JP2012239076A - Imaging device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain a wide dynamic range image.SOLUTION: A control unit 20 shifts a photographing mode from a normal photographing mode to a composition photographing mode in response to detection of the stillness of a subject by a still subject detection unit 34 based on image data captured from an imaging element 14 to execute the composition photographing mode. When the composition photographing mode is executed, an image processing circuit 23 combines three images which are a short-time exposure image, a normal exposure image, and a long-time exposure image generated by imaging an identical subject by the imaging element 14 with different exposure amounts to generate one wide dynamic range image.

Description

  The present invention relates to an imaging apparatus and method for obtaining a single synthesized image by synthesizing a plurality of images acquired by a plurality of times of imaging.

  Conventionally, in order to generate an image with a wide dynamic range (hereinafter referred to as a “wide dynamic range image”), a plurality of images of the same subject picked up with different exposure amounts are combined by, for example, addition averaging to form one image An imaging apparatus that obtains a composite image is known (Patent Document 1). The image synthesizing means of this image pickup device uses image data obtained with an exposure amount larger than the standard as data on the low luminance side, and image data obtained with the standard exposure amount as data on the high luminance side. The image data obtained by the amount is combined as the data on the ultra-high brightness side, or the image data is synthesized in any combination.

Japanese Unexamined Patent Publication No. 7-135599

  By the way, shooting for obtaining a wide dynamic range image is generally performed by changing the shooting mode. To change the shooting mode, a menu button on the back, a cross button, a determination button in the middle of the shooting mode, and the like are operated to display a list of shooting modes on the LCD, and an alternative is selected from the list.

  For example, in order to select a shooting mode list from the menu, the menu button is pressed, and the up or down cursor of the cross button is selected from the menu items to select an item in the shooting mode list, and then the enter button is pressed. Thereafter, in order to select a corresponding mode from the shooting mode list, the up or down cursor is pressed to select the corresponding mode, and then the enter button is pressed. Then, it is necessary to repeatedly press the menu button, the cross button, the enter button, and the like, such as pressing a menu button for ending the menu, which is troublesome.

  In particular, in photographing a wide dynamic range image, it is important that the subject is stationary. If it takes time to change the mode, there is a risk of missing the timing of the shooting.

  In order to solve the above-described problems, an object of the present invention is to provide an imaging apparatus and method that can easily obtain a wide dynamic range image without missing the imaging timing.

  In the present invention, a stationary subject detection means for detecting a stationary subject; and a plurality of main processing image data generated by imaging the same subject with different exposure amounts by an image sensor, and a single wide dynamic range image data And a mode transition means for shifting to a composite photographing mode for executing the main processing composition means in response to detection of a stationary subject.

  The stationary subject detection means detects that the subject is stationary based on image data obtained from the image sensor. For example, it is only necessary to detect that the subject is stationary by comparing all the pixels of two consecutive image data or the pixels of a feature area such as a face image. When the continuous shooting mode is selected as the drive mode, it is preferable to cancel the composite shooting mode and execute the normal shooting mode.

  It is desirable to reduce random noise during the composite shooting mode. Therefore, setting means for setting the sensitivity of the image sensor; and a plurality of main processing image data generated by imaging the same subject with different exposure amounts by the image sensor to synthesize one wide dynamic range image data. A main processing composition unit to be generated; and a plurality of preprocessing images generated by imaging the subject a plurality of times with an exposure amount smaller than a standard exposure when the sensitivity set by the setting unit is low and less than a threshold value Pre-processing composition for combining data as a single image data for noise reduction, and outputting the synthesized image data for noise reduction as image data captured under an exposure condition having the lowest exposure amount among the image data for main processing And means.

  It is desirable that the number of times of imaging for acquiring the preprocessing image data can be changed according to the sensitivity. For example, it is desirable to increase the number of times of imaging in the low sensitivity range of the low sensitivity range where the set sensitivity is less than the threshold.

  In addition, as the pre-processing synthesis means, when the sensitivity set by the setting means is high sensitivity exceeding the threshold value, the short-time exposure imaged under the exposure condition with the lowest exposure amount constituting a plurality of main processing image data Each of image data, standard exposure image data imaged under standard exposure conditions, and long-time exposure data imaged under the exposure conditions with the highest exposure amount is created by combining a plurality of preprocessing image data. This is preferable because random noise that is likely to occur during high-sensitivity imaging can be reduced.

