JP2012039256A - Imaging apparatus, control method therefor and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the changeover of the luminance and colors of images when switching the setting of an aspect ratio, in the case of generating images of different aspect ratios by changing a video region on an image sensor according to the setting of the aspect ratio.SOLUTION: For video regions that an imaging device 14 outputs as image data, respectively different video regions are set according to the setting of the aspect ratio by aspect ratio switching means, the video region to be used at all times independent of the setting of the aspect ratio is defined as a common region, the video region to be used or not used depending on the setting of the aspect ratio is defined as a non-common region, the region for which the common region and the non-common region are put together is defined as the entire video region, and evaluation value calculation means varies the using ratio of the non-common region when calculating an evaluation value for exposure control by exposure control means and white balance control by white balance control means.

Description

  The present invention relates to an image pickup apparatus that photoelectrically converts an optical image of a subject with an image pickup device and generates digital image data from an image signal obtained by the photoelectric conversion, a control method thereof, and a program, and in particular, the aspect ratio of the image signal is variable. Regarding technology.

  Patent Document 1 discloses a system wide-angle image that uses a plurality of target images cut out from a wide-angle image. In the technique disclosed in Patent Literature 1, information is acquired from each of a wide-angle image and a cut-out image, and when the angle of view is changed, a correction value using the information of the wide-angle image is used to switch when the angle of view changes. Can be reduced.

  Patent Document 2 discloses that a camera capable of shooting by changing the aspect ratio can shoot with appropriate exposure on each screen having different aspect ratios by changing the photometry range of exposure control according to the setting of the aspect ratio. Techniques that can do this are disclosed.

JP 2006-222816 A JP-A-6-180467 JP-A-10-232934 JP 2000-48184 A

  In a camera that can shoot with varying aspect ratios, the image data of the widest video area is acquired on the image sensor, and images with different aspect ratios are generated by cutting out part of the image data at the image processing stage. There are many ways to do this.

  On the other hand, in order to make the best use of the optical image circle, a method for generating images with different aspect ratios by changing the video area used on the image sensor according to the aspect ratio setting has appeared. It was.

  In the latter case where the video area to be used on the image sensor is changed by setting the aspect ratio, the processing for evaluating the entire video area changes the image data to be evaluated if the aspect ratio setting is changed. Therefore, there is a problem that the evaluation result is greatly affected by the aspect ratio setting. For example, in the exposure control, the brightness of the entire video area is measured and the brightness of the image is controlled appropriately. However, when the aspect ratio setting changes and the video area to be evaluated changes, the brightness of the entire video area changes. Therefore, there arises a problem that the brightness of the image changes. The same applies to white balance control that measures the color level of the entire video area and adjusts it to an optimal color balance. In other words, switching the aspect ratio setting changes the evaluation value for exposure control and white balance control, causing a problem of switching between brightness and color.

  The present invention has been made in view of the above-described points. When an image having a different aspect ratio is generated by changing a video area on the image sensor according to the setting of the aspect ratio, the aspect ratio is set. The object is to reduce the change in luminance and color of the image when the mode is switched.

  An imaging apparatus according to the present invention includes an imaging unit that captures an image of a subject to obtain image data, an exposure control unit that performs exposure control based on the image data obtained by the imaging unit, and image data obtained by the imaging unit. White balance control means for performing white balance control based on the above, evaluation value calculation means for calculating an evaluation value for at least one of exposure control by the exposure control means and white balance control by the white balance control means; , An aspect ratio switching unit that switches an aspect ratio when image data is obtained by the imaging unit, and a video area output as image data by the imaging unit differs depending on an aspect ratio set by the aspect ratio switching unit. An image area is set, and the evaluation value calculation means When calculating the value, characterized in that the proportion of the image region or not used or used by setting the aspect ratio to the variable.

  According to the present invention, when an image having a different aspect ratio is generated by changing the video area on the image sensor according to the aspect ratio setting, the brightness and color of the image when the aspect ratio setting is switched are changed. It is possible to reduce switching.

