JP2016134655A - Imaging device, control method of imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device capable of acquiring shading image data allowing highly accurate correction when reproducing a captured image, and recording without wasting the recording capacity, and to provide a control method of the imaging device.SOLUTION: A throttle section 2, an imaging section 3, and a gain processing section 5 perform imaging according to set imaging conditions. A system control section 8 set the imaging conditions via a throttle control section 10, a storage time control section 11 and a gain control section 12. Furthermore, the system control section 8 records the captured image data and the imaging conditions at the time of capturing that image in a recording section 7, and after ending the capturing of all frames, controls the imaging section 3 in the shading state to acquire the shading image data captured under the set imaging conditions, and records the shading image data, as the black image data for correction, in the recording section 7 together with the information of imaging conditions.SELECTED DRAWING: Figure 1

Description

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

  In recent years, as the exposure time is increased and the ISO sensitivity is increased, the influence of scratches and dark current noise on the image sensor on the image quality is increasing. As an effective method for removing scratches and dark current noise, a technique called “black drawing” is known. In blacking, every time a subject or the like is actually photographed (hereinafter referred to as “main photographing”), a light-shielded image is photographed under the same conditions as when the subject was exposed, and the difference between the main photographed image and the light-shielded image is obtained. This is a method for removing scratches and dark current components. The black-drawing technique is generally used for still images, and is rarely used for moving images. This is because, when blacking is performed on a moving image, it is necessary to alternately perform imaging for main shooting and imaging for a light-shielded image. In other words, if the imaging for the main shooting and the imaging for the light-shielded image are performed for each frame, the dynamic resolution is lowered, and the power consumption increases because the light-shielding member is operated for each frame, and the processing load increases. .

  On the other hand, Patent Document 1 acquires a light-shielded image when the power is turned on, multiplies the light-shielded image by a dark correction coefficient according to shooting conditions such as temperature and accumulation time, and uses the light-shielded image after the multiplication to perform black subtraction. A technique for reducing scratches and dark current noise by performing is disclosed. According to the technique described in Patent Document 1, it is only necessary to acquire a light-shielded image for one sheet when the power is turned on, so that it is not necessary to reduce the dynamic resolution, and it is not necessary to operate the light-shielding member every frame. Therefore, increase in power consumption and processing load can be suppressed. In Patent Document 2, flaw data and dark current data are stored in a non-volatile memory in a matrix form using temperature and accumulation time as parameters, and flaw data corresponding to the conditions of temperature and accumulation time at the time of actual photographing are described. A technique for reading out dark current data and using it for correction is disclosed. According to the technique described in Patent Document 2, it is possible to eliminate a decrease in dynamic resolution and suppress an increase in power consumption.

JP 2001-28713 A JP 2008-187255 A

  However, in the case of the technique described in Patent Document 1, since the shaded image for blacking is generated by uniformly multiplying the shaded image by a dark correction coefficient stored in advance, the shaded image is corrected with high accuracy depending on the characteristics of the scratch. There are cases where it is not possible. In the case of the technique described in Patent Document 2, it is necessary to store a large amount of table data, and the capacity of the nonvolatile memory becomes unnecessarily large, resulting in an increase in cost.

  The present invention has been made in view of such problems, and can acquire a light-shielded image that can be corrected with high accuracy when a frame image of a moving image is reproduced, and wastes recording capacity. An object of the present invention is to provide an imaging apparatus capable of recording without any problem and a control method thereof.

  The imaging apparatus according to the present invention includes an imaging unit that captures each frame image under imaging conditions set for each frame of the moving image, and the imaging condition that is set for each frame, An imaging control unit that performs imaging, frame image data captured by the imaging unit, and information on imaging conditions set by the imaging control unit when the imaging unit captures the frame image are associated with each other. Recording control means for recording on a recording medium, and the imaging control means captures the moving image to the imaging means in a light-shielded state after the imaging of the moving image by the imaging means is completed. The recording control unit performs imaging corresponding to each imaging condition used at the time of shooting, and the recording control unit captures data of each light shielding image obtained by imaging by the imaging unit in the light shielding state, and captures each light shielding image. It said imaging control means in correspondence with the information of each photographing condition is set when the in, characterized in that to record on the recording medium.

  According to the present invention, it is possible to acquire a light-shielded image that can be corrected with high accuracy when a frame image of a moving image is reproduced, and to record without wasting recording capacity.

It is a figure which shows the main structures of the imaging device of embodiment. It is a flowchart which shows the flow of control after power-on in an imaging device. It is a figure used for description of the recording state with respect to the frame count number and imaging conditions. It is explanatory drawing of the memory | storage operation | movement (1st-3rd frame) of an imaging condition memory | storage part. It is explanatory drawing of the memory | storage operation | movement (after 300th frame) of an imaging condition memory | storage part. It is explanatory drawing of the count frequency | count of the imaging condition of the 301st frame. It is explanatory drawing of the count frequency | count of the imaging condition of the 302nd frame. It is explanatory drawing when the imaging conditions for all the frames are counted. It is a figure used for description of the black image acquisition number for every imaging condition.

<First Embodiment>
Hereinafter, the imaging apparatus according to the first embodiment will be described. FIG. 1A is a schematic diagram illustrating a main configuration of the imaging apparatus according to the first embodiment. The imaging device of the present embodiment is an imaging device that can capture and record a moving image. A description of the configuration of FIGS. 1B and 1C will be given later. In FIG. 1A, the lens 1 forms an optical image of a subject or the like on the light receiving surface of the imaging unit 3. The imaging unit 3 includes an imaging element such as a CCD sensor or a CMOS sensor, and photoelectrically converts an optical image formed on the light receiving surface. The imaging unit 3 outputs an electrical analog imaging signal generated by photoelectric conversion to an AFE (analog front end) unit 4. The AFE unit 4 includes a CDS (correlated double sampling) circuit and an A / D (analog / digital) conversion circuit therein. The CDS circuit in the AFE unit 4 takes the difference between the signal level of the analog imaging signal and the reference level, and outputs a signal represented by an analog voltage value in a state where noise components are removed from the analog imaging signal. The A / D conversion circuit in the AFE unit 4 converts the signal represented by the analog voltage value output from the CDS circuit into a digital signal. A digital signal from the A / D conversion circuit is sent to the gain processing unit 5 as a digital imaging signal output from the AFE unit 4. The gain processing unit 5 performs gain processing on the digital imaging signal output from the AFE unit 4. The digital imaging signal after the gain processing by the gain processing unit 5 is sent to the imaging condition adding unit 6 and the luminance value calculating unit 9 as image data. The shooting condition adding unit 6 adds to the image data output from the gain processing unit 5 information on shooting conditions when the image is shot. Although details will be described later, the imaging conditions in the present embodiment are conditions for exposure control such as the aperture value of the aperture unit 2, the accumulation time of the imaging unit 3, and the gain value of the gain processing unit 5. The shooting condition adding unit 6 adds shooting condition information including an aperture value, an accumulation time value, and a gain value at the time of image shooting to the image data acquired by the image shooting. The image data to which the shooting condition information is added by the shooting condition adding unit 6 is recorded on the recording medium by the recording unit 7.