  In this case, the number of times of imaging for acquiring pre-processing image data for short-time exposure image data is “A”, and the number of times of imaging for acquiring pre-processing image data for standard exposure image data is “B”. If the number of times of imaging for acquiring the pre-processing image data for the long-time exposure data is “C”, it is desirable that the relationship of A> B> C is satisfied.

  Further, in this case, the preprocessing combining unit changes the number of times of imaging for acquiring the preprocessing image data according to the sensitivity so that the number of times of imaging increases as the sensitivity increases in the range determined to be high sensitivity. It is preferable to do this.

  In the present invention, since the transition to the composite shooting mode is automatically performed by detecting a stationary subject, a wide dynamic range image with reduced random noise can be obtained instantaneously.

It is a block diagram which shows the electrical outline of the electronic camera using this invention. It is a block diagram which shows the detailed structure of an image processing circuit. It is a block part which shows the structure of the alignment process. It is a flowchart which shows the operation | movement procedure of composite imaging | photography mode. FIG. 5 is a flowchart showing a continuation of the operation procedure described in FIG. 4. It is a flowchart figure which shows the operation | movement procedure at the time of high sensitivity. FIG. 7 is a flowchart showing a continuation of the operation procedure described in FIG. 6. It is explanatory drawing which shows the example which changed the acquisition number of the short-time exposure image data in the range of a low sensitivity. It is explanatory drawing which shows the example which each changed the acquisition number of each image data with the short time exposure in the range of high sensitivity, standard exposure, and long time exposure.

  An electronic camera will be described as an embodiment of the imaging apparatus of the present invention. In response to a single shutter release, the electronic camera has a composite shooting mode in which a plurality of pieces of image data obtained by imaging with different exposure amounts are combined to generate one wide dynamic range image data. Have.

  As shown in FIG. 1, the electronic camera 10 includes a lens optical system 11, an aperture 12, a mechanical shutter 13, an image sensor 14, an AFETG (analog front-end timing generator) 15, a lens driving unit 16, an aperture driving unit 17, and a shutter driving unit. 18, still object detection circuit, AE / AF circuit 19, control unit 20, operation unit 21, LCD 22, image processing circuit 23, RAM 24, ROM 25, VRAM 26, nonvolatile raw memory 27, memory slot 28, external memory 29, etc. Is done.

  The lens driving unit 16 performs zooming and focusing operations of the lens optical system 11. The aperture driving unit 17 drives the aperture 12. The shutter drive unit 18 drives the mechanical shutter 13. The image sensor 14 is an image sensor such as a CCD or CMOS that photoelectrically converts a subject image formed through the lens optical system 11 and the diaphragm 12.

The AFET G15 includes a TG (timing generator) 30, a V-driver (vertical drive unit) 31, and an AFE (analog front end) 32.
The TG 30 gives the readout timing of the image signal to the image sensor 14 via the V-driver 31. The AFE 32 amplifies the analog image signal read from the image sensor 14 by removing noise or increasing the analog gain, and then A / D converts the digital image data into digital image data. The converted image data is a still subject detection circuit. , Output to the AE / AF circuit 19 and the image processing circuit 23.

  The stationary subject detection circuit 34 detects whether the subject is stationary based on digital image data. Specifically, image data is continuously captured, the absolute value of the luminance difference between pixels at the same position in the preceding and following image data is set as a difference value, the difference value is calculated for each of all pixels, and the difference value is determined in advance. Pixels that are equal to or greater than the threshold value are discriminated, and when there is no cluster area containing many of these pixels, it is determined that the subject is stationary, and information indicating that the subject is a stationary subject is output to the control unit 20.

  As another configuration of the stationary subject detection circuit 34, for example, a face detection circuit is provided, and the face detection circuit uses the two image data to be compared to match the face area of the person included in the image with the face template. And the absolute value of the luminance difference of the pixels in the person's face area is calculated as a difference value, and the subject is stationary when the pixel whose difference value is equal to or greater than a predetermined threshold is less than the predetermined threshold May be determined.

The AE / AF circuit 19 extracts and controls AF (autofocus) information for controlling focus based on contrast information of image data, and optimum AE (auto exposure) information and white balance information based on image data. Send to part 20. The control unit 20 controls the lens driving unit 16, the aperture driving unit 17, the image processing circuit 23, and the like based on the AF information, the AE information, and the white balance information.
The image processing circuit 23 includes white balance processing, compression encoding, decoding processing, image composition processing, and the like. The VRAM 26 is an image memory for displaying on the LCD 22. The LCD 22 displays a captured image, a menu of various camera settings, and a shooting mode.