It is a block diagram which shows the structure of the imaging device which concerns on embodiment. It is a flowchart which shows the operation | movement process of the main routine of the imaging device which concerns on embodiment. It is a flowchart which shows the operation | movement process of the main routine of the imaging device which concerns on embodiment. It is a flowchart which shows a still image shooting process. It is a flowchart which shows an evaluation value calculation process. It is a figure which shows the image | video area | region used on an image sensor when an aspect ratio is 4: 3. It is a figure which shows the video area | region used on an image sensor when an aspect ratio is 16: 9. It is a figure which shows area division | segmentation in case the video area used on an image sensor changes with the settings of an aspect ratio. It is a figure which shows area division | segmentation when an aspect ratio is 16: 9. It is a figure which shows area division | segmentation when an aspect ratio is 4: 3.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating a configuration of an imaging apparatus 100 according to an embodiment of the present invention. Reference numeral 10 denotes a photographing lens, reference numeral 12 denotes a shutter having a diaphragm function, and reference numeral 14 denotes an image sensor that converts an optical image into an electric signal. Reference numeral 16 denotes an A / D converter that converts an analog signal output of the image sensor 14 into a digital signal. A timing generation circuit 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16, and the D / A converter 26. The timing generation circuit 18 is controlled by the memory control circuit 22 and the system control circuit 50.

  An image processing circuit 20 performs predetermined pixel interpolation processing and color conversion processing on the data from the A / D converter 16 or the data from the memory control circuit 22. The image processing circuit 20 performs predetermined calculation processing using the captured image data, and the system control circuit 50 controls the exposure control unit 40 and the distance measurement control unit 42 based on the obtained calculation result. TTL (through-the-lens) AF (autofocus) processing, AE (automatic exposure) processing, and EF (flash pre-emission) processing are performed. Further, the image processing circuit 20 performs predetermined calculation processing using the captured image data, and also performs TTL AWB (auto white balance) processing based on the obtained calculation result. As a calculation process for white balance, the video signal is divided into a plurality of blocks, block integration for obtaining the integrated value of the color signal of each block, and the signal value of each pixel of the video signal is developed into chromaticity coordinates to obtain a predetermined area. Perform white search integration to obtain the integration value of the color signal. The setting of the integration region on the chromaticity coordinates used for the white search integration is held in the image processing circuit 20.

  A memory control circuit 22 controls the A / D converter 16, the timing generation circuit 18, the image processing circuit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression circuit 32. The data of the A / D converter 16 is written into the image display memory 24 or the memory 30 via the image processing circuit 20 and the memory control circuit 22 or the data of the A / D converter 16 is directly passed through the memory control circuit 22. It is.

  Reference numeral 24 denotes an image display memory, 26 denotes a D / A converter, and 28 denotes an image display unit including a TFT LCD or the like. The display image data written in the image display memory 24 is displayed by the image display unit 28 via the D / A converter 26. If the image data captured using the image display unit 28 is sequentially displayed, the electronic viewfinder function can be realized. Further, the image display unit 28 can arbitrarily turn on / off the display according to an instruction from the system control circuit 50. When the display is turned off, the power consumption of the imaging apparatus 100 can be significantly reduced. it can.

  Reference numeral 30 denotes a memory for storing captured still images and moving images, and has a sufficient storage capacity to store a predetermined number of still images and a moving image for a predetermined time. This makes it possible to write a large amount of images to the memory 30 at high speed even in continuous shooting or panoramic shooting in which a plurality of still images are continuously shot. The memory 30 can also be used as a work area for the system control circuit 50. A compression / decompression circuit 32 compresses and decompresses image data by adaptive discrete cosine transform (ADCT) or the like. The compression / decompression circuit 32 reads an image stored in the memory 30, performs a compression process or an expansion process, and writes the processed data to the memory 30.

  Reference numeral 40 denotes an exposure control unit that controls the shutter 12 having a diaphragm function, and has a flash light control function in cooperation with the flash 48. A distance measuring control unit 42 controls focusing of the photographing lens 10. A zoom control unit 44 controls zooming of the photographing lens 10. A barrier control unit 46 controls the operation of the protection unit 102 serving as a barrier. A strobe 48 has an AF auxiliary light projecting function and a flash light control function. The exposure control unit 40 and the distance measurement control unit 42 are controlled using the TTL method. Based on the calculation result obtained by calculating the captured image data by the image processing circuit 20, the system control circuit 50 performs the exposure control unit 40 and the distance measurement. The controller 42 is controlled.

