JP2006295774A - Imaging apparatus, control method thereof, and image processing program for digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus for realizing a high image quality image without variations in the color tone and the gradation among consecutively photographed frames, by obtaining information from all of consecutively photographed image data. <P>SOLUTION: The imaging apparatus obtains the information from all of the consecutively photographed image data to acquire average image data, and applies image processing optimum to the average image data to all of the consecutively photographed image data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging device, an imaging device control method, and a program. More specifically, the present invention relates to an imaging apparatus, an imaging apparatus control method, and a program characterized by obtaining information from a plurality of captured image data and setting image processing means.

  In an imaging device such as a digital camera, so that an image closer to the actual subject can be reproduced from the luminance distribution information and color information of the subject obtained by analyzing the density pattern and color deviation of the captured image, It is known to change image processing settings (for example, gamma correction and white balance) of a photographed image.

  However, since the photographed image is only a part of the environment surrounding the subject, only very limited information can be obtained. For example, when the sky is photographed, it is difficult to determine whether it is a blue sky or a cloudy sky based on the photographed image alone. Further, the dynamic range of the image sensor is narrow, and only a part of the luminance information of the subject can be obtained.

  In a digital single-lens reflex camera, since the optical path to the image sensor is blocked before shooting, image information cannot be obtained from the image sensor before shooting. Therefore, the technique cannot be applied.

  As a method for obtaining color information of a subject from a non-photographed image, a method for obtaining white balance information by providing a sensor capable of measuring a wide range separately from an image sensor is known.

  However, when photographing a landscape from a room through a window, the colorimetric measurement cannot be performed correctly if the sensor's colorimetric range does not match the photographing range. In addition, since a separate sensor is provided, the cost is increased.

  As another method for obtaining color information of a subject from an image other than a photographed image without providing a sensor, a method for obtaining color information by integrating image signals obtained from an image sensor before photographing (see, for example, Patent Document 1). Proposed.

  Further, as a method for measuring the luminance distribution of the subject from other than the photographed image, a method is used in which the exposure distribution is changed and images are taken a plurality of times, and the luminance distribution of the subject is estimated from a plurality of obtained image data.

For example, the number of main flashes and the exposure amount are automatically set according to the luminance distribution of the result of photometry of the reflected light when multiple flashes are made with a strobe device, and multiple exposures are performed. There has been proposed a method (for example, see Patent Document 2) in which the obtained image data is gamma-corrected to synthesize an image.
JP 2004-159183 A JP 2003-198876 A

  In a digital camera, particularly a camera that does not perform live view, such as a single-lens reflex digital camera, the luminance distribution information and color information of a subject are estimated by analyzing a captured image, and image processing settings (for example, gamma) of the image are analyzed. Correction, white balance, etc.), if the information obtained from the image is biased, the optimal image processing setting may not be possible.

  Therefore, by integrating the image signal obtained from the image sensor before photographing as in Patent Document 1 and obtaining color information or performing preliminary light emission a plurality of times before photographing as in Patent Document 2, the subject can be obtained. Techniques have been proposed for obtaining luminance distribution information of the above and ensuring a wide reproduction gradation.

  However, in the imaging devices of Patent Document 1 and Patent Document 2 described above, when a plurality of images are continuously captured, image processing such as gamma correction and white balance is set differently for each captured frame, and image reproduction is performed. Could not solve the problem of variation.

  In addition, the image pickup apparatus disclosed in Patent Document 2 needs to perform preliminary light emission a plurality of times with a strobe device, and also needs to perform a plurality of exposures during main exposure, so that it can be applied only to limited shooting opportunities and subjects. There wasn't.

  The present invention has been made in view of the above problems, and provides an imaging device capable of obtaining a high-quality image without variations in color tone and gradation between frames continuously shot, a method for controlling the imaging device, and a digital camera An object is to provide an image processing program.

  The object of the present invention can be achieved by the following constitution.

(Claim 1)
An image sensor that photoelectrically converts a subject image incident from a lens barrel;
First storage means for temporarily storing image data acquired from the image sensor;
Image processing means for performing predetermined processing on the image data stored in the first storage means;
Second storage means for storing the image data subjected to the predetermined processing;
In an imaging apparatus having
An image pickup apparatus comprising: a control unit that changes a setting of an image processing unit based on all image data stored in the first storage unit within a predetermined time.

(Claim 2)
The imaging apparatus according to claim 1, wherein the setting of the image processing unit is a gradation conversion characteristic of captured image data.

(Claim 3)
The imaging apparatus according to claim 1, wherein the setting of the image processing unit is white balance of captured image data.

(Claim 4)
The control means has a continuous shooting mode for continuously acquiring image data,
The imaging apparatus according to claim 1, wherein the control unit changes settings of the image processing unit based on all image data acquired in the continuous shooting mode.

(Claim 5)
The control means has a bracket mode for continuously acquiring image data obtained by sequentially changing exposure conditions,
The imaging apparatus according to claim 1, wherein the control unit changes the setting of the image processing unit based on all the image data acquired in the bracket mode.

(Claim 6)
The control means includes reference image selection means for selecting a reference image from the image data stored in the first storage means, and the control means is configured to perform image processing on the basis of image data of the selected reference image. The imaging apparatus according to claim 1, wherein the setting is changed.

(Claim 7)
The imaging apparatus according to claim 1, wherein the image processing unit makes the setting of the gradation characteristics of at least two acquired image data the same.

(Claim 8)
The imaging apparatus according to claim 1, wherein the image processing unit makes the white balance settings of at least two acquired image data the same.

(Claim 9)
A first storage step of temporarily storing image data acquired within a predetermined time;
An image processing step of performing a predetermined process on the image data temporarily stored in the first storage step;
A second storage step of storing the image data subjected to the predetermined processing;
A control step of changing settings of the image processing step based on all the image data stored in the first storage step.

(Claim 10)
A program for performing image processing of image data acquired by an imaging device by a computer,
A process for determining shooting information of image data on a computer and grouping it,
A process for determining image processing settings based on all of the grouped image data;
An image processing program for a digital camera, wherein image processing is executed based on the setting.

  According to the first or ninth aspect of the invention, information on the subject is obtained from all image data photographed within a predetermined time, and optimum image processing can be performed on all photographed image data, so that there is little variation. An imaging device capable of obtaining a high-quality image can be provided.

  According to the second aspect of the present invention, since the gradation conversion setting of the captured image data is performed from the information of the subject obtained from all the image data captured within a predetermined time, there is little variation in gradation, It is possible to provide an imaging apparatus capable of reproducing the optimum gradation for all image data.

  According to the third aspect of the invention, the setting value is obtained from the color information of the subject obtained from all the image data photographed within the predetermined time, and the white balance setting of the photographed image data is performed. It is possible to provide an imaging apparatus capable of obtaining an image in which colors are reproduced.

  According to the fourth aspect of the present invention, in the continuous shooting mode in which image data is continuously acquired, subject information is obtained from all the image data photographed in the continuous shooting mode. An imaging device capable of obtaining a captured image can be provided.

  According to the fifth aspect of the present invention, in the bracket mode in which image data obtained by sequentially changing the exposure conditions is continuously acquired, subject information is obtained from all the image data photographed in the bracket mode, so that there is little variation. An imaging device capable of obtaining a high-quality bracket image can be provided.

