JP2010136224A - Imaging apparatus and imaging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus and imaging method, capable of capturing an image of proper exposure even if lightness of a photographing scene is rapidly changed. <P>SOLUTION: An imaging apparatus includes: a photographing section 120 for sequentially outputting image data for each frame; an exposure condition setting section 160 for sequentially setting image data of continuous at least three frames output sequentially as a set of images, setting photographing of at least one frame in the set of images to a first exposure condition and setting photographing of other at least two frames in the set of images to a second exposure condition; and an exposure amount detecting section 140 for detecting an exposure amount of first image data photographed under the first exposure condition and output and an exposure amount of second image data photographed under the second exposure condition and output. When setting the first and second exposure conditions for any optional one set of images, the exposure condition setting section sets the first and second exposure conditions in accordance with the exposure amounts of first and second image data in one set of images preceding by one or more sets. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging apparatus and an imaging method.

  A subject (shooting scene) photographed by the imaging apparatus may have a wide dynamic range (ratio of the brightest part to the darkest part of the subject). At this time, if the dynamic range allowable by the image sensor provided in the imaging device such as a digital still camera or a video camera is narrow, a subject having a wide dynamic range cannot be photographed as it is. At this time, since the exposure is not appropriate, the dark part of the photographed image is crushed black or the bright part is white.

  In view of this, there has been disclosed a technique for photographing one image with a wide dynamic range by performing multiple exposure in one photographing. For example, Patent Document 1 discloses an imaging device that performs two shootings, that is, shooting of a high-luminance portion and shooting of a low-luminance portion. The imaging device has different exposure conditions for the high-luminance portion and the low-luminance portion. Shoot with.

  Further, the technique of Patent Document 2 combines information on the dynamic range of a subject under a plurality of exposure conditions before actual photographing, and detects peaks in a high luminance part and a low luminance part from a luminance histogram of the combined information. . Then, an exposure condition suitable for each of the high luminance part and the low luminance part is set, and the main photographing is performed. Further, Patent Document 3 discloses a technique for determining exposure condition candidates for the (N + 1) -th shooting from the shooting results before the N-th shooting.

JP 7-298142 A JP 2002-135648 A JP 2006-333229 A

  However, even if the technology using conventional multiple exposure is used, when the brightness of the shooting scene changes suddenly, for example, when shooting indoors and sunlight suddenly enters the room It took time until the exposure conditions of the imaging apparatus followed the optimum value. In other words, in order for the imaging apparatus to detect optimal exposure conditions, it is necessary to change the aperture, shutter, and the like little by little. As a result, when the brightness of the shooting scene changes abruptly, there has been a problem that the image becomes white for a while and the image becomes black when the exposure is under exposure.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to obtain an image with appropriate exposure even when the brightness of a shooting scene changes abruptly. It is another object of the present invention to provide a new and improved imaging apparatus and imaging method.

  In order to solve the above-described problems, according to an aspect of the present invention, an imaging unit that performs imaging for each frame in the time axis direction and sequentially outputs image data for each frame, and at least three consecutive outputs that are sequentially output. The frame image data is sequentially set as one image set, at least one frame of the one image set is set as the first exposure condition, and at least two other frames of the one image set are set. An exposure condition setting unit that sets shooting to a second exposure condition that is different from the first exposure condition, an exposure amount of the first image data that is shot and output under the first exposure condition, and a second exposure condition An exposure amount detection unit that detects the exposure amount of the captured and output second image data is provided, and the exposure condition setting unit determines the first exposure condition and the second exposure condition of an arbitrary set of images. One or more when setting There is provided an imaging apparatus for setting the first exposure condition and the second exposure condition in accordance with the exposure amount of the first image data and the exposure amount of the second image data detected in the one image set. The

  According to the detected exposure amount, at least two frames of the image set of one set are combined to generate one frame of combined image data, and one combined image data is output from the one set of images. You may further have an image composition part to perform.

  An image selection unit that selects at least one frame of image data from one set of image sets according to the detected exposure amount and outputs one image data based on the selected one frame of image data. You may have.

