Camera control device, camera control program, and camera control method

Abstract

To prevent a deterioration of an image pickup device mounted on a camera.SOLUTION: A camera control unit comprises: deterioration degree estimation means that estimates a deterioration degree indicating the degree of deterioration of an image pickup device that converts an image of a subject into an electrical signal; and exposure control means that, when the deterioration degree satisfies a predetermined condition, controls a parameter related to the amount of exposure to the image pickup device so as to adjust the amount of exposure to the image pickup device to be equal to or less than a predetermined exposure amount.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a camera control device, a camera control program, and a camera control method. [Background technology]

[0002] Generally, cameras are equipped with an automatic exposure (AE) control function. AE control is a function that mainly controls exposure-related elements such as shutter speed, aperture, and gain according to the brightness of the subject. Furthermore, in recent years, photon-counting SPAD (Single Photon Avalanche Diode) sensors, which are one of the image sensors installed in cameras, have become increasingly multi-pixel, and are expected to be applied to surveillance cameras that emphasize low-light performance. Cameras that use SPAD sensors as image sensors also have a concept of exposure, and it is desirable for suitable exposure control to be performed.

[0003] Patent Documents 1 and 2 are examples of documents disclosing technologies for controlling exposure-related factors. The camera disclosed in Patent Document 1 modifies a program chart based on the characteristics of the imaging means and the characteristics of the photographic optical system, and determines the combination of aperture value and shutter speed based on the modified program chart. The imaging device disclosed in Patent Document 2 reduces the power consumption of a complementary metal-oxide-semiconductor (CMOS) by lowering the amount of light incident on the CMOS. This imaging device reduces the amount of light incident on the photodiode by reducing the opening area of ​​the aperture blades or shortening the exposure time of the shutter curtain. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-178075 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-96714 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the camera and imaging means disclosed in Patent Document 1 do not take into consideration deterioration of the imaging means. Similarly, the imaging device disclosed in Patent Document 2 does not consider deterioration of the CMOS. On the other hand, with a SPAD sensor, dark current and direct current resistance (DCR) can increase as the camera is used for an extended period of time.

[0006] Therefore, an object of the present invention is to provide a camera control device, a camera control program, and a camera control method that can suppress deterioration of the image sensor mounted in the camera. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the camera control device of the present invention comprises: a photon counting means for performing a photon counting process for counting the number of photons incident on an image sensor that converts light from a subject into an electrical signal to generate an image, or a photon number integrating process for integrating the number of photons incident on the image sensor over a predetermined period of time; The number of photons counted by the photon counting process or the number of photons integrated by the photon number integration process is used to calculate the number of photons. a degradation level estimation means for estimating a degradation level indicating a degree of degradation of the imaging element; The degree of deterioration is a predetermined Greater than value case to , than when the degree of deterioration is equal to or less than a predetermined value. The exposure amount to the image sensor Small an exposure control means for controlling parameters relating to the amount of exposure to the image sensor so as to Equipped with. [Effects of the Invention]

[0008] According to the present invention, it is possible to suppress deterioration of the imaging element mounted on the camera. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a camera according to a first embodiment. [Figure 2]2 is a diagram illustrating an example of a detailed configuration of an imaging unit illustrated in FIG. 1. FIG. [Figure 3] 2 is a diagram illustrating an example of a hardware configuration of the camera control device illustrated in FIG. 1. FIG. [Figure 4] FIG. 2 is a diagram showing an example of an image generated by a camera according to the first embodiment. [Figure 5] 5 is a diagram showing examples of areas corresponding to the areas set by the camera control device in the image shown in FIG. 4, and an example of the average brightness measured for each of the areas. FIG. [Figure 6] FIG. 5 is a diagram showing an example of the relationship between the degree of deterioration of the image sensor estimated by the camera control device according to the first embodiment, the average brightness measured for each area shown in FIG. 4, and the amount of exposure correction. [Figure 7] 5 is a flowchart illustrating an example of processing executed by the camera control device according to the first embodiment. [Figure 8] FIG. 11 is a diagram showing an example of a normal program chart according to the second embodiment. [Figure 9] FIG. 11 is a diagram showing an example of a deterioration suppression program diagram according to the second embodiment. [Figure 10] FIG. 11 is a diagram showing an example of a deterioration suppression program diagram according to the second embodiment. [Figure 11] 10A and 10B are diagrams showing examples of the relationship between the short-term deterioration degree and the long-term deterioration degree estimated by the camera control device according to the second embodiment and the program diagram selected by the camera control device. [Figure 12] 10A and 10B are diagrams illustrating an example of processing executed when a camera control device according to a second embodiment switches a program chart used when controlling parameters related to the exposure amount to an image sensor. [Figure 13] FIG. 10 is a diagram showing an example of a graphical user interface for selecting a priority item when a camera control device according to the second embodiment controls parameters related to the amount of exposure to an image sensor. [Figure 14] 10A and 10B are diagrams showing examples of a plurality of regions set in an image according to the second embodiment, and examples of average brightness measured for each region. [Figure 15]10A and 10B are diagrams illustrating an example of the relationship between the short-term deterioration degree and the long-term deterioration degree estimated by the camera control device according to the second embodiment and the correction amount of the exposure amount. [Figure 16] 10A and 10B are diagrams for explaining gamma value correction executed by a camera control device according to a second embodiment. [Figure 17] 10A and 10B are diagrams for explaining gamma value correction executed by a camera control device according to a second embodiment. [Figure 18] 10 is a flowchart illustrating an example of processing executed by a camera control device according to a second embodiment. [Figure 19] 10 is a flowchart illustrating an example of processing executed by a camera control device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment A camera control device according to a first embodiment will be described with reference to Fig. 1 to Fig. 7. Fig. 1 is a diagram showing an example of the configuration of a camera according to the first embodiment. Camera 1 is, for example, a digital still camera or a digital video camera. As shown in Fig. 1, camera 1 includes an imaging unit 10 and a camera control device 20.