  Reference numeral 50 denotes a system control circuit that controls the entire imaging apparatus 100. A memory 52 stores constants, variables, programs, and the like for operating the system control circuit 50. The memory 52 also stores program diagrams used in AE. The program diagram is a table that defines the relationship between the aperture value for the exposure value and the control value for the shutter speed.

  Reference numeral 54 denotes a display unit such as a liquid crystal display device or a speaker, which displays an operation state, a message, and the like using characters, images, sounds, and the like in accordance with execution of a program by the system control circuit 50. The display unit 54 is installed in a single or a plurality of locations near the operation unit of the imaging device 100 so as to be easily visible, and is configured by a combination of, for example, an LCD, an LED, and a sounding element. The display unit 54 is partly installed in the optical viewfinder 104.

  Among the display contents of the display unit 54, what is displayed on the LCD or the like includes single shot / continuous shooting display, self-timer display, compression rate display, number of recorded pixels, number of recorded pixels, number of remaining images that can be captured, shutter Speed display, Aperture value display, Exposure compensation display, Flash display, Red-eye reduction display, Macro shooting display, Buzzer setting display, Clock battery level display, Battery level display, Error display, Multi-digit number information display and recording There are a display state of the media 200 and 210, a communication I / F operation display, a date / time display, and the like. Among the display contents of the display unit 54, what is displayed in the optical viewfinder 104 includes in-focus display, camera shake warning display, flash charge display, shutter speed display, aperture value display, exposure correction display, and the like.

  Reference numeral 56 denotes an electrically erasable / recordable nonvolatile memory such as an EEPROM.

  Reference numerals 60, 61, 62, and 63 denote operation means for inputting various operation instructions of the system control circuit 50. The operation means 60, 61, 62, and 63 are configured by a single or a combination of a switch, a dial, a touch panel, pointing by gaze detection, a voice recognition device, and the like. Is done.

  Here, a specific description of these operating means will be given. Reference numeral 60 denotes a mode dial switch, which can switch and set various function modes such as power OFF, automatic shooting mode, shooting mode, panoramic shooting mode, playback mode, multi-screen playback / erase mode, and PC connection mode.

  Reference numeral 61 denotes a shutter switch SW1, which is turned ON during the operation of a shutter button (not shown) and instructs the start of operations such as AF processing, AE processing, AWB processing, and EF processing. Reference numeral 62 denotes a shutter switch SW2, which is turned on when an operation of a shutter button (not shown) is completed, and instructs the start of a series of processing operations including exposure processing, development processing, and recording processing. In the exposure process, the image data is written into the memory 30 through the signal read from the image sensor 14 via the A / D converter 16 and the memory control circuit 22. The development process is performed using an operation in the image processing circuit 20 and the memory control circuit 22. In the recording process, image data is read from the memory 30, compressed by the compression / decompression circuit 32, and written to the recording medium 200 or 210.

  Reference numeral 63 denotes an operation unit including various buttons, a touch panel, and the like. Menu button, set button, macro button, multi-screen playback page break button, flash setting button, single shooting / continuous shooting / self-timer switching button, menu movement + (plus ) Button, menu shift-(minus) button, playback image shift + (plus) button, playback image-(minus) button, shooting image quality selection button, exposure compensation button, date / time setting button, display switching button, etc. . The display switching button can switch the setting of the electronic viewfinder function using the image display unit 28, and can turn ON / OFF the display on the image display unit 28.

  A power control unit 80 includes a battery detection circuit, a DC-DC converter, a switch circuit that switches a block to be energized, and the like. The power supply control unit 80 detects the presence / absence of a battery, the type of battery, and the remaining battery level, controls the DC-DC converter based on the detection result and the instruction of the system control circuit 50, and requires the necessary voltage. It is supplied to each part including the recording medium for a period. Reference numeral 82 denotes a connector, 84 denotes a connector, 86 denotes a primary battery such as an alkaline battery or lithium battery, a secondary battery such as a BNiCd battery, NiMH battery, or Li battery, an AC adapter, or the like.

