JP6540392B2 - Image processing device - Google Patents

Description

  The present invention relates to image processing for captured images, and more particularly to image correction for lens aberrations.

  In a digital camera or the like, image quality deterioration such as distortion occurs due to lens aberration. In order to prevent this, distortion aberration correction is performed on the photographed image data according to the lens characteristics. Specifically, the coordinates of the pixel are corrected by interpolation processing such as linear interpolation and nearest neighbor interpolation.

  There is known a configuration in which image data before and after correction is superimposed and displayed in order to allow the user to adjust the correction amount while checking the correction accuracy (see Patent Document 1). Here, an object image to be corrected such as an object contour and an object image after correction based on a designated correction amount are displayed on the screen. The user confirms the correction accuracy such as the degree of correction and whether the correction is appropriate from the subject image before and after correction, and corrects the correction amount as appropriate.

JP, 2004-13461, A

  In the case of image quality deterioration due to an aberration or the like, it may be difficult for the user to confirm the correction accuracy even if the subject images before and after correction are superimposed and displayed. For example, when color blurring (fringe) caused by axial chromatic aberration is detected and corrected, the fringe detection portion is the same area and only the color is different.

  Therefore, for image quality deterioration such as chromatic aberration, it is required to be able to confirm in advance a portion detected by the user.

  The image processing apparatus of the present invention is applicable to an image pickup apparatus etc., and a false color detection unit for detecting a false color area in a photographed image and a false color area are identified based on color information of the photographed image. A display processing unit for displaying the detected image on the screen; a correction processing unit for executing a chromatic aberration correction process on the photographed image according to the false color area; and a recording processing unit for storing the photographed image corrected for the chromatic aberration in a memory. Prepare. For example, the correction processing unit can perform chromatic aberration correction in accordance with an operation performed after displaying a detected image before the captured image is corrected.

  The display processing unit may display the detected image based on a mask image obtained by masking the areas other than the false color area of the photographed image before correction. For example, the display processing unit can display, as a detected image, a composite image obtained by combining the photographed image before correction and the mask image.

  It is possible to further provide a false color area correction unit that corrects the false color area according to the input operation. The false color area correction unit can correct the false color area according to the range designated by the input operation for adding the false color area and / or deleting the false color area. Alternatively, the false color area correction unit may divide the correction area and the non-correction area in the false color area according to the input operation.

  The image processing method according to the present invention detects a false color area in a photographed image based on color information of the photographed image, displays a detected image in which the false color area is identified, and displays the detected image on the screen. The chromatic aberration correction process is performed on the photographed image, and the photographed image subjected to the chromatic aberration correction is stored in the memory. In the program according to the present invention, the image processing apparatus displays false color detection means for detecting a false color area in the photographed image based on color information of the photographed image, and a screen for a detected image in which the false color area is identified. It functions as a display processing means for displaying the image, a correction processing means for executing a chromatic aberration correction process on the photographed image according to the false color area, and a recording processing means for storing the photographed image subjected to the chromatic aberration correction in a memory.

  An image processing apparatus according to another aspect of the present invention is a display processing for displaying on a screen a false color detection unit that detects an image quality degradation area based on lens characteristics in a captured image, and a detection image in which the image quality degradation area is differentiated. And a correction processing unit that executes correction processing on the photographed image according to the image quality deterioration area, and a recording processing unit that stores the corrected photographed image in a memory.

  According to the present invention, it is possible to confirm the detection portion with respect to the image quality deterioration caused by the chromatic aberration or the like in the photographed image.

It is a block diagram of a digital camera which is this embodiment. It is a figure showing a photography picture, an image which extracted a fringe color field, and a mask picture which compounded them. It is a figure showing the edit screen of a fringe color field. It is a figure showing the edit screen of a fringe color field. It is the figure which showed the mask image after edit work. FIG. 6 is a view showing a photographed image corrected based on a corrected fringe color area. FIG. 6 is a flowchart of a fringe correction process performed in the image signal processing circuit.

  Hereinafter, the digital camera according to the present embodiment will be described with reference to the drawings.

  FIG. 1 is a block diagram of a digital camera according to the present embodiment.