  Note that in this embodiment, “addition” of shooting condition information is associated with identification information (ID) that specifies image data, for example, in addition to the case where image pickup condition information is added to image data and recorded. And recorded as table data. Therefore, when the shooting condition information is recorded as table data, the table data is recorded in a recording area different from the area where the image data is recorded on the recording medium. In the present embodiment, the recording medium of the recording unit 7 is a semiconductor memory such as a memory card or a disk-shaped recording medium such as a hard disk, and is a recording medium that can be detached from the imaging apparatus. Therefore, the recording unit 7 includes a slot, a connection connector, and the like in which a recording medium is inserted and removed. In the case of this embodiment, the image data recorded on the recording medium is RAW data that has not been subjected to correction processing such as blackening. Accordingly, in the present embodiment, correction processing such as blacking is performed on the image data read from the recording medium. That is, this embodiment assumes a system in which correction processing is performed during image reproduction.

  A system control unit 8 in FIG. 1A controls the entire system of the imaging apparatus according to the present embodiment. In the present embodiment, the system control unit 8 is an example of an imaging control unit and a recording control unit. Although details will be described later, the system control unit 8 performs control such as exposure control, recording start / end control, counting of shooting conditions at the time of image shooting, and addition of shooting condition information to image data.

  The luminance value calculation unit 9 integrates luminance values of subjects and the like using the image data output from the gain processing unit 5. The area where the luminance value calculation unit 9 integrates the luminance values may be an area near the center of the captured image, or an area of the entire image. The system control unit 8 determines shooting conditions based on the integrated luminance value calculated by the luminance value calculation unit 9, and performs exposure control according to the shooting conditions. The imaging apparatus of the present embodiment includes an aperture control unit 10, an accumulation time control unit 11, and a gain control unit 12 for performing exposure control. The system control unit 8 controls the aperture ratio of the diaphragm unit 2 through the diaphragm control unit 10 and the exposure time of the imaging unit 3 through the accumulation time control unit 11 so that the determined imaging condition is satisfied. Further, the system control unit 8 controls the gain of the gain processing unit 5 via the gain control unit 12 so that the amplification factor of the imaging signal is optimized based on the determined imaging condition.

  The shooting condition storage unit 13 stores the shooting condition information determined by the system control unit 8 for each frame obtained by shooting a moving image. Although details will be described later, the system control unit 8 manages the combination of the accumulation time and the gain among the determined imaging conditions as a matrix table, and temporarily stores the table data in the imaging condition storage unit 13. Then, the system control unit 8 counts the number of shooting conditions for which the combination of the accumulation time and the gain is the same for each shooting condition used when shooting each frame after the recording is started. To update the table data. In other words, the system control unit 8 counts the number of frames in which the shooting conditions are set and the shooting conditions are set, and the combination of the accumulation time and the gain is the same, and counts for each shooting condition. Update table data with the number of frames.

  The recording start / end input unit 14 is used when a photographer inputs an instruction to start or end image shooting, and includes a button-like switch, for example. Here, when the power of the imaging apparatus is turned on, the system control unit 8 causes the imaging unit 3 to start an image capturing operation. However, the system controller 8 starts shooting from the photographer via the recording start / end input unit 14. Until the instruction is input, the recording unit 7 does not record the image data. Then, when an instruction to start shooting is input from the photographer via the recording start / end input unit 14, the system control unit 8 controls the recording unit 7 to start recording image data. On the other hand, when a photographing end instruction is input from the photographer via the recording start / end input unit 14, the system control unit 8 controls the recording unit 7 to end the recording of the photographed image data.

  Hereinafter, the operation of the imaging apparatus according to the present embodiment at the time of image capturing will be described with reference to FIGS. 2, 3, 4 (a) to 4 (e), and 5 (f) to 5 (k). To do. FIG. 2 is a flowchart showing a flow of control by the system control unit 8 from when the image capturing apparatus according to the present embodiment is turned on until image capturing is performed and then the power is turned off. FIG. 3 shows a count number of frame images taken by the image pickup unit 3 after power-on of the image pickup apparatus, “shooting conditions (aperture value, accumulation time, gain)” when each frame image is taken, FIG. 6 is a diagram illustrating a correspondence relationship between “recording state” of a frame image on a recording unit. 4 (a) to 4 (e) and FIGS. 5 (f) to 5 (k), when each frame is imaged under the imaging conditions of FIG. It is a figure which shows a mode that the information of "state" and "imaging condition" is memorize | stored in the imaging condition memory | storage part 13, updating as needed for every frame. 4 (a) to 4 (e) show the system control unit when imaging is performed from the first frame (first frame) to the third frame (third frame) in FIG. 3 after the power is turned on. 8 is a diagram illustrating a state in which information of “recording state” and “imaging condition” is stored in the imaging condition storage unit 13. 5 (f) to 5 (k) show that when the imaging is performed from the 300th frame (300th) to the 902nd frame (902th) in FIG. It is a figure which shows a mode that the information of "imaging conditions" is memorize | stored in the imaging condition memory | storage part 13, updating at any time. Note that when the frame image data is recorded in the recording unit 7, the system control unit 8 stores information indicating “recording” as “recording state” information stored in the imaging condition storage unit 13. On the other hand, when the frame image data is not recorded in the recording unit 7, the system control unit 8 stores information indicating “not recorded” as “recording state” information stored in the imaging condition storage unit 13. In addition, the system control unit 8 sets information indicating “not recorded” as the recording state for each frame until the imaging start instruction is input from the recording start / end input unit 14 after the imaging apparatus is turned on. The information is stored in the imaging condition storage unit 13 together with information on the imaging conditions of the frame. When an instruction to start image shooting is input from the recording start / end input unit 14, the system control unit 8 sets information indicating “record” as the recording state for the frame after the input of the image shooting start instruction. The information is stored in the imaging condition storage unit 13 together with information on the imaging conditions of the frame. Thereafter, when an instruction to end image capturing is input from the recording start / end input unit 14, the system control unit 8 sets information indicating “not record” as the recording state for the frame after the image capturing end instruction is input. The information is stored in the imaging condition storage unit 13 together with information on the imaging conditions of the frame.

