WO2009119254A1

WO2009119254A1 - Imaging device

Info

Publication number: WO2009119254A1
Application number: PCT/JP2009/053770
Authority: WO
Inventors: 真介立花; 圭俊中田
Original assignee: 京セラ株式会社
Priority date: 2008-03-24
Filing date: 2009-02-27
Publication date: 2009-10-01

Abstract

Provided is an imaging device free from hunting if black level adjustment takes place. A black level accumulation part (13) extracts black levels per frame received from a frame order detection part (12), averages the extracted black levels for odd-numbered and even-numbered frames, and stores the averaged black level. A black level adjustment part (14) adjusts the black level of an image signal of an odd-numbered frame (21) received from the detection part (12) based on the black level averaged for the odd-numbered frames stored in the accumulation part (13) and sends the odd-numbered frame finished with the black level adjustment to an image division part (16). Further, the part (14) adjusts the black level of an image signal of an even-numbered frame (22) received from the detection part (12) based on the black level averaged for the even-numbered frames stored in the accumulation part (13) and sends the even-numbered frame finished with the black level adjustment to the image division part (16).

Description

Imaging device

The present invention relates to an image pickup apparatus that can use image data output from an image pickup device for a plurality of purposes by dividing it into frames.

There is an imaging apparatus described in Patent Document 1 as a conventional technique that can be used for a plurality of purposes by dividing image data output by an imaging element for each frame. This imaging device sets an exposure condition so that a video signal having a brightness level for display is obtained for an odd-numbered frame when imaging is performed, and performs imaging under the set exposure condition and outputs it. . When an even-numbered frame is imaged, the image is captured and output under an exposure condition in which the exposure condition is set so that a video signal with a brightness level suitable for image processing can be obtained. That is, a frame image suitable for display and a frame image suitable for image processing can be alternately output in time series from one camera unit.
JP 2007-13777 A

Problems to be Solved by the Invention However, when such image processing is performed, the hunting phenomenon becomes a problem. The hunting phenomenon is a phenomenon in which the output value moves back and forth above the target value.
FIG. 6 is a diagram for explaining a hunting phenomenon that occurs in the imaging apparatus. FIG. 6 shows four graphs A1 to A4.
A graph A1 is a gain setting graph representing a gain set in the image sensor. The gain is an amplification factor when an image signal captured by the image sensor is amplified and output. Graph A1 shows the gain set to the image sensor for each frame. The gains G1, G3, and G5 for the frames used in the image analysis process, that is, odd-numbered frames (hereinafter referred to as “odd frames”) 1, 3, and 5, are used in the image drawing process to enhance the brightness. It is set to a value larger than the gains G2, G4, G6 for the frames, that is, even-numbered frames (hereinafter referred to as “even-numbered frames”) 2, 4, 6. For the frame used in the image drawing process, another parameter is set so that the contrast is emphasized rather than the brightness.
A graph A2 is a graph showing the output of the image sensor for each frame. That is, it is an output of an image signal obtained by amplifying a signal of an image captured by the image sensor with a gain indicated by the graph A1. The outputs S1, S3, S5 of the