  Here, the digital camera 10 is configured as a mirrorless camera, and the lens barrel 11 housing the imaging optical system 12 is detachably mounted on the main body of the digital camera 10. A photographing operation, reproduction of a recorded image, mode setting by a user, and the like are performed in accordance with operations on the release button, the cross button, the mode dial (all not shown) and the like.

  The controller 30, which includes a CPU, outputs control signals to the exposure control unit 32, the image signal processing circuit 40, etc., and executes exposure control and photographing / recording operations in accordance with the release operation detected by the release switch 37. Perform overall operation control. The program for camera operation control is stored in a non-volatile memory 18 such as a ROM. In addition, the controller 30 causes the image signal processing circuit 40 configured of a programmable circuit such as a DSP to have an image signal processing circuit and the like mounted.

  An object image is formed on the image sensor 14 by the light from the object passing through the photographing optical system 12. The image sensor 14 is configured by a CCD, a CMOS or the like, and the color filter array 14A is disposed opposite to the light receiving surface of the image sensor 14. Here, in the color filter array 14A, the color elements of R, G and B are arranged in a checkered pattern or Bayer pattern.

  In the photographing mode, in order to display a through image on the LCD monitor 60, pixel signals are read from the image sensor 14 at a predetermined frame rate. The read R, G, B pixel signals are sent to the image signal processing circuit 40 via the AFE circuit 16.

  The image signal processing circuit 40 applies gain processing, color conversion processing, white balance adjustment and the like to the R, G and B pixel signals to generate R, G and B color image signals. The LCD driver (not shown) drives the LCD monitor 60 based on the color image signal, whereby the through image is displayed on the LCD monitor 60.

  When the release button is pressed halfway, the contrast AF process is performed based on the pixel signal read from the image sensor 14. Along with the focusing operation by the contrast AF process, the brightness of the subject image is detected based on the pixel signal read from the image sensor 14, and the exposure value is calculated.

  When the release button is full-pressed, the exposure control unit 32 performs exposure control by driving a shutter, an aperture, and the like (not shown). Thus, pixel signals for one frame are read out from the image sensor 14. The image signal processing circuit 40 generates still image data based on the read pixel signal for one frame, and records the image data in a memory (here, the memory card 46) in a compressed / non-compressed state. When the reproduction mode is set, the image stored in the memory card 46 is displayed on the LCD monitor 60.

  In the function setting mode for the user to change the function etc., it is possible to set the chromatic aberration correction function ON / OFF. In the case of the chromatic aberration correction mode ON state, the image signal processing circuit 40 executes image processing for suppressing color blur and false color (hereinafter referred to as fringe) occurring in the photographed image.

  Specifically, after the image signals of R, G, B are converted into luminance, color difference signals Y, Cb, Cr, an image composed of the color difference signals Cb, Cr (hereinafter referred to as a CbCr image), and luminance A fringe area in a captured image is detected based on an image (hereinafter referred to as a Y image) composed of signals. Then, correction processing is performed to suppress color bleeding in the fringe region.

  Furthermore, when the fringe editing and photographing mode with fringe editing is set by the user, the fringe area is identified and the composite image made to be actualized is displayed on the LCD monitor 60, and the fringe area is corrected according to the editing work by the user. Then, a correction process based on the corrected fringe area is performed. The LCD monitor 60 has a touch panel 61, and in the fringe editing and photographing mode, displays an icon related to the editing operation as well as displaying a composite image. The controller 30 controls the image signal processing circuit 40 according to the screen operation of the user, and performs display according to the input operation.

  The non-volatile lens memory 15 provided in the lens barrel 11 stores data on lens characteristics of the photographing optical system 12, and data on lens chromatic aberration is included therein. The controller 30 reads lens data from the lens memory 15 and stores the lens data in the non-volatile memory 18. The image signal processing circuit 40 detects a fringe area using lens chromatic aberration data. The lens chromatic aberration data may be stored in advance in the non-volatile memory 18, or the lens chromatic aberration data may be stored in the non-volatile memory 18 using software or the like prepared separately from the digital camera 10. Good.

  Hereinafter, the correction of the fringe area before recording of the photographed image will be described with reference to FIGS.

  FIG. 2 is a view showing a photographed image, an image from which a fringe color area is extracted, and a mask image obtained by combining them.

