawing which shows typically an example of the execution result of the area expansion process of a high-intensity pixel. It is a flowchart of the area expansion process of the high-intensity pixel in 1st Embodiment. It is a flowchart of the area expansion process of the high-intensity pixel in 2nd Embodiment. It is explanatory drawing explaining the concept of the area expansion process of a high-intensity pixel.

(First embodiment)
FIG. 1 is a cross-sectional view schematically showing a configuration of a camera according to the first embodiment of the present invention. The camera 1 is a so-called single-lens reflex digital camera. The camera 1 includes a control unit 10, a photographing lens 11, an aperture 12, a quick return mirror 13, a viewfinder screen 14, a pentaprism 15, a photometric lens 16, a photometric sensor 17, a focal plane shutter 18, an image sensor 19, and an eyepiece lens 20. Prepare.

  The control unit 10 includes a CPU (not shown) and its peripheral circuits, and controls the entire camera 1 by reading and executing a predetermined control program from a storage medium (not shown). The taking lens 11 forms a subject image on a predetermined planned focal plane. The diaphragm 12 restricts subject light passing through the photographing lens 11. The quick return mirror 13 is configured to be movable between a normal position and a retracted position. The quick return mirror 13 at the normal position reflects the subject light from the photographing lens 11 toward the pentaprism 15. The reflected subject light enters the pentaprism 15 via the finder screen 14, and then travels to the photometric sensor 17 and the eyepiece 20. The photometric sensor 17 receives the subject light via the photometric lens 16 to measure the amount of the subject light. A user of the camera 1 can visually recognize a subject image through the eyepiece lens 20.

  When shooting (exposure) is performed, the quick return mirror 13 moves to the retracted position. At this time, the subject light that has passed through the photographing lens 11 travels to the image sensor 19. The image pickup device 19 is an image pickup device such as a CMOS or a CCD, for example, and picks up a subject image and outputs an image pickup signal (image signal). The focal plane shutter 18 controls the photographing time (exposure time) by the image sensor 19.

  Next, image processing executed by the control unit 10 to create captured image data will be described. The control unit 10 executes the processes (1) to (8) described below in order to create captured image data.

(1) The controller 10 first performs well-known white balance processing and Bayer interpolation processing (so-called demosaicing processing) on the image signal output from the image sensor 19.

(2) Next, in order to compress the dynamic range, the control unit 10 applies the gradation curve G1 shown in FIG. 2 to the image signal after executing the processing of (1). FIG. 2 is a graph in which the horizontal axis represents an input signal and the vertical axis represents an output signal, and a straight line X passing through the origin is shown by a broken line together with the gradation curve G1.

  The gradation curve G1 is a curve having a characteristic known as a knee characteristic, for example. In the region where the light reception output is lower than the predetermined threshold th1, the input signal and the output signal are in a proportional relationship, and the gradation curve G1 substantially coincides with the straight line X. On the other hand, in the region exceeding the threshold value th1, the output signal becomes lower than the value represented by the straight line X as the input signal increases. The controller 10 compresses the dynamic range of the image signal by applying the gradation curve G1 having the above characteristics to the image signal.

(3) Next, the control unit 10 applies the gradation curve G2 shown in FIG. 3 to the image signal after the processing of (2) is executed. The gradation curve G2 is a curve that gives an inverse gamma of a standard gamma value (2.2 power) of a so-called sRGB monitor.

(4) Next, the control unit 10 converts the color space of the image signal after performing the processing of (3). The image sensor 19 of the present embodiment has image pixels corresponding to red (R), green (G), and blue (B), and the color space of the output signal (image signal) is an RGB space. The control unit 10 converts the color space of the image signal from the RGB space to the YCbCr space using the following formulas (1) to (3) so that it can be easily handled in the area expansion process of the high-luminance pixel described later.
Y = k11 * R + k12 * G + k13 * B (1)
Cb = k21 * R + k22 * G + k23 * B (2)
Cr = k31 × R + k32 × G + k33 × B (3)

  Here, R, G, and B are pixel values corresponding to red, green, and blue of each demosaiced pixel. Kxy (x = 1 to 3, y = 1 to 3) is a predetermined constant for converting the color space from the RGB space to the YCbCr space. These constants are determined in advance based on the color tone required for display and printing.