  The exposure condition setting unit sets shooting of at least one frame out of shooting of at least two frames set as the second exposure condition to a third exposure condition having an exposure amount larger than that of the first exposure condition, The photographing of one frame may be set to a fourth exposure condition where the exposure amount is smaller than the first exposure condition.

  The third exposure condition and the fourth exposure condition may be determined according to the first exposure condition.

  When a plurality of frames are captured for the frame set as the first exposure condition in the one image set, the first exposure condition set for each frame may be different.

  In order to solve the above-described problem, according to another aspect of the present invention, a step of photographing every frame in the time axis direction and sequentially outputting image data for each frame, and sequentially output sequentially The step of sequentially setting at least three frames of image data as one set of images, the shooting of at least one frame of one set of images as a first exposure condition, and the other of one set of images Setting a second exposure condition different from the first exposure condition for photographing at least two frames, an exposure amount of the first image data photographed and output under the first exposure condition, and a second exposure condition The step of detecting the exposure amount of the second image data photographed and output in step 1, and the step of setting the first exposure condition and the second exposure condition of an arbitrary set of images is one or more. There is provided an imaging method for setting the first exposure condition and the second exposure condition in accordance with the exposure amount of the first image data and the exposure amount of the second image data detected in the one image set. The

  In accordance with the detected exposure amount, a step of generating image data of one frame by combining image data of at least two frames of a set of image sets, and one composite image data from the set of image sets May be further included.

  According to the present invention, it is possible to obtain an image with appropriate exposure even when the brightness of a shooting scene changes abruptly.

Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol. The description will be given in the following order.
1. First Embodiment [Configuration of First Embodiment]
[Configuration of Control Unit 113]
[Operation of First Embodiment]

<1. First Embodiment>
[Configuration of First Embodiment]
The imaging apparatus 100 according to the present embodiment is not limited to a digital still camera in which the imaging lens 114 is replaceable or not interchangeable. The imaging apparatus 100 can be applied to an apparatus having an imaging function such as a video camera, a camcorder, a mobile phone, or a PDA (Personal Digital Assistants). In addition, the imaging apparatus 100 according to the present embodiment can be applied to a processing apparatus or a recording apparatus that processes an imaging signal from a small camera such as a videophone or game software connected to a personal computer or the like.

  In addition, each processing function of the imaging apparatus 100 described later can be implemented by hardware or software. Further, the image processing described in this specification is processing for R, G, and B of input data (RAW data) in signal processing of the imaging apparatus 100. Hereinafter, in the present embodiment, a case where Bayer array RAW data is employed will be described.

  First, the configuration of the imaging apparatus 100 according to the present embodiment will be described. FIG. 1 is a block diagram illustrating an imaging apparatus 100 according to the present embodiment.

An imaging apparatus 100 shown in FIG. 1 is a video camera capable of recording video data on a storage medium.
The imaging apparatus 100 includes, for example, an image sensor 101, a preprocessing unit 102, a camera signal processing unit 103, a conversion processing unit 104, a compression / decompression unit 105, a memory control unit 106, a memory 107, and display processing. Unit 108, compression / decompression unit 109, recording device control unit 110, recording device 111, display unit 112, control unit 113, imaging lens 114, and the like.

  The imaging lens 114 is a lens group that collects incident light from a subject and forms a subject image on an image sensor 101 described later.

  The image sensor 101 converts incident light from a subject captured via an optical system (for example, including an imaging lens 114, an infrared filter, an optical low-pass filter, etc.) into an electrical signal by photoelectric conversion. For example, a CMOS (Complementary Metal Oxide Semiconductor) type image sensor is used as the image sensor 101. In the case of a CMOS image sensor, photodiodes, row / column selection MOS transistors, signal lines and the like are two-dimensionally arranged to form a vertical scanning circuit, a horizontal scanning circuit, a noise removal circuit, a timing generation circuit, and the like. Note that a CCD (Charge Coupled Device) may be used as the image sensor 101.

  Further, the image sensor 101 reads out a signal at a frame rate of 30 fps (field / second), for example. The image sensor 101 may read a signal at a high speed at a frame rate of 30 fps or higher, for example, 120 fps, which is four times the normal rate. The image sensor 101 includes a CDS (Correlated Double Sampling) and an A / D converter, and imaging data is output from the image sensor 101.