odd frames

1, 3, 5 are larger than the outputs S2, S4, S6 of the

even frames

2, 4, 6, respectively.
A graph A3 is a graph showing the output of black level correction processing (hereinafter referred to as “black correction processing”) for each frame. That is, the output by the black correction process is an output of the image signal after black correction is performed on the image signal from the image sensor based on the black correction level accumulated during the black correction process (hereinafter referred to as “black level”). . Graph A4 is a graph showing the black level fed back during the black correction processing for each frame.
The black level is a slight level signal output from the image sensor even when no light enters the image sensor from the outside. The black correction is basically a correction in which a net image signal is obtained by subtracting (subtracting) a black level from an image signal obtained by an image sensor.
In the black correction process, the image signal from the image sensor is black-corrected based on the black level of the previous frame in order to follow the environmental change from moment to moment. Specifically, in the black correction process, first, the image signal of the second frame from the image sensor is black-corrected based on the black level K1 obtained from the output T1 of the image signal of the first frame. . That is, since the correction is made based on the black level obtained from the output of the image signal of the odd-numbered frame larger than the output of the image signal of the even-numbered frame, the output after the correction of the output S2 should be the output T2. An output t2 smaller than the output T2 is output.
Next, the image signal of the third frame from the image sensor is black-corrected based on the black level k2 obtained from the output t2 of the image signal of the second frame. That is, since the correction is performed based on the black level obtained from the output of the image signal of the even-numbered frame smaller than the output of the image signal of the odd-numbered frame, the output after the correction of the output S3 should be the output T3. An output t3 larger than the output T3 is output.
Since the fourth and subsequent frames are similarly black-corrected, the output of the output image signal of the odd-numbered frame gradually increases, but the output of the output image signal of the even-numbered frame gradually increases. As a result, the output image signal causes a hunting phenomenon.
An object of the present invention is to provide an imaging apparatus in which a hunting phenomenon does not occur even when black level correction is performed.
Means for Solving the Problem The imaging apparatus of the present invention includes an imaging unit, a classification unit, a storage unit, a black correction unit, and a divided output unit. The imaging unit sequentially outputs image signals obtained by converting received light into electrical signals in units of frames based on input photoelectric conversion conditions. The classifying unit classifies the frame-unit image signals output from the imaging unit into a plurality of groups. The storage unit detects the black level of the image signal output from the imaging unit for each frame, and stores black level information representing the detected black level for each frame. The black correction unit, based on the black level of the frame classified into the same group by the classification unit, out of the black levels indicated by the black level information stored in the storage unit, the image signal in units of frames output from the imaging unit , Correct and output. The division output unit sequentially outputs the image signals in units of frames corrected by the black correction unit for each group classified by the classification unit.
The imaging device of the present invention includes an imaging unit, a classification unit, a storage unit, a photoelectric conversion condition generation unit, a black correction unit, and a divided output unit. The imaging unit sequentially outputs image signals obtained by converting received light into electrical signals in units of frames based on input photoelectric conversion conditions. The classification unit counts the image signal output from the imaging unit in units of frames, and classifies the image signal into an odd-numbered frame group and an even-numbered frame group. The storage unit detects the black level of the image signal output from the imaging unit for each frame, and stores black level information representing the detected black level for each frame. The photoelectric conversion condition generation unit generates a photoelectric conversion condition for the next frame classified into the same group based on the image signal of the frame unit classified into the same group by the classification unit, and images the generated photoelectric conversion condition To the output. The black correction unit is configured to output an odd-numbered frame image signal out of the frame-unit image signals output from the imaging unit, and the classification unit among the black levels indicated by the black level information stored in the storage unit. The output is corrected based on the black level of the frame classified into the group of frames. Further, the black correction unit outputs the image signal of the even-numbered frame out of the frame-unit image signals output from the imaging unit, and the classification unit out of the black levels indicated by the black level information stored in the storage unit. Are corrected and output based on the black level of the frame classified into the group of frames and the photoelectric conversion conditions of the odd-numbered frame group and even-numbered frame group output by the photoelectric conversion condition generation unit. The division output unit sequentially outputs the image signals in units of frames corrected by the black correction unit for each group classified by the classification unit.
The imaging device of the present invention includes an imaging unit, a classification unit, a storage unit, a photoelectric conversion condition generation unit, a black correction unit, and a divided output unit. The imaging unit sequentially outputs image signals obtained by converting received light into electrical signals in units of frames based on input photoelectric conversion conditions. The classification unit counts the image signal output from the imaging unit in units of frames, and classifies the image signal into an odd-numbered frame group and an even-numbered frame group. The storage unit detects the black level of the image signal output from the imaging unit for each frame, and stores black level information representing the detected black level for each frame. The photoelectric conversion condition generation unit generates a photoelectric conversion condition for the next frame classified into the same group based on the image signal of the frame unit classified into the same group by the classification unit, and images the generated photoelectric conversion condition To the output. The black correction unit includes the even-numbered frame image signal output from the imaging unit, and the classification unit out of the black levels indicated by the black level information stored in the storage unit. The output is corrected based on the black level of the frame classified into the group of frames. Further, the black correction unit outputs an odd-numbered frame image signal among the frame-unit image signals output from the imaging unit, and the classification unit among the black levels indicated by the black level information stored in the storage unit. Are corrected and output based on the black level of the frame classified into the group of frames and the photoelectric conversion conditions of the odd-numbered frame group and even-numbered frame group output by the photoelectric conversion condition generation unit. The division output unit sequentially outputs the image signals in units of frames corrected by the black correction unit for each group classified by the classification unit.