  Reference numerals 90 and 94 denote interfaces with recording media such as memory cards and hard disks. Reference numerals 92 and 96 denote connectors for connecting to a recording medium such as a memory card or a hard disk. Reference numeral 98 denotes a recording medium attachment / detachment detection unit that detects whether or not the recording medium 200 or 210 is attached to the connector 92 or 96.

  In the present embodiment, it is assumed that there are two interfaces and connectors for attaching the recording medium. Of course, the interface and the connector for attaching the recording medium may have a single or a plurality of systems, any number of systems. Moreover, it is good also as a structure provided with combining the interface and connector of a different standard. The interface and the connector may be configured using a PCMCIA card, a CF (Compact Flash (registered trademark)) card, or the like that conforms to a standard. Further, when the interfaces 90 and 94 and the connectors 92 and 96 are configured using a PCMCIA card, a CF (compact flash) card, or the like, a LAN card, a modem card, a USB card, an IEEE 1394 card, a P1284 card. By connecting various communication cards such as SCSI cards, PHS and other communication cards, image data and management information attached to the image data can be transferred to and from other computers and peripheral devices such as printers. it can.

  A protection unit 102 is a barrier, and covers the imaging unit including the lens 10 of the imaging device 100 to prevent the imaging unit from being dirty or damaged. Reference numeral 104 denotes an optical viewfinder, which can take an image using only the optical viewfinder without using the electronic viewfinder function of the image display unit 28.

  A communication unit 110 has various communication functions such as RS232C, USB, IEEE1394, P1284, SCSI, modem, LAN, and wireless communication. Reference numeral 112 denotes a connector for connecting the imaging apparatus 100 to another device by the communication unit 110 or an antenna in the case of wireless communication.

  Reference numeral 200 denotes a recording medium such as a memory card or a hard disk. The recording medium 200 includes a recording unit 202 composed of a semiconductor memory, a magnetic disk, and the like, an interface 204 with the imaging device 100, and a connector 206 that connects to the imaging device 100. Similarly, reference numeral 210 denotes a recording medium such as a memory card or a hard disk. The recording medium 210 includes a recording unit 212 composed of a semiconductor memory, a magnetic disk, or the like, an interface 214 with the imaging device 100, and a connector 216 that connects to the imaging device 100.

  2 and 3 are flowcharts showing an operation process of a main routine of the imaging apparatus 100 according to the present embodiment. Upon power-on such as battery replacement, the system control circuit 50 initializes flags, control variables, and the like in step S201, and initializes the image display of the image display unit 28 to an OFF state in step S202.

  In step S203, the system control circuit 50 determines the setting position of the mode dial 60. If the mode dial 60 is set to power OFF in step S203, the process proceeds to step S205. In step S205, a predetermined end process is performed, and then the process returns to step S203. As the predetermined end process, for example, the display on each display unit is changed to an end state. Further, the barrier of the protection unit 102 is closed to protect the imaging unit. In addition, necessary parameters, setting values, and setting modes including flags and control variables are recorded in the nonvolatile memory 56. Further, an unnecessary power source of each part of the image pickup apparatus 100 including the image display unit 28 is shut off by the power source control unit 80.

  If the mode dial 60 is set to the shooting mode in step S203, the process proceeds to step S206. If the mode dial 60 has been set to another mode in step S203, the process proceeds to step S204, and the system control circuit 50 executes processing according to the selected mode, and then returns to step S203.

  In step S <b> 206, the system control circuit 50 determines whether there is a problem in the operation of the imaging apparatus 100 due to the remaining capacity and operation status of the power supply 86 configured by a battery or the like by the power supply control unit 80. If there is a problem in step S206, a predetermined warning is displayed by image or sound using the display unit 54 (step S208), and the process returns to step S203. If there is no problem in step S206, the process proceeds to step S207.

  In step S207, the system control circuit 50 determines whether or not the operation state of the recording medium 200 or 210 has a problem in the operation of the imaging apparatus 100, particularly in the recording / reproducing operation of the image data with respect to the recording medium. If there is a problem in step S207, a predetermined warning is displayed by image or sound using the display unit 54 (step S208), and the process returns to step S203. If there is no problem in step S207, the process proceeds to step S209.

  In step S209, the system control circuit 50 determines whether or not it is in an OVF (optical viewfinder) state. If it is the OVF state in step S209, the through image is not displayed and the process proceeds to step S301.

