JP2008060676A - Image signal processing apparatus, imaging apparatus, image signal processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve convenience to a user, practicality, etc. with respect to photographing and recording of wide-dynamic range composite images. <P>SOLUTION: In a wide dynamic range (WDR) photographic mode, photographic image data in normal AE and WDR photographic image data having a dynamic range widened by WDR photographing are generated, and images of these photographic image data and a histogram are displayed respectively. When the user watches this display to perform a selecting operation, regular photographic image data to be stored in a storage medium, out of these image data are determined. Alternatively, an image signal processing apparatus is so configured that normal photographic image data are settled on the basis of information of the histogram by automatic discrimination. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image signal processing apparatus configured to execute processing on image information obtained by imaging, and a method thereof. The present invention also relates to an imaging apparatus having a configuration as the image signal processing apparatus.

One of the conditions for taking a so-called good photograph is that the exposure is appropriate. However, obtaining an appropriate exposure accurately requires, for example, using an exposure meter, and also requires some skill such as adjustment of the aperture and shutter speed. Not that.
Therefore, imaging apparatuses such as a silver salt camera and a digital still camera have been provided with a function for automating exposure setting. Such a function is also called automatic exposure (AE). As this automatic exposure control, the ambient light amount (brightness) is detected by the imaging device, and one appropriate exposure amount (combination of shutter speed and aperture value) is set according to the detected light amount. The method is common.

  However, in actual shooting, the color and texture of the subject vary, and there are various situations regarding the light that can be captured by the camera's imaging part, such as sunlight and lighting being brighter or darker than necessary. It is. For this reason, even if an image is taken by automatic exposure control, it is often possible that a good photographed image cannot be obtained due to the occurrence of overexposure or blackout. In particular, it is known that such a current situation is remarkable in a digital still camera using a solid-state imaging device such as a CCD (Charge Coupled Device), which has a very narrow dynamic range.

Therefore, in an imaging apparatus such as a digital still camera, a photographed image with appropriate exposure can be obtained as much as possible even in a photographing environment where a normal photographed normal exposure control cannot obtain a good photographed image. The following is proposed as an image signal processing technique for doing so.
That is, as described in Patent Document 1, a plurality of images (SL shooting) shot with different exposure amounts depending on a normal shot image treated as long exposure and a shot image shot with a shorter exposure than this. After obtaining the image data, the plurality of image data are synthesized to obtain a wide dynamic range synthesized image (SL synthesized image). The SL composite image obtained in this way is capable of obtaining a wider characteristic with respect to the dynamic range of brightness as compared with, for example, a case where photographing is performed by normal automatic exposure control. It is possible to obtain an image of the same quality as that taken with an exposure setting that is better than in the case of exposure control.

JP 2000-92378 A

  However, since the wide dynamic range composite image is based on photographing automatically executed by the apparatus, exposure is usually better when photographing by AE control depending on various environments and situations at the time of photographing. It cannot be denied that there is a possibility of being photographed. In view of this, it is possible to automatically or manually select an image to be treated as a regular image between a wide dynamic range composite image and an image obtained by normal AE control. It can be said that it is very useful and preferable. An object of the present invention is to make the practicality sufficient and efficient with respect to a configuration for selecting such a wide dynamic range composite image and an image obtained by normal photographing. To do.

In view of the above-described problems, the present invention is configured as an image signal processing apparatus as follows.
That is, a photographing processing unit that performs photographing processing that is processing for generating image data from an image signal obtained by performing photographing according to a set exposure condition, and a single exposure condition is set to execute the photographing processing. The normal shooting image data generating means configured to generate normal shooting image data and a plurality of different exposure conditions are set, and a plurality of predetermined shooting processes are performed within a predetermined time according to each of these exposure conditions. A plurality of image data obtained by sequentially executing the image, and a composite photographed image data generating unit that generates composite photographed image data by executing an image composition process using the plurality of image data, and one photographing operation The normal captured image data generating means generates the normal captured image data and the composite captured image data generating means And an operation for generating composite photographed image data by executing photographing processing according to a plurality of different exposure conditions set based on the exposure conditions set in the data processing means. For selection operation in which shooting operation control means, images of normal shooting image data and composite shooting image data generated by one shooting operation, and images obtained by visualizing histogram information about these image data are presented Display control means for causing the image to be displayed and output in a predetermined display mode, and any one of the images of the normal captured image data and the composite captured image data displayed and output in the selection operation image. An operation unit that performs an operation for selection, and normal shooting generated by one shooting operation according to the operation performed on the operation unit From among the image data and the composite shooting image data, it was decided and a selection decision means for selecting determines a normal photographed image data should be treated as a regular one.

In addition, the imaging apparatus is configured as follows.
In other words, it is a process of generating image data from the image signal obtained by executing the image pickup by the image pickup means according to the set exposure condition and the image pickup means for obtaining the image signal corresponding to the image light obtained by the image pickup. A shooting processing unit that executes shooting processing, a normal shooting image data generation unit configured to generate normal shooting image data by setting one exposure condition and executing the shooting process, and a plurality of different exposure conditions After setting, a plurality of image data is obtained by sequentially executing a plurality of the above-described photographing processes within a predetermined time in accordance with each exposure condition, and an image composition process using the plurality of image data is performed. The composite photographed image data generating means for generating composite photographed image data by executing and the normal photographed image data generating means for generating the normal photographed image data as one photographing operation. And the composite photographed image data generation means causes the composite photographed image data to execute photographing processing according to a plurality of different exposure conditions set based on the exposure conditions set in the normal image data processing means in the current photographing operation. The image capturing operation control means for controlling so that the operation for generating the image is executed within a predetermined time, each image of the normal captured image data and the composite captured image data generated by one image capturing operation, and these images Display control means for displaying and outputting a selection operation image in which a histogram information of data is visualized is displayed in a predetermined display mode, and normal captured image data displayed and output in the selection operation image And an operation means for performing an operation for selecting one of the images of the composite photographed image data, and the operation In accordance with the operation performed on the stage, normal photographed image data to be treated as a regular one is selected and determined from the normal photographed image data generated by one photographing operation and the composite photographed image data. And a selection determining means.

Further, another image signal processing apparatus is configured as follows.
That is, a photographing processing unit that performs photographing processing that is processing for generating image data from an image signal obtained by performing photographing according to a set exposure condition, and a single exposure condition is set to execute the photographing processing. The normal shooting image data generating means configured to generate normal shooting image data and a plurality of different exposure conditions are set, and predetermined shooting processing is performed within a predetermined time according to each of these exposure conditions. A composite captured image data generating unit that obtains a plurality of image data by sequentially executing them, executes image composition processing using the plurality of image data to generate composite captured image data, and a single photographing operation The normal photographed image data generating means generates the normal photographed image data, and the composite photographed image data generating means performs normal image data in the current photographing operation. An imaging operation for controlling the execution of the imaging processing according to a plurality of different exposure conditions set based on the exposure conditions set in the processing means to generate composite captured image data within a predetermined time. Control means;
Based on the result of comparing the histogram information of the normal captured image data and the composite captured image data generated by the above-described one-time image capturing operation, an image to be improved among the normal captured image data and the composite captured image data. The image data having the contents is provided with a selection determining unit configured to select and determine the regular photographed image data.

Further, the imaging apparatus corresponding to the image signal processing apparatus is configured as follows.
That is, it is a process of generating image data from an image signal obtained by performing image pickup by the image pickup means according to a set exposure condition, and an image pickup means for obtaining an image signal corresponding to the image light obtained by image pickup. A shooting processing unit that executes shooting processing, a normal shooting image data generation unit that generates normal shooting image data by setting one exposure condition and executing the shooting process, and a plurality of different exposure conditions After setting, a plurality of image data is obtained by sequentially executing a plurality of predetermined shooting processes within a predetermined time according to each exposure condition, and an image composition process using the plurality of image data is executed. The composite captured image data generating means for generating composite captured image data and the normal captured image data generating means generate the normal captured image data as a single shooting operation. The combined photographed image data is generated by the combined photographed image data generating unit executing photographing processing according to a plurality of different exposure conditions set based on the exposure condition set in the normal image data processing unit in the current photographing operation. Based on the result of comparison between the shooting operation control means for controlling the generated operation to be executed within a predetermined time and the histogram information of the normal captured image data generated by one shooting operation and the composite captured image data A selection determining unit configured to select and determine, as normal captured image data, image data that has better image content among the normal captured image data and the composite captured image data; It was decided to prepare.

Depending on each of the above configurations, first, as a shooting operation for one time, normal shooting image data is obtained by shooting under a set exposure condition, and a plurality of shootings are performed under a plurality of different exposure conditions. A plurality of image data obtained are combined to execute an operation for obtaining composite photographed image data. That is, the normal captured image data and the composite captured image data are obtained in correspondence with the captured image that is captured with respect to the common subject.
Then, from the normal captured image data and the composite captured image data obtained as described above, the regular captured image data to be treated as a normal one is selected. In this selection, the normal captured image data is selected. Each histogram information of the data and the composite photographed image data is used. In general, the histogram is a graph showing the frequency distribution of the quantifiable factor and characteristic data in the range where the data exists, but the histogram information in the present invention is a single image data. An information unit indicating a frequency distribution in a predetermined luminance range with respect to the brightness (luminance) of a pixel to be formed. Incidentally, in the field of camera technology and related signal processing, a histogram indicating the frequency distribution of the brightness of pixels of such image data is often referred to as a histogram.
Then, by selecting the regular photographed image data based on the histogram in this way, an accurate selection result can be obtained with minimal information. This is because an image with appropriate exposure generally shows a certain histogram frequency distribution pattern.

  Therefore, according to the present invention, for example, the operation procedure for selection is simplified by selecting the regular photographed image data based on the minimum necessary and effective information such as a histogram. Therefore, convenience for the user can be improved.