Objects, features, and advantages of the present invention will become more apparent from the following detailed description and drawings.
It is a block diagram which shows the structure of the imaging module which is one Embodiment of this invention. It is a block diagram which shows the detailed structural example of a black level storage part and a black correction | amendment part. It is a figure for demonstrating that a hunting phenomenon does not generate | occur | produce in an imaging module. It is a block diagram which shows the detailed structural example of a black level storage part and a black correction | amendment part. It is a block diagram which shows the detailed structural example of a black level storage part and a black correction | amendment part. It is a graph for demonstrating the hunting phenomenon which generate | occur | produces with an imaging device.

Hereinafter, preferred embodiments of an imaging device of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration of an imaging module 1 according to an embodiment of the present invention. The imaging module 1 that is an imaging device includes an imaging element 11, a frame order detection unit 12, a black level accumulation unit 13, a black correction unit 14, an exposure condition control unit 15, an image division unit 16, and an image analysis unit. 17, an image drawing unit 18, and a display 19.
The image pickup device 11 that is an image pickup unit is configured by, for example, a CCD (Charge Coupled Device) image sensor, and based on the exposure condition from the exposure condition control unit 15, an image signal obtained by converting received light into an electric signal in units of frames. The data are sequentially output and sent to the frame order detection unit 12. The exposure conditions that are photoelectric conversion conditions are, for example, exposure conditions such as an exposure time of the image sensor 11 and a gain for amplifying the captured signal into an image signal.
The frame order detection unit 12 serving as a classification unit counts image signals received from the image sensor 11 in units of frames, and groups odd-numbered frames (hereinafter referred to as “odd frames”) and even-numbered frames (hereinafter referred to as “even-numbered frames”). And the classified frames are sent to the black level accumulation unit 13, the black correction unit 14, and the exposure condition control unit 15 sequentially in units of frames as odd frames 21 and even frames 22. The black level accumulation unit 13 as a storage unit includes a storage device such as a RAM (Random Access Memory) that stores information, and extracts and extracts the black levels of the odd frames 21 and the even frames 22 received from the frame order detection unit 12. The black level is averaged for every odd frame and every even frame, and black level information representing the averaged black level is stored in the RAM.
The black correction unit 14 averages the odd-numbered frames out of the black levels indicated by the black level information stored in the black level storage unit 13 for the image signals of the odd-numbered frames 21 received from the frame order detection unit 12 for the odd-numbered frames. Black correction is performed based on the converted black level, and the odd-numbered frames after black correction are sent to the image dividing unit 16. Further, for the even frames, the black level obtained by averaging the even frames out of the black levels indicated by the black level information stored in the black level accumulation unit 13 for the image signals of the even frames 22 received from the frame order detection unit 12. Based on the above, black correction is performed, and the even frame after black correction is sent to the image dividing unit 16.
The exposure condition control unit 15, which is a photoelectric conversion condition generation unit, generates an exposure condition for capturing the next frame from the image signals of the odd frame 21 and the even frame 22 received from the frame order detection unit 12, and the generated exposure The condition is sent to the image sensor 11. The exposure condition control unit 15 generates an exposure condition based on the image signal of the previous odd frame when the next frame to be captured is an odd frame, and 1 when the next frame to be captured is an even frame. An exposure condition is generated based on the image signal of the previous even frame.
For example, the exposure condition control unit 15 determines that the contrast of the image signal of the even frame 22 received from the frame order detection unit 12 when the brightness of the image signal of the odd frame 21 received from the frame order detection unit 12 is too bright than the predetermined brightness. If it is too strong than the predetermined contrast, control is performed to lower the gain or shorten the exposure time. The exposure condition control unit 15 also sets the contrast of the image signal of the even frame 22 received from the frame order detection unit 12 when the brightness of the image signal of the odd frame 21 received from the frame order detection unit 12 is too dark than the predetermined brightness. When the contrast is too weak than the predetermined contrast, control is performed to increase the gain or lengthen the exposure time.