  The preprocessing unit 102 performs optical correction processing such as shading correction on the imaging data output from the image sensor 101 and outputs a digital image signal.

  The camera signal processing unit 103 performs camera signal processing such as synchronization processing, white balance correction, aperture correction, gamma correction, and YC generation on the imaging data from the preprocessing unit 102.

  The conversion processing unit 104 performs display thinning and size adjustment for converting the image signal received from the camera signal processing unit 103 into a frame rate and a screen size suitable for display on the display unit 112. Note that display thinning is performed when output to the display processing unit 108. The display thinning is to thin out the fields so as to match the number of fields per unit time (for example, 30 fps) defined in the display standard of the display device that displays an image when the imaging device 100 is in the high-speed imaging mode. .

  The compression / decompression unit 105 performs compression coding processing on the captured image data from the conversion processing unit 104 using a still image coding method such as JPEG (Joint Photographic Experts Group) standard. Further, decompression decoding processing is performed on the encoded data of the still image supplied from the memory control unit 106. The memory control unit 106 controls writing and reading of image data with respect to the memory 107. A memory 107 is a FIFO (First In First Out) buffer memory that temporarily stores image data received from the memory control unit 106. The memory 107 is, for example, an SDRAM (Synchronous Dynamic Random Access Memory).

  The display processing unit 108 generates an image signal to be displayed on the display unit 112 from the image signal received from the conversion processing unit 104 or the compression / decompression unit 109, sends the image signal to the display unit 112, and displays the image. Let The display unit 112 includes, for example, an LCD (Liquid Crystal Display), and displays a camera-through image being captured, an image of data recorded in the recording device 111, and the like.

  The compression / decompression unit 109 performs compression coding processing on the image data received from the conversion processing unit 104 using a moving image coding method such as MPEG (Moving Picture Experts Group). Further, decompression decoding processing is performed on the encoded data of the moving image supplied from the recording device 111 and output to the display processing unit 108. The display unit 112 displays the moving image received from the display processing unit 108.

  The control unit 113 is, for example, a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The control unit 113 comprehensively controls each component of the imaging apparatus 100 by executing a program stored in a ROM or the like.

[Configuration of Control Unit 113]
Next, the control unit 113 in the imaging apparatus 100 of the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram illustrating a partial configuration of the imaging apparatus 100 according to the present embodiment.

  The control unit 113 of the imaging apparatus 100 according to the present embodiment includes, for example, an image storage unit 130, an image composition unit 140, an image processing unit 150, an exposure condition setting unit 160, and the like as illustrated in FIG. The control unit 113 receives image information from the image capturing unit 120. The image capturing unit 120 is a functional block including the above-described image sensor 101, pre-processing unit 102, and camera signal processing unit 103. The image capturing unit 120 is an example of a photographing unit.

  The image storage unit 130 temporarily stores the image information received from the image capturing unit 120. The image composition unit 140 synthesizes image information for a plurality of sheets received from the image storage unit 130. The image processing unit 150 converts image information into a displayable signal or a signal that can be compressed or recorded, and the converted signal is converted into a conversion processing unit 104, a compression / decompression unit 105, a memory control unit 106, and a display processing unit 108. And sent to the compression / decompression unit 109 and the like.

  The exposure condition setting unit 160 sequentially sets image data of at least three consecutive frames that are sequentially output as one image set. Further, the exposure condition setting unit 160 sets at least one frame of the set of image sets as the first exposure condition, and sets at least the other two frames of the set of image sets as the first exposure. A second exposure condition different from the condition is set.

  Further, the exposure condition setting unit 160 sets the first exposure condition and the second exposure condition of an arbitrary set of image sets, and the first detected in one or a plurality of previous sets of images. The first exposure condition and the second exposure condition are set according to the exposure amount of the image data and the exposure amount of the second image data.

  The exposure condition setting unit 160 sets the shooting of at least one frame out of the shooting of at least two frames set as the second exposure condition to the third exposure condition having a larger exposure amount than the first exposure condition. Further, the exposure condition setting unit 160 may set the shooting of at least one other frame to a fourth exposure condition that has a smaller exposure amount than the first exposure condition. Further, the third exposure condition and the fourth exposure condition may be determined according to the first exposure condition. When a plurality of frames are captured for the frame set as the first exposure condition in the one set of images, the first exposure condition set for each frame may be different.