  2, when the power of the imaging apparatus is turned on by a power button (not shown in FIG. 1), the system control unit 8 starts control of each unit in the imaging apparatus of FIG. . After step S200, the system control unit 8 advances the control process to step S201. In step S <b> 201, the system control unit 8 temporarily stores information on the recording state in the current frame in the imaging condition storage unit 13. Specifically, the system control unit 8 monitors whether an instruction to start image capturing is input via the recording start / end input unit 14, and “ Either “record” or “not record” information is temporarily stored in the imaging condition storage unit 13. Here, as shown in FIG. 3, since the recording start instruction is not input from the recording start / end input unit 14 in the first frame after the imaging apparatus is turned on, the system control unit 8 changes the recording state to “ The information is “not recorded” and is temporarily stored in the imaging condition storage unit 13. After step S201, the system control unit 8 advances the control process to step S202. As a result, the recording state of the current frame (first frame) stored in the photographing condition storage unit 13 at this time is “not recorded” information as shown in FIG. In step S <b> 202, the system control unit 8 starts the imaging operation of the imaging unit 3. At this time, the system control unit 8 sets the “shooting condition” to a predetermined fixed value for the first frame after the power is turned on. In the example of FIG. 3, the system control unit 8 sets the aperture value of the aperture unit 2 to F4.0 through the aperture control unit 10 as a fixed value, and sets the accumulation time of the imaging unit 3 through the accumulation time control unit 11. The gain of the gain processor 5 is controlled to 0 dB via the gain controller 12. The shooting conditions stored in the shooting condition storage unit 13 at this time are “aperture value is F4.0”, “accumulation time is 1/60 sec”, and “gain is 0 dB” as shown in FIG. Become. Actually, the shooting conditions are controlled so that the exposure is appropriate in the second and subsequent frames. Therefore, the fixed value of the shooting conditions for the first frame may be an arbitrary set value. In step S202, the system control unit 8 causes the imaging unit 3 to output an imaging signal imaged under the imaging conditions illustrated in FIG. 4A, and further performs image processing by the AFE unit 4 and the gain processing unit 5. Make it. After step S202, the system control unit 8 advances the control process to step S203.

  In step S203, the system control unit 8 controls the luminance value calculation unit 9 to calculate an integrated luminance value from the image data after gain processing in the gain processing unit 5. After step S203, the system control unit 8 advances the control process to step S204. In step S204, the system control unit 8 determines shooting conditions for the next frame, that is, the second frame (second frame) in this case. Specifically, as shown in the second frame in FIG. 3, the aperture value is set to F4.0, the accumulation time is set to 1/70 sec, and the gain is determined to be 0 dB. After determining the shooting conditions in step S204, the system control unit 8 advances the control process to step S205. In step S <b> 205, the system control unit 8 temporarily stores the shooting condition information of the next frame (that is, the second frame) in the shooting condition storage unit 13. That is, as shown in FIG. 4B, the system control unit 8 sets “aperture value is F4.0”, “accumulation time 1/70 sec”, “ Information on the imaging condition with a gain of 0 dB is temporarily stored in the imaging condition storage unit 13. After storing the shooting conditions in step S205, the system control unit 8 advances the control process to step S206.

  In step S206, the system control unit 8 performs exposure control so that the image of the second frame is imaged under the imaging conditions determined in step S204. Specifically, the system control unit 8 controls the aperture area of the diaphragm unit 2 through the diaphragm control unit 10 so that the aperture value becomes F4.0, and the accumulation time through the accumulation time control unit 11. The exposure time of the imaging unit 3 is controlled so that becomes 1/70 sec. Further, the system control unit 8 controls the gain of the signal in the gain processing unit 5 through the gain control unit 12 so that the gain becomes 0 dB. In the flowchart of FIG. 2, the system control unit 8 has a procedure of advancing control processing to step S207 after performing exposure control in step S206. However, since exposure control in step S206 includes mechanical control, It may take time. In that case, the system control unit 8 may advance the control process to step S207 while performing the control of step S206.

  When the control process proceeds to step S207, the system control unit 8 records the current frame (first frame) with reference to the recording state information temporarily stored in the imaging condition storage unit 13 in step S201. It is determined whether the frame is a “record” frame. If the system control unit 8 determines in step S207 that the frame is a “record” frame, the control process proceeds to step S208. In step S208, the system control unit 8 counts shooting conditions. However, at this time, as shown in FIG. 4B, since the current frame (first frame) is a frame that is “not recorded”, the system control unit 8 advances the control process to step S211. Details of the flow of steps S208 to S210 will be described later.

  In step S211, the system control unit 8 determines the “recording state” of the previous frame. Here, when the previous frame is a “record” frame, the system control unit 8 advances the control process to step S212. However, in the case of FIG. 4B, the previous frame does not exist. There is no recording status information. Therefore, the system control unit 8 at this time advances the control process to step S214. Details of the flow of steps S212 and S213 will be described later. In step S214, the system control unit 8 determines whether the power of the imaging apparatus is turned off by the power button. If the system control unit 8 determines in step S214 that the power has been turned off, the system control unit 8 advances the control process to step S215. In step S215, the system control unit 8 performs control for turning off the power supply in the imaging apparatus of FIG. On the other hand, when it determines with the power supply not being turned off by step S215, the system control part 8 returns control processing to step S201.