  According to the sixth aspect of the present invention, since it is possible to perform optimal image processing for captured image data based on image data selected from image data captured within a predetermined time, a high-quality image with little variation An imaging device can be provided.

  According to the seventh aspect of the present invention, the subject information is obtained from all the image data photographed within a predetermined time, and gradation conversion with the same setting is performed on at least two image data. It is possible to provide an imaging device capable of obtaining a high-quality image with less image quality.

  According to the eighth aspect of the present invention, information on the subject is obtained from all image data photographed within a predetermined time, and the same white balance is set for at least two image data. Therefore, there is little color variation. An imaging device capable of obtaining a high-quality image can be provided.

  According to the tenth aspect of the present invention, the shooting information of the image data is determined and grouped, the image processing setting is determined based on all the grouped image data, and the image processing is executed. It is possible to provide a program that can obtain a high-quality image with less image quality.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an external rear view showing a schematic configuration of a digital camera 1 which is an embodiment to which an imaging apparatus according to the present invention is applied.

  A shutter button 61 and a shooting mode dial 64 are provided on the upper surface side of the camera body 2. On the back side of the camera body 2, a power switch 102, a liquid crystal monitor 81, a mode switch 62, a display switching button 63, a cross key 65, an execution button 66, a viewfinder 104, a viewfinder eyepiece 105, and a memory card lid 82 are provided. ing.

  The mode switch 62 is a switch for switching between a photographing mode, a reproduction mode, and a setup mode. The shooting mode is a mode for taking a picture, and the playback mode is a mode for playing back and displaying the shot image recorded on the memory card 25 on the liquid crystal monitor 81. The setup mode is a mode for performing various settings. In the setup mode, the recording mode is a mode in which a captured image to be recorded in the memory card 25 is compressed and recorded after image processing, a mode in which the captured image is recorded without being subjected to image processing and uncompressed, a compressed image after image processing, Either a mode for recording both uncompressed images without image processing can be set. Various settings in the setup mode are set with the cross key 65 and the execution button 66 while viewing the setting screen displayed on the liquid crystal monitor 81 after selecting the setup mode.

  The shooting mode dial 64 is a dial for switching the shooting mode. The shooting mode can be selected from a single frame shooting mode, a continuous shooting mode in which continuous shooting is performed, and a bracket shooting mode in which continuous shooting is performed by changing shooting conditions. The number of images to be continuously shot in the continuous shooting mode is set with the cross key 65 and the execution button 66 while viewing the setting screen displayed on the liquid crystal monitor 81. In the bracket shooting mode, the AE bracket shooting mode in which multiple exposures are taken by changing the exposure little by little, the aperture bracket shooting mode in which the exposure is constant and the combination of the aperture and shutter speed is changed, and the speed bracket shooting mode are the same. This can be set with the cross key 65 and the execution button 66.

  The internal configuration of the digital camera 1 shown in FIG. 1 will be described with reference to FIG. 2A and 2B are cross-sectional views as seen from the side of the digital camera 1 in FIG. FIG. 2A shows a state before photographing, and FIG. 2B shows a state during photographing.

  The digital camera 1 is a so-called digital single-lens reflex camera with interchangeable lenses, and mainly includes a camera main body 2 and a photographing lens 3 coupled to the camera main body 2.

  The photographic lens 3 mainly includes a lens barrel 31, a plurality of lens groups 32 provided in the lens barrel 31, a diaphragm 33, and the like. Most of the light incident along the optical axis L of the plurality of lens groups 32 is bent 90 degrees perpendicularly to the upper direction (upward in the drawing) by the first mirror 34 a and forms an image on the focusing screen 38. The formed optical image is reflected twice inside the pentaprism 35, and the photographer views the subject image through the eyepiece 104. The photometric sensor 41 provided on the upper part of the pentaprism 35 is provided for the purpose of photometrically measuring the subject image formed on the focusing screen 38 and obtaining information on the luminance distribution of the subject for automatic exposure.

  On the other hand, part of the light incident along the optical axis L of the plurality of lens groups 32 is transmitted through the first mirror 34a, which is a semi-transmissive mirror, and is incident on the second mirror 34b. The incident light is bent 90 degrees perpendicular to the lower direction (downward direction in the drawing) by the second mirror 34b, enters the AF sensor optical unit 36 as an optical axis L2, and forms an image on the distance measuring sensor 42.

  Next, a state during photographing will be described with reference to FIG.

  During shooting, the first mirror 34a and the second mirror 34b are retracted from the optical axis L1 by a mirror driving mechanism (not shown) and stored in the upper part of the camera body 2. FIG. 2A shows a state in which the shutter 51 is completely closed so as to block the optical path before photographing. When exposure is performed during shooting, the shutter 51 opens up and down as shown in FIG. 2B to open the optical path.

  In this state, light incident from the plurality of lens groups 32 forms an image on a CCD (charge coupled device) 5 which is an example of an image sensor. In the present invention, the image sensor may be a solid-state image sensor such as a CMOS sensor or a CID sensor instead of the CCD. The video signal acquired by the CCD 5 is converted into a digital signal by a circuit board (not shown), subjected to image processing, and then recorded on the memory card 25.

  2A shows a state in which the flash 94 is housed inside the camera body 2, and FIG. 2B shows a state in which the light emitting portion is projected from the camera body 2 and can emit light toward the subject. Show.

  At the time of flash photography, prior to flash photography, the flash 94 is preliminarily emitted, the reflected light from the subject is measured, and the light quantity at the main emission is set.

  When the flash 94 emits light with a predetermined light amount while the shutter 51 is still closed, the reflected light reflected by the subject enters through the plurality of lens groups 32 and is reflected by the surface of the shutter 51, and the flash light amount photometric sensor. 43 is formed so as to form an image.

  The photographing lens 3 is configured as a zoom lens, and the focal length (imaging magnification) can be changed by changing the arrangement of the lens group 32.

  The CCD 5 is an image sensor composed of fine pixel groups each provided with a color filter, and an optical signal (subject image) of a subject formed by the photographing lens 3 is converted into an image signal having, for example, RGB color components. To photoelectric conversion. The light receiving surface of the CCD 5 is disposed so as to coincide with the imaging plane, and a partial area of the imaging plane including the image circle is acquired as image data (also simply referred to as “image” as appropriate in this specification). The Rukoto.

  The photographing lens 3 is configured as a zoom lens, and the focal length (imaging magnification) can be changed by changing the arrangement of the lens group 32.

  The CCD 5 is an image sensor composed of fine pixel groups each provided with a color filter, and a light image (subject image) of a subject formed by the photographing lens 3 is, for example, R (red), G (green). ) And B (blue) are converted into image signals having photoelectric components. The light receiving surface of the CCD 5 is disposed so as to coincide with the imaging plane, and a partial area of the imaging plane including the image circle is acquired as image data (also simply referred to as “image” as appropriate in this specification). The Rukoto.

  FIG. 3 is a block diagram showing a main functional configuration of the digital camera 1 of FIGS. 1 and 2. The same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted.