  The image composition unit 140 is an example of an exposure amount detection unit. The exposure amount of the first image data photographed and output under the first exposure condition and the second image photographed and output under the second exposure condition. The exposure amount of image data is detected. The image composition unit 140 includes an image selection processing unit 144 that is an example of an image selection unit. The image selection processing unit 144 selects at least one frame of image data from one image set according to the detected exposure amount, and selects one image data based on the selected one frame of image data. Output. The image composition unit 140 synthesizes image data of at least two frames of one set of image sets according to the detected exposure amount to generate one frame of composite image data, and generates one set of image data from the set of image sets. One piece of composite image data may be output. In a plurality of image sets continuous in the time axis direction, moving image can be formed by outputting image data or synthesized image data one by one from one set of images.

[Operation of First Embodiment]
Next, the operation of the imaging apparatus 100 according to the present embodiment will be described with reference to FIG.
First, the image capturing unit 120 sequentially outputs image data of N frames (N> 2) in one image set. The number N of frames output to one image set is set in the exposure condition setting unit 160.

  The sequentially output image information for a plurality of sheets is once sent to the subsequent image storage unit 130 and stored therein. Then, when N pieces of image information or pixel information are prepared, the image information is output to the image composition unit 140. The image composition unit 140 analyzes the N pieces of image information sent from the image storage unit 130, creates an image with a wide dynamic range, and sends the image to the subsequent image processing unit 150. At the same time, the image composition unit 140 sends the shooting state of N images to the exposure condition setting unit 160. The exposure condition setting unit 160 sets new exposure conditions based on the shooting state of N images.

  Hereinafter, a method for setting exposure conditions in the imaging apparatus 100 that performs multiple exposures of N (N> 2) or more using the imaging apparatus 100 of the present embodiment will be described. As an example, a case where N = 4 will be described. 4 to 9 are graphs showing temporal changes in the exposure amount at a certain point on the image sensor 101.

  In a normal shooting scene, if there are one or two images, the entire dynamic range of the shooting scene can be reproduced. Therefore, when the dynamic range of the image sensor 101 is narrow, this embodiment is applied, and as shown in FIG. 4, a set of four frames is used as a set of images, and a predetermined shutter speed is set for each frame. Keep it.

  As a specific example, FIG. 4 shows a temporal change in the exposure amount of the image sensor 101 when the image capturing unit 120 acquires an image at 120 fps and then the image composition unit 140 outputs a composite image at 30 fps.

  Since four images are used to shoot one shooting scene, each frame at the time of shooting each image is set to S1, S2, S3, and S4 in time order. Here, S2 and S3 are set as exposure conditions for normal shooting scene shooting. Then, S1 is set as an exposure condition to cope with a case where the shooting scene is suddenly brightened, and S4 is a case where the shooting scene is suddenly darkened. Therefore, S1 has a shorter shutter speed than S2 and S3, and S4 has a longer shutter speed than S2 and S3.

  FIG. 4 shows an example of shooting a normal shooting scene. In this case, since S2 and S3 are appropriate exposure conditions for shooting a normal shooting scene, an appropriate exposure amount is obtained. On the other hand, since S1 is an exposure condition for a bright shooting scene, the exposure amount is small. Further, since S4 is an exposure condition for a dark shooting scene, the exposure amount is saturated.

  Here, when the dynamic range of the shooting scene is narrow, the entire dynamic range of the shooting scene can be reproduced with one image. In such a case, S2 and S3 may have the same shutter speed. In this case, since exactly the same shooting scene is shot for the two images, S / N can be improved by superimposing the two images. That is, since noise is randomly generated in the image, the noise can be reduced by superimposing a plurality of images.

  When shooting a normal shooting scene, if the shooting scene suddenly becomes bright, the exposure condition cannot be changed suddenly according to the brightness. Therefore, for example, as shown in FIG. 5, the exposure amount of each image is saturated in S2 to S4. However, S1 has a shorter shutter speed than S2 and S3. Therefore, it is possible to take a picture with an appropriate exposure amount in S1. Accordingly, as image data output from one image set, if the information of S1 is selected, there is no problem because an appropriately exposed image is output.