  The above is the control procedure of the system control unit 8 up to the first frame in FIG. Here, the content stored in the imaging condition storage unit 13 at this time is in a state as shown in FIG. At this time, the system control unit 8 rewrites the recording state and shooting conditions of the “current frame” to the recording state and shooting conditions of the “previous frame” for the shooting of the next frame image. Further, the system control unit 8 rewrites the recording state and shooting conditions of “next frame” to the recording state and shooting conditions of “current frame”. The stored contents of the imaging condition storage unit 13 at this time are changed from the state shown in FIG. 4B to the state shown in FIG.

  Next, the control process for the second frame will be described. In the following description, in order to simplify the description, the aperture unit 2, the imaging unit 3, the gain processing unit 5, the control units (10, 11, 12) that control them, the luminance value calculation unit 9, etc. Explanation of the operation is omitted. Similar to the first frame, the second frame will be described with reference to the flowchart of FIG. Here, as shown in FIG. 3, the recording start instruction is not input from the recording start / end input unit 14 even in the second frame. For this reason, in step S201, the system control unit 8 temporarily stores the recording state in the photographing condition storage unit 13 as “not recorded” information. The stored contents of the imaging condition storage unit 13 at this time are in the state shown in FIG. Next, in step S202, the system control unit 8 performs the exposure control in step S206 for the first frame, i.e., the shooting condition in which the aperture value is F4.0, the accumulation time is 1/70 sec, and the gain is 0 dB. To get the image. In step S203, the system control unit 8 calculates a luminance value for the image acquired in step S202, and determines a shooting condition for the third frame in step S204. That is, as shown in FIG. 3, the aperture value in the third frame is F4.0, the accumulation time is 1/80 sec, and the gain is 0 dB.

  The system control unit 8 advances the control process to step S205 after determining the shooting conditions in step S204. In step S205, the system control unit 8 temporarily stores the shooting condition information determined in step S204 in the shooting condition storage unit 13. As shown in FIG. 4E, the stored contents of the shooting condition storage unit 13 at this time are “aperture value is F4.0”, “accumulation time is 1/80 sec”, “ Information with a gain of 0 dB is stored. After storing the shooting conditions in step S205, the system control unit 8 advances the control process to step S206. In step S <b> 206, the system control unit 8 performs exposure control for taking an image of the third frame. Then, after performing the exposure control in step S206, the system control unit 8 advances the control process to step S207.

  In step S207, as in the case of the first frame, the system control unit 8 refers to the recording state information temporarily stored in the imaging condition storage unit 13 in step S201, and the current frame is stored in the recording unit 7. Determine if it is a “record” frame. Here, as shown in FIG. 3, since the second frame is also a “not recorded” frame, the system control unit 8 advances the control process to step S211 as in the case of the first frame. In step S211, the system control unit 8 determines whether the previous frame is a “record” frame. At this time, as shown in FIG. 4E, since the previous frame is a “not recorded” frame, the system control unit 8 advances the control process to step S214. The processing after step S214 is the same as that in the first frame, and the system control unit 8 returns the control processing to step S201 as it is.

  The control procedure of the system control unit 8 up to the second frame in FIG. 3 has been described above. Subsequently, as shown in FIG. 3, since the recording state is “not recorded” until the third frame, the fourth frame,..., The 300th frame, the system control unit 8 sets 2 for each frame. The same processing as that for the frame is performed.

  Subsequently, as shown in FIG. 3, a recording start instruction is input from the recording start / end input unit 14 at the 301st frame, whereby the system control unit 8 starts recording image data in the recording unit 7. . The contents stored in the imaging condition storage unit 13 in the 301st frame are as shown in FIG. That is, in the 301st frame, the system control unit 8 sets a frame to “record” in step S201, and temporarily stores the information in the imaging condition storage unit 13. The stored contents of the imaging condition storage unit 13 at this time are as shown in FIG. In step S202, the system control unit 8 performs shooting conditions determined in step S204 for the 300th frame, that is, shooting conditions with an aperture value of F4.0, an accumulation time of 1/250 sec, and a gain of 0 dB. Let the shoot take place. Furthermore, in step S203, the system control unit 8 calculates a luminance value from the image acquired in step S202. Next, in step S204, the system control unit 8 determines shooting conditions for achieving proper exposure at the 302nd frame. Here, as shown in FIG. 3, the 302nd frame has a proper exposure when the photographing conditions are “aperture value is F4.0”, “accumulation time is 1/220 sec”, and “gain is 0 dB”.

  In step S <b> 205, the system control unit 8 temporarily stores the shooting conditions in the shooting condition storage unit 13. Next, the system control unit 8 performs exposure control in step S206. Note that the contents stored in the imaging condition storage unit 13 at this time are in a state as shown in FIG. After performing exposure control in step S206, the system control unit 8 advances control processing to step S207. In step S207, as in the case of the first to 300th frames, the system control unit 8 refers to the recording state information stored in the shooting condition storage unit 13 in step S201, and the current frame is recorded in the recording unit. 7 determines whether the frame is a “record” frame. Then, as shown in FIG. 5H, since the recording state is the “recording” frame in the 301st frame, the system control unit 8 advances the control process to step S208.

  In step S208, the system control unit 8 counts shooting conditions. Here, a method of counting the shooting conditions will be described using the shooting condition count tables shown in FIGS. 6 to 8 are tables in which the accumulation time and gain among the imaging conditions are arranged in a matrix. The data of the count table is stored in the photographing condition storage unit 13. When the system control unit 8 records the image data in the recording unit 7, the system control unit 8 stores the number of frames in the count table of the shooting condition storage unit 13 that have the same shooting conditions for the combination of the accumulation time and the gain. I will count. FIG. 6 shows a specific example of a table in which shooting conditions are counted in the first frame (301st frame) after the recording state is set to “record”. That is, at the 301st frame, the shooting condition accumulation time is 1/250 sec, and the gain is 0 dB. Therefore, in this case, as shown in FIG. 6, the system control unit 8 counts the shooting conditions corresponding to the accumulation time of 1/250 sec and the gain of 0 dB with respect to the matrix of the count table stored in the shooting condition storage unit 13. The number is changed from “0” to “1”. FIG. 7 shows a specific example of a table in which shooting conditions are counted in the second frame (302th frame) after the recording state is set to “record”. That is, at the 302nd frame, the accumulation time of the shooting conditions is 1/240 sec, and the gain is 0 dB. Therefore, in this case, as shown in FIG. 7, the system control unit 8 sets the count number of the imaging condition corresponding to the accumulation time of 1/240 sec and the gain of 0 dB to “1” to “1” with respect to the count table matrix. Change to Similarly, when the shooting conditions are counted up to all the frames whose recording states are set to “record” (the 301st to 900th frames) and are sequentially updated, a count table of shooting conditions is shown in FIG. It becomes a table like this. In this way, the system control unit 8 updates the table as needed by increasing the count number of the corresponding shooting condition in the count table of the shooting condition storage unit 13 according to the shooting condition for each frame. As a result, the system control unit 8 refers to the count table stored in the shooting condition storage unit 13 to determine which shooting condition was used during image shooting (in actual shooting for actually shooting a subject or the like). It becomes like this.