[0011] The imaging unit 10 generates an image by taking in light from outside the camera 1. Fig. 2 is a diagram showing an example of a detailed configuration of the imaging unit shown in Fig. 1. As shown in Fig. 2, the imaging unit 10 includes a lens 101, an aperture 102, a filter 103, an image sensor 104, and a control amplifier circuit (AGC: Automatic Gain Control) 105.

[0012] The lens 101 is included in an optical system that takes in light from outside the camera 1 and forms an image of a subject on the light-receiving surface of the image sensor 104. The diaphragm 102 adjusts the area of ​​its opening to adjust the amount of light taken into the optical system and thereby adjust the amount of exposure to the image sensor 104. The filter 103 is, for example, an ND (Neutral Density) filter, and reduces the amount of exposure to the image sensor 104. The filter 103 has unique transmittance characteristics, and may be inserted or removed from the optical path to the light-receiving surface of the image sensor 104 to reduce the amount of exposure to the image sensor 104. Alternatively, the filter 103 may reduce the amount of exposure to the image sensor 104 by electrically controlling its transmittance characteristics.

[0013] The image sensor 104 is, for example, a SPAD sensor, and converts an image of a subject into an electrical signal. The image sensor 104 has a light-receiving surface onto which photons passing through the lens 101, the aperture 102, and the filter 103 are incident. The image sensor 104 includes a photon counting unit that performs a photon counting process to count the number of incident photons or a photon number integration process to integrate the incident photons over a predetermined period. The photon counting unit may also perform the photon number counting process or the photon number integration process for each region set on the light-receiving surface of the image sensor 104. This region may be an area corresponding to one pixel of the image converted into an electrical signal by the image sensor 104, or an area corresponding to a plurality of such pixels. For example, if the image sensor 104 is a SPAD sensor, it counts the number of photons incident on an avalanche photodiode (APD) and outputs the counted number of photons as a digital signal.

[0014] The control amplifier circuit 105 executes automatic gain control of the camera 1. Specifically, the control amplifier circuit 105 adjusts the gain for amplifying the digital signal output by the image sensor 104. The camera 1 may also convert the digital signal output by the image sensor 104 into an analog signal using an analog-to-digital converter. In this case, the control amplifier circuit 105 adjusts the gain for amplifying the analog signal output by the analog-to-digital converter.

[0015] Fig. 3 is a diagram showing an example of the hardware configuration of the camera control device shown in Fig. 1. As shown in Fig. 3, the camera control device 20 includes a CPU (Central Processing Unit) 201, a ROM (Read Only Memory) 202, a RAM (Random Access Memory), an input device 204, and an output device 205.

[0016] The CPU 201 realizes the functions of the camera control device 20 by reading and executing programs. The ROM 202 stores programs and the like that are read and executed by the CPU 201. The RAM 203 expands the programs and related data when the CPU 201 executes the programs. The input device 204 is, for example, a touch panel, buttons, etc., and is used to input instructions necessary to operate the camera control device 20. The output device 205 is, for example, a display, speakers, etc., and outputs information to be presented to the user of the camera 1.

[0017] 1, the camera control device 20 includes an image generation unit 21, a deterioration level estimation unit 22, an exposure control unit 23, a brightness adjustment unit 24, a gradation adjustment unit 25, and an output unit 26. The image generation unit 21, the deterioration level estimation unit 22, the exposure control unit 23, the brightness adjustment unit 24, the gradation adjustment unit 25, and the output unit 26 are realized by the CPU 201 shown in FIG. 3 loading a program stored in the ROM 202 into the RAM 203 and executing the program.

[0018] The image generating unit 21 generates an image of the subject from the electrical signal output by the control amplifier circuit 105 .

[0019] The deterioration level estimation unit 22 executes a luminance measurement process to measure the luminance of the image converted into an electrical signal by the image sensor 104, and estimates the degree of deterioration based on the luminance measured by the luminance measurement process. In this case, the deterioration level estimation unit 22 may execute the luminance measurement process for each region set on the light receiving surface of the image sensor 104, and estimate the degree of deterioration for each region.

[0020] Fig. 4 is a diagram showing an example of an image generated by a camera according to the first embodiment. Image P shown in Fig. 4 depicts a nighttime scene generated by camera 1. Area A1 shown in Fig. 4 depicts a street light, and is therefore brighter than other areas of image P. Similarly, area A2 shown in Fig. 4 depicts multiple people in a bright location.