The control by the exposure condition control unit 15 is not limited to the above control, and more complicated control is possible. For example, the exposure condition control unit 15 refers to the brightness of the image signal of the odd frame 21 received from the frame order detection unit 12 and the contrast of the image signal of the even frame 22 received from the frame order detection unit 12 to control the gain. In combination with the control of the exposure time, control that emphasizes lightness rather than contrast, or control that emphasizes contrast rather than lightness can be performed.
Of the frames received from the black correction unit 14, the image division unit 16 that is a division output unit sends the odd frame 25 to the image analysis unit 17 and sends the even frame 26 to the image drawing unit 18. The image analysis unit 17 analyzes the presence / absence of a predetermined object such as a pedestrian from the image signal of the odd frame 25 received from the image dividing unit 16, and if there is a predetermined object in the image signal, the object Is displayed on the image drawing unit 18. The image drawing unit 18 sends the image signal of the even frame 26 received from the image dividing unit 16 to the display 19 for display. Further, the image drawing unit 18 synthesizes the image instructed from the image analysis unit 17 with the image indicated by the image signal of the even frame 26 received from the image dividing unit 16 and sends it to the display 19 for display. The display 19 is a display device such as a liquid crystal display.
FIG. 2 is a block diagram illustrating a detailed configuration example of the black level accumulation unit 13 and the black correction unit 14. The black level accumulation unit 13 includes an odd frame black level accumulation unit 131 and an even frame black level accumulation unit 132. The odd frame black level accumulation unit 131 extracts the black level of the odd frame 21 received from the frame order detection unit 12, adds or accumulates the extracted black levels, and calculates an average value of the added black levels. The calculated average value is stored as black level information for odd frames. The even frame black level accumulation unit 132 extracts the black level of the even frame 22 received from the frame order detection unit 12, adds or accumulates the extracted black levels, and further calculates an average value of the added black levels. The calculated average value is stored as black level information for even frames.
The black correction unit 14 includes an odd frame black correction unit 141 and an even frame black correction unit 142. The odd frame black correction unit 141 displays the average value of the black level of the odd frame read from the odd frame black level storage unit 131 from the image signal of the odd frame 21 received from the frame order detection unit 12 and a predetermined target black level. The difference from the target black level target value is subtracted, and the subtracted image signal is sent to the image dividing unit 16. The even frame black correction unit 142 is a process that is an average value of the black level of the even frame read from the even frame black level accumulation unit 132 from the image signal of the even frame 22 received from the frame order detection unit 12 and a predetermined target black level. The difference from the target black level target value is subtracted, and the subtracted image signal is sent to the image dividing unit 16.
The odd frame 21 and the even frame 22 from the frame order detection unit 12 are respectively sent to the exposure condition control unit 15, and the exposure condition control unit 15 takes an odd number to be imaged next based on the received odd frame 21 and even frame 22. Frame exposure conditions and even frame exposure conditions, for example, exposure conditions such as gain and shutter speed or exposure time are generated, and the generated exposure conditions are sent to the image sensor 11.
FIG. 3 is a diagram for explaining that the hunting phenomenon does not occur in the imaging module 1. FIG. 3 shows four graphs B1 to B4. In the graph shown in FIG. 3, the same values as those in the graph shown in FIG. 6 are given the same reference numerals to indicate that the values are the same.
A graph B1 is a gain setting graph representing the gain set in the image sensor 11, and shows the gain set in the image sensor 11 for each frame. The gain is an amplification factor when an image signal captured by the image sensor 11 is amplified and output. The gains G1, G3, and G5 for the frames used in the image analysis unit 17, that is, the