FIG. 1 shows an example of the appearance of a digital still camera, which is an image signal processing apparatus and imaging apparatus as the best mode for carrying out the present invention (hereinafter referred to as an embodiment).
In this figure, the back view of the digital still camera 1 of the present embodiment is shown by a plan view. As shown in this figure, on the back surface of the digital still camera 1, a display screen portion 7A is provided so as to be exposed. The display screen portion 7A is a portion that becomes a display screen of a display device such as an LCD (Liquid Crystal Display). Further, the size of the display screen portion 7A depends on the actual size of the digital still camera 1, but is generally around 2 to 3 for example. At the time of imaging, a photographed image is displayed on the display screen portion 7A, and a user who is a photographer takes a picture while viewing the image displayed on the display screen portion 7A instead of the viewfinder. Shooting can be performed. Further, for example, image data such as a captured image recorded in a predetermined type of storage medium 20 can be reproduced and displayed as an image. Furthermore, for example, an operation screen corresponding to various operations on the digital still camera 1 is also displayed.

The digital still camera 1 is provided with various controls for taking pictures and other necessary operations. FIG. 1 illustrates a general one of these operators.
The shutter button 31 is an operator for recording a photographed image as a photographic image. When the shutter button 31 is operated, the captured image obtained at the timing corresponding to the operation is loaded into the digital still camera 1 or stored in a storage medium as still image data of a predetermined format, for example. Written and stored.
The zoom key 32 is essentially an operator used to change the angle of view of the captured image. For example, if the operation is performed on the wide (W: Wide) side, the captured image has an enlarged angle of view. If the operation is performed on the telephoto (T: Tele) side, the angle of view becomes narrow and a telephoto image is obtained.
The cross key 33 is an operator for performing an operation of alternatively specifying one of the up, down, left, and right directions. The operation of the cross key 33 in response to the operation differs depending on the operation mode, operation mode, etc. at that time. For example, when used for movement between buttons displayed on the display screen portion 7A, etc., the highlighted display for the button is moved in one of the upper, lower, left and right directions according to the operation on the cross key 33. The center portion of the cross key 33 can be pressed. This pressing operation is often a determination operation when some item is selected, for example.
In this figure, button keys 34 and 35 are also shown. These button keys 34 and 35 are simply keys that can be pressed / released, and the operation in response to the operation differs depending on the operation mode, operation mode, etc. at that time.
Note that, for example, a camera lens unit that is an imaging optical system is provided on the front side of the digital still camera 1 that is not illustrated in FIG.

FIG. 2 is a block diagram showing a configuration example of the digital still camera 1 as the present embodiment.
In the digital still camera 1 shown in this figure, the optical system unit 2 includes an imaging lens, a diaphragm, and the like, and forms incident light on the photoelectric conversion unit 3 as imaging light. Further, the optical system unit 2 includes a focus adjustment mechanism for focus adjustment, a diaphragm variable mechanism that varies the diaphragm according to the diaphragm value, and the like. Is performed by a drive signal output from the camera function unit 6. The camera function unit 6 is configured to output a required drive signal so as to obtain an appropriate focus, aperture adjustment state, and the like, under the control of the CPU 10. The aperture adjustment is one of parameters set as an exposure condition together with a shutter speed described later.
For example, when an optical zoom function is to be provided, a zoom mechanism for moving the zoom lens is provided in the optical system unit 2 and driving for moving the zoom mechanism in accordance with the control of the CPU 10 in the same manner as described above. What is necessary is just to provide a part. Furthermore, the camera function unit 6 may be configured to provide a strobe light emission function after providing a strobe.

  The photoelectric conversion unit 3 according to the present embodiment is a photoelectric conversion element (solid-state imaging device) including a CMOS sensor, and photoelectrically picks up the imaging light incident from the optical system unit 2 and imaged on the light receiving surface. By converting, an imaging signal is generated and output to the image signal processing unit 4. At the time of shooting, for example, an instruction of a shutter speed determined according to the exposure setting is notified from the CPU 10 to the image signal processing unit 4. The image signal processing unit 4 outputs a scanning timing signal corresponding to the notified shutter speed to the photoelectric conversion unit 3. The photoelectric conversion unit 3 performs scanning according to the scanning timing signal, executes photoelectric conversion processing, and outputs a video signal.

  As is well known, the CMOS sensor has a characteristic that it is more sensitive than a CCD. Therefore, for example, if it is desired to obtain the same exposure amount with a fixed aperture, The CMOS sensor can set a faster shutter speed than the CCD. Therefore, it is easy for the CMOS sensor to promote high-speed shooting as compared with the CCD, and even under the present applicant, high-speed shooting technology using the CMOS sensor as an image sensor has been developed. , Have been filed. In this embodiment, a CMOS sensor is employed, and such a high-speed imaging technique is also employed.

  The image signal processing unit 4 performs waveform shaping on the analog video signal input from the photoelectric conversion unit 3 by, for example, gain adjustment and sample hold processing, and then performs A / D conversion to perform digital conversion. Is converted into image signal data. The digital image signal obtained by the conversion process is displayed on the display unit 7 including, for example, a process for generating display luminance data (display image data) corresponding to color display. Image signal processing is executed. Accordingly, the image signal processing unit 4 can execute signal processing for a so-called on-screen display so that a character image or the like can be displayed superimposed on the captured image under the control of the CPU 10.

  In addition, in the digital still camera 1 of the present embodiment, as described later, it is possible to perform a shooting operation corresponding to the wide dynamic range shooting mode. In addition to the process of generating captured image data corresponding to a normal capturing operation, the captured image (wide dynamic range captured image) corresponding to the wide dynamic range capturing mode can be generated.

  Further, the image signal processing unit 4 performs, for example, image data compression processing by a predetermined method on a digital image signal (captured image data) obtained by converting the analog image signal input from the photoelectric conversion unit 3, thereby compressing the compressed image. It is also possible to generate data. The compressed image data is transferred to the media controller 13 as recording data, for example, under the control of the CPU 10. In this figure, the recording data is shown as being transferred to the media controller 13 via the CPU 10.

The image signal processing unit 4 converts an image (video) signal input from the photoelectric conversion unit 3 or image data read from a storage medium 20 described later into an analog image signal or digital image signal of a predetermined method. The image can be converted and output to an external device or the like via the image input / output unit 5.
The image signal processing unit 4 is configured to execute various signal processes described so far while holding the data to be processed in the memory 4a.

Further, the image input / output unit 5 can input an image signal of a predetermined method from the outside, and can display the input image signal on the display unit 7 through the processing of the image signal processing unit 4. Is done. The image signal processing unit 4 converts the image signal input by the image input / output unit 5 into recording data and transfers the image signal to the media controller 13 in the same manner as the analog image signal input from the photoelectric conversion unit 3. You can also.
Correspondingly, the image input / output unit 5 includes, for example, a video (image) signal output terminal / video signal input terminal according to a predetermined method.

The media controller 13 cooperates with the CPU 10 to execute data writing (recording) and reading (playback) corresponding to a predetermined type of storage medium (media) 20, as well as formatting processing and storage of the storage medium 20. Write / read processing of a file and information for file management (file management information) with respect to the storage area of the medium 20 is executed.
Here, the type and type of the storage medium 20 are not particularly limited, but at present, a removable storage medium such as a flash memory is widely used. A specific configuration of the media controller 13 corresponding to such a removable storage medium includes a physical device as a drive that directly executes data writing and reading with respect to the loaded storage medium, and this drive and the CPU 10. A program for realizing communication with the user.

  According to the above description, the captured image data as a still image obtained by capturing with the optical system unit 2 is subjected to compression encoding by a predetermined method in the image signal processing unit 4 and then recorded. The data is passed to the media controller 13 as data. The media controller 13 writes and stores the received recording data in the storage medium 20. The data stored in the storage medium 20 in this way is managed as a photographic image (still image) file in a predetermined format by, for example, a file system on which the media controller 13 is mounted.

For example, when reproducing an image file of a still image stored in the storage medium 20, the CPU 10 and the media controller 13 access and read out the designated image file and transfer it to the image signal processing unit 4.
When the image file is transferred in this way, the image signal processing unit 4 executes image signal processing so that the image of the still image file is reproduced and displayed on the display unit 7.

In addition, the digital still camera 1 according to the present embodiment includes an audio processing unit 8 and an audio input / output unit 9 so that audio signals can be input / output.
As for voice input, a microphone or the like is provided as the voice input / output unit 9, and external voice is collected and converted into a voice signal to input voice. Alternatively, an audio signal is input from an external audio device provided with an audio signal input terminal or the like. Then, the audio signal input in this way is output to the audio processing unit 8. The audio processing unit 8 performs audio signal processing such as conversion into digital audio data encoded in a predetermined format. The digital audio data is stored in the storage medium 20 as described above, for example, as recording data such as audio data in a predetermined format attached to still image data or an audio data file in a predetermined format under the control of the CPU 10. Is possible.
Further, the audio data stored in the storage medium 20 as described above can be reproduced and output as sound by the sound processing unit 8 and the sound input / output unit 9. For example, the CPU 10 reads audio data from the storage medium 20 and transfers it to the audio processing unit 8. The audio processing unit 8 performs necessary audio signal processing such as decoding processing according to the format of the transferred audio data, and outputs it to the audio input / output unit 9 as an analog audio signal. The audio input / output unit 9 includes a speaker or a headphone terminal, for example, amplifies an audio signal input from the audio processing unit 8, drives the speaker, and outputs reproduced audio. Or it supplies to a headphone terminal. For example, the audio data reproduced from the storage medium 20 is subjected to audio signal processing by the audio processing unit 8 and then output to the outside as an audio signal and audio data in a predetermined format via the audio input / output unit 9. It is also possible. In this case, the audio input / output unit 9 includes an audio output terminal corresponding to the format of the audio signal and audio data output from the audio processing unit 8.