[0021] FIG. 5 shows examples of regions corresponding to the regions set by the camera control device in the image shown in FIG. 4 and examples of average luminance measured for each region. The degradation level estimation unit 22 sets, for example, rectangular regions arranged in four rows and five columns on the rectangular light-receiving surface of the image sensor 104 and performs a luminance measurement process for each region. As shown in FIG. 5, these regions correspond to 20 regions on the image P. The luminance of each of these regions is, for example, the numerical values ​​shown in FIG. 5. Each numerical value shown in FIG. 5 indicates the average luminance for each region when the luminance of image P is normalized to a total of 256 levels, from 0 to 255. For example, a region with a numerical value exceeding 200 indicates a greater number of photons incident on the light-receiving surface of the image sensor 104 than other regions, and therefore indicates a higher degree of degradation of the image sensor 104 than other regions.

[0022] The deterioration degree estimation unit 22 estimates the deterioration degree based on the maximum average value of the 20 brightness values ​​shown in Fig. 5. The deterioration degree estimation unit 22 may estimate the deterioration degree based on the arithmetic average or weighted average of the 20 brightness values ​​shown in Fig. 5.

[0023] FIG. 6 shows the deterioration degree of the image sensor estimated by the camera control device according to the first embodiment, and 5 6 shows an example of the relationship between the average brightness measured for each region shown in FIG. 6 and the amount of exposure correction. The first line from the top of the table shown in FIG. 6 shows an example of classification of the degree of deterioration estimated by the deterioration degree estimation unit 22. The second line from the top of the table shown in FIG. 6 shows an example of classification of the maximum average brightness of the total of 20 points shown in FIG. 5. The third line from the top of the table shown in FIG. 6 shows an example of the amount of exposure correction executed by the exposure control unit 93.

[0024] As shown in FIG. 6, when the degradation level estimation unit 22 estimates that the maximum average value of luminance is 150 or less, it estimates that the degradation level is "low". Also, as shown in FIG. 6, when the degradation level estimation unit 22 estimates that the maximum average value of luminance is 151 or more and less than 200, it estimates that the degradation level is "medium". Also, as shown in FIG. 6, when the degradation level estimation unit 22 estimates that the maximum average value of luminance is 200 or more, it estimates that the degradation level is "high". In the case shown in FIG. 5, since the maximum average value of luminance is "180", the degradation level estimation unit 22 estimates that the degradation level of the image sensor 104 is " Medium The deterioration level estimation unit 22 may estimate the deterioration level using a scale other than the three levels of "low", "medium", and "high" shown in FIG. 6, for example, four or more levels or two levels.

[0025] Furthermore, the deterioration degree estimation unit 22 executes a luminance integration process to integrate, over a predetermined period, the luminance of the image converted into an electrical signal by the image sensor 104, and estimates the degree of deterioration based on the luminance integrated by the luminance integration process. In this case, the deterioration degree estimation unit 22 may execute the luminance integration process for each region set on the light receiving surface of the image sensor 104, and estimate the degree of deterioration for each region.

[0026] The degradation degree estimation unit 22 may estimate a degradation degree indicating the degree of degradation of the image sensor 104. For example, the degradation degree estimation unit 22 may estimate the degradation degree based on the number of photons counted by the above-described photon number counting process. Furthermore, when the photon number counting process is performed for each region set on the light receiving surface of the image sensor 104, the degradation degree estimation unit 22 may estimate the degradation degree for each region. Furthermore, for example, the degradation degree estimation unit 22 may estimate the degradation degree based on the number of photons integrated by the above-described photon number integration process. Furthermore, when the photon number integration process is performed for each region set on the light receiving surface of the image sensor 104, the degradation degree estimation unit 22 may estimate the degradation degree for each region.

[0027] Alternatively, the deterioration degree estimation unit 22 may execute an evaluation value calculation process to calculate an evaluation value related to the brightness of the image converted into an electrical signal by the image sensor 104, and estimate the deterioration degree based on the evaluation value calculated by the evaluation value calculation process. In this case, the deterioration degree estimation unit 22 may execute the evaluation value calculation process for each region set on the light receiving surface of the image sensor 104, and estimate the deterioration degree for each region.

[0028] Furthermore, the deterioration degree estimation unit 22 may execute an evaluation value accumulation process that accumulates, over a predetermined period of time, evaluation values ​​related to the brightness of an image converted into an electrical signal by the image sensor 104, and estimate the deterioration degree based on the evaluation values ​​accumulated by the evaluation value accumulation process. In this case, the deterioration degree estimation unit 22 may execute the evaluation value accumulation process for each region set on the light receiving surface of the image sensor 104, and estimate the deterioration degree for each region.

[0029] When the degree of deterioration satisfies a predetermined condition, the exposure control unit 23 controls a parameter related to the exposure amount to the image sensor 104 so that the exposure amount to the image sensor 104 is equal to or less than a predetermined exposure amount. The predetermined condition here is, for example, that the degree of deterioration is equal to or greater than a predetermined threshold. The parameter related to the exposure amount to the image sensor 104 is, for example, at least one of the shutter speed, the aperture value, the transmittance of the filter, and the gain.