  An external memory 29 is detachably connected to the memory slot 28. The external memory 29 stores the compressed and encoded image data generated by the image processing circuit 23.

  The RAM 24 is used as a work area for the control unit 20 and the image processing circuit 23. The ROM 25 stores a program executed by the control unit 20. The non-volatile memory 27 stores various adjustment data of the electronic camera 10, a shooting mode and sensitivity (ISO sensitivity) set by the user, and the like.

  The control unit 20 is configured around a CPU (central processing unit) that operates according to a program stored in the ROM 25 and controls each unit of the electronic camera 10. For example, the control unit 20 gives an instruction to read the image signal of the image sensor 14 to the TG 30 of the AFETG 15, inputs the image signal read from the image sensor 14 to the image processing circuit 23 via the AFE 32, and the image processing circuit 23 After the processing corresponding to the shooting mode is executed, the processed image data is controlled to be recorded in the external memory 29 via the bus 33.

  The operation unit 21 includes a sensitivity setting unit, a shutter button, a mode setting unit, a drive mode setting unit, a power button, and the like, which send operation signals and setting signals to the control unit 20. The sensitivity setting unit is an operation unit for changing the sensitivity (ISO sensitivity) of the image sensor 14 in a plurality of stages. Sensitivity is set to an arbitrary sensitivity in advance.

  When the control unit 20 obtains the subject luminance information from the AE / AF circuit 19, the standard exposure is performed according to the program diagram corresponding to the sensitivity set at that time so as to approach the appropriate exposure determined by the sensitivity and the subject luminance. The amount (exposure amount obtained from the aperture value and shutter speed value) is determined.

  The mode setting unit is an operation unit that selectively selects the normal shooting mode and the reproduction mode. In the normal shooting mode, continuous shooting and single-frame shooting can be alternatively selected by operating the drive mode setting unit.

  The normal shooting mode is a mode in which image data is generated by imaging with the image sensor 14 with a standard exposure amount. When single-frame shooting is selected, one image data is recorded in the external memory 29 in response to one shutter release, and when continuous shooting is selected, it is substantially the same as long as the shutter button is pressed. A plurality of image data picked up by exposure are recorded in the external memory 29. The reproduction mode is a mode in which image data recorded in the external memory 29 is reproduced on the LCD 22.

  When the still subject detection circuit 34 determines that the subject is a still subject, the control unit 20 automatically shifts from the normal shooting mode to the composite shooting mode. The composite shooting mode is a mode in which a plurality of main processing image data generated by imaging the same subject with different exposure amounts are combined by the image sensor 14 and one wide dynamic range image data is recorded in the external memory 29. It is.

  In the composite photographing mode, the exposure amount is controlled by a combination of an electronic shutter that changes the accumulation time of the image sensor 14 and the aperture 12. The shutter speed may be determined by, for example, opening / closing the mechanical shutter 13 instead of the electronic shutter, or the exposure timing may be determined by the electronic shutter, and the end of exposure may be determined by the mechanical shutter 13.

  As illustrated in FIG. 2, the control unit 20 includes a composite shooting mode transition unit 42, a sensitivity determination unit 35, and a counter 36. The composite photographing mode transition unit 42 transitions the photographing mode from the normal photographing mode to the composite photographing mode in response to receiving a signal indicating that the subject is a stationary subject from the stationary subject detection circuit 34. The composite shooting mode transition unit 42 cancels the transition to the composite shooting mode when continuous shooting is selected.

  The sensitivity determination unit 35 recognizes the set sensitivity set in the sensitivity setting unit at the time of shooting and compares the recognized sensitivity with a predetermined threshold value to determine whether the sensitivity is high or low. The counter 36 counts the number of times image data has been captured. The control unit 20 changes the degree at which the analog image data is amplified by increasing the analog gain of the AFE 32 according to the sensitivity determined by the sensitivity determination unit 35.

  The image processing circuit 23 includes a distribution unit 37, a preprocessing composition unit 38, and a main processing composition unit 39. The distribution unit 37 distributes the image data to the pre-processing synthesis unit 38 and the main-processing synthesis unit 39, and this distribution processing is either pre-processing image data at high sensitivity or low sensitivity or an image for main processing. It is controlled by the control unit 20 based on the data.