A CPU (Central Processing Unit) 10 executes various control processes for the digital still camera 1 by executing a program. The ROM 11 stores various setting information used for the CPU 10 to execute processing in addition to various programs executed by the CPU 10. The RAM 12 is used as a work area when the CPU 10 executes processing according to a program, and holds data such as various arithmetic processing results.
The non-volatile memory 12a is formed of a memory element such as a flash memory that does not erase the stored contents even when the power supply is stopped, and data writing / reading is executed under the control of the CPU 10. The The data (information) to be stored in the nonvolatile memory 12a is generally setting information whose contents are appropriately changed, but is not particularly limited, and the actual specifications of the digital still camera 1 It is sufficient to store various necessary information according to the above.

  The operation input unit 15 in this case includes the operators shown in FIG. 1 and collectively indicates various operators provided in the digital still camera 1. For example, the operators in the operation input unit 15 include a shutter button operated at the time of taking a picture, an operator for selecting a shooting mode, an operator for increasing / decreasing parameters, and the like. Further, as the operation input unit 15, for example, a configuration such as a touch panel for realizing an operation performed by touching the display screen unit of the display unit 7 with a finger may be provided.

  Further, as described above, the display unit 7 is a part on which, for example, a monitor image, an operation screen, an image of image data reproduced from the storage medium 20, and the like are displayed. For such image display, for example, as described above, the image signal processing unit 4 generates a display image signal according to the display control of the CPU 10 and outputs it to the display unit 7. The display unit 7 includes, for example, a display device including a display panel and a driving circuit thereof as a display device, and executes a display driving operation based on an input image signal. Thereby, an image is displayed on the display screen unit 7A as the display panel. Note that an actual display device employed as the display unit 7 is not particularly limited, but at present, LCDs are widely employed as described above.

  The communication unit 16 is a part configured by mounting hardware and software for communicating with an external device by a predetermined data communication method according to the control of the CPU 10. The data communication system supported by the communication unit 16 is not particularly limited regardless of whether it is wired or wireless, and the number of corresponding data communication systems should not be limited. At present, examples of data communication methods include a network such as Ethernet (trademark), a data bus standard such as USB (Universal Serial Bus), IEEE1394, and the like. In the case of wireless, short-range wireless communication between devices such as Bluetooth (trademark) and wireless LAN (Local Area Network) standards such as IEEE802.11a / b / g can be cited.

  The power supply unit 17 supplies operating power to various hardware devices in the digital still camera 1, and includes, for example, a power supply circuit that operates by receiving power supply from a battery or a power adapter.

The digital still camera 1 of the present embodiment having the above-described configuration performs wide dynamic range (WDR) imaging in addition to normal AE imaging that performs imaging operation with normal automatic exposure control. It can be executed.
The operation corresponding to WDR shooting in the digital still camera 1 will be described later. WDR shooting refers to the following shooting operation.

In WDR shooting, for example, as a shooting operation in response to a single shooting instruction corresponding to, for example, a single shutter button operation or a single self-timer shooting, for example, a predetermined plurality of shooting processes are different from each other. An exposure amount (exposure condition: parameters are aperture value and shutter speed) is set and executed. Thus, a plurality of photographed image data (still image data) corresponding to the number of different photographing processes is to be obtained as material image data. Each of the plurality of material image data obtained in this way has image contents captured with different exposure amount settings, while each of the same subject is captured.
Note that the imaging processing here refers to imaging with one opening and closing of the shutter (capture of imaging light) and an image signal obtained based on this imaging, for example, one still image data (material image data). The signal processing for generating the data.

In the configuration of the digital still camera 1 of the present embodiment shown in FIG. 1, the operation as a plurality of shooting processes in the WDR shooting described above is, for example, as follows.
First, in WDR shooting, first, as a process of the CPU 10, a plurality of exposure conditions corresponding to each of a plurality of predetermined shooting processes are obtained. In this embodiment, how to obtain the plurality of exposure conditions will be described later. For confirmation, the parameters for determining the exposure condition in a still camera are generally the aperture value (F value) and the shutter speed, and this embodiment also follows this.
Then, if a plurality of exposure conditions are obtained as described above, a predetermined plurality of photographing operations are executed after actually setting these exposure conditions. That is, the aperture value (F value) and the shutter speed, which are one exposure condition, in the obtained plurality of exposure conditions are instructed to the camera function unit 6 to control the optical system unit 2 to open and close the shutter once. The imaging with is executed. Then, the image signal processing unit 4 executes signal processing for generating one predetermined format of still image data from the image signal obtained by the imaging, and uses the generated image data as material image data, for example, a memory It is made to hold | maintain to 4a. This is one shooting process, and such a shooting process is executed a predetermined number of times while changing and setting the exposure condition.
In addition, in this way, when performing a plurality of shooting processes, it is performed continuously in a relatively short time in consideration of the fact that the image contents shot by these shooting processes are the same. To be done. In the present embodiment, as described above, a CMOS sensor is employed for the solid-state imaging device, thereby enabling high-speed shooting. That is, it is possible to shorten the time required for capturing the imaging light in one imaging process, and in this respect, the digital still camera 1 of the present embodiment is suitable for WDR imaging. It can be said that it has a configuration.

  As described above, after performing the required number of shooting processes, the material image data obtained for each of these shooting processes is held in the memory 4a. In the plurality of material image data held in the memory 4a in this way, for example, for some, the whole or a part is so-called whiteout or blackout, or a state close thereto. Even if the image content is too bright or too dark as a whole, the other material image data has a relative tendency to reduce the tendency of overexposure or underexposure. It is expected that the image will be well exposed. Alternatively, it is expected that a certain material image data has a relatively low or too high contrast, while other material image data has a relatively good contrast. From this, for example, between the plurality of material image data photographed with different exposure amounts, as described above, the appropriate combination processing is executed by using the portion where the image to be improved is obtained. If one image data is regenerated, it can be expected to obtain an image with better exposure in the entire image as compared with the case of shooting by normal AE control.

  Therefore, in WDR shooting, for example, an image portion that has been shot with the best possible exposure is extracted from a plurality of shot image data (material image data) obtained as described above, and these extracted image portions are joined together. In this way, one image data (WDR photographed image data) is generated by combining.

The WDR captured image data obtained in this way is, for example, not too dark or too bright over the entire screen when compared with captured image data obtained by performing a normal AE control. Therefore, it is expected that the image content is improved so that the contrast is more appropriate. That is, depending on the WDR shooting mode, it is possible to obtain a shot image with improved exposure when shooting with a normal exposure control is difficult.
Note that image data obtained by WDR shooting tends to expand the dynamic range of brightness (brightness), for example, as compared with shot image data obtained by normal AE shooting. WDR is a name based on this.

  The digital still camera 1 according to the present embodiment is configured so as to be able to perform WDR shooting by the above-described operation, and as a shooting mode, at least a normal AE shooting mode in which shooting is performed by normal AE control, and Switching between WDR shooting modes for performing WDR shooting is performed. In addition to this, the shooting mode may include a so-called manual mode in which, for example, setting of exposure conditions and the like, focusing and the like are set manually so that shooting can be performed.

Here, the shooting / recording operation when the mode is switched to the WDR shooting mode described above is considered. However, in the proper case, it can be considered to be the same as the normal AE shooting mode. That is, in the normal AE shooting mode, one shooting process is executed as a shooting operation in response to one shot shooting instruction, thereby generating shot image data for one photo and storing it in the storage medium 20. Remember. Similarly, in the WDR shooting mode, in response to a single shutter button operation or the like, shooting as a single WDR shooting and signal processing operation (consisting of a plurality of predetermined shooting processes) are executed, and Photo 1 WDR photographed image data for one sheet is generated and stored in the storage medium 20.
However, although the image content of the WDR captured image data is expected to be in a better exposure state than an image obtained by normal AE shooting (normal AE captured image), it is necessary to generate WDR captured image data. In reality, the WDR captured image has improved exposure compared to the normal AE captured image because the signal processing function cannot cope with the fact that the surrounding lighting environment during actual shooting is extremely diverse. It is known that the image content is not always the same. In particular, in an environment in which sufficiently good image content can be captured even by normal AE shooting, the possibility that the normal AE captured image is better exposed than the WDR captured image is higher.
In consideration of the above, when it is assumed that only the WDR photographed image is generated and recorded in accordance with the photographing operation when the WDR photographing mode is set, Although it is possible to record a good quality image by performing AE photography normally, there is a possibility that the opportunity will be missed. This is detrimental for users who want to shoot with the best possible image quality. Therefore, the digital still camera 1 of the present embodiment is configured as described below with respect to the WDR shooting mode, for example, in order to avoid the above inconvenience.

