JP3955080B2 - Digital camera and operation control method thereof - Google Patents

Description

  The present invention relates to an image data adjusting device and a control method thereof.

  With a digital camera, a subject can be imaged and the captured subject image can be displayed on a display screen of a display device. In some digital cameras, an imaging assist frame is displayed on a display screen so that an image can be captured with an appropriate composition according to the type of subject. The subject is imaged so that the main subject is positioned in the assist frame.

  In a digital camera, automatic focus adjustment is generally performed so that a subject at the center of an imaging region is in focus.

  For this reason, when the subject is imaged using the assist frame that is shifted from the center of the imaging area, the main subject image in the assist frame may be out of focus. The same applies to exposure control.

  An object of this invention is to be able to obtain a suitable image about the desired part of the image after imaging.

  A first invention is a digital camera capable of at least one of focus control and exposure control, which captures an object and outputs image data representing the object image, and image data output from the image capturing means Recording control means for recording the image on the recording medium, image display control means for controlling the display device so as to display the subject image represented by the image data output from the imaging means on the display screen, on the display screen Assist frame display control means for controlling the display device to display a frame for imaging assistance, and imaging control means for performing at least one of focus control and exposure control based on the subject image in the assist frame. It is characterized by being.

  The first invention also provides an operation control method suitable for the digital camera. That is, this method is a digital camera capable of at least one of focus control and exposure control, and displays an imaging assist frame on the display screen of the display device, and images a subject according to the assist frame. The subject image obtained by imaging is displayed on the display screen, the image data representing the subject image obtained by imaging is recorded on a recording medium, and focus control and exposure are performed based on the subject image in the assist frame. At least one of the controls is performed.

  According to the first invention, the assist frame is displayed on the display screen of the display device. At least one of focus control and exposure control is performed based on the subject image existing in the assist frame.

  The subject image existing in the assist frame is focused and has an appropriate brightness. In general, the subject image existing in the assist frame is often important. It is possible to obtain an in-focus image with appropriate brightness for important images.

  An illuminating angle can be adjusted, a stroboscopic light emitting means for irradiating auxiliary light, and an adjusting means for adjusting the illuminating angle of the stroboscopic light emitting means so as to irradiate the subject corresponding to the subject image in the assist frame. May be further provided.

  The subject corresponding to the subject image existing in the assist frame is irradiated with light from the strobe light emitting means. The subject image within the assist frame has an appropriate brightness.

  You may further provide the setting means which sets at least one of the magnitude | size and position of the said assist frame. In this case, the assist frame is displayed at the size and position set by the setting means.

  The assist frame can be displayed at a desired position with a desired size.

  An image data adjustment device according to a second aspect of the invention is an image display control means for controlling a display device so as to display a subject image for one frame represented by image data on a display screen, and an appropriate area on the display screen A designated frame display control means for controlling the display device to display a designated frame for designating, and a subject image outside the designated frame so that the subject image in the designated frame becomes an image of appropriate brightness. The image data adjustment means for adjusting the level of the image data representing the subject image for one frame is provided.

  The second invention provides a method suitable for the apparatus. That is, this method displays the subject image for one frame represented by the image data on the display screen of the display device, displays a designation frame for designating the image adjustment area on the display screen, and The level adjustment of the image data representing the subject image for one frame is performed based on the subject image outside the designated frame so that the subject image in the frame becomes an image of appropriate brightness.

  According to the second invention, the subject image is displayed on the display screen. The designated frame is also displayed on the display screen. Level adjustment is performed based on the subject image outside the designated frame so that the subject image existing within the designated frame becomes an image of appropriate brightness. With respect to an image of a desired portion, an image with appropriate brightness can be obtained. For example, it is possible to find a location where the brightness is appropriate in the subject image and adjust the image so that the image in the designated frame is the same as the brightness of the location.

  FIG. 1 shows an embodiment of the present invention and is a block diagram showing an electrical configuration of a digital still camera.

  The entire operation of the digital still camera is controlled by the CPU 10.

  A ROM 18 in which an operation program is stored is externally attached to the CPU 10.

  The CPU 10 includes a DRAM 21 that temporarily stores image data representing an image for one frame. The CPU 10 also includes a compression / decompression unit 2 that compresses image data and decompresses the compressed image data, an AE for performing automatic exposure adjustment processing and automatic focus adjustment processing, an AF control unit 23, and image data levels A level correction control unit 24 for adjusting the color balance, a color balance adjustment unit 25 for adjusting the color balance of image data, and a contour correction unit 26 for performing contour correction processing. These compression / decompression unit 22, AE, AF control unit 23, level correction control unit 24, color balance adjustment unit 25 and contour correction unit 26 are expressed as hardware, but are realized by software. Needless to say. Of course, it can also be configured by hardware.