  Conversely, when shooting a normal shooting scene, even if the shooting scene suddenly becomes dark, the exposure condition cannot be changed suddenly according to the brightness. Therefore, as for the exposure amount of each image, for example, as shown in FIG. However, the shutter speed of S4 is longer than that of S2 and S3. Therefore, it is possible to take a picture with an appropriate exposure amount in S4. Accordingly, as the image data output from one image set, if the information in S4 is selected, there is no problem because an appropriately exposed image is output.

  Also, unlike the case shown in FIG. 4, when the dynamic range of the normal shooting scene cannot be accommodated by one image, the shutter speeds of S2 and S3 are finely adjusted as shown in FIG. Either one is made longer or shorter than the other. This makes it possible to cover a wider dynamic range of the shooting scene than when the shutter speeds of S2 and S3 are the same.

  In this case, if the images of S2 and S3 are taken at close shutter speeds, the S / N can be improved by superimposing pixels that are taken in an appropriate exposure state in both images. Good.

  When the dynamic range of the shooting scene further expands, the shooting scene may be shot using three frames S1 to S3 as shown in FIG. Then, using S4 whose shutter speed is longer than S1 to S3, a case where the shooting scene suddenly becomes dark is prepared. Conversely, the shooting scene may be shot using three frames from S2 to S4. Then, using S1, which has a shutter speed shorter than S2 to S4, prepares for a case where the shooting scene suddenly becomes brighter. Whether to use the three frames from S1 to S3 or the three frames from S2 to S4 can select two methods by determining whether the photographic scene is entirely bright or dark.

  When the dynamic range is further expanded as compared with the example shown in FIG. 8, the photographing scene may be photographed using four frames S1 to S4.

  Here, processing when the brightness of an image is concentrated near the upper limit or lower limit of the dynamic range of the image sensor 101 will be described. Here, FIG. 9 illustrates the case where the brightness of the image is concentrated near the lower limit of the dynamic range of the image sensor 101, that is, the case where the entire image becomes dark. When the shooting scene becomes dark, S2 to S4 are set to the same shutter speed. Then, by superimposing the frames obtained in S2 to S4, it is possible to obtain a single image with improved S / N. In S1 other than S2 to S4, an exposure condition is set as a preparation for a case where the shooting scene is rapidly brightened. When the shooting scene is rapidly brightened, S2 to S4 are saturated. However, since S1 is appropriate exposure, one appropriate image can be obtained from one image set.

  On the other hand, although not shown, when the shooting scene becomes bright, S1 to S3 are set to the same shutter speed. Then, by superimposing the frames obtained from S1 to S3, it is possible to obtain a single image with improved S / N. In S4 other than S1 to S3, an exposure condition is prepared as a preparation for a case where the shooting scene is suddenly darkened. When the shooting scene becomes dark rapidly, S1 to S3 are underexposed. However, since S4 is an appropriate exposure, an appropriate image can be obtained from a set of images.

  Next, setting examples of S1 and S4 will be described. In S1 and S4, an exposure condition corresponding to a sudden change in brightness of the shooting scene is set. Thereby, even when there is a sharp change in brightness in the shooting scene, an image with appropriate exposure can be shot.

  S1 is set to correspond to a bright image. Therefore, for example, there is a method of setting the shortest shutter speed that can be set by the imaging apparatus 100. However, the upper limit of brightness may be known depending on the shooting scene. Therefore, the exposure condition corresponding to the upper limit value of brightness may be set manually. On the basis of appropriate exposure conditions, the shutter speed of S1 is set to a parameter 1 / X times (X> 1) the shutter speed of the appropriate exposure conditions (for example, X is a fixed value and X = 10 or the like) It may be given in advance.

  Similarly, S4 may be set to the longest shutter speed that can be set by the imaging apparatus 100. Further, the exposure conditions may be manually given in advance. Alternatively, on the basis of an appropriate exposure condition, a parameter (for example, Y is a fixed value and a value such as Y = 10) that is Y times the appropriate exposure condition (Y> 1) is given in advance as the shutter speed in S4. Also good.