First, an example of an operation procedure when setting the WDR shooting mode as the shooting mode will be described with reference to FIG.
For example, when the user tries to switch or change the shooting mode, a predetermined operation such as an operation on a predetermined operator as the operation input unit 15 or a touch panel provided on the display screen of the display unit 7 is performed. 3A to display the shooting mode selection screen shown in FIG. 3A on the display screen portion 7A of the display portion 7.
In the shooting mode selection screen shown in FIG. 3A, for example, a mode selection button Bt1 written as “normal AE shooting mode”, a mode selection button Bt2 written as “WDR shooting mode”, and an OK button Bt3 is displayed in a predetermined layout pattern. In addition, a selection instruction frame Wk1 is displayed for either of the mode selection buttons Bt1 and Bt2. The selection instruction frame Wk1 indicates which shooting mode is currently selected between the normal AE shooting mode indicated on the mode selection button Bt1 and the WDR shooting mode indicated on the mode selection button Bt2. Show.
The user can perform a predetermined operation corresponding to pressing of the mode selection buttons Bt1 and Bt2, for example, by operating the operation input unit 15. For example, if a pressing operation is performed on the mode selection button Bt1, a selection instruction frame Wk1 is arranged and displayed on the mode selection button Bt1 as shown in FIG. 3A, and the normal AE shooting mode is currently selected. Is shown. Further, for example, if an operation is performed on the mode selection button Bt2 from this state, the selection instruction frame Wk1 is moved to the mode selection button Bt2 and displayed, indicating that the WDR shooting mode is being selected.
As described above, the user places the selection instruction frame Wk1 on the mode selection button in which the shooting mode that the user wants to set is described, and then presses the OK button Bt3 to confirm the selection. The operation corresponding to is performed. As a result, the shooting mode corresponding to the mode selection button in which the selection instruction frame Wk1 is arranged when the OK button Bt3 is operated is set. That is, if the OK button Bt3 is operated in a state where the selection instruction frame Wk1 is arranged on the mode selection button Bt1, the normal AE shooting mode is set. On the other hand, when the OK button Bt3 is operated in a state where the selection instruction frame Wk1 is arranged on the mode selection button Bt2, the WDR shooting mode is selected and determined. When the selection is determined, a stored image determination mode, which is a sub mode under the WDR shooting mode, is further selected. For this reason, the saved image confirmation mode selection screen shown in FIG. 3B is displayed on the display screen portion 7A.

In the WDR shooting mode of the present embodiment, as will be described later, as a shooting operation in response to a single shooting instruction, only a WDR shooting operation for generating and acquiring WDR shot image data is used. Without executing the normal AE shooting operation, normal AE shot image data is also generated and acquired. That is, WDR photographed image data and normal AE photographed image data are obtained with the same subject content by a photographing operation in response to one photography instruction. Finally, either one of the two photographic image data is selected as the regular photographic image data, and the selected photographic image data is captured and recorded in, for example, the normal AE shooting mode. It is stored as image data that should be formally stored in the storage medium 20 in the same manner as data.
The saved image confirmation mode is related to selecting (determining) image data to be officially saved in the storage medium 20 from the WDR photographed image data obtained by WDR photography as described above and the normal AE photographed image data. The stored image determination mode selection screen shown in FIG. 3B is an operation screen for the user to select and determine the stored image determination mode.

In the stored image determination mode in this case, first, the opportunity to determine the stored image is divided into a case of shooting and a case of reproduction. Further, when determining the stored image, it is classified according to whether it is executed manually (user operation) or automatically by the digital still camera 1. Accordingly, the saved image confirmation mode is a combination of these cases, and is “shooting / manual mode”, “shooting / automatic mode”, “playback / manual mode”, “playback / automatic mode”. 4 modes are prepared.
Accordingly, in the stored image determination mode selection screen of FIG. 3B, as a button for selecting an opportunity to determine the stored image, a mode selection button Bt11 described as “at the time of shooting”, A mode selection button Bt12 indicated as “during reproduction” is displayed. Further, in this figure, the selection instruction frame Wk11 arranged and displayed on the mode selection button Bt11 moves between the mode selection button Bt11 and the mode selection button Bt12, so that the saved image can be confirmed as an opportunity for shooting and playback. Of which is being selected. Further, as buttons for selecting either manual or automatic, a mode selection button Bt21 expressed as “manual” and a mode selection button Bt22 expressed as “during reproduction” are displayed. Here, the selection instruction frame Wk21 arranged and displayed on the mode selection button Bt22 moves between the mode selection button Bt21 and the mode selection button Bt22 to indicate whether manual or automatic is being selected.
The OK button Bt3 is a display button to be operated when confirming the selection content on the saved image confirmation mode selection screen.

The user performs an operation corresponding to pressing of one of the mode selection buttons Bt11 and Bt12 in order to select an opportunity to confirm the stored image. The selection instruction frame Wk11 is arranged and displayed so as to move to the mode selection button in which this operation has been performed, so that either “at the time of shooting” or “at the time of reproduction” is selected as an opportunity to confirm the stored image. To be shown.
In addition, the user performs an operation equivalent to pressing a mode selection button Bt21 or Bt22 in order to select whether to execute manually or automatically as a method for determining the stored image confirmation. In response to this operation, the selection instruction frame Wk21 is arranged and displayed on the mode selection button in which the operation has been performed, and thereby indicates whether “manual” or “automatic” is selected.
Then, as described above, after confirming that the user's desired one is selected in “at the time of shooting” / “at the time of playback” and “manual” / “automatic”, An operation equivalent to pressing the OK button Bt3 is performed. As a result, any one of the four modes described above is determined as the saved image determination mode.

Next, as the stored image determination mode, first, an operation example in the WDR shooting mode when “at the time of shooting / manual mode” is set will be described together with an operation procedure by the user at that time.
For example, in the state where the WDR shooting mode is set and no operation is performed, the display screen of the display unit 7 of the digital still camera 1 of the present embodiment is the same as in the normal shooting mode. It is assumed that an image taken by the optical system unit 2 is displayed as a monitor image on the unit 7A.
Then, it is assumed that the user performs an operation on the shutter button 31 for taking and recording a photograph. Alternatively, it is assumed that the timer time has elapsed after operating the self-timer. Then, in the digital still camera 1, for example, first, a shooting operation by normal AE control is executed, and subsequently, an operation of WDR shooting is executed. For the sake of confirmation, the WDR shooting here means that, as described above, a plurality of shooting processes are executed with different exposure condition settings, and a material image obtained by the plurality of shooting processes is obtained. This is an operation for recombining data to generate WDR image data.
In this way, in the WDR shooting mode of the present embodiment, as a shooting operation in response to a single shooting instruction, not only WDR shooting but WDR shooting image data is generated, but also normal AE shooting is performed. Is also executed to generate normal AE photographed image data. That is, in the WDR shooting mode of the present embodiment, two shot image data of WDR shot image data and normal AE shot image data obtained by shooting a common subject content are obtained.
Note that here, the case where “shooting / manual mode” is set as the saved image confirmation mode has been described. However, as described above, a common subject is responded to one photo shooting instruction. The operation of obtaining the WDR captured image data and the normal AE captured image data is performed in other sub-modes in the saved image determination mode (“shooting / automatic mode”, “playback / manual mode”, “shooting / automatic mode”). ) Is the same.
In order to capture the same subject content in the WDR captured image data and the normal AE captured image data as described above, the normal AE capture and the subsequent WDR capture operations are performed, for example, It is necessary to execute it within a short time (for example, within about 1 second) to the extent that the same subject content that is captured by the optical system unit 2 is easily obtained. Regarding this point, as described above, the digital still camera 1 according to the present embodiment includes a CMOS sensor as an image pickup element in the optical system unit 2, thereby increasing the shooting speed. In addition, it can be easily realized. In addition, as for the technology for increasing the shooting speed, a technology that has been developed and proposed so far may be adopted, and in the future, a technology proposed in the following may be adopted. .

If it is assumed that the WDR photographed image data and the normal AE photographed image data are generated as described so far, in the “shooting / manual mode”, the display screen section 7A displays FIG. The saved image selection screen shown in FIG.
The saved image selection screen shown in FIG. 4A is a photograph image file stored in the storage unit 20 from the WDR photographed image data and the normal AE photographed image data for the common subject obtained by the current photographing. This is an operation screen for allowing the user to select photographed image data (regularly photographed image data) to be stored and saved formally (normally).
In the saved image selection screen, for example, a normal AE shot image display area Pic1 in which normal AE shot image data is displayed as an image is arranged on the left side of the screen. Further, on the right side, a WDR captured image display area Pic2 in which WDR captured image data is displayed as an image is arranged. In addition, histogram display areas ARh1, ARh2 in which histograms indicating the pixel number distribution with respect to the luminance range of the image are displayed at predetermined positions in each of the normal AE captured image display area Pic1 and the WDR captured image display area Pic2. Are superimposed and displayed.
Further, an image selection button Bt31 used for an operation for the user to select a normal AE captured image as normal captured image data is arranged and displayed above the normal AE captured image display area Pic1. Similarly, on the upper side of the WDR captured image display area Pic2, an image selection button Bt32 used for an operation for the user to select a WDR captured image as normal captured image data is arranged and displayed.
Further, an OK button Bt33 for confirming selection of a captured image is arranged and displayed on the lower right side of the screen.

As can be understood from the above description, the WDR photographed image data and the normal AE photographed image data obtained by one WDR photographing are assumed to photograph the same subject content, and therefore the normal AE photographed image display area The image contents displayed in Pic1 and WDR captured image display area Pic2 have the same subject and composition. In addition, the brightness and contrast of the image differ depending on the difference between normal AE shooting and WDR shooting.
The user can recognize at a glance which of the images is normally captured by viewing the images displayed in the normal AE captured image display area Pic1 and the WDR captured image display area Pic2 as described above. Can do.
In addition, by referring to the histogram display areas ARh1 and ARh2 displayed in the normal AE captured image display area Pic1 and the WDR captured image display area Pic2, respectively, it is possible to It will be more accurate. As is well known, the histogram is considered to be one of the most important indicators for appropriateness of exposure.
In this way, the user looks at the saved image selection screen and determines which of the normal AE captured image and the WDR captured image has been captured well. Then, the user performs an operation corresponding to pressing an image selection button arranged corresponding to the display area of the captured image that is determined to have been captured well. In the case of this figure, it is assumed that the user has judged that the WDR photographed image is better, and has performed a pressing operation on the image selection button Bt32 corresponding thereto. In response to this operation, on the saved image selection screen, the image selection button Bt32 corresponding to the WDR captured image is highlighted as shown in FIG. The image is shown to be selected.
If the user performs an operation corresponding to pressing the OK button Bt33 under the above state, the WDR captured image data is determined as regular image data. That is, in the normal AE captured image data and the WDR captured image data, the captured image data corresponding to the image selection button highlighted when the OK button Bt33 is operated is handled as the regular captured image data. . That is, image data to be stored as a photographic image file in the storage medium 20 according to the current shooting.
Therefore, in the digital still camera 1, the WDR photographed image data that is regular photographed image data is stored in the storage medium 20 as a photograph image file. Further, the normal AE photographed image data that has not been selected as the regular photographed image data is discarded.