  In the captured image IM shown in FIG. 2, a fringe F0 is generated in the outline portion of the subject P, and an image of the outline portion is formed by a color different from the actual color. In order to detect this fringe F, the luminance and color difference signals Y, Cb and Cr of one frame are separated into a luminance signal Y and color difference signals Cb and Cr, and a CbCr consisting of a Y image consisting of luminance signals and a color difference signal. Generate an image.

  For CbCr images, an image FI (hereinafter referred to as a fringe color extraction image) in which a region corresponding to the fringe color (hereinafter referred to as a fringe color region) is extracted based on color information with high possibility of fringe included in the other chromatic aberration. ) Is obtained. The color difference information used is a color distribution area regarded as a fringe color defined in the CbCr color space (color difference coordinate system), and the area is different for each lens. In FIG. 2, in the fringe extraction image FI, the pixel portion determined to be the fringe color is shown in white, and the other pixels are shown in black.

  When the fringe extraction image FI is obtained, the fringe correction image (hereinafter referred to as a composite image) IC is generated by combining the generated fringe extraction image (mask image) FI and the captured image IM, and the LCD monitor 60 is generated. Is displayed on. The combining process may be performed by addition of pixel values, calculation of an average value, comparative bright combining, or the like. The photographed image IM, the fringe extraction image FI, and the composite image IC are temporarily stored in a memory such as a RAM.

  In FIG. 2, the fringe portion F detected by the image processing includes a false detection portion F1. In addition, there is a detection leakage portion F2 which is not detected although it is a contour portion. Therefore, the user finds a false detection and a false detection part from the composite image IC, and uses the graphic function to correct the false detection and the false detection part.

  FIG. 3 and FIG. 4 are diagrams showing an editing screen of a fringe color area. FIG. 5 is a view showing the mask image after the editing operation. FIG. 6 is a view showing a photographed image corrected based on the corrected fringe color area.

  When the fringe edit photographing mode is set, the composite image IC shown in FIG. 2 is displayed on the LCD monitor 60 after the release button is operated. At this time, icons G1 and G2 indicating graphic functions are simultaneously displayed on the LCD monitor screen 60S. G1 is an icon for setting the line to be drawn on the screen, and G2 is an icon for setting the line drawn on the screen to be deleted.

  The user presses an icon G1 with a touch pen (not shown) with respect to the detection leakage portion F2 and moves a pencil mark PM displayed thereby, thereby drawing a line on the detection leakage portion F2. The drawn line is newly set as part of the fringe area. On the other hand, the user erases the false detection portion F1 by moving the eraser mark EM displayed by pressing the icon G2. The erased portion is excluded from the fringe area.

  As shown in FIG. 5, the fringe color area F shown in FIG. 2 is changed to a fringe color area F 'by the editing operation by the user. When the user performs an input operation of editing end using a cross button or the like, an image correction process according to the fringe color area F 'is performed. As a result, the contour portion of the object P that has become a false color becomes an accurate object color, and a photographed image P with fringe removal is obtained (see FIG. 6).

  FIG. 7 is a flowchart of the fringe correction process performed in the image signal processing circuit.

  When the photographing operation is performed, a fringe color area is detected as shown in FIG. 2, a mask image IC is generated by combining the photographed image IM and the fringe extraction image, and is displayed on the LCD monitor 60 (steps S1 to S3). Then, when the user performs an input operation to correct the fringe color area, the fringe color area is corrected based thereon (step S4). Then, based on the corrected fringe color area, chromatic aberration correction processing is performed (step S5). If the correction is not made, the detected fringe color area is subjected to the chromatic aberration correction processing as it is. The photographed image from which the fringes have been removed is recorded on the memory card 46 (step S6). At this time, the captured image to be stored is displayed on the LCD monitor 60.

  As described above, according to the present embodiment, before recording a captured image, a composite image in which the detected fringe area can be identified on the screen is displayed. Thereby, the user can confirm the fringe erroneous detection part and the detection omission part. In particular, since it is a composite image based on a color photographed image as a background, false detection of a fringe portion can be easily found.