  The shutter release button 27 is of a two-stage stroke type and can be pushed down in the first stage and pushed down in the second stage. A signal indicating depression of the first stage and the second stage is input to the CPU 10. When the shutter release button 27 is depressed in the first stage, automatic focus control and automatic exposure control by the AE / AF control unit 23 are performed. As the shutter release button 27 is depressed in the second stage, image data representing the subject image obtained by imaging is recorded in the memory card 30.

  The digital still camera includes a strobe light emitting device 17 so that strobe photography is possible. The strobe light emitting device 17 can change the irradiation angle. In the strobe light emitting device 17, the irradiation angle and the light emission timing are controlled by a strobe control device 16 controlled by the CPU 10.

  As will be described later, the digital still camera can display an assist frame for assisting the composition of imaging on the display screen of the display device 9. A user (especially a novice user) learns the imaging technique by imaging the subject so that the main subject image is aligned with the assist frame displayed on the display device 9. Some assist frames are displayed in various sizes and positions. The assist frame selection switch 28 selects an assist frame corresponding to the subject. A signal indicating the assist frame selected by the assist frame selection switch 28 is given to the CPU 10.

  The imaging lens 1 can be moved in the optical axis direction by a motor 11, and the focal length can be changed. The aperture of the aperture 2 can be changed by the motor 12, and the aperture value changes. A motor driver 13 for controlling these motors 11 and 12 is controlled by the CPU 10.

  The digital still camera includes a timing generator 15, and a clock signal is generated by the timing generator 15. The clock signal generated by the timing generator 15 is given to the CCD driver 14. The CCD driver 14 controls the CCD 3.

  A subject image is formed on the CCD 3 through the diaphragm 2 by the imaging lens 1. A video signal representing the subject image is output from the CCD 3 and input to the analog signal processing circuit 4. The video signal is subjected to white balance adjustment in the analog signal processing circuit 4. The white balance adjusted video signal is converted into RGB digital image data by the analog / digital conversion circuit 5. The digital image data is input to the digital signal processing circuit 6. The digital signal processing circuit 6 has functions of gamma correction, luminance data and color difference data generation, and can output RGB image data as necessary.

  The RGB image data output from the digital signal processing circuit 16 is given to the digital / analog conversion circuit 8 and converted into an analog video signal. The converted analog video signal is given to the display device 9 to display the captured subject image.

  When the shutter release button 27 is depressed in the first stage, the RGB image data is input to the DRAM 21 in the CPU 10 and temporarily stored. The RGB image data is read from the DRAM 21 and the luminance data and color difference data are generated in the CPU 10. Luminance data and color difference data are stored in the DRAM 21. Luminance data and color difference data temporarily stored in the DRAM 21 are read, and level correction in the level correction control unit 24, AE, AE control and AF control in the AF control unit 23 are performed. Details of the level correction processing in the level correction control unit 24 and the AE and AF processing in the AE and AF control unit 23 will be described later.

  When the shutter release button 27 is depressed in the second stage, luminance data and color difference data generated in the digital signal processing circuit 16 are given to the DRAM 21 of the CPU 10 and temporarily stored. Luminance data and color difference data temporarily stored in the DRAM 21 are read and given to the compression / decompression unit 22 for compression processing. The compressed luminance data and color difference data are given to the memory card 30 and recorded.

  FIG. 2 shows an example of the assist frame. FIG. 3 shows how the composition of the subject is determined using the assist frame shown in FIG. In these drawings, the same reference numerals as those of the display device 9 are used for the display screen.

  The size and position of the assist frame 31 are determined so that the composition of the assist frame 31 is good for a knee shot in vertical shooting (capturing a subject with the camera held vertically). The horizontal direction and the vertical direction are each ¼ of the shooting area.

  By determining the composition so that the face of the subject is positioned at the position of the assist frame 31, the subject can be imaged with a good composition for the knee shot.

  FIG. 4 shows another example of the assist frame. FIG. 5 shows how the composition of the subject is determined using the assist frame shown in FIG.

  The assist frame is an example of an assist frame for group shooting. The assist frame 32 shown in FIG. 4 shoots so that a tall person is positioned at the center. As shown in FIG. 5, a captured image in which the height is balanced is obtained by imaging the subject using the assist frame 32.

  FIG. 6 shows still another example of the assist frame. FIG. 7 shows how the composition of the subject is determined using the assist frame shown in FIG.

  This assist frame is also an example of a group photographing assist frame, similar to the assist frame shown in FIG. The assist frame 33 shown in FIG. 6 positions a tall person and a short person alternately. As shown in FIG. 7, a photographic image with a sense of rhythm is obtained with accents.

  8 to 11 are flowcharts showing the processing procedure of the digital still camera according to this embodiment.

  FIG. 8 shows an integration area setting process procedure.