  The main processing composition unit 39 performs processing for generating one wide dynamic range image data by combining a plurality of main processing image data captured with different exposure amounts in the composite photographing mode. The image data for processing is composed of, for example, short exposure image data, standard exposure image data, and long exposure image data.

  The short-time exposure image data is image data generated by capturing an image with an exposure amount smaller than the standard by the image sensor 14. The standard exposure image data is image data generated by imaging with a standard exposure amount by the image sensor 14. The long-exposure image data is image data generated by imaging with an exposure amount larger than the standard by the image sensor 14.

  When the preprocessing composition unit 38 determines that the sensitivity is low in the composite photographing mode, a plurality of preprocessing images generated by imaging with an exposure amount smaller than the standard by the imaging device 14 in order to reduce random noise. The data is synthesized to generate one piece of noise reduction image data, and the noise reduction image data is output to the main processing synthesis unit 39 as short exposure image data of the main processing image data.

  Further, when the pre-processing synthesis unit 38 determines that the sensitivity is high in the composite shooting mode, the pre-processing synthesis unit 38 synthesizes a plurality of pieces of image data generated by taking an image with an exposure amount smaller than the standard by the imaging device 14 into one piece of image data. The short-exposure image data is used as the short-exposure image data, and a plurality of pieces of image data generated by imaging with the standard exposure amount are combined into one image data, and the standard exposure image data is used. A combination of a plurality of pieces of image data generated by imaging with an exposure amount and one piece of image data is output to the processing composition unit 39 as long-time exposure image data.

  The preprocessing and main processing synthesis units 38 and 39 include buffer memories 40 and 44, alignment processing 41 and 45, and image synthesis 43 and 47, respectively. The buffer memories 40 and 44 temporarily store a plurality of image data. The alignment processes 41 and 45 perform a process of comparing the image data and correcting the coordinates so that the positions of the image data match. The image compositing 43 and 47 add each image data based on the corrected coordinate information, and then perform an averaging process of dividing by the number of image data to generate one piece of image data.

  As shown in FIG. 3, the alignment processes 41 and 45 include an evaluation unit 48, a determination unit 49, and an alignment unit 50. The evaluation unit 48 evaluates each image data by obtaining at least one of a predetermined condition, for example, a level (brightness) of image data, a contrast, and a high frequency component of spatial frequency. In this case, the evaluation value is increased as the brightest image data among the image data whose monochrome level of the image data does not reach the saturation level, the image data with the highest contrast value, or the image data with the highest high-frequency component. .

  Instead, the main subject is detected from each image data, and the reference image data is obtained by evaluating the condition that the evaluation value is increased as the detected amount of movement of the main subject is smaller, the focus state, the degree of deformation of the main subject, etc. You can decide.

  The determination unit 49 determines the image data most suitable for synthesis based on the evaluation value of each image data obtained by the evaluation unit 48 as the reference image data. The alignment unit 50 performs alignment processing so that the coordinate position matches the remaining image data with reference to the reference image data. Thereby, the image quality of the image data synthesized by the image synthesis 43 and 47 is improved. Note that, after the evaluation unit 48 evaluates each image data, if the evaluation value is lower than a predetermined threshold value, a process of selecting the image data not to be used for composition may be performed. .

Next, the operation of the above configuration will be described with reference to FIGS. The sensitivity of the image sensor 14 is set in advance to an initial value, for example, ISO sensitivity “400”.
The control unit 20 captures image data obtained by capturing with the image sensor 14 in response to one shutter release (S-1) into the AE / AF circuit 19 and the stationary subject detection circuit 34, and captures the captured image. Based on the data, the standard exposure amount is determined (S-2), and it is determined whether or not the subject is stationary (S-3).

  When the stationary subject detection circuit 34 determines that the subject is a stationary subject, the control unit 20 determines whether or not the continuous shooting mode is set in the composite shooting mode transition unit 42 (S-4), and the continuous shooting mode is set. If it is not set, the process shifts to the composite shooting mode (S-5). Note that the control unit 20 executes the normal shooting mode when it is determined as a moving object and when it is determined as the continuous shooting mode (S-6).

  When shifting to the composite shooting mode, the control unit 20 determines whether or not the sensitivity set at that time is less than the threshold (S-7). For example, when the set sensitivity is ISO sensitivity “400” and the threshold is ISO sensitivity “800”, it is determined that the set sensitivity is low.