  Returning to the description of the flowchart of FIG. 2, the system control unit 8 counts the shooting conditions in step S <b> 208, and then advances the control process to step S <b> 209. In step S209, the system control unit 8 controls the shooting condition adding unit 6 to add shooting condition information to the image data. Specifically, since the shooting conditions for the 301st frame are “accumulation time 1/250 sec” and “gain is 0 dB”, the system control unit 8 sends information on the shooting conditions to the shooting condition adding unit 6. It is added corresponding to the image data. The addition in this case may be an addition to the frame image itself, or an addition that is recorded as table data in association with identification information (ID) that identifies the frame image.

  After performing the shooting condition addition control in step S209, the system control unit 8 advances the control process to step S210. In step S210, the system control unit 8 controls the recording unit 7 to record the image data and information on the shooting conditions corresponding to the image data on the recording medium. After performing the recording control in step S210, the system control unit 8 advances the control process to step S214. The processing after step S214 is the same as the processing described above, and the system control unit 8 returns the processing to step S201 as it is.

  The control procedure of the system control unit 8 up to the 301st frame in FIG. 3 has been described above. Subsequently, the system control unit 8 starts photographing the 302nd frame. Since the 302th frame is also a “record” frame as shown in FIG. 3, the system control unit 8 counts the shooting conditions in step S208. Next, the system control unit 8 adds shooting condition information to the image data of the frame in step S209, and further causes the recording unit 7 to record the image data in step S210. After performing the recording control of the image data in step S210, the system control unit 8 advances the process to step S214. If the power is not turned off, the system control unit 8 returns the process to step S201 again.

  The control procedure of the system control unit 8 up to the 302th frame in FIG. 3 has been described above. Subsequently, as shown in FIG. 3, the system control unit 8 performs the same control as described above because it is a “record” frame from the 303th frame, the 304th frame,.

  Next, as shown in FIG. 3, the control process of the system control unit 8 in the 901st frame in which a recording end instruction is input from the recording start / end input unit 14 will be described. The stored contents of the imaging condition storage unit 13 in the 901st frame are as shown in FIG. That is, the system control unit 8 temporarily stores in the photographing condition storage unit 13 that the 901st frame is a “not recorded” frame in step S201. The contents stored in the imaging condition storage unit 13 at this time are in the state shown in FIG. Since the control processing in steps S202 to S206 is the same as that before the 900th frame, description thereof is omitted. In addition, the stored contents of the shooting condition storage unit 13 at this time are as shown in FIG. 5K because the shooting conditions of the 902nd frame are temporarily stored. At this time, the system control unit 8 determines that the recording state is “not recorded” in step S207 after the exposure control in step S206. Then, the system control unit 8 advances the control process to step S211. In step S211, the system control unit 8 determines whether the recording state of the previous frame is “recording”.

  Here, as shown in FIG. 3, since the recording state of the 900th frame, which is the previous frame, is “recording”, the system control unit 8 advances the control process to step S212. That is, at this time, the system control unit 8 shifts to a control process for acquiring a black image that is a light-shielded image. Hereinafter, a control process for obtaining a black image will be described. Here, the description will be made assuming that the count number of the shooting condition at the time of black image acquisition is as shown in the shooting condition count table of FIG.

  When the control process proceeds to step S212, the system control unit 8 refers to the number of shooting conditions counted in step S208 from the table data stored in the shooting condition storage unit 13. And the system control part 8 extracts the information of the imaging condition about the imaging condition in which the counted number of times exists even once. The table of FIG. 8 shows a total of 28 shootings, with 23 accumulation times corresponding to 1/30 sec to 1/250 sec and gain corresponding to 0 dB and 5 corresponding accumulation times of 1/30 sec and gain corresponding to 1 dB to 5 dB. Each condition stores a count number of one or more times. Therefore, the system control unit 8 in this case extracts 28 shooting conditions from the table data in the shooting condition storage unit 13. When the system control unit 8 extracts the shooting conditions from the table data, the system control unit 8 acquires a light-shielded image corresponding to each of the extracted shooting conditions. Specifically, in a light-shielded state in which the aperture section 2 is closed (iris closed), exposure control is performed so as to obtain an accumulation time and gain for each of the extracted photographing conditions, and a light-shielded image corresponding to each photographing condition. To image. Further, the system control unit 8 provides information on the shooting conditions corresponding to each of the light-shielded image data captured by the exposure control corresponding to each of the extracted shooting conditions. It is added and recorded in the recording unit 7. That is, the system control unit 8 performs such exposure control, shooting condition addition control, and shading image data recording control using all the extracted shooting conditions. In the case of the table example of FIG. 8, the system control unit 8 performs the above-described exposure control, addition control of the shooting conditions, and recording control of the light-shielded image data for the extracted 28 shooting conditions. Then, as shown in FIG. 3, the system control unit 8 acquires and records the light-shielded image data to which the shooting condition information is added as described above for 28 frames from the 903th frame to the 930th frame. Let Note that, as described above, the addition of the shooting condition information to the light-shielded image may be added to the light-shielded image itself, or is recorded as table data in association with identification information (ID) that identifies the frame of the light-shielded image. Such addition may be possible. As a result, the recording unit 7 records the data of the light-shielded image captured according to each of the extracted photographing conditions and the information of each photographing condition when the respective light-shielded images are acquired. Therefore, the system control unit 8 refers to the image data recorded in the recording unit 7 and the shooting conditions added to the light-shielded image, so that the light-shielded image data corresponding to the shooting conditions of the recorded image data is obtained. Which light-shielded image data is known.