(5) Next, the control unit 10 applies the gradation curve G3 shown in FIG. 4 to the luminance Y of the image signal after executing the processing of (4). FIG. 4 is a graph in which the horizontal axis represents the input signal and the vertical axis represents the output signal, and the straight line X passing through the origin is shown by a broken line together with the gradation curve G3. The gradation curve G3 has an S-shaped value so that the contrast of the luminance Y is increased. That is, in the gradation curve G3, the output signal is lower than the input signal in the region where the input signal is less than the predetermined threshold th2, and the output signal is input in the region where the input signal is the predetermined threshold th2 or more. The curve is higher than the signal.

(6) Next, the control unit 10 executes the area enlargement process of a high-luminance pixel, which will be described later, on the image signal after the process of (5) is executed.

(7) Next, the control unit 10 performs well-known image processing such as contour enhancement processing and noise reduction processing on the image signal after performing the processing of (6).

(8) Finally, the control unit 10 performs well-known image processing on the image signal after executing the processing of (7), and creates captured image data in a format such as JPEG, for example. The control unit 10 stores the created captured image data in a storage medium (not shown) (for example, a memory card).

(Explanation of high-luminance pixel area expansion processing)
Next, (6) the area expansion process of the high luminance pixel will be described in detail. In the area expansion process of the high-luminance pixel, the pixel value (luminance Y, color difference Cb, Cr) of the high-luminance pixel is reflected in the pixels located around the pixel having the luminance Y that is equal to or higher than a certain value (high luminance pixel) (Mixing) process.

  When the area expansion process of the high luminance pixel is executed, an effect like so-called halation is applied to the high luminance pixel. That is, it is possible to obtain a result in which the high luminance pixel is expanded in all directions.

  First, the control unit 10 selects one pixel from all pixels. The pixel selected here is referred to as a target pixel. For the target pixel, the control unit 10 searches for a pixel having the maximum luminance Y from the surrounding 5 × 5 pixels (a total of 24 pixels). In the following description, the pixel found here is referred to as a high luminance pixel, and the luminance Y of the high luminance pixel is referred to as luminance Ymax.

  Next, the control unit 10 sets the mixing coefficients W1, W2, and W3, respectively. These three mixing coefficients W1 to W3 are numerical values of 0 or more and 1 or less, respectively, and are set according to the procedure described below.

  The controller 10 applies the luminance Ymax to the graph shown in FIG. 5 and determines the mixing coefficient W1. In the graph of the mixing coefficient W1 shown in FIG. 5, the horizontal axis represents the luminance Ymax, and the vertical axis represents the value of the mixing coefficient W1. As shown in FIG. 5, the mixing coefficient W1 is set to 0 when the luminance Ymax is less than the threshold th3, and is set to increase as the luminance Ymax increases when the luminance Ymax is greater than or equal to the threshold th3.

  The threshold value th3 in FIG. 5 is substantially the same as the threshold value th1 in the tone curve G1 having the knee characteristic shown in FIG. That is, the mixing coefficient W1 shown in FIG. 5 corresponds to the knee characteristic, and is set to increase as the input signal (image signal) moves away from the linear value and approaches the saturation value. The mixing coefficient W1 is set to be smaller than 1 even when the luminance Ymax reaches the maximum value (saturation value).

  Next, the control unit 10 sets the mixing coefficient W2 based on the distance between the target pixel and the high luminance pixel. For example, as shown in FIG. 6, the mixing coefficient W2 is 1.0 when one of the eight pixels adjacent to the high luminance pixel 31 is the target pixel, and is one pixel separated from the high luminance pixel 31. If any of the 16 pixels is the target pixel, 0.5 is set.

  Next, the control unit 10 sets a mixing coefficient W3. The mixing coefficient W3 is a coefficient that can be arbitrarily designated by the user. The control unit 10 sets a numerical value designated in advance by the user as the mixing coefficient W3.

Next, the control part 10 mixes a high-intensity pixel with an attention pixel by following Formula (4)-(7).
Wm = W1 × W2 × W3 (4)
Yt ′ = (1−Wm) × Yt + Wm × Ym (5)
Cbt ′ = (1−Wm) × Cbt + Wm × Cbm (6)
Crt ′ = (1−Wm) × Crt + Wm × Crm (7)

  Here, Wm is a final weight determined based on the mixing coefficients W1, W2, and W3. Yt, Cbt, and Crt are the original luminance and color difference of the pixel of interest (before the area expansion process of the high luminance pixel), and Yt ′, Cbt ′, and Crt ′ are the new (high) of the pixel of interest. Luminance and color difference (after execution of luminance pixel area expansion processing).