odd frames

1, 3, and 5, respectively, are the frames that are used in the image drawing unit 18 to enhance the brightness, that is, even frames 2, 4 , 6 is set to a value larger than the respective gains G2, G4, G6. The frame used in the image drawing unit 18 is set by another parameter so that contrast is emphasized rather than brightness.
A graph B2 is a graph showing the output of the image sensor 11 for each frame. That is, it is an output of an image signal obtained by amplifying the image signal captured by the image sensor 11 with the gain indicated by the graph B1. The outputs S1, S3, S5 of the

odd frames

1, 3, 5 are larger than the outputs S2, S4, S6 of the even frames 2, 4, 6, respectively.
A graph B3 is a graph showing the output of the black correction unit 14 for each frame. That is, it is an output of the image signal after the black correction unit 14 performs black correction on the image signal from the image sensor 11 based on the black level notified from the black level storage unit 13. The graph B4 is a graph showing the black level fed back from the black level accumulation unit 13, that is, the black level notified from the black level accumulation unit 13 to the black correction unit 14 for each frame.
The black correction unit 14 performs black correction on the image signal from the image sensor 11 based on the black level of the frame informed from the black level accumulation unit 13 in order to follow the environmental change from moment to moment. Specifically, the black correction unit 14 first corrects the image signal of the third frame from the image sensor 11 based on the black level K1 obtained from the output T1 of the image signal of the first frame. To do. That is, since the black correction unit 14 corrects the odd-numbered frame based on the black level obtained from the output of the image signal of the odd-numbered frame, the output after the correction of the output S3 is the output T3 that should be can do.
Next, the black correction unit 14 corrects the image signal of the fourth frame from the image sensor 11 based on the black level K2 obtained from the output T2 of the image signal of the second frame. That is, since the black correction unit 14 corrects the even-numbered frame based on the black level obtained from the output of the image signal of the even-numbered frame, the output after the correction of the output S4 is the output T4 that should be can do.
Since the fifth and subsequent frames are similarly black-corrected, the output of the image signal of the odd-numbered frame output from the black correction unit 14 does not gradually increase and is output from the black correction unit 14. The imaging module 1 can prevent the occurrence of the hunting phenomenon without gradually decreasing the output of the even-numbered frame image signal.
In the embodiment described above, the image signals received from the image sensor 11 are counted in units of frames and classified into two groups, an odd frame group and an even frame group, but the classification is limited to two groups. For example, if there are other uses other than display and processing, the number of groups to be classified according to the use is increased, and black correction is performed for each group, thereby preventing the occurrence of the hunting phenomenon. .
As described above, the image pickup device 11 sequentially outputs image signals obtained by converting received light into electrical signals based on the input exposure conditions, and outputs them from the image pickup device 11 by the frame order detection unit 12. The image signals in units of frames are classified into a plurality of groups, and the black level of the image signal output from the image sensor 11 is detected for each frame by the black level accumulating unit 13, and black level information representing the detected black level Is stored for each frame.
Then, the black correction unit 14 classifies the image signals in units of frames output from the image sensor 11 into the same group by the classification unit among the black levels indicated by the black level information stored in the black level accumulation unit 13. Based on the black level of the frame, the image signal is corrected and output, and is corrected by the image dividing unit 16 by the black correcting unit 14, and is sequentially divided into groups classified by the frame order detecting unit 12. Is output.
Therefore, the correction is not performed using the black level of a different group, and the occurrence of the hunting phenomenon can be prevented even if the black level correction is performed.
Further, the exposure condition control unit 15 generates and generates the exposure conditions for the next frame classified into the same group based on the image signals in units of frames classified into the same group by the frame order detection unit 12. Since the exposure condition is output to the image sensor 11, the next exposure condition can be determined based on the image signal that is not affected by the black correction.