  The digital camera 1 includes an AD conversion unit 21, an image processing unit 22 that is an image processing unit of the present invention, an operation unit 60, a main microcomputer unit 7, a buffer memory 26 that is a first storage unit of the present invention, an image memory 23, It has a memory card 25 or the like as the second storage means of the present invention.

  The main microcomputer 7 that functions as a control means is configured to include a microcomputer. That is, the main microcomputer unit 7 includes a CPU 70 that performs various arithmetic processing, a RAM 75 that is a work area for performing arithmetic, and a ROM 76 that stores a control program and the like, and performs operations of the respective processing units of the digital camera 1. Control all over. As the ROM 76 which is a non-volatile memory, for example, an EEPROM capable of electrically rewriting data is adopted. As a result, the ROM 76 can rewrite data and retains the contents of the data even when the power is turned off.

  The outputs of the shutter button 61, the mode switch 62, the display switching button 63, the shooting mode dial 64, the cross key 65, the execution button 66 and the power switch 102, which are a plurality of operation members provided independently of the operation unit 60, are the main microcomputer. It is input to part 7.

  An operator (user) can perform various setting operations by performing predetermined operations on the operation unit 60.

  For example, the operator can switch the mode of the digital camera 1 between the playback mode and the shooting mode by operating the mode switch 62. The power switch 102 can also be used to turn on / off the power.

  The shooting mode dial 64 is a dial for switching between a single frame shooting mode, a continuous shooting mode, and a bracket shooting mode.

  A switch that is turned on when the shutter button 61 is half-pressed (S1) and a switch that is turned on when the shutter button 61 is fully pressed (S2) are linked to each other, so that the CPU 70 can detect the timing of S1 and S2.

  In single-frame shooting mode, the shutter button 61 is fully pressed (S2), and one frame is shot. In continuous shooting mode, the shutter button 61 is fully pressed (S2). In this mode, shooting is performed.

  The bracket shooting mode automatically shoots by shifting the exposure amount gradually from the standard exposure conditions. The AE bracket shooting mode and exposure amount are constant, and priority is given to either the aperture or shutter speed, and the shooting is shifted gradually. There are aperture bracket shooting mode and speed bracket shooting mode.

  When the shooting mode dial 64 is set to the bracket shooting mode, a screen for selecting and setting the AE bracket shooting mode, aperture bracket shooting mode, speed bracket shooting mode, etc. on the LCD 81 is displayed. Either one is selected using the button 66.

  For example, in the AE bracket shooting mode, each mode is set by displaying a screen for selecting the exposure shift amount setting value M (EV) and the number of shot frames K on the LCD 81. Use to select M. For example, the exposure shift amount setting value M can be selected from 1/2 (EV) and 1/3 (EV), and the number K of shooting frames can be selected from 3 frames and 5 frames.

  As an example, if the exposure shift amount setting value M (EV) is set to 1/2 (EV) and the number of shot frames K is set to 3 frames, -1/2 (EV), 0 (EV), +1/2 (EV ) And automatically shoots three frames by shifting the exposure amount by 1/2 (EV).

  Further, the operator can switch the state of the LCD 81 of the digital camera 1 between the display state and the non-display state by operating the display switching button 63.

  The mirror driving unit 91 drives the mirror 34 according to a command from the main microcomputer unit 7 and retracts it from the optical path of the photographing lens 3. Further, the shutter drive unit 93 opens the shutter 51 in response to a command from the main microcomputer unit 7.

  The A / D conversion unit 21, the buffer memory 26, the image processing unit 22, and the image memory 23 are processing units that handle images acquired by the CCD 5.

  The analog signal image acquired by the CCD 5 is sequentially converted into, for example, a 14-bit digital signal by the A / D converter 21 and temporarily stored in the buffer memory 26 as digital image data. The image data is called raw data before image processing, that is, RAW data. In the continuous shooting mode and the bracket mode, the set predetermined number of RAW data is temporarily stored in the buffer memory 26.

  The image processing unit 22 includes image processing such as a WB (White Balance) correction unit 220, a pixel interpolation unit 221, a linear matrix processing unit 222, a gamma correction unit 223, a color difference matrix processing unit 224, a contour correction unit 225, and an image compression unit 226. It has a function. The set values of the correction amounts of the gamma correction unit 223, the contour correction unit 225, and the WB correction unit 220 are set by commands from the gradation conversion control unit 77, the frequency response control unit 78, and the WB control unit 73 of the main microcomputer unit 7. .

  The WB correction unit 220 multiplies the coefficient set by the WB control unit 73 by the R and B image data of the RAW data obtained from the CCD 5 and adjusts the white balance.

  The pixel interpolation unit 221 separates pixel data for each of R, G, and B after white balance adjustment, performs pixel interpolation, and creates frame sequential R, G, and B image data.

  The linear matrix processing unit 222 adds the coefficients corresponding to the spectral sensitivity to the R, G, and B image data by a 3 × 3 matrix calculation and adds the coefficients to correct the color error due to the spectral sensitivity.

  The gamma correction unit 223 has a look-up table that represents gradation characteristics as input / output characteristics, and has a function of converting the input digital values into digital values and outputting the digital values. That is, the R, G, B image data is tone-converted with the tone characteristics set by the tone conversion control unit 77 in the lookup table.

  The color difference matrix processing unit 224 performs a 3 × 3 matrix operation on the R, G, and B image data subjected to gradation conversion by the gamma correction unit 223 to convert it into luminance Y, color difference Cr, and Cb signals.

  The contour correcting unit 225 corrects the contour of the luminance Y with the frequency response characteristic that is the input / output characteristic set by the frequency response control unit 78 and temporarily stores it in the image memory 23.

  The image compression unit 226 compresses the image data after image processing into a JPEG format or the like.

  The distance measuring sensor 42 is used for automatic focusing control, and the photometric sensor 41 and the flash light quantity measuring sensor 43 are used for automatic exposure control. The main microcomputer unit 7 includes an A / D converter (not shown) that converts the input output voltage of each sensor into a digital value and inputs the digital value to the main microcomputer unit 7.

  The main microcomputer unit 7 is an automatic focusing control unit (AF control unit) 71, an automatic exposure control unit (AE control unit) 72, a gradation conversion control unit 77, a frequency response control unit 78, and a reference image selection unit of the present invention. Various control functions such as a reference image selection unit 74 are provided. Various functions of the main microcomputer unit 7 are realized by the CPU 70 performing arithmetic processing according to a control program stored in the ROM 76 in advance.

  In addition, it has a control function for recording the compressed image in the memory card 25 and displaying it on the LCD 81 or the like. Various processes for such an image are also performed based on the control of the main microcomputer unit 7.

  The AF control unit 71 obtains an in-focus evaluation value from the luminance information obtained from the distance measuring sensor 42 and adjusts the focal position of the photographing lens 3 to realize automatic focusing control.

  The reference image selection unit 74 selects reference image data that serves as a reference for image processing from image data that has been continuously captured using a predetermined algorithm. The reference image data selection algorithm will be described in detail later.

  3 includes a zoom / focus drive unit 332 and an aperture drive unit 331. The zoom / focus drive unit 332 appropriately drives the lenses included in the lens group 32 in the optical axis direction so that the focal length is set by the user and is in focus (focusing).