  Since the mixing coefficients W1, W2, and W3 all take values in the range of 0 to 1, the weight Wm is also in the range of 0 to 1 from the above equation (4). The above equations (5) to (7) are colors for calculating a weighted average of the luminance and color difference of the target pixel and the luminance and color difference of the high luminance pixel using the weight Wm. The smaller the weight Wm, the greater the influence of the high luminance pixel on the target pixel.

  For example, when the luminance Yt of the high-luminance pixel is much larger than the luminance Ym of the pixel of interest and the weight Wm is small, the luminance Yt ′ of the pixel of interest is greatly increased from the original luminance Yt by the area expansion process of the high-luminance pixel. Become bigger. That is, it is greatly affected by the high luminance pixels.

  The control unit 10 repeatedly executes the above processing while changing the target pixel one after another. The control unit 10 performs the above processing until all the pixels are selected as the target pixel. As a result, the above-described Yt ′, Cbt ′, and Crt ′ are calculated for all the pixels.

  FIG. 7 is an explanatory diagram schematically illustrating an example of the execution result of the area enlargement process of the high luminance pixel. FIG. 7A is a diagram one-dimensionally showing the luminance Y of the pixels Pa to Po before processing in the form of a bar graph, and FIG. 7B is the area of the high luminance pixels with respect to the pixels Pa to Po. It is a figure which shows the result of having performed the expansion process.

  In the process of enlarging the area of the high luminance pixel, when all the pixels existing in the 5 × 5 range around the target pixel have luminance lower than the threshold value th3, the mixing coefficient W1 is set to zero. In this case, since the weight Wm is 0, the luminance Yt and the color differences Cbt and Crt of the target pixel do not change before and after the execution of the area expansion process of the high luminance pixel. Therefore, the luminance Y or the like does not change before and after the execution of the area expansion process of the high luminance pixel for the pixels (pixel Pb, pixel Pc, etc.) existing in the vicinity of the pixel Pa having the luminance Y less than the threshold th3.

  On the other hand, when attention is paid to a pixel having a luminance Y higher than the threshold th3, such as the pixel Pg and the pixel Pm, when a peripheral pixel (pixel Pf, pixel Ph, pixel Pl, etc.) is selected as the target pixel, the pixel Pg, pixel Pm, and the like are selected as high luminance pixels, and the luminance Y of the target pixel increases as the luminance Y of the high luminance pixel increases. Therefore, as shown in FIG. 7B, the pixels (pixel Pf, pixel Pl, etc.) existing in the vicinity of the pixel Pg and the pixel Pm correspond to the luminance Y of the high-luminance pixel by the area enlargement process of the high-luminance pixel. As a result, the luminance Y and the like increase. Further, the closer to the high-luminance pixel (pixel Pg, pixel Pm, etc.), the greater the luminance Y.

  As a result, as shown in FIG. 7B, high-luminance blur such as so-called halation occurs around the pixel Pg and the pixel Pm having high luminance Y. For example, when an object having a high luminance Y and a small area is reflected on the shooting screen, such as a point light source, the area of the object is enlarged by the area enlargement process of the high luminance pixel.

  Note that, in the area enlargement process of the high-luminance pixel in the present embodiment, the area of the object is enlarged even if the object has a large luminance Y and a large area. However, since such an object originally has a large area, even if the area is enlarged by 1 to 2 pixels in radius, the appearance in the image is hardly affected. That is, in a high-luminance subject having a large area, the area expansion effect obtained by the area expansion process of the high-luminance pixel is small. Accordingly, the area enlargement process of the high-luminance pixels is a process that works more effectively for a subject with a higher luminance Y and a smaller area.

  Next, the reason for executing the area expansion process of the high luminance pixel described above will be described. FIG. 10 is an explanatory diagram for explaining the concept of the process for enlarging the area of a high-luminance pixel. Assume that there is a pixel P with high brightness. As shown in FIG. 10A, since the actual luminance Yh of the pixel P is higher than the saturation level th4 of the image sensor 19, the brightness of the image sensor 19 cannot be fully expressed. That is, in the image photographed by the image sensor 19, the pixel P is expressed as a pixel having a luminance of about th4 at the maximum, and the viewer who appreciates this image feels that the scenery actually photographed is felt with the naked eye. Pixel P cannot be felt bright.