Further, among the black levels indicated by the black level information stored in the black level accumulation unit 13 from the frame unit image signal output from the image sensor 11 by the black correction unit 14, the frame order detection unit 12 makes the same group. The difference between the average black level value of the classified frames and the black level target value for display or processing is subtracted and corrected.
Therefore, since the black correction is performed using the average value of the past black level, the black-corrected image output thereafter is prevented from becoming extremely large even when receiving strong light temporarily. be able to.
Furthermore, the image signal output from the image sensor 11 is counted by the frame order detection unit 12 and is classified into an odd-numbered frame group and an even-numbered frame group. It can be applied when used for.
FIG. 4 is a block diagram illustrating a detailed configuration example of the black level accumulation unit 23 and the black correction unit 14. The black level accumulation unit 23 as a storage unit is used instead of the black level accumulation unit 13 shown in FIG. The black level accumulation unit 23 includes an odd frame black level accumulation unit 131 and an even frame black level prediction unit 232. The odd frame black level accumulation unit 131 is the same as the odd frame black level accumulation unit 131 shown in FIG.
The even frame black level prediction unit 232 reads the average value of the black level of the odd frame read from the odd frame black level storage unit 131, the exposure condition for the odd frame generated by the exposure condition control unit 15, and the exposure for the even frame. Based on the conditions, the predicted black level to be corrected is predicted by equation (1), and the predicted black level predicted value is sent to the even frame black correction unit 142.
Black level prediction value = (gain of even frame / gain of odd frame) × (exposure time of even frame / exposure time of odd frame) × average black level of odd frame (1)
The odd frame black correction unit 141 of the black correction unit 14 is the same as the odd frame black correction unit 141 shown in FIG. 2, but the even frame black correction unit 142 is an even frame read from the even frame black level accumulation unit 132. In place of the average value of the black level, black level correction is performed by subtracting the difference between the black level prediction value received from the even frame black level prediction unit 232 and the processing target black level target value that is a predetermined target black level. Do.
As described above, the image pickup device 11 sequentially outputs image signals obtained by converting received light into electrical signals based on the input exposure conditions, and outputs them from the image pickup device 11 by the frame order detection unit 12. Image signals are counted in units of frames and classified into odd-numbered frame groups and even-numbered frame groups, and the black level of the image signal output from the image sensor 11 by the black level storage unit 23 is set for each frame. And the black level information representing the detected black level is stored for each frame, and the exposure condition control unit 15 determines the black level information based on the frame unit image signals classified into the same group by the frame order detection unit 12. An exposure condition for the next frame classified into the same group is generated, and the generated exposure condition is an image sensor. Is output to the 1.
As a method for detecting the black level of the image signal output from the image sensor 11 for each frame, a method called frame division black level clamping is used.
Then, among the image signals in units of frames output from the image sensor 11 by the black correction unit 14, the image signal of the odd-numbered frame is the black level indicated by the black level information stored in the black level accumulation unit 23. The black level information stored in the black level storage unit 23 indicates that the image signal of the even number frame is output after being corrected based on the black level of the frame classified into the odd number frame group by the classification unit. Among the black levels, the black levels of the frames classified into the odd-numbered frame groups by the frame order detection unit 12 and the odd-numbered frame groups and the even-numbered frame groups output by the exposure condition control unit 15 Corrected based on the exposure conditions and output, and corrected by the black correction unit 14 by the image dividing unit 16 Image signal of frame units are sequentially outputted separately for each group classified by the frame sequence detecting unit 12.