[0030] For example, as shown in the third row from the top in Fig. 6, when the exposure control unit 23 estimates the degree of deterioration of the image sensor 104 to be "low," the exposure control unit 23 controls the parameters related to the amount of exposure to the image sensor 104 so that the correction amount of the amount of exposure to the image sensor 104 becomes 0.0 EV (Exposure Value). When this correction amount is a negative value, it indicates that the brightness of the image is to be reduced, and when it is a positive value, it indicates that the brightness of the image is to be increased.

[0031] Similarly, as shown in the third line from the top of Fig. 6, when the level of deterioration of the image sensor 104 is estimated to be "medium," the exposure control unit 23 controls the parameters related to the amount of exposure to the image sensor 104 so that the correction amount of the amount of exposure to the image sensor 104 is -0.5 EV. Furthermore, as shown in the third line from the top of Fig. 6, when the level of deterioration of the image sensor 104 is estimated to be "high," the exposure control unit 23 controls the parameters related to the amount of exposure to the image sensor 104 so that the correction amount of the amount of exposure to the image sensor 104 is -1.0 EV. In the case shown in Fig. 5, the maximum average luminance value is estimated to be "180," so the exposure control unit 23 controls the parameters related to the amount of exposure to the image sensor 104 so that the correction amount of the exposure to the image sensor 104 is -0.5 EV.

[0032] Furthermore, the exposure control unit 23 may control a parameter relating to the amount of exposure to the image sensor 104 based on the brightness of an area where the degree of deterioration is equal to or greater than a predetermined degree of deterioration.

[0033] The brightness adjustment unit 24 increases the brightness of an image generated after the parameters related to the amount of exposure to the image sensor 104 are controlled by the exposure control unit 23. For example, the brightness adjustment unit 24 adjusts the gain and amplifies the signal so as to brighten the image by the amount of exposure reduced by the exposure control unit 23. Note that although it is preferable that the processing by the brightness adjustment unit 24 be performed, it does not have to be performed.

[0034] The gradation adjustment unit 25 adjusts the gradation of an image generated after the exposure control unit 23 controls parameters related to the amount of exposure to the image sensor 104. For example, the gradation adjustment unit 25 adjusts the gamma value so as to brighten the image by the amount of exposure reduced by the exposure control unit 23. Note that although it is preferable that the processing by the gradation adjustment unit 25 be performed, it does not have to be performed.

[0035] The output unit 26 outputs an image generated after the exposure control unit 23 controls parameters related to the amount of exposure to the image sensor 104. When processing by the brightness adjustment unit 24 is being performed, the output unit 26 outputs an image to which the processing has been applied. When processing by the gradation adjustment unit 25 is being performed, the output unit 26 outputs an image to which the processing has been applied.

[0036] Next, processing executed by the camera control device according to the first embodiment will be described with reference to Fig. 7. Fig. 7 is a flowchart showing an example of processing executed by the camera control device according to the first embodiment.

[0037] In step S701, camera 1 executes a process of capturing an image.

[0038] In step S702, the photon counting unit counts the number of photons incident on the image sensor 104.

[0039] In step S703, the deterioration level estimation unit 22 estimates the deterioration level of the image sensor 104.

[0040] In step S704, the exposure control unit 23 determines whether the degree of deterioration estimated in step S702 satisfies a predetermined condition. If the exposure control unit 23 determines that the degree of deterioration estimated in step S702 satisfies the predetermined condition (step S704: YES), the exposure control unit 23 proceeds to step S705. On the other hand, if the exposure control unit 23 determines that the degree of deterioration estimated in step S702 does not satisfy the predetermined condition (step S704: NO), the exposure control unit 23 proceeds to step S707.

[0041] In step S705, the exposure control unit 23 controls parameters relating to the amount of exposure to the image sensor 104 so that the amount of exposure to the image sensor 104 is equal to or less than a predetermined amount of exposure.

[0042] In step S706, the brightness adjuster 24 increases the brightness of the image.

[0043] In step S707, the exposure control unit 23 controls the parameters relating to the amount of exposure to the image sensor 104 so that the amount of exposure to the image sensor 104 is the normal amount of exposure.

[0044] In step S708, the output unit 26 outputs the image.

[0045] Second Embodiment A camera control device according to the second embodiment will be described with reference to Figures 8 to 19. In the description of the second embodiment, differences from the first embodiment will be mainly described, and descriptions of the same contents as in the first embodiment will be omitted as appropriate. Furthermore, in the description of the second embodiment, the same components as in the first embodiment will be assigned the same reference numerals as in the first embodiment.

[0046] The exposure control unit 23 controls parameters related to the amount of exposure to the image sensor 104 based on a program diagram related to the amount of exposure to the image sensor 104, the program diagram being selected based on the degree of deterioration. The program diagram is a diagram showing the relationship between each parameter related to the amount of exposure to the image sensor 104 and the brightness of the subject and its surroundings, and defines the order in which each parameter is controlled and the range in which each parameter is controlled. The exposure control unit 23 may also execute a process of selecting a program diagram related to the amount of exposure to the image sensor 104. At least one program diagram is stored in, for example, the ROM 202, and is read out by the CPU 201 when used.

[0047] If the degree of deterioration does not satisfy the above-mentioned predetermined condition, the exposure control unit 23 selects the normal program diagram as the program diagram and controls parameters related to the amount of exposure to the image sensor 104 based on the normal program diagram. Fig. 8 is a diagram showing an example of a normal program diagram according to the second embodiment. The normal program diagram is a program diagram that sets the image quality of the image converted into an electrical signal by the image sensor 104 to a predetermined level or higher.