  In the digital still camera according to this embodiment, automatic focus adjustment and automatic exposure adjustment are performed using image data representing an image in an area based on the assist frame selected by the user. The process of setting the areas used for these automatic focus adjustment and automatic exposure adjustment is the integrated area setting process.

  The user turns on the power of the digital still camera, and the assist frame selection switch 28 selects the assist frame (step 40). The selected assist frame is displayed on the display screen of the display device 9 as described above.

  It is determined which assist frame is the selected assist frame (step 41).

  If the selected assist frame is the frame 31 suitable for the knee shot shown in FIG. 2, the area defined by the selected frame 31 is set as the automatic exposure adjustment area (step 42).

  The frame 31 suitable for the knee shot selected as the assist frame is a relatively small area as compared with the entire imaging area. Therefore, it is possible to focus relatively accurately when automatic focal length adjustment is performed based on image data representing an image in an area defined by the assist frame 31. An area defined by the assist frame 31 is set as an area for automatic focus adjustment (step 43).

  If the selected assist frame is a frame 32 suitable for group photographing shown in FIG. 4, the area defined by the selected frame 32 is set as an area for automatic exposure adjustment (step 44).

  The frame 32 selected as the assist frame is a relatively large area compared to the entire imaging area. For this reason, when automatic focal length adjustment is performed based on image data representing an image in an area defined by the assist frame 32, erroneous focus adjustment may occur. For this purpose, an area 32A smaller than the area of the assist frame 32 is set as an area for automatic focus adjustment (step 45). Needless to say, the small area 32A for auto-focusing is preset according to the assist frame 32.

  If the selected assist frame is a frame 33 suitable for group shooting shown in FIG. 6, the area defined by the selected frame 33 is set as an area for automatic exposure adjustment (step 46).

  Similar to the assist frame 32, the frame 33 selected as the assist frame 33 is a relatively large frame as compared with the entire imaging region. For this reason, erroneous focus adjustment may occur when automatic focus adjustment is performed based on image data representing an image in an area defined by the assist frame 32. For this reason, as in the case where the assist frame 32 is selected, an area 33A smaller than the assist frame 33 is set as an autofocus area (step 47).

  The automatic exposure adjustment is performed based on the image in the area defined by the assist frame selected by the user. In the assist frame, a portion selected by the user as a main subject or an important portion of the main subject is positioned. The exposure adjustment for the important part is performed relatively accurately.

  In addition, since the automatic focus adjustment is performed based on the portion that the user determines to be important, the important portion is focused. When a relatively large assist frame is selected, focus adjustment is performed so that an image in an area smaller than the area defined by the assist frame is in focus. Focus control is relatively accurate.

  FIG. 9 shows a processing procedure for automatic exposure adjustment. This process starts when the shutter release button 27 is depressed in the first stage.

  First, the diaphragm 2 is driven by the motor 12 so as to have the initial diaphragm value (step 51). The subject is imaged by the CCD 3 and the luminance data and color difference data representing the subject image are temporarily stored in the DRAM 21 in the CPU 10 as described above.

  Of the luminance data stored in the DRAM 21, luminance data corresponding to the AE integration area set as described above is read out (it can be easily done by controlling the addressing). The read luminance data in the AE integration area is given to the AE / AF control unit 23, and a photometric value is calculated (step 52).

  It is confirmed whether or not the calculated photometric value is within an allowable range (step 53). If it is outside the allowable range (NO in step 53), the aperture value is changed and the subject is imaged again (step 54). Similarly, the photometric value is calculated from the luminance data representing the image within the assist frame of the captured subject image.

  If the calculated photometric value is within the allowable range (YES in step 53), an exposure calculation process is performed from the calculated photometric value (step 55), and the aperture value and shutter speed are calculated.

  When the automatic exposure adjustment process ends, the process shifts to an automatic focus adjustment process.

  FIG. 10 is a flowchart showing a processing procedure of automatic focus adjustment processing.

  From the luminance data temporarily stored in the DRAM 21, luminance data representing an image in the AF integration area set as described above is read (step 61). The imaging lens 1 is driven until the search is completed. Of the luminance data obtained by imaging the subject at the position where the imaging lens 1 has moved, contrast data representing the blur of the image in the AF integration area is read (steps 63 and 64).

  The imaging lens 1 is driven, the subject is imaged at all positions, and contrast data representing the blur of the subject image is temporarily stored in the built-in memory of the digital signal processing circuit 6. A peak value is detected from the stored contrast data (step 65). When the peak value is detected, the position of the imaging lens 1 from which the peak value is obtained is determined as the focus position. The motor 11 is driven so that the imaging lens 1 is positioned at the in-focus position (step 66). If the peak position is not detected (NO in step 65), the motor 11 is driven so that the imaging lens 1 is positioned at a predetermined designated position (step 66).

  When the shutter release button 27 is depressed in the second stage, the process proceeds to the recording control process.