Therefore, when correcting even frames, the black level correction is performed using the black level predicted from the past black level of the odd frame group based on the odd and even next exposure conditions. It is possible to prevent the occurrence of the hunting phenomenon even if the process is performed.
FIG. 5 is a block diagram illustrating a detailed configuration example of the black level accumulation unit 33 and the black correction unit 14. The black level accumulation unit 33 as a storage unit is used instead of the black level accumulation unit 13 shown in FIG. The black level accumulation unit 33 includes an odd frame black level prediction unit 331 and an even frame black level accumulation unit 132. The even frame black level accumulating unit 132 is the same as the even frame black level accumulating unit 132 shown in FIG. 2, and the same reference numerals are assigned to indicate the same.
The odd frame black level prediction unit 331 calculates the average value of the black level of the even frame read from the even frame black level storage unit 132, the exposure condition for the odd frame generated by the exposure condition control unit 15, and the exposure for the even frame. Based on the conditions, the black level to be corrected is predicted by Expression (2), and the predicted black level is sent to the odd-numbered frame black correction unit 141.
Black level prediction value = (gain of odd frame / gain of even frame) × (exposure time of odd frame / exposure time of even frame) × black level average value of even frame (2)
The even frame black correction unit 142 of the black correction unit 14 is the same as the even frame black correction unit 142 shown in FIG. 2, but the odd frame black correction unit 141 is an odd frame read from the odd frame black level accumulation unit 131. Instead of the average value of the black level, black level correction is performed by subtracting the difference between the black level prediction value received from the odd frame black level prediction unit 331 and the display black level target value that is a predetermined target black level. Do.
As described above, the image pickup device 11 sequentially outputs image signals obtained by converting received light into electrical signals based on the input exposure conditions, and outputs them from the image pickup device 11 by the frame order detection unit 12. Image signals are counted in units of frames, and are classified into odd-numbered frame groups and even-numbered frame groups, and the black level of the image signal output from the image sensor 11 by the black level accumulation unit 33 is set for each frame. And the black level information representing the detected black level is stored for each frame, and the exposure condition control unit 15 determines the black level information based on the frame unit image signals classified into the same group by the frame order detection unit 12. An exposure condition for the next frame classified into the same group is generated, and the generated exposure condition is an image sensor. Is output to the 1.
Then, among the image signals in units of frames output from the image sensor 11 by the black correction unit 14, the image signals of even-numbered frames are among the black levels indicated by the black level information stored in the black level accumulation unit 33. The black level information stored in the black level storage unit 33 indicates that the image signal of the odd numbered frame is output after being corrected based on the black level of the frame classified into the even numbered frame group by the classification unit. Among the black levels, the black levels of the frames classified into the even-numbered frame groups by the frame order detection unit 12 and the odd-numbered frame groups and the even-numbered frame groups output by the exposure condition control unit 15 It is corrected based on the exposure conditions and output, and is corrected by the image dividing unit 16 by the black correcting unit 14. Image signal in units of frames and are sequentially outputted separately for each group classified by the frame sequence detecting unit 12.
Therefore, when correcting odd-numbered frames, correction is performed using the black level predicted from the past black level of the group of even-numbered frames based on the odd-numbered and even-numbered next exposure conditions. It is possible to prevent the occurrence of the hunting phenomenon even if the process is performed.
The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all respects, and the scope of the present invention is shown in the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the scope of the claims are within the scope of the present invention.
DESCRIPTION OF SYMBOLS 1, 9 Imaging module 11, 91 Imaging device 12 Frame