  If it is an EVF (electronic viewfinder) state that displays a through image (a live image captured by the image sensor 14 to be displayed as a finder function before and after taking a still image) in step S209, the process proceeds to step S210. In step S <b> 210, the system control circuit 50 initializes shooting preparation for displaying a through image on the image display unit 28. When the preparation is completed, the through image is displayed on the image display unit 28 (step S211). Then, it progresses to step S301. In the through display state, the data sequentially written in the image display memory 24 via the image sensor 14, the A / D converter 16, the image processing circuit 20, and the memory control circuit 22 are transferred to the memory control circuit 22 and the D / A. An electronic finder function is realized by sequentially displaying images on the image display unit 28 via the converter 26.

  Here, the display setting on the image display unit 28 by the operation unit 63 can be set to an OVF state and an EVF state, and in the EVF state, two types of aspect ratios of 4: 3 and 16: 9 are available. It is possible to switch the aspect ratio. That is, it is possible to switch to three states of OVF / EVF (4: 3) / EVF (16: 9).

  In step S301, the system control circuit 50 determines whether or not the setting position of the mode dial 60 has been changed. If the setting position of the mode dial 60 has been changed in step S301, the process returns to step S203 to check the dial state. If the setting position of the mode dial 60 is not changed in step S301, the process proceeds to step S302.

  In step S302, the system control circuit 50 determines whether or not it is in the OVF state. If it is the OVF state in step S302, the through image is not displayed and the process proceeds to step S307. If the EVF state in which the through image is displayed in step S302, the process proceeds to step S303.

  In step S303, the system control circuit 50 calculates an evaluation value corresponding to the multi-aspect ratio for the AE process and the AWB process. Evaluation value calculation processing corresponding to the multi-aspect ratio will be described later with reference to FIG.

  Next, in step S304, the system control circuit 50 performs AE processing based on the evaluation value obtained in step S303. At this time, a difference from the appropriate exposure is calculated from the evaluation value (photometric result) calculated in step S303, and AE processing is performed on the through image using the exposure control unit 40.

  In step S305, the system control circuit 50 performs AWB processing based on the evaluation value obtained in step S303. At this time, a coefficient for optimizing the color balance is calculated from the evaluation value (color level) calculated in step S303, and the AWB process for the through image is performed using the image processing circuit 20.

  Thereafter, in step S306, the system control circuit 50 displays the through image on the image display unit 28, and proceeds to step S307.

  In step S307, the system control circuit 50 determines whether or not the shutter switch SW1 (61) has been pressed. If not, the system control circuit 50 returns to step S203 to check the dial status and battery status. If it is pressed, the process proceeds to step S308.

  In step S <b> 308, the image processing circuit 20 performs a predetermined distance measurement operation on the signal obtained from the image sensor 14 under the control of the system control circuit 50, and stores the calculation result in the memory 30. The system control circuit 50 performs AF processing using the distance measurement control unit 42 based on the distance calculation result, and focuses the photographing lens 10 on the subject. Thereafter, in step S309, the system control circuit 50 displays the through image on the image display unit 28, and proceeds to step S310.

  In step S310, the system control circuit 50 determines whether or not the shutter switch SW2 (62) has been pressed. If the shutter switch SW2 (62) has been pressed, the system control circuit 50 proceeds to step S312 and executes shooting processing. The photographing process will be described later with reference to FIG. If not, the process proceeds to step S311.

  In step S311, the system control circuit 50 determines again whether or not the shutter switch SW1 (61) has been pressed. If the shutter switch SW1 (61) has been pressed, the system control circuit 50 returns to step S309 and continues to hold the shutter switch SW1 (61). If not, the process returns to step S203 to check the dial state and the battery state.

  In step S312, the system control circuit 50 executes still image shooting processing. Thereafter, in step S313, the compressed image data stored in the memory 30 is written into the recording medium 200 as a still image file. In step S314, the image captured in step S312 is displayed as a through image on the image display unit 28, and the still image shooting process is completed.

  In step S315, the system control circuit 50 determines whether or not the shutter switch SW1 (61) has been pressed. If the shutter switch SW1 (61) has been pressed, the system control circuit 50 returns to step S309, displays a through image, and returns to the shooting standby state. If not, the process returns to step S203 to check the dial status.