  In the case of shooting with steady light, the AE control unit 72 calculates an AE evaluation value based on the luminance value obtained by the photometric sensor 41 that photoelectrically converts the subject image into a plurality of photometric blocks, and performs automatic exposure control. To realize.

  The aperture driving unit 331 adjusts the aperture diameter of the aperture 33 so that the aperture value set by the AE control unit 72 is obtained. The zoom / focus drive unit 332 and the aperture drive unit 331 are also electrically connected to the main microcomputer unit 7 and operate under the control of the main microcomputer unit 7.

  Similarly, in the case of shooting with flash light, the AE control unit 72 calculates an AE evaluation value based on the representative luminance value of the photometry block obtained by the flash light quantity photometry sensor 43, and sets the light emission amount of the flash 94. Control to achieve automatic exposure control.

  FIG. 4 is a flowchart for explaining a schematic procedure at the time of photographing performed by the imaging apparatus of the present invention, FIG. 5 is a flowchart for explaining a first image processing routine of the present invention, and FIG. 6 is a second image processing routine of the present invention. It is a flowchart explaining these. In FIG. 4, processing after the digital camera 1 is turned on, the shooting mode is selected, and the camera enters a shooting standby state will be described. In FIG. 4, it is assumed that a mode for compressing and recording a captured image after image processing is selected.

  When the shutter button 61 is half-pressed (S1) (step S102), the AE control unit 72 performs automatic exposure control according to the output of the photometry sensor 41, and the AF control unit 71 performs autofocus according to the output of the distance measurement sensor 42. Take control. The AE control unit 72 obtains a combination of the aperture value and the shutter speed from the exposure value E (EV) obtained by the automatic exposure control, and records the exposure value E (EV) and the obtained aperture value and shutter speed value in the RAM 75. (Step S103).

  Next, when the shutter button 61 is fully pressed (S2) (step S104), the main microcomputer unit 7 starts a shooting sequence, sends a command to the mirror drive unit 91 at a predetermined timing, and moves the mirror 34. Retreat from the optical path of the taking lens 3 (step S105).

  Next, the main microcomputer unit 7 determines whether the set mode is the AE bracket shooting mode (step S106). When the set mode is not the AE bracket shooting mode (step S106; No), the main microcomputer unit 7 determines whether the set mode is the aperture bracket shooting mode or the speed bracket shooting mode (step S107).

  When the set mode is not the aperture bracket shooting mode or the speed bracket shooting mode (step S107; No), the AE control unit 71 performs one frame exposure with a normal exposure value. That is, the AE control unit 71 instructs the aperture value recorded in the RAM 75 in step S103 to set the aperture 33 by instructing the aperture drive unit 331, and similarly during the exposure time determined by the recorded shutter speed. The drive unit 93 is instructed to open the shutter 51 and expose the CCD 5. When a predetermined exposure time has elapsed, the AE control unit 71 sends a command to the shutter drive unit 93 to close the shutter 51. The main microcomputer unit 7 temporarily stores the RAW data read from the CCD 5 in the buffer memory 26 (step S108).

  Next, the main microcomputer unit 7 determines whether or not the set mode is the continuous shooting mode and the shutter button 61 is fully pressed (S2) (step S109). When the set mode is the continuous shooting mode and the shutter button 61 is fully pressed (S2) (step S109; Yes), the main microcomputer unit 7 returns to step S108 to perform the next one frame with the normal exposure amount. Exposure is performed, and RAW data is temporarily stored in the buffer memory 26.

  If the set mode is not the continuous shooting mode or the shutter button 61 is not fully pressed (S2) (step S109; No), the process proceeds to step S111, and the main microcomputer unit 7 sends a command to the mirror driving unit 91, The mirror 34 is returned to a predetermined state (step S111).

  When the set mode is the aperture bracket shooting mode or the speed bracket shooting mode (step S107; Yes), the AE control unit 71 exposes the first frame to the CCD 5 with the normal exposure amount in the same manner as in step S108. The microcomputer unit 7 temporarily stores the RAW data read from the CCD 5 after completion of exposure in the buffer memory 26 together with the frame number. Thereafter, the AE control unit 71 exposes the CCD 5 while shifting the aperture value or the shutter speed without changing the exposure amount based on the set aperture or speed shift amount. The main microcomputer unit 7 temporarily stores the RAW data read from the CCD 5 in the buffer memory 26 sequentially. The main microcomputer unit 7 repeats exposure to the CCD 5 and temporary storage of the RAW data in the buffer memory 26 for the set number of frames. When shooting is performed for the set number of frames, the process proceeds to step S111, where the main microcomputer unit 7 sends a command to the mirror drive unit 91 to return the mirror 34 to a predetermined state (step S111).

  Next, proceeding to the image processing routine 1, the image processing unit 22 performs image processing such as pixel interpolation, matrix processing, WB correction, gamma correction, and contour correction on the RAW data temporarily stored in the buffer memory 26 (step S200). ). The image processing routine 1 is characterized in that the image data of all shot frames is averaged to determine a reference frame, and WB correction, gamma correction, and contour correction are performed on all frames with the same setting values as the reference frame. The image processing routine 1 performed in step S200 will be described in detail later.

  Next, the image compression unit 226 compresses the image data that has been subjected to image processing in step S <b> 200 and temporarily stores the compressed image data in the image memory 23. Thereafter, the main microcomputer unit 7 sequentially records the image data on the memory card 25 (step S130). This is the end of shooting.

  When the set mode is the AE bracket shooting mode (step S106; Yes), the AE control unit 71 exposes the first frame to the CCD 5 with the normal exposure value as in step S108, and the main microcomputer unit 7 ends the exposure. Thereafter, the RAW data read from the CCD 5 is temporarily stored in the buffer memory 26. Next, the AE control unit 71 determines the exposure amount based on the set exposure shift amount setting value M (EV) and the number K of shot frames. Thereafter, the AE control unit 71 changes the exposure value by changing the aperture value and the shutter speed value based on the set exposure shift amount setting value M, and exposes the CCD 5. The main microcomputer section 7 temporarily stores the RAW data read from the CCD 5 together with the frame number in the buffer memory 26 sequentially. The main microcomputer unit 7 repeats exposure to the CCD 5 and temporary storage of the RAW data in the buffer memory 26 for the set number of frames. When shooting is performed for the set number of frames, the process proceeds to step S121, and the main microcomputer unit 7 sends a command to the mirror drive unit 91 to return the mirror 34 to a predetermined state (step S121).

  Next, proceeding to the AE bracketing image processing routine, the image processing unit 22 performs image processing such as pixel interpolation, matrix processing, WB correction, gamma correction, and contour correction on the RAW data temporarily stored in the buffer memory 26 ( Step S300). The AE bracketing image processing routine differs from the image processing routine 1 in that the gamma correction characteristic is changed according to the exposure shift amount of each frame, with the shot frame shot at the normal exposure amount as the reference frame. It is. The AE bracketing image processing routine performed in step S300 will be described in detail later.

  Next, the image compression unit 226 compresses the image data that has been subjected to image processing in step S300, and temporarily stores the compressed image data in the image memory 23. Thereafter, the main microcomputer unit 7 sequentially records the image data on the memory card 25 (step S320). This is the end of shooting.