  Then, by correcting the fringe detection area after the input operation, it is possible to designate an appropriate fringe area before the execution of the chromatic aberration correction processing, and the photographed image in which only the image quality deterioration portion of the lens chromatic aberration is appropriately suppressed. It can be recorded. In addition, even for a captured image in which the subject color and the fringe color overlap, by creating a screen state that allows editing work before performing the fringe correction and recording the corrected image, the range and the degree of correction according to the user's preference It can be adjusted.

  A mask image may be displayed instead of the composite image in which the photographed image before correction and the mask image are superimposed. In this case, the background portion other than the fringe color area may be set to a gray tone or the like for icon display. The detected fringe area may be identified on the screen. For example, a specific color may be added to the fringe detection portion and displayed superimposed on the captured image, or the fringe detection portion may be blinked.

  Instead of setting an editing screen for adding, deleting and correcting a fringe area by the user, the user may set the editing area for dividing the correction area and the non-correction area. For example, the composite image may be divided by a grid, and the user may select an area to be edited therein.

  It is also possible that the user does not have an editing function for correcting the fringe color area. Even in this case, the user can confirm on the screen before image recording whether there is a false detection or a false detection portion in the detected fringe color area.

  In the present embodiment, correction processing is performed on chromatic aberration based on axial chromatic aberration. However, with regard to other lens aberrations such as magnification chromatic aberration and coma aberration, an image in which an image quality degradation area similarly detected is displayed It is possible to display before recording. Further, an image may be displayed in which the image quality deteriorated portion caused due to lens characteristics other than the aberration such as color moiré is actualized.

  The configuration shown in the present embodiment is also applicable to imaging devices other than digital cameras, and is also applicable to image processing devices such as PCs.

Reference Signs List 10 digital camera 14 image sensor 30 controller 40 image signal processing circuit (image processing apparatus, correction processing unit, display processing unit, false color detection unit, recording processing unit)
60 LCD Monitor (Display Processing Unit)

Claims (11)

A false color detection unit that detects a false color area in the captured image based on color information of the captured image;
A display processing unit for displaying on a screen a detected image in which a false color area is identified;
A correction processing unit that executes a chromatic aberration correction process on the photographed image according to the false color area;
An image processing apparatus comprising: a recording processing unit that stores in a memory a photographed image that has been subjected to chromatic aberration correction.   The image processing apparatus according to claim 1, wherein the display processing unit displays the detection image based on a mask image obtained by masking a portion other than the false color area of the photographed image before the correction.   The image processing apparatus according to claim 2, wherein the display processing unit displays a combined image obtained by combining the photographed image before correction and the mask image as a detected image.   The image processing apparatus according to any one of claims 1 to 3, further comprising a false color area correction unit that corrects a false color area according to an input operation.   5. The false color area correction unit according to claim 4, wherein the false color area correction unit corrects the false color area according to the range designated by the input operation for adding the false color area and / or deleting the false color area. Image processing device.   5. The image processing apparatus according to claim 4, wherein the false color area correction unit divides the correction area and the non-correction area in the false color area according to the input operation.   The image processing apparatus according to any one of claims 1 to 6, wherein the correction processing unit performs the chromatic aberration correction according to an operation performed after the detection image is displayed.   An imaging apparatus comprising the image processing apparatus according to any one of claims 1 to 7. Based on color information of the photographed image, false color area is detected in the photographed image,
Display on the screen the detection image that has identified the false color area,
Execute chromatic aberration correction processing on the photographed image according to the false color area;
An image processing method characterized in that a photographed image subjected to chromatic aberration correction is stored in a memory. Image processing device,
False color detection means for detecting a false color area in the photographed image based on color information of the photographed image;
Display processing means for displaying on a screen a detected image in which a false color area is identified;
Correction processing means for performing chromatic aberration correction processing on the photographed image according to the false color area;
A program characterized in that it functions as recording processing means for storing in a memory a photographed image corrected for chromatic aberration. A false color detection unit that detects an image quality degradation area based on lens characteristics in a captured image;
A display processing unit for displaying on a screen a detected image in which an image quality deterioration area is identified;
A correction processing unit that performs correction processing on the captured image according to the image quality deterioration area;
An image processing apparatus comprising: a recording processing unit configured to store a corrected captured image in a memory.