  When it is determined that the sensitivity is low, the control unit 20 sets an exposure amount that is smaller than the standard exposure amount, for example, an exposure amount that has been corrected for exposure of “−1 EV”, and continuously captures images by the image sensor 14, for example, Five pieces of preprocessing image data are acquired (S-8), and the distribution unit 37 is controlled to fetch the five pieces of preprocessing image data into the buffer memory 40 of the preprocessing composition unit 38.

  The preprocessing synthesis unit 38 receives a signal responding to the count-up from the control unit 20 and sequentially reads out the five preprocessing image data from the buffer memory 40, and the evaluation unit 48 preliminarily reads each preprocessing image data. Evaluation is performed based on the determined conditions, reference image data is determined by the determination unit 49 based on the evaluation result (S-9), and the alignment unit 50 determines the remaining image data based on the reference image data. Then, alignment processing is performed (S-10), and then image composition 43 synthesizes the image data that has undergone alignment processing with respect to the reference image data in order by addition averaging processing, and performs short exposure for this processing. Image data is generated (S-11), and the short-time exposure image data is output to the buffer memory 44 of the processing composition unit 39.

  When acquiring five pre-processing image data, the control unit 20 initializes the counter 36 (S-12), and counts the number of times of imaging in short exposure with the counter 36 (S-13). It is determined whether or not the number of times of imaging has reached a predetermined number (S-14).

  Subsequently, the control unit 20 changes the standard exposure amount to capture one image and generates standard exposure image data for the main processing (S-15), and controls the distribution unit 37 to combine the standard exposure image data with the main processing composition. Then, the exposure is set to an exposure amount larger than the standard, for example, “+1 EV” exposure correction, and one image is captured to obtain long exposure image data for this processing. The long-time exposure image data is taken into the buffer memory 44 (S-16).

  In response to the three main processing image data, that is, the short-exposure image data, the standard exposure image data, and the long-exposure image data, being fetched into the buffer memory 44, the main processing composition unit 39 performs the alignment processing 45. The reference image data is determined by performing the same process as the alignment process 41 described above (S-17), and the remaining image data is aligned with the reference image data (S-18). Then, the image data that has undergone alignment processing with respect to the reference image data is sequentially synthesized by the averaging process to generate one wide dynamic range image data (S-19), and the wide dynamic range image data is externally generated. Record in the memory 29. The wide dynamic range image obtained in the composite shooting mode with low sensitivity determination is an image in which random noise that is likely to occur in low sensitivity shooting is reduced in addition to suppressing the occurrence of overexposure and underexposure.

  Next, the case where the sensitivity determination unit 35 determines that the sensitivity is high in FIG. 4 (S-7) will be described with reference to FIG. In this case, the control unit 20 sets the exposure amount that is smaller than the standard exposure amount, for example, an exposure amount that is corrected for exposure of “−1 EV”, and continuously captures images by the imaging device 14 to obtain a plurality of, for example, six images. The processing image data is acquired (S-20), the distribution unit 37 is controlled, and six pieces of preprocessing image data are taken into the buffer memory 40 of the preprocessing composition unit 38.

  The preprocessing composition unit 38 sequentially reads the six pieces of preprocessing image data from the buffer memory 40 in response to the increase in the number of shootings in the short exposure from the control unit 20, and performs the same processing as described above. This is performed in the alignment process 41 and the image composition 43 (S-21) to generate short-exposure image data for the main process (S-22), and the short-exposure image data is stored in the buffer memory 44 of the main process composition unit 39. Output to.

  Subsequently, the control unit 20 sets the standard exposure amount and continuously captures images with the image sensor 14, thereby obtaining a plurality of pre-processing image data, for example, four images, which are smaller than the number of images to be captured with short exposure. (S-23), the distribution unit 37 is controlled, and the four preprocessing image data are taken into the buffer memory 40 of the preprocessing composition unit 38.

  In response to the increase in the number of shootings with standard exposure from the control unit 20, the preprocessing composition unit 38 sequentially reads four preprocessing image data from the buffer memory 40 and aligns the same processing described above. The processing 41 and the image composition 43 are performed (S-24) to generate standard exposure image data for the main processing (S-25), and the standard exposure image data is output to the buffer memory 44 of the main processing composition section 39. .