  Next, the image processing routine 1 (step S200) according to the first embodiment of the present invention will be described with reference to FIG.

  FIG. 7 is an explanatory diagram for explaining an example of image data distribution obtained from the image pickup apparatus, FIG. 8 is an explanatory diagram for explaining an example of gradation conversion characteristics implemented according to the subject luminance distribution in the present invention, and FIG. It is explanatory drawing explaining the example of the frequency response characteristic implemented according to subject brightness distribution by invention.

  Hereinafter, FIGS. 7, 8, and 9 will be described together with the flowchart shown in FIG.

  When the image processing routine 1 is started, the main microcomputer unit 7 sequentially sends the RAW data of each frame temporarily stored in the buffer memory 26 to the image processing unit 22. The WB correction unit 220 separates and adds pixel data for each color of R, G, and B from the RAW data of each frame, and obtains average values Rav, Gav, and Bav for each color of R, G, and B of all frames. Next, the WB correction unit 220 calculates the WB coefficients Rg and Bg to be applied to the R and B pixel data for WB correction from the R, G, and B average values Rav, Gav, and Bav using the equations (1) and (2). Ask for. Note that an upper limit value and a lower limit value are determined for the values of Rg and Bg, and correction is not performed more than necessary (step S211).

Rg = Gav / Rav (1)
Bg = Gav / Bav (2)
The WB correction unit 220 performs WB correction by applying the WB coefficients Rg and Bg obtained in step S211 to the R and B pixel data of the RAW data of each frame. The image data of each frame obtained as a result is temporarily stored in the buffer memory 26 (step S212).

  Next, the pixel interpolating unit 221 interpolates the RAW data of each frame after WB correction temporarily stored in the buffer memory 26 to obtain R, G, and B frame sequential image data. Next, the linear matrix processing unit 222 obtains R ′, G ′, and B ′ by multiplying the R, G, and B pixel data of each frame by a coefficient that corrects the spectral sensitivity by 3 × 3 matrix calculation. Obtain frame sequential image data of ', G', B '. The pixel interpolation unit 221 temporarily stores the obtained frame sequential image data of each frame in the image memory 23 (step S213).

  Next, the reference image selection unit 74 performs R ′, G ′, B ′ of each frame from the R ′, G ′, B ′ plane sequential image data of all the frames temporarily stored in the image memory 23 in step S213. Average values R′h (i), G′h (i), and B′h (i) for each color are obtained. Here, i is a frame number. The reference image selection unit 74 calculates the average value R′t of all frames from the average values R′h (i), G′h (i), and B′h (i) of R ′, G ′, and B ′ of each frame. , G′t and B′t are obtained (step S214).

  Next, the reference image selection unit 74 obtains the evaluation value S (i) from the obtained average value of all frames and the average value of each frame, using Equation (3).

S (i) = (R′t−R′h (i)) ² + (G′t−G′h (i)) ² + (B′t−B′h (i)) ² (3)
The reference image selection unit 74 selects a frame having the smallest evaluation value S (i) obtained by Expression (3) as a reference frame (step S215). Here, the frame number of the reference frame is k.

  Next, the WB correction unit 220 obtains coefficients Rg (k) and Bg (k) for WB correction optimal for the reference frame in the same procedure as in step S212.

  The WB correction unit 220 separates and adds pixel data for each color of R, G, and B from the RAW data of the reference frame, and averages Rav (k), Gav (k), and Bav for each of the R, G, and B colors of the reference frame. (K) is obtained, and WB coefficients Rg (k) and Bg (k) to be applied to the R and B pixel data for WB correction are obtained by Expressions (1) and (2).

  The WB correction unit 220 performs WB correction by applying the WB coefficients Rg (k) and Bg (k) of the reference frame to the R and B pixel data of the RAW data of each frame. The image data of each frame obtained as a result is temporarily stored in the image memory 23 (step S216).

  Next, pixel interpolation and matrix processing are performed in the same manner as in step S213 to obtain frame sequential image data of R ″, G ″, and B ″. The pixel interpolation unit 221 temporarily stores the obtained frame sequential image data of each frame in the image memory 23 (step S217).

  Next, the main microcomputer unit 7 counts the number of pixels having the same numerical data from the frame sequential image data of R ″, G ″, B ″ of the reference frame temporarily stored in the image memory 23 ( Step S218).

  FIG. 7 is a graph showing the results counted in step S218. Here, it is assumed that each pixel has numerical data of 14 bits, that is, a maximum of 16384. FIG. 7A shows an example of numerical data distribution obtained when the subject contrast is low, and FIG. 7B shows the numerical data distribution obtained when the subject contrast is high.

  Next, the gradation conversion control unit 77 sets the gradation characteristics of the gamma correction unit in accordance with the numerical data distribution of the reference frame obtained in step S218 (step S219).

  Here, the procedure for setting the gradation characteristics of the gamma correction unit in step S219 will be described with reference to FIGS.

  FIG. 8 is an explanatory diagram for explaining an example of gradation characteristics selected according to the numerical data distribution of the reference frame. FIGS. 8A and 8B are log-log graphs, in which the horizontal axis represents the numerical data of each input pixel, and the vertical axis represents the output numerical data. In FIG. 8, the input is 14 bits and the output is 8 bits. Further, the gradient of the gradation characteristic in FIG. 8 corresponds to the gamma value. Such gradation characteristics are stored in the ROM 76, and the gradation conversion control unit 77 selects an optimum gradation characteristic and sets it in the gamma correction unit 223.

  Next, a procedure for the gradation conversion control unit 77 to select an optimum gradation characteristic will be described. The gradation conversion control unit 77 evaluates the correlation between the numerical data distribution of the reference frame obtained in step S218 and the standard numerical data distribution when the contrast is low or high, and the contrast of the numerical data distribution of the reference frame is high. Or low.

  FIG. 8A shows an example of gradation characteristics to be applied when the luminance distribution of the subject has a low contrast as shown in FIG. 7A.

  When the contrast is low, the gamma value is set large so that the gradation can be reproduced as richly as possible. That is, in the example of FIG. 8 (a), since the numerical data 8200 is distributed in a narrow range, the numerical data in this narrow range is recorded so that it can be reproduced with the maximum possible gradation. The output characteristics are tilted. For example, the gamma value is 0.7.

  FIG. 8B shows an example of gradation characteristics to be applied when the luminance distribution of the subject has a high contrast as shown in FIG. 7B.

  When the contrast is high, the gamma value is set small so that the gradation can be reproduced as richly as possible. That is, in the example of FIG. 8B, since the numerical data 8200 is distributed over a wide range, the numerical data in the wide range is recorded so that it can be reproduced with the maximum possible gradation. The slope of the output characteristics is laid down. For example, the gamma value is 0.4.

  As described above, the gamma correction unit 223 sequentially performs gamma correction on the image data of all the frames temporarily stored in the image memory 23 based on the gradation characteristics optimum for the reference frame set in step S219 (step S220), and the color difference. The matrix unit 224 converts the luminance Y and the color differences Cr and Cb, and temporarily stores them in the image memory 23 (step S221).

  Next, the main microcomputer unit 7 determines the contrast status of the subject from the numerical data distribution obtained in step S218, and sets the frequency response characteristic of the contour correction unit optimal for the reference frame (step S222).