  When the area enlargement process of the high-brightness pixel is executed, the brightness Y of the pixels around the pixel P is raised as shown in FIG. 10B, and the area of the point light source expressed by the pixel P is enlarged. . This can be said that the original luminance Yh of the pixel P is transferred to the area. In other words, the brightness of the pixel P expressed in the vertical direction of the paper in FIG. 10B is virtually expressed by the area expressed in the horizontal direction of the paper in FIG. As a result, a viewer who appreciates this image can feel the subject portion represented by the pixel P brighter, and can approach the impression when the scenery actually captured is viewed with the naked eye. In other words, an image with high reproducibility of a light source such as a point light source can be created.

  FIG. 8 is a flowchart of the area enlargement process of the high luminance pixel. The process shown in FIG. 8 is included in a control program executed by the control unit 10. First, in step S10, the control unit 10 selects one unselected pixel from all the pixels as a target pixel. In step S20, the control unit 10 detects high-luminance pixels around the selected target pixel. In other words, the control unit 10 detects the peripheral maximum luminance value near the selected target pixel. In step S30, the control unit 10 determines the mixing coefficients W1 to W3. In step S40, the control unit 10 determines the weight Wm based on the above equation (4). In step S50, the control unit 10 calculates Yt ', Cbt', and Crt 'based on the above equations (5) to (7), respectively. In other words, the control unit 10 corrects the luminance value of the target pixel so that the luminance value of the target pixel increases as the detected peripheral maximum luminance value increases. In step S60, the control unit 10 determines whether all the pixels have been selected as the target pixel. If there is an unselected pixel, the control unit 10 advances the process to step S10. On the other hand, when all the pixels have been selected, the control unit 10 ends the process shown in FIG.

According to the camera according to the first embodiment described above, the following operational effects can be obtained.
(1) The control unit 10 includes a region detection unit (not shown) that detects a high luminance pixel (high luminance region) having a predetermined luminance or more from an image, and a peripheral region of the high luminance pixel detected by the region detection unit. A reflection unit (not shown) that reflects the luminance and color tone of the high-luminance pixel. Since it did in this way, an image with high reproducibility of light sources, such as a point light source, can be created. In particular, in an image in which the dynamic range is compressed, the luminance of such a light source is expressed while being suppressed more than actual, so that a higher effect can be obtained.

(2) The reflection unit determines a weight Wm that represents the degree to which the luminance and color tone of the high luminance pixel are reflected in the peripheral region, and based on the weight Wm, a weighted average of the luminance Ym of the high luminance pixel and the luminance Yt of the peripheral region. By calculating, the luminance Yt ′ of the peripheral region reflecting the luminance Ym of the high luminance pixel is determined, and the weight of the color tone (color difference Cbm, Crm) of the high luminance pixel and the color tone of the peripheral region (color difference Cbt, Crt) is determined. By calculating the average based on the weight Wm, the color tone (color difference Cbt ′, Crt ′) of the peripheral region reflecting the color tone (color difference Cbm, Crm) of the high luminance region is determined. Since it did in this way, an image with high reproducibility of light sources, such as a point light source, can be created.

(3) The reflection unit makes the weight Wm smaller when the high-luminance pixel has the first luminance than when the high-luminance pixel has the second luminance smaller than the first luminance. Since it did in this way, a brightness | luminance and a color tone can be reflected in a surrounding pixel by an appropriate quantity with respect to the brightness | luminance Ym of a high-intensity pixel.

(4) The reflection unit reduces the weight Wm in the first peripheral region separated from the high-luminance pixel by the first distance than in the second peripheral region separated from the high-luminance pixel by the second distance smaller than the first distance. Calculate the weighted average. Since it did in this way, the light which spreads centering on a high-intensity pixel can be reproduced.

(Second Embodiment)
The camera according to the second embodiment of the present invention will be described below. The camera of this embodiment has the same configuration as that of the camera 1 according to the first embodiment, except that the processing content of the area enlargement process for high-luminance pixels is different. Therefore, in the following, the content of the area expansion process of the high-luminance pixel executed by the control unit 10 in the present embodiment will be described, and description of other points will be omitted.