  In the imaging apparatus 100 according to the present embodiment, images having different aspect ratios are generated by changing the video area on the image sensor (imaging device 14). 6 and 7 are diagrams showing that the video area used on the image sensor changes depending on the aspect ratio setting. FIG. 6 is a diagram when the aspect ratio is 4: 3, where 601 indicates the entire area of the image sensor, and 602 indicates an area used as an image. FIG. 7 is a diagram when the aspect ratio is 16: 9, where 701 indicates the entire area of the image sensor, and 702 indicates an area used as an image.

  As shown in FIGS. 6 and 7, the video area used on the image sensor is different between 4: 3 and 16: 9, and FIG. 8 illustrates this state in more detail. FIG. 8 is a diagram of area division when the video area used on the image sensor differs depending on the aspect ratio setting as shown in FIGS. 6 and 7. In FIG. 8, reference numeral 801 denotes the entire area of the image sensor. Reference numeral 802 denotes a video area that is always used regardless of the aspect ratio setting, that is, a video area that is used regardless of whether the aspect ratio is set to 4: 3 or 16: 9. A common area. Reference numeral 803 denotes a video area that is used or not used depending on the aspect ratio setting. In this embodiment, this area is a non-common area. In this embodiment, the common area and the non-common area are combined to form the entire video area.

  FIG. 9 is a diagram showing area division when the aspect ratio is 16: 9. Reference numeral 901 denotes the entire area of the image sensor. Reference numeral 902 denotes a common area. Reference numeral 903 denotes a non-common area. FIG. 10 is a diagram showing area division when the aspect ratio is 4: 3. Reference numeral 1001 denotes the entire area of the image sensor. Reference numeral 1002 denotes a common area. Reference numeral 1003 denotes a non-common area.

  FIG. 5 is a flowchart showing the evaluation value calculation processing corresponding to the multi-aspect ratio in the EVF state in step S303 in FIG. In step S501, the system control circuit 50 refers to the setting of display on the image display unit 28 by the operation unit 63. When the aspect ratio is 4: 3, the process proceeds to step S502, and when the aspect ratio is 16: 9. The process proceeds to step S503.

  In step S502, the system control circuit 50 sets an area for obtaining an evaluation value when the aspect ratio is 4: 3 display. The common area 1002 and the non-common area 1003 shown in FIG. 10 are set in the image processing circuit 20 as areas (windows) for calculating evaluation values. In step S503, the system control circuit 50 sets an area for obtaining an evaluation value when the aspect ratio is 16: 9 display. The common area 902 and the non-common area 903 shown in FIG. 9 are set in the image processing circuit 20 as areas (windows) for calculating evaluation values.

  Next, in step S504, integration processing of all video regions (common region and non-common region) is performed under the control of the system control circuit 50. For the image data read from the image sensor 14, the image processing circuit 20 executes signal value integration processing for the entire video region in the window set in step S 502 or step S 503.

  In step S505, the system control circuit 50 calculates an evaluation value from the result of integration of the entire video area performed in step S504. From the integration result, a luminance value for AE processing and a color level for AWB processing are obtained. An integrated value for the luminance signal is calculated as a luminance value and used as an evaluation value for the AE process. Further, an integrated value for each color is calculated as a color level and used as an evaluation value for AWB processing.

  In step S506, under the control of the system control circuit 50, the image processing circuit 20 performs face recognition processing (processing for detecting a face in the image) in the entire video area using the image data read from the image sensor 14. Various techniques are known as techniques for detecting a face. For example, there is a method using learning represented by a neural network. In addition, there is a technique for identifying parts having physical shape features such as eyes, nose, mouth, and facial contour from image data using template matching. In addition, there is a method in which a feature amount of image data such as skin color or eye shape is detected and statistical analysis is used (see, for example, Patent Documents 3 and 4). In this embodiment, a face identification process is performed by detecting a pair of eyes (both eyes), nose, mouth, and face outline and determining a person's face from their relative positions.

  In step S507, the common region is integrated under the control of the system control circuit 50 in the same manner as in step S504. For the image data read from the image sensor 14, the image processing circuit 20 executes signal value integration processing on the common region in the window set in step S 502 or step S 503.