  FIG. 9 is an explanatory diagram illustrating an example of frequency response characteristics selected according to the contrast of the numerical data distribution. 9A and 9B, the horizontal axis represents the spatial frequency of the captured image, and the vertical axis represents the output response.

  FIG. 9A shows an example of frequency response characteristics to be applied when the luminance distribution of the subject has a low contrast as shown in FIG. 7A.

  When the contrast of the subject brightness is low, the high frequency response is set so that the contour can be reproduced with the emphasis as much as possible. That is, as in the example of FIG. 9A, the response of the high frequency is raised compared to the low frequency region.

  FIG. 9B shows an example of frequency response characteristics to be applied when the luminance distribution of the subject has a high contrast as shown in FIG. 7B.

  When the contrast of the subject brightness is high, the screen becomes glaring if the outline is emphasized too much, so the high frequency response of the frequency response is set to be low. That is, as in the example of FIG. 9B, the high frequency response is lowered than in the low frequency region.

  Based on the frequency response characteristic of the reference frame set in this way, the contour correcting unit 225 sequentially performs contour correction of all the frames, and temporarily stores the image data after the contour correction in the image memory 23 (step S218). This completes the image processing routine 1, returns to step S130 of the original routine, and records the image on the memory card 25 after the image compression.

  Next, an image processing routine 2 (step S300) according to the second embodiment of the present invention will be described with reference to FIG. The image processing routine 2 is an image processing routine performed in the AE bracket shooting mode. Since the basic processing content is the same as the processing described in FIG. 5, the same processing as in FIG.

  When the image processing routine 2 is activated, the main microcomputer unit 7 sequentially sends the RAW data of each frame temporarily stored in the buffer memory 26 to the image processing unit 22. The WB correction unit 220 obtains average values Rav, Gav, Bav of R, G, B colors of all the frames from the RAW data of each frame, and obtains WB coefficients Rg, Bg to be applied to the R, B pixel data (step) S211).

  The WB correction unit 220 performs WB correction by applying the WB coefficients Rg and Bg obtained in step S211 to the R and B pixel data of the RAW data of each frame. The image data of each frame obtained as a result is temporarily stored in the buffer memory 26 (step S212).

  In selecting the reference frame, in the AE bracket shooting mode, a frame with a different exposure is shot based on the frame exposed with the normal exposure value. Therefore, if the frame exposed with the normal exposure value is used as the reference frame, good. The reference image selection unit 74 sends the RAW data of the frame exposed with the normal exposure value temporarily stored in the buffer memory 26 to the image processing unit 22 (step S311).

  The WB correction unit 220 obtains coefficients Rg (k) and Bg (k) for WB correction optimum for the reference frame in the same procedure as in step S216, and calculates the WB coefficients Rg (k) and Bg (k) of the reference frame. WB correction is performed on the R and B pixel data of the RAW data of each frame. The image data of each frame obtained as a result is temporarily stored in the image memory 23 (step S216).

  Next, pixel interpolation and matrix processing are performed in the same manner as in step S213 to obtain frame sequential image data of R ″, G ″, and B ″. The pixel interpolation unit 221 temporarily stores the obtained frame sequential image data of each frame in the image memory 23 (step S217).

  Next, the main microcomputer unit 7 counts the number of pixels having the same numerical data from the frame sequential image data of R ″, G ″, B ″ of the reference frame temporarily stored in the image memory 23 ( Step S218).

  Next, the main microcomputer unit 7 sets the optimum gradation characteristics for the reference frame from the numerical data distribution of the reference frame obtained in step S218 (step S319).

  In the AE bracket shooting mode, the exposure is shifted with respect to the normal exposure except for the reference frame. Therefore, the gradation conversion control unit 77 uses the gradation characteristics optimum for the reference frame as a reference and sets the levels other than the reference frame. The tone characteristic is shifted and set according to the exposure amount (step S320).

  FIG. 10 shows an example of gradation characteristics used in the AE bracket shooting mode. For example, the gradation characteristic applied to the shooting data of the reference frame is γ1, and the gradation characteristic applied to the shooting data shifted by −1/2 (EV) is the floor applied to the shooting data shifted by γ2, +1/2 (EV). The tonal characteristic is γ3. These characteristics are stored in the ROM 76, and the gradation conversion control unit 77 reads these and sets them in the gamma correction unit 223.

  The gamma correction unit 223 sequentially performs gamma correction on the image data of all frames temporarily stored in the image memory 23 (step S220), and converts them into luminance Y and color differences Cr and Cb in a color difference matrix unit (not shown). (Step S221).

  Next, the main microcomputer unit 7 determines the contrast status of the subject from the numerical data distribution obtained in step S218, and sets the frequency response characteristic of the contour correction unit optimal for the reference frame (step S222).

  Based on the frequency response characteristics of the reference frame set in this way, the contour correcting unit 225 sequentially performs contour correction of all the frames, and temporarily stores the image data after the contour correction in the image memory 23 (step S223). This completes the image processing routine 1, returns to the original routine step S130, and records the image in the memory card 25 after image compression.

  Next, as third and fourth embodiments of the present invention, a case where image processing of image data captured by the digital camera 1 is performed by a computer will be described.

  FIG. 11 is a block diagram of a digital camera 1 according to the present invention, a memory card 25 for recording captured image data, and a computer 500 for performing image processing. FIG. 12 is a flowchart for explaining a schematic procedure at the time of photographing performed by the imaging apparatus in the third and fourth embodiments of the present invention. FIG. 13 is a computer in the third and fourth embodiments of the present invention. 5 is a flowchart for explaining a schematic procedure of an image processing program for a digital camera executed by 500.

  First, the block diagram of FIG. 11 will be described.

  The computer 500 includes a CPU 530 that performs various arithmetic processes, a RAM 501 that is a work area for performing arithmetic operations, and an HDD 502 that stores an OS, an image processing program for a digital camera, and various data such as contents, and the like. A card interface 504 (hereinafter referred to as a card IF 504) capable of reading various data recorded on a memory card 25 as a medium is provided. Further, the computer 500 is connected with an input unit 505 including a keyboard and a mouse, and a monitor 580 such as a liquid crystal monitor.

  Next, functions of the CPU 530 will be described.

  The image processing unit 521 includes an image processing unit such as a WB (White Balance) correction unit 520, a pixel interpolation unit 521, a linear matrix processing unit 522, a gamma correction unit 523, a color difference matrix processing unit 524, a contour correction unit 525, and an image compression unit 526. 22, and all functions are performed by software processing of the CPU 530. For this reason, the set values of the correction amounts of the gamma correction unit 523, the contour correction unit 525, and the WB correction unit 520 are set in software processing performed by the CPU 530.

  The WB correction unit 520 multiplies the coefficient set by the CPU 530 with R and B image data of RAW data (to be described later) obtained by the digital camera 1 obtained from the memory card 25, and adjusts the white balance.

  The pixel interpolation unit 521 separates pixel data for each of R, G, and B after the white balance adjustment, performs pixel interpolation, and creates frame sequential R, G, and B image data.

  The linear matrix processing unit 522 adds a coefficient corresponding to the spectral sensitivity to each of the R, G, and B image data by a 3 × 3 matrix calculation, and corrects the color error due to the spectral sensitivity.