In this way, for example, in the WDR shooting mode, when the saved image determination mode is “at the time of shooting / manual”, the normal AE shot image data and the WDR shot image are obtained by one shot as the WDR shooting mode. Each time data is obtained, the saved image selection screen shown in FIG. 4 is displayed, and the user determines and selects which captured image data has been successfully captured. With such an operation procedure and device operation at the time of shooting, the user can first compare images actually captured by normal AE shooting and WDR shooting when selecting regular shot image data. In addition, it is possible to make a comprehensive judgment by comparing the histograms.
For example, Patent Document 1 describes that various imaging control parameters are presented in order to determine whether or not WDR imaging according to the present embodiment is possible. In this way, a large number of parameters are presented. However, there is a high possibility that the user will get lost or confused, which may be inconvenient.
In contrast, in this embodiment, as described above, it is only necessary to compare the captured image with the histogram. The captured image visually presents an actual photographing result, and the histogram is an index that accurately indicates whether the exposure is good or bad. In other words, in the present embodiment, the determination for selecting the regular captured image data can be accurately performed by using the determination material that can be regarded as the minimum necessary, that is, the captured image content and the histogram. Will be easy to use.
In addition, since only the histogram information is used as the determination material, it is possible to easily configure the hardware and software configuration necessary for determining the regular photographed image data, which is advantageous in terms of design.

As for the saved image selection screen, a normal AE shot image and a WDR shot image to be compared are displayed, and histograms of these images are displayed, and a button display that allows a user to perform a selection operation is even performed. In this case, various display modes other than those shown in FIG. 4 can be considered.
Therefore, another display mode example as such an image storage screen is shown in FIG. In FIG. 5, the same parts as those in FIGS. 4 (a) and 4 (b) are denoted by the same reference numerals and description thereof is omitted.
In the image saving screen shown in FIG. 5, the histogram display areas ARh1 and ARh2 are not displayed in the areas of the normal AE captured image display area Pic1 and the WDR captured image display area Pic2, as shown in FIG. One histogram display area ARh is arranged and displayed by an area independent of the display area Pic1 and the WDR captured image display area Pic2. In this histogram display area ARh, the histogram of the normal AE shot image displayed in the normal AE shot image display area Pic1 and the histogram of the WDR shot image displayed in the WDR shot image display area Pic2 are superimposed. Is displayed. In order to enable the user to distinguish the correspondence between these two histograms and the normal AE captured image and the WDR captured image, for example, the histogram is color-coded, or the captured image is displayed in the histogram display area ARh. For example, the histogram may be indicated by inserting a character or design pattern that clearly indicates the symbol.

  By the way, in the “shooting / manual mode” described so far, the saved image selection screen shown in FIG. 4 (or FIG. 5) is displayed one by one for each shooting, and the regular shooting image data is displayed to the user. You will be prompted to make a choice decision. With such a user interface, regular photographed image data is determined each time photographing is performed, and no troublesome work for selecting regular photographed image data is left behind. Further, in order to be able to select regular photographed image data later, both normal AE photographed image data and WDR photographed image data obtained in response to one photographing are used as regular photographed image data until then. It is necessary to store the data in some storage area (for example, the storage medium 20, the non-volatile memory 12a, etc.) in the digital still camera 1 so that the selection is managed as indefinite. On the other hand, in the “shooting / manual mode”, there is no need for this, and therefore, for example, the storage area can be saved and used effectively.

However, the fact that the saved image selection screen is displayed each time one shooting is performed and the selection of the regular shooting image data is requested has the above-mentioned advantages, but for example, a shooting opportunity can be missed. There is a high possibility that an inconvenience of higher performance will occur, and in this respect, a trade-off relationship occurs.
In consideration of the above, in the present embodiment, “reproduction time” is provided for “confirmation opportunity” in the image confirmation mode as opposed to “shooting time”.

For example, when the image confirmation mode is set to “reproduction / manual mode”, the operation of the device as the digital still camera 1 and the operation procedure of the user are as follows.
First, when the image confirmation mode is set to “playback / manual mode”, for example, normal AE captured image data and WDR captured image data generated every time WDR shooting in response to a shutter button operation or the like is Non-volatile storage provided in the digital still camera 1 such as the storage medium 20 or the non-volatile memory 12a that is pre-photographed image data and is managed as data of a different type from the normal image data. An area is written and held. That is, in this case, a set of normal AE photographed image data and WDR photographed image data generated each time WDR photographing is performed is stored by performing photographing accumulation. Here, the set of these normal AE captured image data and WDR captured image data is stored in the storage medium 20 in accordance with the operation in the playback mode described below.
Then, it is assumed that the WDR shooting mode is once canceled and the playback mode is entered. In the playback mode, first, as a basic operation, image data stored as a photographic image file in the storage medium 20 can be selected according to a user operation. It can be reproduced and displayed on the display unit 7. In addition, in the digital still camera 1 according to the present embodiment, a set of normal AE photographed image data and WDR photographed image data generated by WDR photographing before being confirmed as the regular photograph image file (unconfirmed image file). Also, it is possible to select from the list of data stored in the storage medium 20. When this unconfirmed image file is selected, the saved image selection screen shown in FIG. 4 or 5 is displayed instead of the reproduction display image of the normal image data file.
In the saved image selection screen, the images of the normal AE captured image data and the WDR captured image data as the unconfirmed image files selected as described above are displayed in the normal AE captured image display area Pic1 and the WDR captured image display area Pic2. Is displayed. Then, in the same manner as described above, the user determines selection for these images and operates the OK button Bt33. As a result, of the normal AE captured image data and the WDR captured image data that have been treated as unconfirmed image files until now, the selected captured image data becomes the regular captured image data. It is stored in the storage medium 20 so as to be managed as a file. The photographed image data that is not selected is erased from the storage medium 20. In other words, instead of deleting the undetermined image file so far from the storage medium 20, the photographic image data newly selected and designated as the regular photographic image data is stored as a photographic image file.

  With the above operation and operation procedure, the selection of the normal AE captured image data generated by WDR imaging and the regular captured image data targeted for WDR captured image data is performed by performing WDR imaging as much as desired. After saving, you can do it all together. That is, during shooting in the WDR shooting mode, there is no need to perform the selection operation of the regular shot image data, and the shooting opportunity is not missed. Further, in this case, as described above, since the image data for two sheets are substantially stored as the unconfirmed image file, the storage capacity of the storage medium 20 is compressed accordingly. However, in recent years, since the capacity of an actual storage medium used for storing photographic image data can be increased at a relatively low cost, this is a particularly serious problem. It will not be.

In the description of the image confirmation mode so far, “shooting / manual mode” and “playback / manual mode” have been explained. As the image confirmation mode, there are other “shooting / automatic mode”. “Playback / automatic mode” is prepared.
Each of these modes is a mode in which the determination of the quality of the normal AE captured image and the WDR captured image for selecting the regular captured image data and the selection determination according to the determination result are automatically executed. In the “shooting / automatic mode”, the automatic execution of the regular shooting image data selection as described above is performed with the normal AE shooting image data obtained by the WDR shooting every time WDR shooting is executed. This is performed for WDR photographed image data. On the other hand, in the “playback / automatic mode”, each time WDR shooting is executed, a set of normal AE shot image data and WDR shot image data obtained by the WDR shooting is stored and held as an undefined image file. To be kept. This operation is the same as that in the “reproduction / manual mode”. For example, if an unconfirmed image file is selected as an image to be reproduced and displayed in the reproduction mode, the process of selecting regular photographed image data is automatically executed for the selected unconfirmed image file. To be done.
It should be noted that in automatically executing the selection processing of the regular photographed image data, the histogram information of each image is used in order to determine which is the better image content. The photographed image data selected as the regular photographed image data is stored in the storage medium 20 as a photograph image file, and the photographed image data not selected is erased.

In this way, when the regular photographed image data selection is automatically executed as the image confirmation mode, the image quality judgment by the user himself is not reflected. However, in the determination, it is expected that a determination result with correspondingly high accuracy can be obtained by using a histogram that is appropriate for determining the quality of exposure. In other words, if the image confirmation mode is set to “shooting / automatic mode” or “playback / automatic mode”, the user does not have to confirm, judge, or determine the user's own image, and the above level is exceeded. Regular photographed image data is selected according to accuracy, and high convenience is obtained for a user who wants to perform a particularly simple operation.
In comparison between “shooting / automatic mode” and “playback / automatic mode”, when “shooting / automatic mode” is selected, the selection processing of the regular photographed image data is automatically performed for each WDR shooting. Since it is executed, the advantage of not pressing the capacity of the storage area can be obtained in the same manner as in the “shooting / manual mode”. On the other hand, if the “reproducing / automatic mode” is set, the selection processing of the regular photographed image data is not executed for each photographing, but this is an advantage. In other words, when the selection processing of the regular captured image data is executed for each shooting, the digital still camera 1 cannot execute other operations during the period in which the selection processing is executed, or the selection processing is performed in the background. Even if other processes can be executed in parallel with each other, there is a possibility that the process becomes heavy. This does not occur in “playback / automatic mode”.