  Returning to the flowchart of FIG. 2, when the acquisition of the light-shielded image data corresponding to all the imaging conditions extracted in step S212 is completed, the system control unit 8 advances the control process to step S213. In step S213, the system control unit 8 ends the recording control for the recording unit 7. Then, after the recording in step S213 is completed, the system control unit 8 advances the control process to step S214. The processing after step S214 is the same as described above, and the system control unit 8 returns the processing to step S201 as it is. Thereafter, from the 931st frame, the recording state is returned to the [not record] again, and the same control process as that in the first frame is resumed.

  As described above, the image pickup apparatus according to the present embodiment records the light-shielded image data (black image data) corresponding to the photographing conditions of the photographed and recorded image, and reproduces the recorded image data. Blacking can be performed using black image data under the same shooting conditions as when shooting the image. For this reason, the image reproduced from the recorded image data and displayed on the monitor panel is a high-quality image in which scratches are corrected with high accuracy and dark current noise is reduced.

  Next, a method for reproducing image data recorded on a recording medium by the imaging apparatus according to the present embodiment will be briefly described. Although not shown in the drawings, the playback apparatus mainly includes a playback unit of a recording medium, a RAM in which data read from the recording medium is developed, and a recorded image using light-shielded image data (black image data). A correction unit that performs correction processing on data, a system control unit that controls each unit, and the like are provided. When image reproduction is performed, the system control unit of the reproduction apparatus first reads all light-shielded image data from the recording medium and develops it in the RAM. The shaded image data at this time is black image data acquired in accordance with the shooting conditions when the recorded image data is shot as described above. Note that if there is a large number of shaded image data corresponding to the shooting conditions, the capacity of the RAM may be compressed, so it is not necessary to develop all the shaded image data in the RAM. In other words, the shading image data corresponding to the shooting conditions of the recorded image data to be reproduced may be controlled so as to be developed from the recording medium to the RAM as necessary. When the system control unit sequentially reads the recording image data of each frame from the recording medium and starts reproduction, the system control unit refers to the imaging condition added to the recording image data. The system control unit selects black image data corresponding to the referenced shooting condition from the black image data in the RAM. The recorded image data read from the recording medium and the black image data read from the RAM are sent to the correction unit. The correction unit performs a blacking process for generating a difference image by taking the difference between the recorded image data and the black image data acquired under the same shooting conditions as the recorded image data. Then, the difference image data after the blackening processing by the correction unit is output to an image display unit such as a monitor panel. That is, the image displayed on the monitor panel is a high quality image with reduced scratches and dark current noise. Although details regarding the blacking process are omitted, the blacking process may be performed by hardware for generating a difference image between the recorded image data and the black image data, or the difference between all pixels may be calculated by a program. You may perform by calculating and producing | generating a difference image. As described above, according to the present embodiment, at the time of reproduction, the black drawing process using the black image data acquired under the same shooting conditions as when the image data was shot is performed. Noise removal is realized.

  As described above, according to the first embodiment, the black image data to be recorded on the recording medium is only the black image data acquired corresponding to the shooting conditions used at the time of image shooting. As in this embodiment, if black image data corresponding to the shooting conditions when an image is recorded by actual shooting is acquired, the recording capacity is not wasted, and scratches and darkness can be accurately reproduced during playback. Current noise can be removed.

  Here, the imaging apparatus according to the above-described embodiment is compared with the technique described in Patent Document 1, for example. In the case of the technique described in Japanese Patent Laid-Open No. 2004-228561, the shaded image for blacking is generated by multiplying the shaded image by a dark correction coefficient stored in advance, so that correction may not be performed with high accuracy depending on the scratch characteristics. is there. For example, as a characteristic of the image pickup device, it is assumed that the scratch level increases in proportion to the accumulation time when the accumulation time is relatively short, and there is a characteristic scratch such that the rate of change of the scratch level decreases as the accumulation time increases. . In this case, scratches cannot be reduced with high accuracy simply by uniformly multiplying the light-shielded image by the dark correction coefficient disclosed in Patent Document 1. Further, when the scratch level of a certain pixel in the photographed image increases in direct proportion to the accumulation time, but the scratch level does not increase in direct proportion to the scratch of another certain pixel, the correction coefficient is uniformly multiplied. If it is only, the pixel which a correction error produces will come out. In other words, since the correction error may be increased depending on the characteristics of the scratch, it is very difficult to correct the scratch accurately with respect to the scratch of all characteristics. On the other hand, in the case of this embodiment, when reproducing recorded image data, blacking processing using light-shielded image data corresponding to shooting conditions at the time of image shooting can be performed, so that scratches can be corrected with high accuracy, Dark current noise can also be reduced.

  Further, the imaging apparatus of the present embodiment will be compared with the technique described in Patent Document 2, for example. In the case of the technique described in Patent Document 2, it is impossible to predict what shooting conditions will be used at the time of actual shooting. Therefore, if accurate defect correction is performed, a large amount of table data including shooting conditions that are not used for actual shooting will be stored. It is necessary to memorize in advance. For this reason, since a light-shielded image that is not used for actual photographing is also acquired, the capacity of the non-volatile memory is unnecessarily increased and the cost is increased. Some scratch levels change over time, and there are also scratches whose level fluctuates with a relatively long period. For this reason, even under the same shooting conditions (temperature and accumulation time), there is a possibility that the scratch generation state when the table data is acquired and the scratch generation state during the main shooting are different. Even if the shooting conditions for acquiring scratch data and dark current data in advance are the same as the shooting conditions for main shooting, if the scratch level changes over time, a correction error occurs and the scratch correction can be performed with high accuracy. There may not be. If a large amount of table data is updated frequently, the correction accuracy for the temporal change of the scratch level increases. However, since the shading image is frequently re-acquired even under shooting conditions that are not used in actual shooting, the acquired shading image is wasted. there is a possibility. On the other hand, in the case of this embodiment, black image data is acquired immediately after image shooting (immediately after the main shooting). For example, black image data is acquired before the state of a flaw changes due to aging. I can do it. Therefore, according to the present embodiment, it is possible to reduce a defect correction error due to a change with time. In the case of the present embodiment, black image data is acquired after the main shooting, so that the dynamic resolution at the time of the main shooting does not decrease, and the power consumption and the processing load do not increase.