  In the first embodiment described above, the area expansion process of the high-luminance pixel is implemented as a process in the form of a general spatial filter. That is, the control unit 10 performs an operation of a spatial filter to determine a new pixel value of the target pixel for each target pixel while changing the target pixel based on the surrounding 5 × 5 pixels. Yes. Such a process has the advantage of being easy to implement.

  In the high-luminance pixel area enlargement processing according to the present embodiment, first, the control unit 10 scans the entire image signal and specifies a pixel whose luminance Y is equal to or higher than a predetermined threshold th3. In the following description, an area composed of pixels with a high luminance Y specified here is referred to as a high luminance area. Next, the control unit 10 checks whether or not the area of each high brightness area specified in this way is equal to or larger than a predetermined area. Here, the high-luminance region determined to have an area equal to or larger than the predetermined area is excluded from the subsequent processing targets. That is, the subsequent processing is executed only for the high-luminance region having an area less than the predetermined area.

  Next, the control unit 10 selects each pixel existing in the peripheral region of each high-luminance region as a target pixel, and determines the mixing coefficients W1 to W3 and the above equation (as in the above-described first embodiment). The high luminance pixel is mixed with the target pixel according to 4) to (7). Here, the peripheral area is an area obtained by excluding the high luminance area from an area obtained by enlarging the outline of the high luminance area by a predetermined number of pixels (for example, two pixels) in the vertical and horizontal directions.

  FIG. 9 is a flowchart of the area enlargement process of the high luminance pixel in the second embodiment. The process shown in FIG. 9 is included in a control program executed by the control unit 10. First, in step S80, the control unit 10 scans the entire image signal and specifies a high luminance area. In step S90, the control unit 10 excludes a high luminance region having an area equal to or larger than a predetermined area from all the high luminance regions specified in step S80. In step S <b> 110, the control unit 10 selects one pixel as a target pixel from the peripheral region of each identified high luminance region. In step S120, the control unit 10 detects high-luminance pixels around the selected target pixel. In step S130, the control unit 10 determines the mixing coefficients W1 to W3. In step S140, the control unit 10 determines the weight Wm based on the above equation (4). In step S150, the control unit 10 calculates Yt ′, Cbt ′, and Crt ′ based on the above equations (5) to (7), respectively. In step S160, the control unit 10 determines whether all the pixels have been selected as the target pixel. If there is an unselected pixel, the control unit 10 advances the process to step S110. On the other hand, when all the pixels have been selected, the control unit 10 ends the process shown in FIG.

According to the camera of the second embodiment described above, the following operational effects can be obtained.
(1) A reflection unit (not shown) included in the control unit 10 does not reflect the luminance and color tone of the high luminance region in the peripheral region when the area of the high luminance region is a predetermined value or more. Since it did in this way, a superior image can be created, without adding an extra effect with respect to the bright object different from a point light source etc.

  The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.

(Modification 1)
In the second embodiment, when the area of the high brightness area is equal to or larger than a predetermined value, the high brightness area is excluded from the area enlargement process. A condition other than this may be used to exclude the high luminance region from the area expansion process. For example, only when the length of the short side of the high-luminance region is a certain length or more, the high-luminance region is excluded from the area expansion process. In this way, not only the point light source but also the area of a high-brightness elongated object is enlarged. Therefore, for example, accessories such as necklaces and sea surface sparkling are emphasized in the same way as point light sources, and the appearance of the image is improved.

(Modification 2)
Various information such as characteristic information (lens information) of the photographic lens 11 may be used in the process of enlarging the area of the high luminance pixel. For example, when it is found from the lens information that the photographic lens 11 having a large aberration is attached to the camera 1, the weight Wm is reduced as compared with the case where the photographic lens 11 having a small aberration is attached. More desirable results can be obtained. This is because when the aberration is large, the point light source or the like appears slightly more blurry than the original, and if the area enlargement process is further performed on this, the area becomes excessively large.

(Modification 3)
Color space conversion need not be performed. That is, the area enlargement process of the high luminance pixel may be executed in the RGB color space. In this case, correction is performed with the maximum value around the pixel of interest for each color of red (R), green (G), and blue (B).