Based on the description so far, an example of the processing procedure of the digital still camera 1 related to the WDR shooting mode of the present embodiment is shown in the flowcharts of FIGS.
Note that the processing procedure shown in these flowcharts can be understood to be realized by the CPU 10 executing a program stored in the ROM 11 or the nonvolatile memory 12a, for example. Such a program is written and stored in the ROM 11 or the non-volatile memory 12a at the time of manufacture, for example, as described above, and is stored in a removable storage medium and then installed from this storage medium. It is conceivable to store the data in an appropriate storage device (nonvolatile memory 12a or the like) in the digital still camera 1 as described above. In addition, the digital still camera 1 may be provided with a network function after being stored in a storage device such as a server on a network, and may be downloaded from the server and installed in a predetermined storage device. It is done.

First, the flowchart of FIG. 6 shows an example of a procedure for executing shooting recording when the WDR shooting mode is set as the shooting mode.
First, in step S101, the system waits for a photo shooting instruction to be generated in response to one shutter button operation for photo shooting or the expiration of the timer time in self-timer shooting. If this photo shooting instruction is generated, the process proceeds to step S102 and subsequent steps.

  In step S102, an operation as normal AE shooting is executed. That is, the camera function unit 6 is controlled based on the state of the captured image at that time, or the exposure (exposure amount) acquired from the measured value of an exposure meter provided in the main body of the digital still camera 1, and the exposure condition For example, the aperture value (F value) and shutter speed parameters are set. Then, under this set exposure condition, the system from the optical system unit 2 to the image signal processing unit 4 is controlled to execute shooting processing, and normal AE shot image data, which is still image data for one sheet, is obtained. Generate. Then, in the next step S103, the normal AE photographed image data generated in step S102 is held in, for example, the memory 4a.

  As described above, if normal AE image data is obtained by normal AE shooting, next, WDR shooting is executed in step S104. As described above, in WDR shooting, a plurality of material image data is obtained by executing a predetermined plurality of shooting processes under different exposure conditions, and combined to obtain one shot image data (WDR shot image). Data).

An example of the procedure for WDR imaging as step S104 is shown in the flowchart of FIG.
As a procedure shown in FIG. 7, first, in step S201, parameters of exposure conditions (aperture value and shutter) that are set when the normal AE photographing executed in the previous step S102 is executed and stored in the register, for example. Read the speed value).
In the next step S202, the exposure condition parameter sets 1 to n to be set in the current WDR shooting are determined based on the exposure condition parameters for the normal AE shooting acquired in step S201. Is done. One parameter set indicates a set of an aperture value and a shutter speed designated value that are parameters of an exposure condition used in one shooting process in a plurality of shooting processes as WDR shooting. Each of the parameter sets 1 to n is a parameter set corresponding to each of the last n imaging processes from the first imaging process in WDR imaging. In step S202, the aperture value and shutter speed value in each of these parameter sets 1 to n are obtained by executing, for example, a predetermined calculation based on the exposure condition parameters for normal AE photography. The

Here, as described above, obtaining the parameter set of the exposure condition for WDR shooting based on the parameter of the exposure condition at the time of normal AE shooting is based on the situation such as the surrounding illumination at that time. It can be said that a parameter set of exposure conditions for WDR shooting is set so that the best image content of WDR shot image data can be obtained.
For example, as another method for setting the exposure condition parameter set for WDR shooting, the simplest method is to set the exposure condition parameter sets 1 to n regardless of the exposure condition parameters set during normal AE shooting. It is conceivable to use a predetermined fixed value for each. In this case, however, the set values of the parameter sets 1 to n of the exposure conditions become inappropriate depending on the surrounding conditions where the image is being picked up, and the image content of the WDR captured image data with very low quality Is likely to be. On the other hand, according to the procedure in step S202, it is expected that the image content of the WDR photographed image data in the best exposure state is obtained as much as possible in accordance with the surrounding situation.

Depending on step S203 and subsequent steps, an operation of repeatedly executing n times of shooting processing in WDR shooting can be obtained.
First, in step S203, 1 is substituted as an initial value for a variable n indicating the number of times of photographing processing (which also corresponds to parameter set numbers 1 to n) to be repeatedly executed thereafter, and step S204. Proceed to the following procedure.

  In step S204, an aperture value and a shutter speed as parameter set n (parameter set 1 is set in the first step S204) are set, and one shooting process is executed. The n-th material image data (which becomes the first material image data in the first step S204), which is still image data for one sheet, is generated. In the next step S205, the nth material image data generated in step S204 is held in the memory 4a. The processing as step S204 and step S205 corresponds to one photographing process.

In the next step S206, it is determined whether or not the variable n has reached the maximum value corresponding to the prescribed number of imaging processes in WDR imaging. That is, it is determined whether or not all of the prescribed number of shooting processes have been completed at the present time. If a negative determination result is obtained on the assumption that the photographing process still remains, the variable n is incremented in step S207, and the process returns to step S204. That is, the next photographing process is executed to generate and hold the next n-th material image data.
Then, the procedure of steps S204 and S205 for the specified number of times is repeated in this way, and when a positive determination result is obtained in step S206, the process proceeds to step S208.

At the stage of reaching step S208, the memory 4a holds the first to nth material image data corresponding to the prescribed number of photographing processes. Therefore, in step S208, control is performed to generate one WDR photographed image data using these first to n-th material image data.
As an operation of the image signal processing unit 4 according to this control, an image portion that is photographed with an exposure that is as good as possible as compared with each common image portion in the first to n-th material image data. Are extracted from the material image data. As a result, the best quality image portion is selected and extracted from the first to n-th material image data as an image for forming one piece of still image data. In step S208, these extracted image portions are combined to generate one image data. The image data generated in this way becomes WDR captured image data. As a detailed algorithm for generating WDR captured image data in step S208, a technique that has been developed and proposed so far, or a technique that is appropriate from techniques developed and proposed in the future is adopted. What should I do?

By the way, the following can be said according to the procedure of the flowchart of FIG. 6 demonstrated so far, and the procedure of WDR imaging | photography by the said FIG.
First, in obtaining normal AE shot image data and WDR shot image data in accordance with one shot of the shooting operation in the WDR shooting mode, shooting processing for generating normal AE shot image data and shooting for generating a WDR shot image are performed. Each process is executed individually. This is as described in step S102 and step S103 in FIG. This makes it possible to set the exposure condition parameter set during WDR shooting without being limited by the exposure conditions set during normal AE shooting. In this embodiment, when setting a parameter set of exposure conditions at the time of WDR shooting, it is obtained based on the exposure conditions set at the time of normal AE shooting, so that it corresponds to the ambient light situation at that time. The parameter values optimized as much as possible are obtained.

This point will be compared with Patent Document 1.
In Patent Document 1, for example, as described in FIG. 3 and the description of the specification corresponding thereto, in the automatic SL shooting mode corresponding to the WDR shooting mode of the present embodiment, the short exposure image data and the long time exposure data are set. Two pieces of exposure image data are obtained, and an SL composite image corresponding to the WDR captured image data of the present embodiment is obtained by combining the two pieces of exposure image data. In addition, as is clear from the description of the specification corresponding to FIG. 18, in the automatic SL shooting mode, the image data corresponding to the normal AE shot image data of the present embodiment is a length that is a material of the SL composite image. Time exposure image data is used.
Then, the long exposure image data is photographed based on normal AE (automatic exposure) information. Therefore, the SL composite image is photographed by normal AE regardless of the ambient light environment. The long-time exposure image and the short-time exposure image taken with a shorter exposure amount, that is, the short-time exposure image taken with a smaller exposure amount are generated. In this way, in Patent Document 1, a captured image obtained by normal AE is shared as material image data of an SL image, and the image data is fixedly determined as long-time exposure image data. For this reason, it is considered that there is a low possibility that an improved image quality can be obtained as compared with a captured image obtained by normal AE. For example, in a situation where the ambient light is dark, the short-time exposure image becomes darker, and it is difficult to desire a result that is improved as the SL image generated as a result approaches the proper exposure. Become.
On the other hand, in the present embodiment, the parameter set can be set based on the exposure conditions set during normal AE shooting in consideration of the fact that the exposure amount tends to be smaller when the ambient light is too bright. On the contrary, when the ambient light is too dark, the parameter set can be set in consideration of the exposure amount having a larger tendency. That is, WDR captured image data can be generated by setting exposure conditions that are more suitable for ambient light. As a result, the WDR captured image data obtained by the present embodiment is expected to have a higher possibility that the exposure state has been improved, and the practicality and reliability will be increased accordingly. .

Returning to FIG.
The WDR captured image data generated by the WDR imaging procedure as step S104 shown in FIG. 7 is stored in the memory 4a in step S105.

As described above, under the WDR shooting mode, the saved image confirmation modes are “shooting / manual mode”, “shooting / automatic mode”, “playback / manual mode”, “playback / automatic mode”. 4 modes are prepared. In response to this, in step S106 following step S105, it is determined what the currently set saved image determination mode is.
If it is determined in step S106 that the stored image confirmation mode is either “reproduction / manual mode” or “reproduction / automatic mode”, the procedure of step S107 is executed, and then After exiting the routine shown in this figure, it waits again for a photography instruction to be generated in step S101.
In step S107, the pair of the normal AE photographed image data and the WDR photographed image data held in the memory 4a by steps S103 and S105 is handled as the unconfirmed image file described above and stored in the storage medium 20. Try to keep it.

If it is determined in step S106 that the stored image determination mode is the “shooting / manual mode”, the procedure of step S108 is executed.
In step S108, the normal AE photographed image data held in the memory 4a is analyzed in step S103, and the information of the histogram is generated. The histogram information generated in this way is stored in, for example, the RAM 12. As for the processing for generating the histogram, a technique that has been developed and proposed so far, or a technique that is appropriate from techniques developed and proposed in the future may be employed. In the present embodiment, if the histogram information is generated, for example, by the CPU 10 based on luminance (brightness) information for each pixel that is assumed to be taken in from the image signal processing unit 4, for example. Good. Alternatively, it is conceivable that the image signal processing unit 4 adopting a configuration as a DSP (Digital Signal Processor) can be completed internally and generate histogram information in accordance with an instruction from the CPU 10.
In the next step S109, histogram information of the WDR captured image held in the memory 4a in step S105 is generated and held in the RAM 12.