<Second Embodiment>
Next, an imaging apparatus according to the second embodiment will be described. The imaging apparatus according to the second embodiment can realize more accurate scratch reduction. Specifically, the imaging apparatus of the present embodiment acquires a plurality of light-shielded image data when the shooting conditions when acquiring image data are predetermined shooting conditions in which scratches and random noise are easily noticeable, for example. One piece of black image data is generated from a plurality of shaded image data. For this reason, the imaging apparatus according to the second embodiment temporarily accumulates shading image data for a plurality of frames, and generates one piece of black image data by averaging the shading image data for the accumulated frames. It is possible to execute processing for

  FIG. 1B shows only the configuration of the main part of the imaging apparatus according to the second embodiment. The second imaging device illustrated in FIG. 1B also includes the components illustrated in FIG. 1A, but description of the components that overlap those in FIG. 1A is omitted. That is, the imaging apparatus according to the second embodiment includes an image temporary storage unit 16 that temporarily accumulates shaded image data, and an addition average processing unit 17 that adds and averages the accumulated shaded image data of a plurality of frames. Yes. The image temporary storage unit 16 accumulates the light-shielded image data output from the gain processing unit 5 for a plurality of frames under the control of the system control unit 8. The light-shielded image data for a plurality of frames accumulated at this time is data captured by setting the imaging unit 3 in a light-shielded state to predetermined imaging conditions. In addition, the addition average processing unit 17 performs addition average calculation of the light-shielded image data of a plurality of frames read from the image temporary storage unit 16 under the control of the system control unit 8 to obtain one black image data. Generate. Then, the black image data generated by the addition average processing unit 17 is sent to the shooting condition adding unit 6 under the control of the system control unit 8 and the shooting condition information is added in the same manner as described above. To be recorded.

  In the case of the second embodiment, the system control unit 8 controls each unit according to the procedure of the flowchart shown in FIG. 2, similarly to the first embodiment. Since the first embodiment and the second embodiment differ only in the black image acquisition process in step S212, only the process in step S212 will be described below. In the second embodiment, the processing for obtaining black image data in step S212 will be described with reference to FIG. FIG. 9 shows a light-shielded image acquired by a combination of accumulation time and gain set as predetermined photographing conditions when generating one piece of black image data by an averaging process using a plurality of light-shielded image data. Indicates the number of frames. For example, in the case of a predetermined shooting condition in which the gain is 0 dB and the accumulation time is 1/70 sec, the system control unit 8 acquires only the light-shielded image for one frame and uses the light-shielded image as black image data. On the other hand, for example, in the case of a predetermined shooting condition in which the gain is 0 dB and the accumulation time is 1/40 sec, the system control unit 8 acquires a light-shielded image of two frames under the shooting condition and stores it in the image temporary storage unit 16. Then, the system control unit 8 reads out these two frames of light-shielded image data from the temporary image storage unit 16 and sends them to the addition average processing unit 17. The addition average processing unit 17 calculates the addition average for all the pixels of the shaded image of the two frames, and generates one piece of black image data. Similarly, for example, in the case of a predetermined shooting condition with a gain of 0 dB and an accumulation time of 1/50 sec and 1/60 sec, the system control unit 8 acquires a light-shielded image of 2 frames for each shooting condition, and temporarily stores the image. 16 is accumulated. Then, the system control unit 8 reads out the light-shielded image data of 2 frames from the temporary image storage unit 16 and sends it to the addition average processing unit 17. The addition average processing unit 17 performs an averaging process on the light-shielded image data of two frames, and generates one piece of black image data. For example, when the gain is 0 dB and the accumulation time is 1/30 sec, the system control unit 8 acquires a four-frame light-shielded image under the photographing conditions and accumulates it in the image temporary storage unit 16. Then, the system control unit 8 reads the four frames of the shaded image data from the image temporary storage unit 16 and sends them to the addition average processing unit 17. The addition average processing unit 17 calculates the addition average for all the pixels of the light-shielded image data of the four frames to generate one piece of black image data. In the example of FIG. 9, a predetermined shooting condition in which a light-shielded image of two frames or more is acquired and the averaging process is performed is, for example, a shooting condition in which scratches and random noise are conspicuous. The system control unit 8 records the black image data generated for each shooting condition shown in FIG. 9 in association with information on a predetermined shooting condition in the recording unit 7.

  According to the imaging apparatus of the second embodiment, as described above, for shooting conditions in which scratches and random noise are conspicuous, blackout image data of a plurality of frames is acquired and averaged to generate black image data. doing. As a result, the imaging apparatus of the second embodiment can enhance the effect of reducing random noise, particularly for shooting conditions in which random noise is conspicuous, and can remove fixed scratches during image reproduction. I can do it.

  In addition, since the scratch level itself is high under a predetermined shooting condition in which frame addition is performed, the scratch level fluctuation amount is large with respect to a scratch whose level varies. In such a case, if the black drawing process is performed using the black image data acquired when the level happens to be large, the level of the scratch pixel will be too low. In this embodiment, in order to avoid such a situation, it is possible to stably reduce scratches by using an image obtained by averaging a plurality of black images.

  As described above, the imaging apparatus according to the second embodiment generates a single piece of black image data by adding and averaging a plurality of pieces of light-shielded image data, thereby reducing random noise during image reproduction and a scratch level. It is possible to suppress the correction error due to the fluctuation of the defect and improve the defect correction accuracy.

<Third Embodiment>
Next, an imaging apparatus according to a third embodiment will be described. The image pickup apparatus according to the third embodiment can cope with a flaw level change due to temperature. Specifically, the imaging apparatus according to the third embodiment has imaging conditions relating to temperature in addition to the above-described aperture value, accumulation time, and gain as imaging conditions to be added to image data and black image data obtained by actual imaging. Use. In the third embodiment, when the recorded image data is reproduced, the black image data is multiplied by a temperature conversion coefficient corresponding to the temperature difference between the image data obtained by the actual photographing and the black image data, so that the temperature-induced scratch level is increased. The error can be reduced.