  The gamma correction unit 523 has a look-up table that represents gradation characteristics that are input / output characteristics, and has a function of converting the input digital values into digital values and outputting the digital values. That is, the R, G, B image data is tone-converted with the tone characteristics set by the CPU 530 in the look-up table.

  The color difference matrix processing unit 524 performs a 3 × 3 matrix operation on the R, G, and B image data subjected to gradation conversion by the CPU 530, and converts the result into luminance Y, color difference Cr, and Cb signals.

  The contour correcting unit 525 corrects the contour of the luminance Y with the frequency response characteristic which is the input / output characteristic set by the CPU 530 and temporarily stores it in the RAM 501.

  The image compression unit 526 compresses the image data after the image processing into a JPEG format or the like.

  Next, with reference to FIG. 12, an outline procedure at the time of shooting performed by the imaging apparatus in the third embodiment of the present invention will be described.

  In FIG. 12, the processing after the digital camera 1 is turned on, the shooting mode is selected, and the shooting standby state is entered will be described. In FIG. 12, it is assumed that a mode for recording a photographed image without performing image processing without compression is selected.

  Since the basic processing content is the same as the processing described in FIG. 4, the same processing as in FIG. That is, since steps S102 to S111 and 121 are the same processing as in FIG. 5, the description thereof will be omitted and will be described from step S400.

  When step S111 or step 121 is completed, the RAW data for the number of shots is temporarily stored in the image memory 23. The CPU 70 adds shooting information to the beginning of the RAW data file for each frame (step S400). The CPU 70 is an adding means for adding shooting information of the present invention. An example of shooting information added to the RAW data file is shown in FIG.

  In FIG. 16, the items of shooting information are the camera model name, camera manufacturer name, shooting date and time, shooting mode, shift amount, total number of frames, and frame number. The model name and maker name of the digital camera 1 are recorded in the item of the camera model name and the camera manufacturer name, and the shooting date and time, the hour, minute, and second are recorded in the shooting date and time item.

The shooting mode is recorded as 0 in the normal mode, 1 in the continuous shooting mode, 2 in the aperture bracket mode, 3 in the speed bracket mode, and 4 in the AE bracket mode. The maximum shift amount M in the bracket mode is recorded in the shift amount item. The total number of frames is the total number K of frames taken at one time in the continuous shooting mode and the bracketing mode, and the frame number KM records the number of frames shot in that. The CPU 70 records the RAW created in step S400. Data files are sequentially recorded on the memory card 25, and shooting is finished (step S401).

  Next, the procedure of a digital camera image processing program executed by a computer in the third embodiment of the present invention will be described with reference to FIG.

  It is assumed that the computer 500 is in an activated state and the memory card 25 on which an image photographed by the digital camera 1 is recorded is inserted into the card IF 504 of the computer 500 and is readable.

  The CPU 530 reads the shooting information added to the head of the RAW data recorded in the memory card 25 (step S501), and extracts the RAW data in which the camera model name and the camera manufacturer name match those of the digital camera 1. .

  Next, the CPU 530 groups the RAW data shot in the same shooting mode and whose shooting date and time is within a certain time, creates a folder for each group, and stores it in the RAM 501. Assuming that the number of folders F created by the CPU 530 is F, folders 1 to F are created (step S502).

  N representing the folder number is initialized to 1 (step S503).

  It is determined whether or not the shooting condition of the RAW data classified into the folder N is the AE bracketing mode (step S504).

  When the shooting condition is other than the AE bracketing mode (step S504; No), the image processing routine 3 is executed, and the image processing unit 521 performs pixel interpolation, matrix processing, WB correction, and gamma correction on the RAW data temporarily stored in the RAM 501. Then, image processing such as contour correction is performed (step S505). Similar to the image processing routine 1, the image processing routine 3 determines the reference frame by averaging the image data of all the shot frames, and performs WB correction, gamma correction, and contour correction for all the frames with the same setting values as the reference frame. It is a feature to do. The image processing routine 3 performed in step S505 will be described in detail later.

  When the shooting condition is the AE bracketing mode (step S504; Yes), the image processing routine 4 is executed. The image processing unit 521 performs image processing such as pixel interpolation, matrix processing, WB correction, gamma correction, and contour correction on the RAW data temporarily stored in the RAM 501 (step S506). In the image processing routine 4, similar to the image processing routine 1, the image data of all the shot frames is averaged to determine the reference frame, and the WB correction, gamma correction, and contour correction of all the frames are performed with the same setting values as the reference frame. It is a feature to do. The image processing routine 4 performed in step S506 will be described in detail later.

  Next, in step S507, the image data after image processing is displayed on the monitor 580 (step S507).

  Next, it is determined whether N = F (step S509). If N = F, since the image processing of the RAW data in all the folders has been completed, the image processing is terminated (step S509; Yes). If N ≠ F (step S509; No), N = N + 1 (step S510) and step S505 is executed.

  Next, an image processing routine 3 (step S506) according to the third embodiment of the present invention will be described with reference to FIG. The image processing routine 3 is an image processing routine that is executed on RAW data shot in a mode other than the AE bracket shooting mode. Since the basic processing content is the same as the processing described in FIG. 6, the same processing as in FIG.

  When the image processing routine 3 is activated, the CPU 530 sequentially executes image processing on the RAW data of all frames temporarily stored in the folder N of the RAM 501. The WB correction unit 520 obtains average values Rav, Gav, Bav of R, G, B colors of all the frames from the RAW data of each frame, and obtains WB coefficients Rg, Bg to be applied to the R, B pixel data (step) S511).

  The WB correction unit 520 performs WB correction by applying the WB coefficients Rg and Bg obtained in step S211 to the R and B pixel data of the RAW data of each frame. The image data of each frame obtained as a result is temporarily stored in the RAM 501 (step S512).

  Next, the WB correction unit 520 interpolates the RAW data of each frame after WB correction temporarily stored in the RAM 501 into pixel sequential image data of R, G, and B. Next, the linear matrix processing unit 522 obtains R ′, G ′, and B ′ by multiplying the R, G, and B pixel data of each frame by a coefficient that corrects the spectral sensitivity by 3 × 3 matrix calculation. Obtain frame sequential image data of ', G', B '. The pixel interpolation unit 521 temporarily stores the obtained frame sequential image data of each frame in the RAM 501 (step S513).

  Next, the reference image selection unit 527 uses the R ′, G ′, and B ′ frame sequential image data of all frames temporarily stored in the folder N of the RAM 501 in step S513 to perform R ′, G ′, B ′ Average values R′h (i), G′h (i), and B′h (i) for each color are obtained. Here, i is a frame number. The reference image selection unit 527 calculates the average value R′t of all frames from the average values R′h (i), G′h (i), and B′h (i) of R ′, G ′, and B ′ of each frame. , G′t and B′t are obtained (step S514).

  Next, the CPU 520 selects a reference frame using the algorithm of step S215 (step S515). Here, the frame number of the reference frame is k.

  Next, the WB correction unit 520 obtains coefficients Rg (k) and Bg (k) for WB correction optimum for the reference frame in the same procedure as in step S212, and WB coefficients Rg (k) and Bg ( k) is applied to R and B pixel data of RAW data of each frame to perform WB correction. The image data of each frame obtained as a result is temporarily stored in the RAM 501 (step S516).