At the stage where the procedure up to step S109 is completed, the memory 4a holds the normal AE shot image data and the WDR shot image data, and the RAM 12 holds the histogram information for each shot image data. Is in a state.
Therefore, in step S110 following step S109, the display of the saved image selection screen shown in FIG. 4 or 5 is performed using the normal AE captured image data, the WDR captured image data, and the histogram information of each captured image data. Control image data is generated, and control is performed so that the display image data is displayed on the display unit 7. As a result, the saved image selection screen is displayed on the display screen portion 7A.

Next, in step S111, a captured image that is a selection target between a normal AE captured image and a WDR captured image in response to an operation (image selection operation) on the image selection button described in FIG. The switching setting is performed. By this processing, the highlight display of the image selection button Bt31 or the image selection button Bt32 is also switched.
The procedure as step S111 is in accordance with the operation performed on the user's image selection buttons Bt31 and Bt32 until a positive determination result is obtained as a result of the operation on the OK button Bt33 being performed in step S112. Can be executed.
If a positive determination result is obtained in step S112 that the operation on the OK button Bt33 has been performed, the process proceeds to step S113.

  In step S113, the photographed image data (which is the regular photographed image data) selected on the saved image selection screen when the OK button Bt33 is operated is saved in the storage medium 20 and has not been selected. This image data is discarded. For example, if a normal AE shot image is selected, the baseband normal AE shot image data stored in the memory 4a is subjected to compression encoding processing by the image signal processing unit 4, for example. Transfer to the media controller 13. Then, the media controller 13 stores the compression-encoded normal AE photographed image data in the storage medium 20 so as to be managed as a regular photograph image file. At the same time, the WDR photographed image data that has not been selected is deleted from the memory 4a.

If it is determined in step S106 that the stored image confirmation mode is “reproduction / automatic mode”, the procedure from step S114 is executed.
In step S114 and subsequent step S115, similarly to the previous steps S108 and S109, histogram information is generated for each of the normal AE captured image data and the WDR captured image data held in the memory 4a. This is held in the RAM 12.

In this case, in step S116, as an analysis process for each of the histogram information generated in steps S114 and S115, for example, a reference histogram indicating a luminance vs. pixel number distribution determined as normal A process for comparing with information is executed, and based on the comparison result, regular photographed image data is selected and determined from normal AE photographed image data and WDR photographed image data in step S107. At this time, for example, as a result of comparison with the reference histogram information, the one having a smaller error amount with respect to the reference histogram information is selected as the normal photographed image data.
In the next step S118, the captured image data selected and determined in step S117 is stored in the storage medium 20 as a photographic image file, and the captured image data not selected and determined is discarded. Is done.

  The flowchart of FIG. 8 shows an unconfirmed image file stored in the storage medium 20 by photographing in the WDR photographing mode in which the image confirmation mode of “reproduction / manual mode” or “reproduction / automatic mode” is set. As an object, an example of a procedure for determining regular photographed image data in the reproduction mode is shown.

  In FIG. 8, first, in step S301, for example, a file selection operation for reproducing a photographic image file performed by the user waits for an undetermined image file to be selected as a reproduction target. If an affirmative determination result is obtained in step S301, the process proceeds to step S302, and the image confirmation modes when the unconfirmed image file is stored are “reproduction / manual mode” and “reproduction / It is determined which of the “automatic mode” was selected. For example, when data is stored in the storage unit 20 as an undetermined image file, identification information indicating the image deciding mode at that time is stored as additional information together with the data of the undetermined image file. In the determination in step S302, this identification information is referred to.

If it is determined in step S302 that the image confirmation mode is “reproduction / manual mode”, steps S303 to S310 are executed.
First, the normal AE photographed image data and the WDR photographed image data as the unconfirmed image file selected this time are read from the storage medium 20 through step S303 and subsequent step S304. The subsequent steps S305 to S310 are the same as the steps S108 to S113 corresponding to the “shooting / manual mode” in FIG. However, in step S310, the photographic image data selected on the saved image selection screen is managed again as a photographic image file and stored again in the storage medium 20. For example, this processing can be realized only by rewriting the management information without re-storing the actual data of the captured image data. In addition, the photographed image data that has not been selected on the saved image selection screen is erased and deleted from the storage unit 20.

If it is determined in step S302 that the image confirmation mode is “reproduction / automatic mode”, the procedure of steps S311 to S317 is executed.
First, in steps S311 and S312, the normal AE captured image data and the WDR captured image data as the unconfirmed image file selected this time are read from the storage unit 20 in the same manner as in steps S303 and S304. Further, the procedure from the subsequent steps S313 to S317 follows the steps S114 to S118 in FIG. Regarding step S317, similarly to step S310, the photographic image data selected as the regular photographic image data is re-stored in the storage medium 20 as a photographic image file, and the photographic image data not selected is stored in the storage medium 20. Erase from

  Note that the procedure for WDR imaging as the present embodiment and the configuration corresponding thereto may be changed as appropriate. For example, in the description so far, the histogram information used for determining the stored image is generated for the first time during the process of determining the stored image. On the other hand, for example, when performing normal AE shooting and when performing WDR shooting, normal AE captured image data and WDR captured image data are generated, respectively, and histogram information is generated based on the generated image data. You may make it produce | generate. Also, in this case, if the confirmation mode of the image confirmation mode is set to “during playback” mode, the generated histogram information is included in the structure of the unconfirmed image file and stored and retained. You should keep it.

Further, in the above-described embodiment, an unconfirmed image file is selected as an image to be reproduced and displayed as an image to be reproduced and displayed as an opportunity to confirm the regular photographed image data when the mode of “during reproduction” is set as the confirmation opportunity of the image confirmation mode. There are other possibilities for this. For example, in the playback mode, it may be possible to set a dedicated mode for confirming the regular photographed image data so that the regular photographed image data can be confirmed manually or automatically while only the unconfirmed image file is selectively displayed. It is done.
In addition, when the mode of “playback” is set for the confirmation opportunity of the image confirmation mode, the regular photographed image data is confirmed after the user completes the shooting and recording. It is necessary to store it as a fixed image file. Thus, in the above embodiment, the storage medium 20 is stored and held. However, as a storage area for storing and storing the unconfirmed image file, for example, if there is a capacity, the nonvolatile memory 12a may be used. In this case, since the non-volatile memory 12a is an internal memory in the digital still camera 1, it can be accessed at a higher speed than the storage medium 20, for example, and it is expected that the process for determining the regular photographed image data will be accelerated accordingly. Is done. Further, if the data is stored in the nonvolatile storage area such as the storage medium 20 or the nonvolatile memory 12a in this way, the unconfirmed image file is not deleted even when the main power of the digital still camera 1 is turned off. For example, even after the user turns off the main power supply and does not use it for a while, the regular photographed image data can be confirmed, which is convenient. However, if it is not necessary to consider this for some reason or circumstances, the undetermined image file may be held in a volatile storage area such as the RAM 12 or the memory 4a. .
Similarly, the “reproduction” mode is set for the confirmation opportunity of the image confirmation mode. As an unconfirmed image file, instead of storing the generated WDR captured image data, the material image is stored. In order to store the data, the procedure may be to generate WDR photographed image data from these material image data when it is time to determine the regular photographed image data.
In the present embodiment, the present invention is applied to a digital still camera. However, at present, a photographic still image is originally used in a video camera device that records and reproduces a captured image of a moving image. Since it is widely known that it is configured to be capable of recording and recording, the present invention can be applied to various imaging apparatuses including these video camera apparatuses.
In the embodiment, still image data is targeted as photographed image data. However, as a concept of the present invention, it is also possible to apply moving image data as a target. For example, if the high speed shooting and the video signal processing speed increase in the future reach a certain level or more, the moving image data corresponding to the WDR shot image of the present embodiment is generated by combining the plurality of moving image data. It will be possible.

It is a figure which shows the example of an external appearance of the digital still camera as embodiment of this invention. It is a figure which shows the internal structural example of the digital still camera of embodiment. It is a figure which shows the example of a display mode of the operation screen for demonstrating the operation procedure for setting WDR imaging | photography mode in embodiment. It is a figure which shows the example of a display mode of the preservation | save image selection screen in case "manual mode" is set as a method of confirmation of image confirmation mode. It is a figure which shows the other example of a display mode about a preservation | save image selection screen. It is a flowchart which shows the example of a procedure for imaging | photography recording in case the WDR imaging | photography mode is set. It is a flowchart which shows the example of a procedure for WDR imaging | photography. It is a figure which shows the example of a procedure for the regular picked-up image data confirmation in case the image confirmation mode is set to "reproduction / manual mode" or "reproduction / automatic mode".