  FIG. 1C shows only the configuration of the main part of the imaging apparatus according to the third embodiment. The third imaging device shown in FIG. 1C also includes the components shown in FIG. 1A, but the description of the components that overlap those in FIG. That is, the imaging apparatus of the third embodiment includes a temperature detection unit 19 that detects the temperature of the imaging element of the imaging unit 3. The temperature detection unit 19 is provided in the vicinity of the image sensor of the imaging unit 3 and outputs the detected temperature information to the system control unit 8. The system control unit 8 temporarily stores in the imaging condition storage unit 13 information on imaging conditions obtained by adding the temperature value detected by the temperature detection unit 19 to the above-described aperture value, accumulation time, and gain. Then, the system control unit 8 sends the shooting condition information temporarily stored in the shooting condition storage unit 13 to the shooting condition adding unit 6. As a result, the shooting condition adding unit 6 adds shooting condition information to the image data and the light-shielded image data (black image data) obtained by the main shooting in the same manner as described above. Then, the image data and the light-shielded image data obtained by the actual photographing are recorded on the recording medium of the recording unit 7 together with the photographing condition information as described above.

  In the case of the third embodiment, the system control unit 8 controls each unit according to the procedure of the flowchart shown in FIG. 2, similarly to the first embodiment. Since the first embodiment and the third embodiment differ only in the processes in steps S206, S209, and S212, only the processes in steps S206, S209, and S212 will be described below. In the third embodiment, when the system control unit 8 temporarily stores the shooting condition in the shooting condition storage unit 13 in step S206, the temperature detection unit 19 includes the aperture value, the accumulation time, and the gain setting value. The detected temperature value is also stored. Then, the system control unit 8 adds the temperature value together with the aperture value, the accumulation time, and the gain setting value when adding the imaging condition in step S209. In addition, the system control unit 8 adds information on imaging conditions including a temperature value to the black image data (light-shielded image data) acquired in step S212 and causes the recording unit 7 to record the information.

  In the third embodiment, when reproducing the image data recorded on the recording medium, the reproducing apparatus corresponds to the temperature value added to the black image data from the predetermined temperature conversion coefficients. A temperature conversion coefficient is acquired, and the black image data is multiplied by the temperature conversion coefficient. Then, the playback device generates a difference image between the recorded image and the black image after the temperature conversion coefficient multiplication, and displays the difference image on a monitor panel or the like. As the temperature conversion coefficient, a generally used coefficient may be used, or an actual measurement value may be used.

  According to the third embodiment, by performing a temperature conversion operation on the black image data, it is possible to reduce the error of the scratch level due to the temperature, and it is possible to further enhance the scratch reduction effect during reproduction. As described above, the imaging apparatus according to the third embodiment multiplies the black image data by the temperature conversion coefficient corresponding to the temperature difference between the acquisition of the image data and the acquisition of the black image data. Thereby, when reproducing the recorded image data, it is possible to reduce the error of the scratch level due to the temperature and further improve the scratch correction accuracy.

<Other embodiments>
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

  DESCRIPTION OF SYMBOLS 1 Lens, 2 Aperture part, 3 Imaging part, 4 AFE part, 5 Gain processing part, 6 Imaging condition addition part, 7 Recording part, 8 System control part, 9 Brightness value calculation part, 10 Aperture control part, 11 Accumulation time control Unit, 12 gain control unit, 13 photographing condition storage unit, 14 recording start / end input unit, 16 image temporary storage unit, 17 addition average processing unit, 19 temperature detection unit

Claims (6)

Imaging means for imaging each frame image under imaging conditions set for each frame of the moving image;
Imaging control means for setting the imaging condition for each frame and causing the imaging means to capture each frame image;
Recording control for recording data on a recording medium in association with data of a frame image captured by the imaging unit and information on imaging conditions set by the imaging control unit when the imaging unit captures the frame image Means,
The imaging control unit performs imaging corresponding to each imaging condition used at the time of imaging of the moving image to the imaging unit in a light-shielded state after imaging of the moving image by the imaging unit is completed. Let
The recording control unit corresponds to the data of each light-shielded image obtained by imaging by the imaging unit in the light-shielded state and information on each shooting condition set by the imaging control unit at the time of capturing each light-shielded image. Then, the image pickup apparatus is recorded on the recording medium. It further has an averaging means for averaging a plurality of images,
The imaging control unit causes the imaging unit to capture a plurality of light-shielded images for a predetermined imaging condition among the imaging conditions used at the time of imaging the moving image,
The averaging means averages the plurality of light-shielded images captured by the imaging means under the predetermined imaging condition,
The imaging apparatus according to claim 1, wherein the recording control unit records the data of the light-shielded image obtained by the averaging and the predetermined photographing condition on the recording medium in association with each other. The predetermined shooting condition includes a plurality of predetermined shooting conditions,
The imaging apparatus according to claim 2, wherein the imaging control unit causes the imaging unit to capture a number of light-shielded images determined for the different imaging conditions. A temperature detecting means for detecting the temperature of the imaging means;
The recording control means causes the temperature information detected by the temperature detecting means to be recorded on the recording medium in association with the frame image when each frame image of the moving image is captured, and the light-shielded image is 4. The temperature information detected by the temperature detection means when imaged is recorded on the recording medium in correspondence with the data of the light-shielded image. 5. Imaging device.   The imaging control unit counts, for each imaging condition, the number of frames in which the same imaging condition is set among the imaging conditions set when imaging each frame image of the moving image, and the number of counts 2. The image capturing condition is set to 1 or more as image capturing conditions used at the time of capturing the moving image, and the image capturing unit is configured to capture the light-shielded image. 5. The imaging device according to any one of items 1 to 4. A method for controlling an imaging apparatus including an imaging unit that captures each frame image under imaging conditions set for each frame of a moving image,
An imaging control step for setting the imaging condition for each frame and causing the imaging unit to capture each frame image;
Recording control for recording data on a recording medium in association with data of a frame image captured by the imaging unit and information on imaging conditions set in the imaging control step when the imaging unit captures the frame image Including steps,
The imaging control step performs imaging corresponding to each imaging condition used at the time of imaging the moving image on the imaging unit in a light-shielded state after imaging of the moving image by the imaging unit is completed. Let
The recording control step corresponds to data of each light-shielded image obtained by imaging by the imaging means in the light-shielded state and information on each shooting condition set by the imaging control step at the time of imaging each light-shielded image. And a method of controlling the imaging apparatus, wherein recording is performed on the recording medium.

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