  Next, the processing operation of the imaging apparatus 100 when the brightness of the photographic scene has changed suddenly will be described.

  As an example, a case will be described in which the shooting scene suddenly becomes dark. When a normal shooting scene is shot, if the shooting scene suddenly becomes dark, the images of S2 and S3 that have been suitable until then become too dark, resulting in insufficient exposure and failure. On the other hand, when the shooting scene becomes dark suddenly, S4 is an appropriate exposure, so that an easy-to-view shooting scene can be shot by adopting the image of S4.

  In the next image shooting, S2 and S3 are set to values close to S4 when the shooting scene becomes dark. In S4 at the next image shooting, the shutter speed is changed to a longer shutter speed.

  Next, a method for changing the shutter speed will be described with reference to FIGS. 2 and 3 together with examples of the image composition method of S1 to S4. FIG. 3 is a block diagram illustrating a partial configuration of the imaging apparatus 100 according to the present embodiment.

  First, as shown in FIG. 2, the image acquired by the image capturing unit 120 is temporarily stored in the image storage unit 130. This is to make it possible to simultaneously use image information of four images captured at different shutter speeds included in one image set.

  Then, when the image information for four sheets is prepared, the image information is sent to the image composition unit 140. In the image composition unit 140, the image coefficient correction processing unit 142 shown in FIG. 3 performs coefficient correction on the images of S1 to S4 taken at different shutter speeds based on coefficients obtained by reversing the shutter speed. To do. For example, the coefficient is large when the shutter speed is short, and is small when the shutter speed is long. Such a coefficient is applied to the pixel information of each image to be corrected. The image coefficient correction processing unit 142 sends the corrected image information to the image selection processing unit 144.

  Next, the image selection processing unit 144 selects one or more pieces of image information having an appropriate exposure amount from the corrected four image information values. Then, the image selection processing unit 144 outputs the selected image information to the image processing unit 150. Here, when a plurality of pieces of image information are selected, the image selection processing unit 144 outputs one value by performing an averaging process on the value of the image information. If the noise added to the image is random, the image S / N can be improved by performing an averaging process.

  On the other hand, the image information accumulation processing unit 146 accumulates exposure related information regarding the four pieces of input image information. As the exposure related information, for example, the following can be considered. (1) Which of S1 to S4 is selected in the image selection processing unit 144, (2) Distribution of values of each of S1 to S4, and the like. The exposure related information is sent to the exposure condition setting unit 160 in FIG.

  The exposure condition setting unit 160 sets the shutter speeds (exposure conditions) of S1 to S4 used in the subsequent one image set. First, (1) depending on which of S1 to S4 is selected in the image selection processing unit 144, the most frequently selected shutter speed is set as the optimum exposure condition from the next time, and is arranged in S2 or S3. Then, S1 and S4 are determined by the setting means as described above. Also, (2) fine adjustment of the shutter speed is performed using the distribution of values of each of S1 to S4. For example, if the distribution of S2 values is biased toward the dark side, the shutter speed of S2 is increased. At that time, if the bright side of S2 is expected to be saturated, it can be dealt with by maintaining or shortening the shutter of S3.

  In addition, although the exposure of S1-S4 in FIGS. 4-9 was displayed in order with the short shutter speed in the time-axis direction, there is no dependence on these order. However, from the viewpoint of improving the S / N, the two images to be superimposed (for example, when the number of frames N in one image set is N = 4) should be adjacent to each other because it is better that there is no time difference. It is desirable.

In the above-described embodiment, the case where the number N of frames in one image set is N has been mainly described, but the present invention is not limited to such an example.
For example, when the number of frames in one image set is N = 3, one image (one frame) can be captured under appropriate exposure conditions. The exposure conditions for the other two frames are such that the shutter speed is made longer or shorter than the appropriate exposure conditions. As a result, although the S / N cannot be improved, it can cope with a rapid change in brightness.

  Further, when the number of frames N> 4 in one set of images is set to N-2 images to be captured under appropriate exposure conditions, further improvement in S / N can be achieved.