  Next, pixel interpolation and matrix processing are performed in the same manner as in step S513 to obtain frame sequential image data of R ″, G ″, and B ″. The pixel interpolation unit 521 temporarily stores the obtained frame sequential image data of each frame in the RAM 501 (step S517).

  Next, the CPU 520 counts the number of pixels having the same numerical data from the frame sequential image data of R ″, G ″, B ″ of the reference frame temporarily stored in the RAM 501 (step S518).

  Next, the CPU 520 sets the gradation characteristics of the gamma correction unit according to the numerical data distribution of the reference frame obtained in step S518 (step S519).

  Based on the gradation characteristics optimum for the reference frame set in step S519, the gamma correction unit 523 sequentially gamma-corrects all frame image data temporarily stored in the RAM 501 (step S520), and the color difference matrix unit 524 performs luminance. Y and color differences Cr and Cb are converted and temporarily stored in the RAM 501 (step S521).

  Next, the CPU 520 determines the contrast status of the subject from the numerical data distribution obtained in step S518, and sets the frequency response characteristic of the contour correction unit optimal for the reference frame (step S522).

  Based on the frequency response characteristics of the reference frame set in this way, the contour correction unit 525 sequentially performs contour correction of all frames, and temporarily stores the image data after the contour correction in the RAM 501 (step S523). This completes the image processing routine 3 and returns to step S507 of the original routine, and displays the image data after the image processing on the monitor 580.

  Next, an image processing routine 4 (step S506) according to the fourth embodiment of the present invention will be described with reference to FIG. The image processing routine 4 is an image processing routine executed for RAW data shot in the AE bracket shooting mode. Since the basic processing content is the same as the processing described in FIG. 6, the same processing as in FIG.

  Steps S511 and S512 are the same as those shown in FIG.

  The CPU 520 reads the shooting information added to the RAW data temporarily stored in the RAM 501 and selects a frame with a shift amount of 0 as a reference frame (step S611).

  The processing performed from step S516 to step S518 is the same as that in FIG.

  Next, the CPU 520 sets an optimum gradation characteristic for the reference frame from the numerical data distribution of the reference frame obtained in step S518 (step S619), and sets the gradation characteristics other than the reference frame based on the optimum gradation characteristic for the reference frame. The gradation characteristics are shifted and set according to the exposure amount (step S620).

  The processing from step S520 to step S522 is the same as that in FIG.

  Thus, the image processing routine 4 ends, and the process returns to step S508 of the original routine, and the image data after the image processing is displayed on the monitor 580.

  As described above, according to the present embodiment, since the setting of the image processing means is changed based on the image data of all shot frames, there is no variation in the color tone and gradation between the frames shot continuously. An image processing program for obtaining a high-quality image and an image processing program for a digital camera can be provided.

  In addition, if such an imaging apparatus is used, a small-sized and high-quality digital camera can be provided at low cost.

  Although a digital single-lens reflex camera is exemplified as the present embodiment, the present invention can also be applied to digital cameras other than single-lens reflex systems, mobile phones, video cameras, and the like.

  The photographer may be able to select the reference image. By doing so, it is possible to perform image processing according to the photographer's intention.

1 is an external view of a digital camera 1 according to the present invention. It is sectional drawing which shows the structure of the digital camera 1 which concerns on this invention. 1 is a functional block diagram of a digital camera 1 according to the present invention. It is a flowchart explaining one of the outline procedures at the time of imaging | photography which the imaging device of this invention performs. It is a flowchart explaining the image processing routine 1 which is the 1st Embodiment of this invention. It is a flowchart explaining the image processing routine 2 which is the 2nd Embodiment of this invention. It is explanatory drawing explaining the example of distribution of the numerical data obtained from the image | photographed image data. It is explanatory drawing explaining the example of the gradation conversion characteristic applied to picked-up image data in this invention. It is explanatory drawing explaining the example of the frequency response characteristic applied to picked-up image data in this invention. In this invention, it is explanatory drawing explaining the example of the frequency response characteristic applied to the image data image | photographed in AE bracket imaging mode. FIG. 3 is a functional block diagram of a computer that performs image processing of captured image data in the present invention. It is a flowchart explaining another procedure of the outline at the time of the imaging | photography which the imaging device of this invention performs. 6 is a flowchart illustrating image processing of captured image data performed by a computer in the present invention. It is a flowchart explaining the image processing routine 3 which is the 3rd Embodiment of this invention. It is a flowchart explaining the image processing routine 4 which is the 4th Embodiment of this invention. In this invention, it is explanatory drawing explaining the imaging | photography information added to the image | photographed image data.

Explanation of symbols

1 Digital Camera 2 Camera Body 3 Shooting Lens 5 CCD
22 Image processing unit 70 CPU
73 WB control unit 74 Reference image selection unit 77 Gradation conversion control unit 78 Frequency response control unit 220 WB correction unit 221 Image interpolation unit 222 Linear matrix processing unit 223 Gamma correction unit 224 Color difference matrix processing unit 225 Contour correction unit 226 Image compression Part L Optical axis of taking lens

Claims (10)

An image sensor that photoelectrically converts a subject image incident from a lens barrel;
First storage means for temporarily storing image data acquired from the image sensor;
Image processing means for performing predetermined processing on the image data stored in the first storage means;
Second storage means for storing the image data subjected to the predetermined processing;
In an imaging apparatus having
An image pickup apparatus comprising: a control unit that changes a setting of an image processing unit based on all image data stored in the first storage unit within a predetermined time. The imaging apparatus according to claim 1, wherein the setting of the image processing unit is a gradation conversion characteristic of captured image data. The imaging apparatus according to claim 1, wherein the setting of the image processing unit is white balance of captured image data. The control means has a continuous shooting mode for continuously acquiring image data,
The imaging apparatus according to claim 1, wherein the control unit changes settings of the image processing unit based on all image data acquired in the continuous shooting mode. The control means has a bracket mode for continuously acquiring image data obtained by sequentially changing exposure conditions,
The imaging apparatus according to claim 1, wherein the control unit changes the setting of the image processing unit based on all the image data acquired in the bracket mode. The control means includes reference image selection means for selecting a reference image from the image data stored in the first storage means, and the control means is configured to perform image processing on the basis of image data of the selected reference image. The imaging apparatus according to claim 1, wherein the setting is changed. The imaging apparatus according to claim 1, wherein the image processing unit makes the setting of the gradation characteristics of at least two acquired image data the same. The imaging apparatus according to claim 1, wherein the image processing unit makes the white balance settings of at least two acquired image data the same. A first storage step of temporarily storing image data acquired within a predetermined time;
An image processing step of performing a predetermined process on the image data temporarily stored in the first storage step;
A second storage step for storing the image data subjected to the predetermined processing;
A control step of changing settings of the image processing step based on all the image data stored in the first storage step. A program for performing image processing of image data acquired by an imaging device by a computer,
A process for determining shooting information of image data on a computer and grouping it,
A process for determining image processing settings based on all of the grouped image data;
An image processing program for a digital camera, wherein image processing is executed based on the setting.

Images