  Subsequently, as shown in FIG. 7, the control unit 20 sets the exposure amount larger than the standard, for example, the exposure amount corrected for exposure of “+1 EV”, and continuously captures images with the image sensor 14, thereby performing standard exposure. A plurality of preprocessing image data, for example, two sheets, which are smaller than the number of images to be captured in (2), are acquired (S-26), and the distribution unit 37 is controlled so that the two preprocessing image data are stored in the preprocessing composition unit 38. The data is taken into the buffer memory 40.

  In response to the increase in the number of shootings with standard exposure from the control unit 20, the preprocessing composition unit 38 sequentially reads two preprocessing image data from the buffer memory 40 and aligns the same processing described above. The processing 41 and the image composition 43 are performed (S-27) to generate long exposure image data for the main processing (S-28), and the long exposure image data is stored in the buffer memory 44 of the main processing composition section 39. Output.

  Then, as described in FIG. 5 (S-17 to S-19), the main processing composition unit 39 responds to the acquisition of the three main processing image data into the buffer memory 44, and the alignment processing 45. In step S-29, the reference image data is determined (S-29), the remaining image data is aligned with the reference image data (S-30), and the reference image data is aligned. These image data are sequentially combined by the averaging process to generate wide dynamic range image data (S-31), and the wide dynamic range image data is recorded in the external memory 29.

  As a result, the wide dynamic range image generated by the high sensitivity determination becomes an image in which random noise that is likely to occur during high sensitivity shooting is reduced in addition to suppressing the occurrence of overexposure and blackout.

  Note that the control unit 20 desirably performs control to clear the buffer memories 40 and 44 after recording the wide dynamic range image data.

  Further, in the above embodiment, it goes without saying that the number of shots and the exposure correction value determined according to the sensitivity are not limited to the above-described numerical values. For example, as shown in FIG. 8, it is preferable to increase the number of acquired short-time exposure image data as the setting sensitivity is lower in the range where the setting sensitivity is less than the threshold. Also, for example, as shown in FIG. 9, it is preferable to increase the number of pieces of exposure image data acquired for the short time, the standard, and the long time as the set sensitivity is higher in the range where the set sensitivity exceeds the threshold. is there. If the number of acquired image data for short-time exposure, standard exposure, and long-time exposure is A, B, and C in order, the acquired number of image data is set so as to maintain the relationship of A> B> C. It is preferable to change.

  In addition, a change operation unit such as a cursor button or an OK button is provided on the operation unit, and for example, the number of shots in short exposure at low sensitivity, the number of shots in short exposure at high sensitivity, the number of shots in standard exposure, and the length You may comprise so that the image | photographing number by time exposure can each be set freely.

  In the embodiment described above, a wide dynamic range image is generated by synthesizing three image data of the short exposure, the standard exposure, and the long exposure. However, the present invention is not limited to this, and two exposures with different exposures are generated. A wide dynamic range image may be generated by synthesizing image data or by synthesizing four or more image data to which image data of ultra-low time exposure or ultra-long time exposure is added.

  In the above embodiment, when it is determined that the sensitivity is low, first the pre-processing image is imaged a plurality of times with short exposure, then imaging with standard exposure, and finally imaging with long exposure, In the present invention, the order is not limited to the above order. For example, imaging may be performed in the reverse order, or first in standard exposure, then multiple times in short exposure, and finally in long exposure.

  Similarly, when it is determined that the sensitivity is high, the imaging period for acquiring the preprocessing image data for the short exposure image data, the imaging period for acquiring the preprocessing image data for the standard exposure image data, The order of the period and the imaging period for acquiring the preprocessing image data for the long exposure data may be any order.

  In the above-described embodiment, each time image data is acquired, alignment processing is performed and combined. However, all imaging is performed first and image data is recorded in the RAM. You may comprise so that image data may be read and synthesize | combined. In addition, all images are taken first and image data is recorded in a flash memory or the like, and image processing software is installed in an electronic camera or the like in advance. You may make it synthesize | combine data.

  Furthermore, although the present invention has been described using the electronic camera 10 in the above embodiment, the present invention is not limited to this and can be used for a video camera, a television camera, and the like.