(Modification 4)
The method for setting the mixing coefficient W1 is not limited to that described above. For example, the threshold th3 may be different from the threshold th1 related to the knee characteristic. The mixing coefficient W1 may be set to 1. Further, the graph for determining the threshold th3 may be different from that in FIG. For example, when the luminance Ymax is greater than or equal to the threshold th3, the mixing coefficient W1 may be a value proportional to the luminance Ymax. Or, more simply, when the luminance Ymax is equal to or higher than the threshold th3, the mixing coefficient W1 is set to 1, and when the luminance Ymax is lower than the threshold th3, the mixing coefficient W1 is set to 0. You can also.

(Modification 5)
In determining the weight Wm, the mixing coefficient W2 and the mixing coefficient W3 may not be used. That is, the weight Wm may be determined using at least the mixing coefficient W1.

(Modification 6)
The search range of the high luminance pixel may not be a 5 × 5 range around the target pixel. For example, it may be within a circular range with a radius of 5 centering on the pixel of interest, or a high luminance pixel may be searched from a larger or smaller range.

(Modification 7)
In the above-described embodiment, the present invention is applied to a camera. However, the present invention is not limited to this, and an image processing apparatus that applies and outputs an area expansion process of high-luminance pixels to input image data. It is also possible. Note that the image processing apparatus here includes an apparatus that displays and prints image data, such as a printer, a copier, and a photo frame.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

DESCRIPTION OF SYMBOLS 1 ... Camera, 10 ... Control part, 11 ... Shooting lens, 12 ... Aperture, 13 ... Quick return mirror, 14 ... Viewfinder screen, 15 ... Pentaprism, 16 ... Photometric lens, 17 ... Photometric sensor, 18 ... Focal plane shutter, 19 ... Image sensor, 20 ... Eyepiece

Claims (10)

An area detection unit for detecting a high-luminance area having a predetermined luminance or higher from the image;
A reflection unit that reflects the luminance and color tone of the high-luminance region on the peripheral region of the high-luminance region detected by the region detection unit;
An image processing apparatus comprising: The image processing apparatus according to claim 1.
The reflection unit determines a weight representing a degree to which the luminance and color tone of the high luminance region are reflected in the peripheral region, and calculates a weighted average of the luminance of the high luminance region and the luminance of the peripheral region based on the weight. By determining the luminance of the peripheral region reflecting the luminance of the high luminance region, and calculating a weighted average of the color tone of the high luminance region and the color tone of the peripheral region based on the weight, An image processing apparatus for determining a color tone of the peripheral area reflecting a color tone of a high luminance area. The image processing apparatus according to claim 2,
The reflection unit is an image processing apparatus that reduces the weight when the high-luminance region has the first luminance, as compared with the case where the high-luminance region has the second luminance smaller than the first luminance. The image processing apparatus according to claim 2 or 3,
The reflection unit reduces the weight in the first peripheral area separated from the high brightness area by a first distance than in the second peripheral area separated from the high brightness area by a second distance smaller than the first distance. An image processing apparatus for calculating the weighted average. In the image processing apparatus according to any one of claims 2 to 4,
The reflection unit is an image processing apparatus that determines the weight based on characteristics of an optical system used for photographing the image. The image processing apparatus according to claim 5.
The reflection unit is photographed using a second optical system having a second aberration smaller than the first aberration for the image photographed using the first optical system having the first aberration. An image processing apparatus that makes the weight smaller than an image. In the image processing device according to any one of claims 2 to 6,
When the area of the high luminance region is equal to or greater than a predetermined value, or the length of the short side of the high luminance region is equal to or greater than the predetermined value, the reflecting unit has a luminance of the high luminance region in the peripheral region. And an image processing apparatus that does not reflect color tone. A peripheral maximum luminance detection unit for detecting the peripheral maximum luminance near the pixel of interest;
A spatial filter that corrects the pixel of interest so that the luminance of the pixel of interest increases as the peripheral maximum luminance detected by the peripheral maximum luminance detector increases.
An image processing apparatus comprising:   A camera comprising the image processing apparatus according to claim 1. An area detecting step for detecting an area having a predetermined luminance or more from an image;
A reflecting step of reflecting the brightness and color tone of the region on the peripheral region of the region detected by the region detecting step;
An image processing program for causing a computer to execute.

Images