[0048] For example, the normal program diagram may be a program diagram that takes into consideration image quality such as the signal-to-noise ratio of the image and does not actively apply gain by the control amplifier circuit 105 when the brightness of the subject and its surroundings is equal to or greater than a predetermined brightness. Alternatively, the normal program diagram may be a program diagram that takes into consideration correction of depth of field, subject blur, light source flicker, etc. and specifies the order and range of controlling the shutter speed set by the aperture 102 or the image sensor 104.

[0049] The horizontal axis in FIG. 8 represents the brightness of the subject and its surroundings, and indicates a BV (Brightness Value) value that has a positive correlation with the exposure amount to the image sensor 104. Line 8a in FIG. 8 defines the relationship between the gain adjusted by the control amplifier circuit 105 and the brightness of the subject and its surroundings. Line 8b in FIG. 8 defines the relationship between the shutter speed and the brightness of the subject and its surroundings. The shutter speed also correlates with the accumulation time of the image sensor 104. Line 8c in FIG. 8 defines the relationship between the aperture value of the aperture 102 and the brightness of the subject and its surroundings.

[0050] 8, the exposure control unit 23 sets the gain to 0 dB, the shutter speed to 1 / 2000 seconds, and the aperture value to F11.0 to obtain a brightness of +10 BV. In this case, the exposure control unit 23 also controls the image sensor 104 so that the accumulation time of the image sensor 104N is 1 / 60 seconds.

[0051] When decreasing the brightness from +10BV, the exposure control unit 23 first changes the aperture value from F11.0 to F2.0 as shown in FIG. 8. The BV value becomes +5BV when the aperture value reaches F2.0. Next, when decreasing the brightness from +5BV, the exposure control unit 23 changes the shutter speed from 1 / 2000 seconds to 1 / 60 seconds as shown in FIG. 8. The BV value becomes 0BV when the shutter speed reaches 1 / 60 seconds. Finally, when decreasing the brightness from 0BV, the exposure control unit 23 changes the gain from 0 dB to 60 dB as shown in FIG. 8. The BV value becomes -10 dB when the gain reaches 60 dB.

[0052] The exposure control unit 23 controls parameters related to the exposure amount to the image sensor 104 based on the normal program diagram shown in Fig. 8, thereby generating an image with suitable image quality in the range from +10 BV to -10 BV. Note that the exposure control unit 23 may follow a normal program diagram that changes at least one parameter in each of multiple non-overlapping BV value ranges, instead of the normal program diagram shown in Fig. 8. The exposure control unit 23 may also follow a normal program diagram that does not change one or two of the gain, shutter speed, and aperture value, for example.

[0053] If the degree of deterioration satisfies the above-described predetermined condition, the exposure control unit 23 selects the deterioration suppression program diagram as the program diagram and controls parameters related to the amount of exposure to the image sensor 104 based on the deterioration suppression program diagram. Fig. 9 is a diagram showing an example of a deterioration suppression program diagram according to the second embodiment. The deterioration suppression program diagram is a program diagram that sets the amount of exposure to the image sensor 104 to a predetermined amount or less.

[0054] The horizontal axis in FIG. 9 represents the BV value. Line 9a in FIG. 9 defines the relationship between the gain adjusted by the control amplifier circuit 105 and the brightness of the subject and its surroundings. Line 9b in FIG. 9 defines the relationship between the shutter speed and the brightness of the subject and its surroundings. The shutter speed is also correlated with the accumulation time of the image sensor 104. Line 9c in FIG. 9 defines the relationship between the aperture value of the aperture 102 and the brightness of the subject and its surroundings.

[0055] When controlling parameters related to the exposure amount to the image sensor 104 based on the deterioration suppression program diagram shown in FIG. 9 , the exposure control unit 23 sets the gain to 60 dB, the shutter speed to 1 / 60 seconds, and the aperture value to F2.0 to obtain a brightness of −10 BV. When increasing the brightness from −10 BV, the exposure control unit 23 first changes the gain from 60 dB to 12 dB. Next, when further increasing the brightness, the exposure control unit 23 changes the shutter speed from 1 / 60 seconds to 1 / 2000 seconds. Next, when further increasing the brightness, the exposure control unit 23 changes the aperture value from F2.0 to F11.0. Finally, when further increasing the brightness, the exposure control unit 23 changes the gain from 12 dB to 0 dB.

[0056] In the degradation suppression program diagram shown in Fig. 9, the range of BV values ​​over which the shutter speed is controlled is darker than in the normal program diagram shown in Fig. 8. Also, in the degradation suppression program diagram shown in Fig. 9, the range of BV values ​​over which the aperture is controlled is darker than in the normal program diagram shown in Fig. 8. Therefore, the degradation suppression program diagram shown in Fig. 9 can suppress degradation of the image sensor 104 more than the normal program diagram shown in Fig. 8.

[0057] Note that the exposure control unit 23 may insert or remove the filter 103 at a predetermined BV value instead of changing the shutter speed and the aperture value in accordance with the deterioration prevention program diagram shown in Fig. 9. Even with such processing, the exposure control unit 23 can achieve the same effect as when the shutter speed and the aperture value are changed in accordance with the deterioration prevention program diagram shown in Fig. 9.