  In step S508, the system control circuit 50 calculates an evaluation value from the integration result of the common area performed in step S507 by the same method as in step S505. In step S509, the system control circuit 50 performs face recognition processing in the common area by the same method as in step S506.

  In step S510, the system control circuit 50 compares the face detection results obtained in step S506 and step S509, and determines whether a human face is also included in the non-common area. That is, when the number of faces in the entire video area obtained in step S506 is larger than the number of faces in the common area obtained in step S509, it is determined that a human face is included in the non-common area, and the process proceeds to step S512. . If the number of faces in the entire video area obtained in step S506 is the same as the number of faces in the common area obtained in step S509, it is determined that no human face is included in the non-common area, and step S511. Proceed to

Step S511 is a final evaluation value calculation process in the case where a person's face is not included in the non-common area. The system control circuit 50 converts the evaluation value of all the video areas and the evaluation value of the common area obtained in steps S505 and S508, respectively, into the evaluation values of all video areas including the non-common area as shown in the following equation (1). The final evaluation value is obtained by applying a large coefficient and mixing the two evaluation values.
Final evaluation value = evaluation value of all video regions × 0.8 + evaluation value of common region × 0.2 (1)

  By mixing the two evaluation values in this way, it is possible to make an evaluation with emphasis placed on the entire video area while making the non-common area the object of evaluation. The mixture of evaluation values is applied to each of an evaluation value for exposure control and an evaluation value for auto white balance control.

On the other hand, step S512 is a final evaluation value calculation process in the case where a human face is included in the non-common area. The system control circuit 50 applies two coefficients by applying coefficients that are comparable to each other as shown in the following equation (2), using the evaluation values of the entire video area and the evaluation value of the common area obtained in steps S505 and S508, respectively. The final evaluation value is obtained by mixing the values.
Final evaluation value = evaluation value of all video regions × 0.5 + evaluation value of common region × 0.5 (2)

  By mixing the two evaluation values in this way, it is possible to perform an evaluation for optimizing the luminance and color balance of the main subject when there is a person who is the main subject in a non-common area. . The mixture of evaluation values is applied to each of an evaluation value for exposure control and an evaluation value for auto white balance control.

  FIG. 4 is a flowchart showing still image shooting processing in step S312 of FIG. In step S <b> 401, the system control circuit 50 starts reading video signals from the image sensor 14 in synchronization with the timing generator 18. At this time, if the result of the AE process in step S304 is strobe shooting, the strobe 48 emits light in synchronization with the front curtain or rear curtain of the video signal. The video signals sequentially read from the image sensor 14 are converted into image data through the A / D converter 16 and are sequentially stored in the memory 30.

  In step S402, integration processing of the entire video region is performed on the video signal read in step S401. Using the image processing circuit 20, signal value integration processing is executed for all the video regions shown in FIGS. 9 and 10 according to the aspect ratio setting.

  In step S403, the system control circuit 50 calculates an evaluation value from the result of integration of the entire video area performed in step S402. From the integration result, a luminance value for AE processing and a color level for AWB processing are obtained. An integrated value for the luminance signal is calculated as a luminance value and used as an evaluation value for the AE process. Further, an integrated value for each color is calculated as a color level and used as an evaluation value for AWB processing.

  In step S404, the system control circuit 50 performs WB processing for still images. Using the evaluation value obtained in step S403, a predetermined WB calculation is executed to obtain a WB control value for a still image. The WB control value for the still image is stored in the memory 30, and the process proceeds to step S405.

  In step S405, the signal processing circuit 20 executes development processing under the control of the system control circuit 50. The development process is a series of processes for performing predetermined development and compression processes such as JPEG and storing the processed image data in the memory 30. The signal processing circuit 20 is instructed to perform development processing, the developed image is stored in the memory 30, and a series of development processing ends.

  As described above, the method of reducing the brightness and color switching that occurs when the aspect ratio setting is switched when the video area used on the image sensor changes depending on the aspect ratio setting has been described.