order detection unit

13, 23, 33, 93 Black level accumulation unit 14, 94 Black correction unit 15, 95 Exposure condition control unit 16, 96 Image division unit 17, 97 Image analysis unit 18, 98 Image drawing unit 19, 99 Display 131 Odd frame black level accumulation unit 132 Even frame black level accumulation unit 141 Odd frame black correction unit 142 Even frame black correction unit 232 Even frame black level prediction unit 331 Odd frame Black level prediction unit

Claims

An image pickup unit that sequentially outputs image signals obtained by converting received light into electric signals based on input photoelectric conversion conditions in units of frames;
A classification unit that classifies image signals in units of frames output from the imaging unit into a plurality of groups;
A storage unit that detects the black level of the image signal output from the imaging unit for each frame, and stores black level information representing the detected black level for each frame;
A frame unit image signal output from the imaging unit is corrected and output based on the black level of the frame classified into the same group by the classification unit among the black levels indicated by the black level information stored in the storage unit. A black correction unit to
An image pickup apparatus comprising: a divided output unit that sequentially outputs image signals in units of frames corrected by the black correction unit for each group classified by the classification unit.
A photoelectric conversion condition for the next frame classified into the same group is generated based on image signals in units of frames classified into the same group by the classification unit, and the generated photoelectric conversion condition is output to the imaging unit. The imaging apparatus according to claim 1, further comprising a conversion condition generation unit.
The black correction unit is configured to select black of frames classified into the same group by the classification unit from among the black levels indicated by the black level information stored in the storage unit from image signals in units of frames output from the imaging unit. The imaging apparatus according to claim 1, wherein a correction is performed by subtracting a difference between an average value of the levels and a predetermined target black level.
4. The classification unit according to claim 1, wherein the classification unit counts the image signal output from the imaging unit in units of frames and classifies the image signal into an odd-numbered frame group and an even-numbered frame group. The imaging device as described in any one.
An image pickup unit that sequentially outputs image signals obtained by converting received light into electric signals based on input photoelectric conversion conditions in units of frames;
A classification unit that counts image signals output from the imaging unit in units of frames, and classifies the signal into an odd-numbered frame group and an even-numbered frame group;
A storage unit that detects the black level of the image signal output from the imaging unit for each frame, and stores black level information representing the detected black level for each frame;
Based on image signals in units of frames classified into the same group by the classification unit, the photoelectric conversion conditions for the next frame classified into the same group are generated, and the generated photoelectric conversion conditions are output to the imaging unit. A generator,
Of the image signals in units of frames output from the imaging unit,
The image signal of the odd-numbered frame is corrected and output based on the black level of the frame classified into the group of the odd-numbered frame by the classification unit among the black levels indicated by the black level information stored in the storage unit. ,
Among the black levels indicated by the black level information stored in the storage unit, the black level of the frame classified into the odd-numbered frame group by the classification unit, and the photoelectric conversion condition generation unit A black correction unit for correcting and outputting based on the photoelectric conversion conditions of the odd-numbered frame group and the even-numbered frame group to be output;
An image pickup apparatus comprising: a divided output unit that sequentially outputs image signals in units of frames corrected by the black correction unit for each group classified by the classification unit.
An image pickup unit that sequentially outputs image signals obtained by converting received light into electric signals based on input photoelectric conversion conditions in units of frames;
A classification unit that counts image signals output from the imaging unit in units of frames, and classifies the signal into an odd-numbered frame group and an even-numbered frame group;
A storage unit that detects the black level of the image signal output from the imaging unit for each frame, and stores black level information representing the detected black level for each frame;
Based on image signals in units of frames classified into the same group by the classification unit, the photoelectric conversion conditions for the next frame classified into the same group are generated, and the generated photoelectric conversion conditions are output to the imaging unit. A generator,
Of the image signals in units of frames output from the imaging unit,
The image signal of the even-numbered frame is corrected and output based on the black level of the frame classified into the even-numbered frame group by the classification unit among the black levels indicated by the black level information stored in the storage unit. ,
Of the black level indicated by the black level information stored in the storage unit, the black level of the frame classified into the even-numbered frame group by the classification unit, and the photoelectric conversion condition generation unit A black correction unit for correcting and outputting based on the photoelectric conversion conditions of the odd-numbered frame group and the even-numbered frame group to be output;
An image pickup apparatus comprising: a divided output unit that sequentially outputs image signals in units of frames corrected by the black correction unit for each group classified by the classification unit.