[0058] If the degree of deterioration satisfies the above-described predetermined condition, the exposure control unit 23 selects the deterioration suppression program diagram as the program diagram, and controls parameters related to the amount of exposure to the image sensor 104 based on the deterioration suppression program diagram. Fig. 10 is a diagram showing an example of a deterioration suppression program diagram according to the second embodiment.

[0059] The horizontal axis in FIG. 10 represents the BV value. Line 10a in FIG. 10 defines the relationship between the gain adjusted by the control amplifier circuit 105 and the brightness of the subject and its surroundings. Line 10b in FIG. 10 defines the relationship between the shutter speed and the brightness of the subject and its surroundings. The shutter speed is also correlated with the accumulation time of the image sensor 104. Line 10c in FIG. 10 defines the relationship between the aperture value of the aperture 102 and the brightness of the subject and its surroundings.

[0060] When the exposure control unit 23 controls parameters related to the exposure amount to the image sensor 104 based on the deterioration suppression program diagram shown in FIG. 10 , the exposure control unit 23 sets the gain to 60 dB, the shutter speed to 1 / 60 seconds, and the aperture value to F2.0 to obtain a brightness of −10 BV. When increasing the brightness from −10 BV, the exposure control unit 23 first changes the gain from 60 dB to 24 dB. Next, when further increasing the brightness, the exposure control unit 23 changes the shutter speed from 1 / 60 seconds to 1 / 2000 seconds. Next, when further increasing the brightness, the exposure control unit 23 changes the aperture value from F2.0 to F11.0. Finally, when further increasing the brightness, the exposure control unit 23 changes the gain from 24 dB to 0 dB.

[0061] In the degradation prevention program diagram shown in Fig. 10, the range of BV values ​​over which the shutter speed is controlled is darker than in the degradation prevention program diagram shown in Fig. 9. Also, in the degradation prevention program diagram shown in Fig. 10, the range of BV values ​​over which the aperture is controlled is darker than in the degradation prevention program diagram shown in Fig. 9. Therefore, the degradation prevention program diagram shown in Fig. 10 can suppress deterioration of the image sensor 104 more than the degradation prevention program diagram shown in Fig. 9.

[0062] In addition, the exposure control unit 23 may select a program diagram based on instructions input using the input device 204, and control multiple parameters in sequence based on the program diagram to achieve the target exposure amount for the image sensor 104.

[0063] The degradation level estimation unit 22 may estimate a short-term degradation level, which is the degradation level in a first period, and a long-term degradation level, which is the degradation level in a second period longer than the first period. The first period is, for example, a period going back a predetermined time from the current time. The predetermined time may be, for example, several minutes, several tens of minutes, or several hours. The second period is, for example, a predetermined period prior to the first period. The predetermined period may be, for example, one day to several months. The degradation level estimation unit 22 estimates the short-term degradation level and the long-term degradation level by a photon number measurement process, a photon number integration process, a luminance measurement process, a luminance integration process, an evaluation value calculation process, or an evaluation value integration process. For example, the degradation level estimation unit 22 may record the maximum average luminance value in the region shown in FIG. 5 at predetermined intervals and estimate at least one of the short-term degradation level and the long-term degradation level from these maximum values. The degradation level estimation unit 22 may record these maximum values, for example, at the timing of each captured frame, or at a timing taking into account the capacity of the storage medium installed in the camera 1.

[0064] Fig. 11 is a diagram showing an example of the relationship between the short-term deterioration degree and long-term deterioration degree estimated by the camera control device according to the second embodiment and the program diagram selected by the camera control device. The "normal program diagram" shown in Fig. 11 refers to the normal program diagram shown in Fig. 8. The "deterioration suppression program diagram (low level)" shown in Fig. 11 refers to the degradation suppression program diagram shown in Fig. 9. The "deterioration suppression program diagram (high level)" shown in Fig. 11 refers to the degradation suppression program diagram shown in Fig. 10.

[0065] The exposure control unit 23 selects a program diagram based on at least one of the degree of short-term deterioration and the degree of long-term deterioration. For example, as shown in FIG. 11 , regardless of whether the degree of long-term deterioration is "low," "medium," or "high," the higher the degree of short-term deterioration, the greater the effect of suppressing deterioration of the image sensor 104. Also, as shown in FIG. 11 , for example, regardless of whether the degree of short-term deterioration is "low," "medium," or "high," the higher the degree of long-term deterioration, the greater the effect of suppressing deterioration of the image sensor 104. Furthermore, when the program diagram to be selected changes due to a change in at least one of the degree of short-term deterioration and the degree of long-term deterioration, the exposure control unit 23 switches the program diagram according to, for example, FIG. 11.

[0066] FIG. 12 is a diagram illustrating an example of processing executed when switching the program chart used by the camera control device according to the second embodiment to control parameters related to the exposure dose to the image sensor. The horizontal axis in FIG. 12 represents the degree of deterioration. After selecting the normal program chart, the exposure control unit 23 may switch to the degradation suppression program chart when the degree of deterioration increases and is estimated to be a first degree of deterioration, as indicated by the solid arrow in FIG. 12 . On the other hand, after selecting the degradation suppression program chart, the exposure control unit 23 may switch to the normal program chart when the degree of deterioration decreases and is estimated to be a second degree of deterioration, which is greater than the first degree of deterioration, as indicated by the dashed-dotted arrow in FIG. 12 . The difference between the first degree of deterioration and the second degree of deterioration is not particularly limited. By employing these processes, the camera control device 20 can prevent frequent switching of the program chart when the degree of deterioration increases or decreases within a narrow range.