  As described above, in an imaging device that generates images with different aspect ratios by changing the video area on the image sensor according to the aspect ratio setting, the brightness of the image when the aspect ratio setting is switched It is possible to reduce the switching of colors. Further, when a person's face is included in the non-common area, it is possible to perform processing for optimizing the luminance of the subject by increasing the usage ratio of the non-common area.

  In the description of the present embodiment, in the calculation of the final evaluation value, the ratio between the evaluation value of all the video areas and the evaluation value of the common area is fixed, but the present invention is not limited to this. For example, the mixing ratio may be switched according to the aspect ratio.

  In the present embodiment, the method of changing the use ratio of the non-common area in the EVF state and using the evaluation values of the entire video area at the time of still image shooting has been described. However, the present invention is not limited to this. For example, in a state where the change in aspect ratio is prohibited, such as a moving image shooting mode, a method using the evaluation values of the entire video area is possible as in the case of still image shooting.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. It is a process to be executed.

10: photographing lens, 12: shutter, 14: imaging device, 20: image processing circuit, 50: system control circuit, 100: imaging device

Claims (8)

Imaging means for capturing an image of a subject and obtaining image data;
Exposure control means for performing exposure control based on image data obtained by the imaging means;
White balance control means for performing white balance control based on image data obtained by the imaging means;
Evaluation value calculating means for calculating an evaluation value for at least one of exposure control by the exposure control means and white balance control by the white balance control means;
Aspect ratio switching means for switching the aspect ratio when obtaining image data by the imaging means,
Different video areas are set according to the aspect ratio setting by the aspect ratio switching means for the video areas output by the imaging means as image data,
The evaluation apparatus according to claim 1, wherein when the evaluation value is calculated, a use ratio of a video area that is used or not used is made variable depending on the setting of the aspect ratio. Regardless of the aspect ratio setting, a video area that is always used is a common area, a video area that is used or not used depending on the aspect ratio setting is a non-common area, and the common area and the non-common area are The combined area is the entire video area.
The evaluation value calculation means makes the use ratio of the non-common area variable in a standby state in which a live image is displayed before shooting a still image, and uses the entire video area when shooting a still image. The imaging apparatus according to 1.   The imaging apparatus according to claim 1, wherein the evaluation value calculation unit uses the entire video area in a state where setting of the aspect ratio by the aspect ratio switching unit is prohibited.   The imaging apparatus according to claim 3, wherein a state in which setting of an aspect ratio by the aspect ratio switching unit is prohibited includes a moving image shooting mode.   5. The imaging apparatus according to claim 1, further comprising a face detection unit that detects a face of a person who is a subject from image data obtained by the imaging unit. 6.   When the image area used or not used according to the aspect ratio setting includes a human face detected by the face detection means, the evaluation value calculation means uses or uses the face according to the aspect ratio setting. The imaging apparatus according to claim 5, wherein a use ratio of a video area that is not used is increased. Imaging means for capturing an image of a subject to obtain image data, exposure control means for performing exposure control based on image data obtained by the imaging means, and white balance control based on image data obtained by the imaging means A control method for an imaging apparatus comprising white balance control means for performing and aspect ratio switching means for switching an aspect ratio when obtaining image data by the imaging means,
An evaluation value calculating step of calculating an evaluation value for at least one of exposure control by the exposure control means and white balance control by the white balance control means;
Different video areas are set according to the aspect ratio setting by the aspect ratio switching means for the video areas output by the imaging means as image data,
In the evaluation value calculation step, when the evaluation value is calculated, a use ratio of a video area that is used or not used is made variable depending on the setting of the aspect ratio. Imaging means for capturing an image of a subject to obtain image data, exposure control means for performing exposure control based on image data obtained by the imaging means, and white balance control based on image data obtained by the imaging means A program for controlling an imaging apparatus comprising white balance control means to perform and an aspect ratio switching means for switching an aspect ratio when obtaining image data by the imaging means,
Causing the computer to execute an evaluation value calculation process for calculating an evaluation value for at least one of exposure control by the exposure control unit and white balance control by the white balance control unit;
Different video areas are set according to the aspect ratio setting by the aspect ratio switching means for the video areas output by the imaging means as image data,
In the evaluation value calculation process, when the evaluation value is calculated, a use ratio of a video area that is used or not used is made variable depending on the setting of the aspect ratio.

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