14 Image sensor 12 Aperture 13 Mechanical shutter 15 AFETG
23 Image processing circuit 38 Pre-processing synthesis unit 39 Main processing synthesis unit

Claims (14)

A stationary subject detection means for detecting a stationary subject;
A main processing composition unit configured to combine a plurality of main processing image data generated by imaging the same subject with different exposure amounts by using an imaging element to generate one wide dynamic range image data;
An image pickup apparatus comprising: a mode transition unit that shifts to a composite photographing mode that executes the processing composition unit in response to detecting a stationary subject. The imaging device according to claim 1,
The mode shift means shifts from the composite shooting mode to the normal shooting mode in response to the continuous shooting mode being set. The imaging apparatus according to claim 1 or 2,
Setting means for setting the sensitivity of the image sensor;
When the sensitivity set by the setting means is low sensitivity less than a threshold value, a plurality of pre-processing image data generated by imaging the subject a plurality of times with an exposure amount smaller than the standard exposure are combined to generate a single image. Pre-processing synthesis means for generating image data for noise reduction, and outputting the image data for noise reduction as image data captured under an exposure condition having the lowest exposure amount among the image data for main processing;
An imaging apparatus comprising: The imaging device according to claim 3.
An imaging frequency changing means is provided for changing the imaging frequency for acquiring the preprocessing image data according to the sensitivity so that the imaging frequency is increased as the sensitivity is lower in a range where the sensitivity is determined to be the low sensitivity. An imaging device characterized by comprising: In the imaging device according to claim 3 or 4,
The plurality of pieces of main processing image data were imaged under the short-exposure image data imaged under the exposure condition with the lowest exposure amount, the standard exposure image data imaged under the standard exposure condition, and the exposure condition with the highest exposure amount. Consisting of long exposure data,
When the sensitivity set by the setting unit is high sensitivity that exceeds the threshold, the pre-processing composition unit converts each of the short-time exposure image data, the standard exposure image data, and the long-time exposure data to a plurality of front images. An image pickup apparatus characterized by combining image data for processing. The imaging device according to claim 5.
“A” is the number of times of capturing preprocessing image data for creating the short-time exposure image data, “B” is the number of times of capturing preprocessing image data for creating the standard exposure image data, and An imaging apparatus characterized by satisfying a relationship of A>B> C, where “C” is the number of imaging times for acquiring preprocessing image data for creating the long-time exposure data. The imaging device according to claim 6,
An imaging number changing means for changing the number of imaging times “A”, “B”, and “C” according to the sensitivity so that the number of imaging times increases as the sensitivity is higher in the high sensitivity range. An imaging apparatus comprising:   In response to detecting a stationary subject, a plurality of main processing image data generated by imaging the stationary subject with an image sensor with different exposure amounts are combined to generate a single wide dynamic range image data. An imaging method characterized by transitioning to a composite shooting mode. The imaging method according to claim 8,
An imaging method, wherein transition from the composite shooting mode to the normal shooting mode is performed in response to the setting of the continuous shooting mode. The imaging method according to claim 8 or 9,
When the sensitivity of the image sensor is lower than a threshold value, a plurality of pre-processing image data generated by imaging the subject a plurality of times with an exposure amount smaller than the standard exposure is used as a single noise reduction image data. An image pickup method comprising: synthesizing and outputting the synthesized image data for noise reduction as image data picked up under an exposure condition having the lowest exposure amount among the image data for main processing. The imaging method according to claim 10.
The number of the pre-processing image data for generating the noise reduction image data is changed according to the sensitivity so that the number of times of imaging increases as the sensitivity is lower in the range where the sensitivity is determined as the low sensitivity. An imaging method characterized by the above. The imaging method according to any one of claims 8 to 11,
The plurality of pieces of main processing image data were imaged under the short-exposure image data imaged under the exposure condition with the lowest exposure amount, the standard exposure image data imaged under the standard exposure condition, and the exposure condition with the highest exposure amount. Consisting of long exposure data,
When the sensitivity of the image sensor is higher than a threshold value, each of the short-time exposure image data, the standard exposure image data, and the long-time exposure data is created by combining a plurality of pre-processing image data. A characteristic imaging method. The imaging method according to claim 12,
“A” is the number of times of capturing preprocessing image data for creating the short-time exposure image data, “B” is the number of times of capturing preprocessing image data for creating the standard exposure image data, and An imaging method characterized by satisfying a relationship of A>B> C, where “C” is the number of times of imaging for obtaining preprocessing image data for creating the long-time exposure data. The imaging method according to claim 13.
Each of the number of imaging times “A”, “B”, and “C” is changed according to the sensitivity so that the number of imaging times increases as the sensitivity is higher in the high sensitivity range. Imaging method.

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