[0067] Fig. 13 is a diagram showing an example of a graphical user interface for selecting a priority when controlling parameters related to the exposure amount to an image sensor by a camera control device according to the second embodiment. Fig. 13 shows a graphical user interface (GUI) including a slider L, which is displayed on a display, which is an example of the output device 205.

[0068] When the slider L is positioned to the left of the center, the exposure control unit 23 receives an instruction to prioritize suppression of the deterioration degree of the image sensor 104, and controls parameters related to the amount of exposure to the image sensor 104 based on the deterioration degree suppression program diagram. For example, the exposure control unit 23 controls parameters based on the deterioration suppression program diagram shown in Fig. 9, and when the slider L is positioned to the left of the center, the exposure control unit 23 switches to control the parameters based on the deterioration suppression program diagram shown in Fig. 10.

[0069] On the other hand, when the slider L is located to the right of the center, the exposure control unit 23 receives an instruction to prioritize suppression of the deterioration degree of the image sensor 104, and controls parameters related to the amount of exposure to the image sensor 104 based on the normal program diagram. For example, the exposure control unit 23 controls parameters based on the deterioration suppression program diagram shown in Fig. 9, and when the slider L is located to the right of the center, the exposure control unit 23 switches to control the parameters based on the normal program diagram shown in Fig. 8.

[0070] FIG. 14 is a diagram showing examples of regions corresponding to regions set by the camera control device in an image according to the second embodiment, and an example of the average luminance measured for each region. The degradation level estimation unit 22 sets, for example, rectangular regions arranged in four rows and five columns on the rectangular light-receiving surface of the image sensor 104, and performs a luminance measurement process for each region. As shown in FIG. 14, these regions correspond to 20 regions on the image P. The luminance of each of these regions is, for example, the numerical values ​​shown in FIG. 14. The numerical values ​​shown in FIG. 14 indicate the average luminance for each region when the luminance of the image P is normalized to a total of 256 levels, from 0 to 255. However, the numerical values ​​shown in FIG. 14 were measured at different times or periods from the times or periods at which the numerical values ​​shown in FIG. 5 were measured.

[0071] The exposure control unit 23 may determine whether or not there is a region where the average luminance shown in FIG. 14 is estimated and, for example, when the slider L shown in FIG. 13 is positioned to the left of the center. If the exposure control unit 23 determines that there is no region where the average luminance is equal to or greater than the predetermined threshold, it selects the normal program diagram. On the other hand, if the exposure control unit 23 determines that there is a region where the average luminance is equal to or greater than the predetermined threshold, it selects the degradation suppression program diagram. The predetermined threshold in these cases is, for example, 220.

[0072] Furthermore, when the exposure control unit 23 determines that there is an area in which the average brightness is equal to or greater than a predetermined threshold in the case shown in FIG. 14 , the exposure control unit 23 may select a program diagram according to the table shown in FIG. 15. FIG. 15 is a diagram showing an example of the relationship between the degree of short-term deterioration and the degree of long-term deterioration estimated by the camera control device according to the second embodiment and the correction amount of the exposure. For example, when the degree of short-term deterioration is estimated to be "high" and the degree of long-term deterioration is estimated to be "low," the exposure control unit 23 may set the correction amount of the exposure amount for the image sensor 104 to -1.0 EV according to the table shown in FIG. 15. Furthermore, the exposure control unit 23 may adjust the correction amount of the exposure amount for the image sensor 104 according to the position of the slider L shown in FIG. 13.

[0073] The gradation adjustment unit 25 adjusts the gradation of an image generated after the exposure control unit 23 controls parameters related to the amount of exposure to the image sensor 104. FIGS. 16 and 17 are diagrams for explaining gamma value correction performed by a camera control device according to the second embodiment. The horizontal axis in FIG. 16 and the horizontal axis in FIG. 17 represent gamma input. The vertical axis in FIG. 16 and the vertical axis in FIG. 17 represent gamma output. Curve C shown in FIGS. 16 and 17 is a reference gamma value correction curve.

[0074] When the gradation adjustment unit 25 adjusts the gradation according to the curve C shown in Fig. 16, it outputs the same image as when the gain is adjusted by the control amplifier circuit 105. On the other hand, when the gradation adjustment unit 25 adjusts the gradation according to the curve C shown in Fig. 17, it can suppress blown-out highlights and gradation loss in bright areas more than when the gradation is adjusted according to the curve C shown in Fig. 16. Also, for example, as shown in Fig. 14, when the maximum average value of the luminance of each region is 220 or more, the gradation adjustment unit 25 adjusts the gradation so as to compensate for the luminance of the image according to the gamma correction curve C shown in Fig. 17 by the amount of exposure reduced by the exposure control unit 23.