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Digital still camera, 2 Optical system part, 3 Photoelectric conversion part, 4 Image signal processing part, 5 Image input / output part, 6 Camera function part, 7 Display part, 7A Display screen part, 8 Audio processing part, 9 Audio input / output Part, 10 CPU, 11 ROM, 12 RAM, 12a nonvolatile memory, 13 media controller, 15 operation input part, 16 communication part, 20 storage medium, 31 shutter button, 32 zoom key, 33 cross key, 34, 35 button key

Claims (16)

Photographing processing means for performing photographing processing which is processing for generating image data from an image signal obtained by performing imaging according to a set exposure condition;
Normal photographed image data generating means configured to generate normal photographed image data by setting one exposure condition and executing the photographing process;
After setting a plurality of different exposure conditions, a plurality of image data are obtained by sequentially executing a predetermined plurality of times of the photographing process within a predetermined time according to each of these exposure conditions, and the plurality of image data are obtained. A composite photographed image data generating means for generating composite photographed image data by executing the used image composition processing;
As the one-time shooting operation, the normal shooting image data generation unit generates the normal shooting image data, and the composite shooting image data generation unit is set as the normal image data processing unit in the current shooting operation. Shooting operation control means for controlling the execution of shooting processing according to the plurality of different exposure conditions set based on the exposure condition to generate the composite shot image data within a predetermined time; and
An image for selection operation in which each image of the normal photographed image data and the composite photographed image data generated by the one-time photographing operation and an image obtained by visualizing the histogram information on the image data are presented. Display control means for displaying and outputting in a predetermined display mode;
An operation means for performing an operation for selecting one of the images of the normal captured image data and the composite captured image data displayed and output in the selection operation image;
Regular photographed image data to be treated as a regular one of the normal photographed image data and the composite photographed image data generated by the one-time photographing operation according to the operation performed on the operation means. A selection determining means for selecting and determining
An image signal processing apparatus comprising: Display output of the image for selection operation by the display control means;
The selection determination of the regular photographed image data by the selection determination means is
Each time the one shooting operation by the shooting operation control means is executed,
The image signal processing apparatus according to claim 1. Further provided is a photographed image storage means capable of storing a plurality of sets of the normal photographed image data and the composite photographed image data obtained each time the one photographing operation by the photographing operation control means is executed. so,
The display output of the selection operation image by the display control unit and the selection determination of the regular photographed image data by the selection determination unit are performed corresponding to the playback mode stored by the previous photographing operation. In this case, the display output of the selection operation image by the display control means at this time includes the normal photographed image data and the composite photographed image data stored in the photographed image storage means, At least using the histogram information generated corresponding to the image data,
The image signal processing apparatus according to claim 1. One of the normal photographed image data and the composite photographed image data selected and determined as the regular photographed image data by the selection determining means is stored in the storage means as image data photographed by the one photographing operation. Further comprising storage control means for causing
The image signal processing apparatus according to claim 1. Each of the plurality of shooting processes to be executed by the composite shot image data generating unit is a process separate from the shooting process executed by the normal shot image data generating unit.
The image signal processing apparatus according to claim 1. The composite photographed image data generating means sets each of the plurality of different exposure conditions based on one exposure condition set by the normal photographed image data generating means in a corresponding one shooting operation. ing,
The image signal processing apparatus according to claim 1. Imaging means for obtaining an image signal corresponding to the image light obtained by imaging;
Photographing processing means for performing photographing processing which is processing for generating image data from the image signal obtained by performing imaging by the imaging means according to a set exposure condition;
Normal photographed image data generating means configured to generate normal photographed image data by setting one exposure condition and executing the photographing process;
After setting a plurality of different exposure conditions, a plurality of image data are obtained by sequentially executing a predetermined plurality of times of the photographing process within a predetermined time according to each of these exposure conditions, and the plurality of image data are obtained. A composite photographed image data generating means for generating composite photographed image data by executing the used image composition processing;
As the one-time shooting operation, the normal shooting image data generation unit generates the normal shooting image data, and the composite shooting image data generation unit is set as the normal image data processing unit in the current shooting operation. Shooting operation control means for controlling the execution of shooting processing according to the plurality of different exposure conditions set based on the exposure condition to generate the composite shot image data within a predetermined time; and
An image for selection operation in which each image of the normal photographed image data and the composite photographed image data generated by the one-time photographing operation and an image obtained by visualizing the histogram information on the image data are presented. Display control means for displaying and outputting in a predetermined display mode;
An operation means for performing an operation for selecting one of the images of the normal captured image data and the composite captured image data displayed and output in the selection operation image;
Regular photographed image data to be treated as a regular one of the normal photographed image data and the composite photographed image data generated by the one-time photographing operation according to the operation performed on the operation means. A selection determining means for selecting and determining
An imaging apparatus comprising: A shooting process execution procedure for executing a shooting process, which is a process of generating image data from an image signal obtained by executing shooting according to a set exposure condition;
A normal shooting image data generation procedure for generating normal shooting image data by setting one exposure condition and executing the shooting process;
After setting a plurality of different exposure conditions, a plurality of image data are obtained by sequentially executing a predetermined plurality of times of the photographing process within a predetermined time according to each of these exposure conditions, and the plurality of image data are obtained. A composite photographed image data generation procedure for generating composite photographed image data by executing the used image composition processing;
As the one-time shooting operation, the normal shooting image data generation procedure generates the normal shooting image data and the composite shooting image data generation procedure is set as the normal image data processing procedure in the current shooting operation. A shooting operation control procedure for controlling the execution of the shooting process according to the plurality of different exposure conditions set based on the exposure condition to generate the composite shot image data within a predetermined time;
An image for selection operation in which each image of the normal photographed image data and the composite photographed image data generated by the one-time photographing operation and an image obtained by visualizing the histogram information on the image data are presented. A display control procedure for displaying and outputting in a predetermined display mode;
In response to an operation for selecting one of the images of the normal captured image data and the composite captured image data displayed and output in the selection operation image being performed, A selection determination procedure for selecting and determining regular captured image data to be treated as regular from the normal captured image data and the composite captured image data generated by the capturing operation for each time,
The image signal processing method characterized by performing. Photographing processing means for performing photographing processing which is processing for generating image data from an image signal obtained by performing imaging according to a set exposure condition;
Normal photographed image data generating means configured to generate normal photographed image data by setting one exposure condition and executing the photographing process;
After setting a plurality of different exposure conditions, a plurality of image data are obtained by sequentially executing a predetermined plurality of times of the photographing process within a predetermined time according to each of these exposure conditions, and the plurality of image data are obtained. A composite photographed image data generating means for generating composite photographed image data by executing the used image composition processing;
As the one-time shooting operation, the normal shooting image data generation unit generates the normal shooting image data, and the composite shooting image data generation unit is set as the normal image data processing unit in the current shooting operation. Shooting operation control means for controlling the execution of shooting processing according to the plurality of different exposure conditions set based on the exposure condition to generate the composite shot image data within a predetermined time; and
Based on the result of comparison of the histogram information of the normal captured image data and the composite captured image data generated by the single shooting operation, the normal captured image data and the composite captured image data are better. Selection and determination means configured to select and determine the image data that has the image content as the normal captured image data;
An image signal processing apparatus comprising: The selection determination of the regular photographed image data by the selection determination means is
Each time the one shooting operation by the shooting operation control means is executed,
The image signal processing apparatus according to claim 9. Further provided is a photographed image storage means capable of storing a plurality of sets of the normal photographed image data and the composite photographed image data obtained each time the one photographing operation by the photographing operation control means is executed. so,
The selection determination of the regular photographed image data by the selection determination means is performed in correspondence with the playback mode assumed to be stored by the previous photographing operation, and the selection determination means at this time performs the selection For selection determination of the regular photographed image data, histogram information generated corresponding to the normal photographed image data and the composite photographed image data stored in the photographed image storage means is used.
The image signal processing apparatus according to claim 9. One of the normal photographed image data and the composite photographed image data selected and determined as the regular photographed image data by the selection determining means is stored in the storage means as image data photographed by the one photographing operation. Further comprising storage control means for causing
The image signal processing apparatus according to claim 9. Each of the plurality of shooting processes to be executed by the composite shot image data generating unit is a process separate from the shooting process executed by the normal shot image data generating unit.
The image signal processing apparatus according to claim 9. The composite photographed image data generating means sets each of the plurality of different exposure conditions based on one exposure condition set by the normal photographed image data generating means in a corresponding one shooting operation. ing,
The image signal processing apparatus according to claim 9. Imaging means for obtaining an image signal corresponding to the image light obtained by imaging;
Photographing processing means for performing photographing processing which is processing for generating image data from the image signal obtained by performing imaging by the imaging means according to a set exposure condition;
Normal photographed image data generating means configured to generate normal photographed image data by setting one exposure condition and executing the photographing process;
After setting a plurality of different exposure conditions, a plurality of image data are obtained by sequentially executing a predetermined plurality of times of the photographing process within a predetermined time according to each of these exposure conditions, and the plurality of image data are obtained. A composite photographed image data generating means for generating composite photographed image data by executing the used image composition processing;
As the one-time shooting operation, the normal shooting image data generation unit generates the normal shooting image data, and the composite shooting image data generation unit is set as the normal image data processing unit in the current shooting operation. Shooting operation control means for controlling the execution of shooting processing according to the plurality of different exposure conditions set based on the exposure condition to generate the composite shot image data within a predetermined time; and
Based on the result of comparison of the histogram information of the normal captured image data and the composite captured image data generated by the single shooting operation, the normal captured image data and the composite captured image data are better. Selection and determination means configured to select and determine the image data that has the image content as the normal captured image data;
An imaging apparatus comprising: A shooting process execution procedure for executing a shooting process, which is a process of generating image data from an image signal obtained by executing shooting according to a set exposure condition;
A normal shooting image data generation procedure for generating normal shooting image data by setting one exposure condition and executing the shooting process;
After setting a plurality of different exposure conditions, a plurality of image data are obtained by sequentially executing a predetermined plurality of times of the photographing process within a predetermined time according to each of these exposure conditions, and the plurality of image data are obtained. A composite photographed image data generation procedure for generating composite photographed image data by executing the used image composition processing;
As the one-time shooting operation, the normal shooting image data generation procedure generates the normal shooting image data and the composite shooting image data generation procedure is set as the normal image data processing procedure in the current shooting operation. A shooting operation control procedure for controlling the execution of the shooting process according to the plurality of different exposure conditions set based on the exposure condition to generate the composite shot image data within a predetermined time;
Based on the result of comparison of the histogram information of the normal captured image data and the composite captured image data generated by the one-time capturing operation, the normal captured image data and the composite captured image data are better. A selection determination procedure for selecting and determining the image data that has the image content as the normal captured image data;
The image signal processing method characterized by performing.

Images