  FIG. 11 is a flowchart showing the processing procedure of the recording control process.

  The aperture 2 and the CCD driver 14 are controlled so that the aperture value and shutter speed calculated in the AE control are obtained (step 71, photographing setting). A subject image is exposed on the light receiving surface of the CCD 3 (step 72), and a video signal representing the subject image is output from the CCD 3. As described above, luminance data and color difference data are output from the digital signal processing circuit 6 and temporarily stored in the DRAM 21 of the CPU 10.

  The image data is given to the compression / decompression unit 22 and data compression processing is performed (step 73). The compressed image data is again applied to the DRAM 21 and temporarily stored.

  The compressed image data is read from the DRAM 21 and given to the memory card 30 for recording.

  Of the subject image represented by the image data recorded on the memory card 30, the image portion within the assist frame set by the user has an appropriate brightness and is in focus. .

  In the above-described embodiment, the flash control circuit 16 and the flash 17 may be controlled by the CPU 10 so as to irradiate the corresponding subject within the selected assist frame. Light of appropriate brightness is irradiated to the portion of the subject corresponding to the image portion selected by the user.

  FIG. 12 shows an example of a subject image.

  When the assist frame 61 is displayed on the display screen of the display device 9 and the subject image is captured as described above, the image in the assist frame 61 has an appropriate brightness. However, the image portion of the region 62 may be dark.

  The digital still camera in this embodiment is capable of reproducing an image and adjusting the brightness of an image of a desired portion to an appropriate brightness.

  FIG. 13 shows an example of a reproduced image.

  Image data recorded in the memory card 30 is read out, and an image represented by the image data is displayed on the display screen of the display device 9.

  The user sets an area 63 in the reproduced image in which brightness is appropriate. In order to make this setting, a setting switch will be provided on the camera.

  The image portion in the area 61 has an appropriate brightness (if necessary, data indicating that the image in the area 61 has an appropriate brightness is associated with the image data when the image data is recorded, Will be recorded on card 30). The CPU 10 detects the luminance value of the image portion in the area 61. Level correction processing is performed on all the image data of one frame representing the reproduced image so that the luminance value of the image portion of the setting area 63 becomes the detected luminance value in the area 61. Needless to say, this level correction processing is performed in the level correction control unit 24 in the CPU 10.

  An image in which the image in the setting area 63 has an appropriate brightness is obtained. The level-adjusted image is again applied to the memory card 30 as necessary and recorded.

  In the embodiment described above, a desired area 63 is set and level correction processing is performed so that an image in the area 63 has appropriate brightness. However, not only brightness processing but also color balance correction is performed. Processing, contour correction processing, and the like may be similarly controlled.

  For example, in the case of color balance correction processing, color balance adjustment is performed in the color balance adjustment unit 25 in the CPU 10 so that the set area has an appropriate color balance. In the case of contour correction processing, the contour correction processing is performed by the contour correction circuit 26 in the CPU 10 so that the set area has an appropriate contour.

It is a block diagram which shows the electric constitution of a digital still camera. It is an example of an assist frame. It is an example of a to-be-photographed image. It is an example of an assist frame. It is an example of a to-be-photographed image. It is an example of an assist frame. It is an example of a to-be-photographed image. It is a flowchart which shows the process sequence of integration area setting. It is a flowchart which shows the process sequence of AE control. It is a flowchart which shows the process sequence of AF control. It is a flowchart which shows the process sequence of recording control. It is an example of a to-be-photographed image. It is an example of a to-be-photographed image.

Explanation of symbols

1 Imaging lens 3 CCD
9 Display device
10 CPU
11, 12 motor
13 Motor driver
16 Strobe control circuit
17 Strobe
21 DRAM
23 AE, AF control unit
24 Level correction controller
25 Color balance adjustment section
27 Shutter release button
28 Assist frame selection switch

Claims (3)

Image display control means for controlling the display device to display a subject image for one frame represented by the image data on the display screen;
A designated frame display control means for controlling the display device so as to display a designated frame for designating an appropriate area on the display screen, and a subject image in the designated frame to be an image having an appropriate brightness. , Image data adjusting means for adjusting the level of the image data representing the subject image for one frame based on the subject image outside the designated frame;
An image data adjustment apparatus comprising: A setting means for setting at least one of the size and position of the designated frame;
The designated frame display control means controls the display device to display the designated frame at the size and position set by the setting means.
The image data adjustment apparatus according to claim 1. The subject image for one frame represented by the image data is displayed on the display screen of the display device.
A designated frame for designating the image adjustment area is displayed on the display screen.
The level adjustment of the image data representing the subject image for one frame is performed based on the subject image outside the designated frame so that the subject image within the designated frame becomes an image of appropriate brightness.
A method for controlling an image data adjustment apparatus.

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