  As described above, according to the present embodiment, when continuous image sets are output, multiple exposures of three or more frames are performed in one image set. By setting the exposure condition of each frame according to the shooting scene, even when the brightness of the shooting scene changes abruptly, the exposure amount can be adjusted instantaneously. In addition, S / N can be improved by superimposing images of frames with close shutter speeds.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

1 is a block diagram illustrating an imaging apparatus according to a first embodiment of the present invention. It is a block diagram which shows the structure of a part of imaging device which concerns on the same embodiment. It is a block diagram which shows the structure of a part of imaging device which concerns on the same embodiment. It is a graph which shows the time change of the exposure amount of a certain point on an image sensor. It is a graph which shows the time change of the exposure amount of a certain point on an image sensor. It is a graph which shows the time change of the exposure amount of a certain point on an image sensor. It is a graph which shows the time change of the exposure amount of a certain point on an image sensor. It is a graph which shows the time change of the exposure amount of a certain point on an image sensor. It is a graph which shows the time change of the exposure amount of a certain point on an image sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Imaging device 101 Image sensor 102 Pre-processing part 103 Camera signal processing part 104 Conversion processing part 105,109 Compression / decompression part 106 Memory control part 107 Memory 108 Display processing part 110 Recording device control part 111 Recording device 112 Display part 113 Control part DESCRIPTION OF SYMBOLS 114 Imaging lens 120 Image pick-up part 130 Image preservation | save part 140 Image composition part 142 Image coefficient correction process part 144 Image selection process part 146 Image information storage process part 150 Image processing part 160 Exposure condition setting part

Claims (8)

An imaging unit that performs imaging for each frame in the time axis direction and sequentially outputs image data for each frame;
The sequentially output image data of at least three frames that are sequentially output are sequentially set as one set of images, and at least one frame of the one set of images is set as a first exposure condition, and the one set of images is set. An exposure condition setting unit that sets a second exposure condition different from the first exposure condition for photographing at least two other frames of the image set;
An exposure amount detector for detecting an exposure amount of the first image data photographed and output under the first exposure condition, and an exposure amount of the second image data photographed and output under the second exposure condition; ,
Have
The exposure condition setting unit detects the one or a plurality of previous image sets detected when setting the first exposure condition and the second exposure condition of any one set of image sets. An imaging apparatus that sets the first exposure condition and the second exposure condition according to an exposure amount of the first image data and an exposure amount of the second image data.   According to the detected exposure amount, at least two frames of the one set of image sets are combined to generate one frame of combined image data, and one combined image is generated from the one set of images. The imaging apparatus according to claim 1, further comprising an image composition unit that outputs data.   An image selection unit that selects at least one frame of image data from the one set of images according to the detected exposure amount and outputs one image data based on the selected one frame of image data. The imaging device according to claim 1, further comprising:   The exposure condition setting unit sets at least one frame shooting out of at least two frames shooting set as the second exposure condition to a third exposure condition having an exposure amount larger than the first exposure condition, The imaging device according to any one of claims 1 to 3, wherein the photographing of at least one frame is set to a fourth exposure condition having an exposure amount smaller than that of the first exposure condition.   The imaging apparatus according to claim 4, wherein the third exposure condition and the fourth exposure condition are determined according to the first exposure condition.   The first exposure condition set for each of the frames is different when shooting of a frame set for the first exposure condition in the one set of images is a plurality of frames. The imaging device according to any one of 5. Photographing every frame in the time axis direction and sequentially outputting image data for each frame;
Sequentially setting the sequentially output image data of at least three frames as a set of images;
Shooting of at least one frame of the one set of images is set as a first exposure condition, and shooting of at least two other frames of the one set of images is different from the first exposure condition. A step for setting exposure conditions;
Detecting the exposure amount of the first image data photographed and output under the first exposure condition, and the exposure amount of the second image data photographed and output under the second exposure condition;
Have
The step of setting the first exposure condition and the second exposure condition of any one set of image sets includes the step of setting the first image data detected in one or a plurality of previous image sets. An imaging method, wherein the first exposure condition and the second exposure condition are set according to an exposure amount and an exposure amount of the second image data. Generating at least two frames of image data of the one set of images to generate one frame of combined image data according to the detected exposure amount;
Outputting one piece of the composite image data from the one set of images;
The imaging method according to claim 7, further comprising:

Images