[0075] Next, processing executed by the camera control device according to the second embodiment will be described with reference to Fig. 18 and Fig. 19. Fig. 18 and Fig. 19 are flowcharts showing an example of processing executed by the camera control device according to the second embodiment.

[0076] In step S1801, camera 1 executes a process of capturing an image.

[0077] In step S1802, the camera control device 20 executes one of photon number counting processes, etc. Specifically, the camera control device 20 executes photon number counting process, photon number integration process, luminance measurement process, luminance integration process, evaluation value calculation process, or evaluation value integration process.

[0078] In step S1803, the deterioration level estimation unit 22 estimates the deterioration level of the image sensor 104.

[0079] In step S1804, the exposure control unit 23 determines whether the degree of deterioration estimated in step S1802 satisfies a predetermined condition. If the exposure control unit 23 determines that the degree of deterioration estimated in step S1802 satisfies the predetermined condition (step S1804: YES), the process proceeds to step S1806. On the other hand, if the exposure control unit 23 determines that the degree of deterioration estimated in step S1802 does not satisfy the predetermined condition (step S1804: NO), the process proceeds to step S1805.

[0080] In step S1805, the exposure control unit 23 controls parameters related to the amount of exposure to the image sensor 104 so that the amount of exposure to the image sensor 104 is a normal amount of exposure. The normal amount of exposure here refers to an amount of exposure necessary to ensure that the image quality of the image converted into an electrical signal by the image sensor 104 is at or above a predetermined level.

[0081] In step S1806, the exposure control unit 23 determines whether or not an instruction to prioritize suppression of deterioration of the image sensor 104 over image quality has been received. If the exposure control unit 23 determines that an instruction to prioritize suppression of deterioration of the image sensor 104 over image quality has been received (step S1806: YES), the process proceeds to step S1809. On the other hand, if the exposure control unit 23 determines that an instruction to prioritize suppression of deterioration of the image sensor 104 over image quality has not been received (step S1806: NO), the process proceeds to step S1807.

[0082] In step S1807, the exposure control unit 23 selects the normal program diagram.

[0083] In step S1808, the exposure control unit 23 controls parameters relating to the amount of exposure to the image sensor 104 based on the normal program chart.

[0084] In step S1809, the exposure control unit 23 determines whether or not there are a predetermined number or more regions whose average brightness is equal to or greater than a predetermined brightness. If the exposure control unit 23 determines that there are a predetermined number or more regions whose average brightness is equal to or greater than a predetermined brightness (step S1809: YES), the exposure control unit 23 proceeds to step S1812. On the other hand, if the exposure control unit 23 determines that there are not a predetermined number or more regions whose average brightness is equal to or greater than a predetermined brightness (step S1809: NO), the exposure control unit 23 proceeds to step S1810.

[0085] In step S1810, the exposure control unit 23 selects a deterioration suppression program diagram.

[0086] In step S1811, the exposure control unit 23 controls parameters relating to the amount of exposure to the image sensor 104 based on the deterioration suppression program chart.

[0087] In step S1812, the exposure control unit 23 controls parameters relating to the amount of exposure to the image sensor 104 so that the amount of exposure to the image sensor 104 is equal to or less than a predetermined amount of exposure.

[0088] In step S1813, the gradation adjustment unit 25 adjusts the gradation of the image.

[0089] In step S1814, the output unit 26 outputs the image whose gradation has been adjusted in step S1813.

[0090] The encoding device 2 according to the embodiment has been described above. The camera control device 20 estimates a degradation level indicating the degree of degradation of the image sensor 104, which converts an image of a subject into an electrical signal. For example, the camera control device 20 estimates the degradation level by photon number counting processing, photon number integration processing, luminance measurement processing, luminance integration processing, evaluation value calculation processing, or evaluation value integration processing. Then, when the degradation level satisfies a predetermined condition, the camera control device 20 controls a parameter related to the exposure amount of the image sensor 104 so that the exposure amount of the image sensor 104 is equal to or less than a predetermined exposure amount. In this way, the camera control device 20 can suppress degradation of the image sensor 104 mounted on the camera 1.

[0091] Furthermore, the camera control device 20 executes photon number counting processing, photon number integration processing, luminance measurement processing, luminance integration processing, evaluation value calculation processing, or evaluation value integration processing for each region set on the light receiving surface of the image sensor 104, and estimates the degree of deterioration for each region. Alternatively, the camera control device 20 controls parameters related to the amount of exposure to the image sensor 104 based on the brightness of a region whose degree of deterioration is equal to or greater than a predetermined degree of deterioration. This allows the camera control device 20 to prevent further deterioration in the most deteriorated portion of the light receiving surface of the image sensor 104.

[0092] Furthermore, the camera control device 20 controls parameters related to the amount of exposure to the image sensor 104 based on a program diagram selected based on the degree of degradation. For example, if the degree of degradation does not satisfy a predetermined condition, the camera control device 20 selects a normal program diagram as the program diagram and controls parameters related to the amount of exposure to the image sensor 104 based on the normal program diagram. For example, if the degree of degradation satisfies a predetermined condition, the camera control device 20 selects a degradation suppression program diagram as the program diagram and controls parameters related to the amount of exposure to the image sensor 104 based on the degradation suppression program diagram. Therefore, the camera control device 20 can select an appropriate program diagram according to the degree of degradation and control parameters appropriately in accordance with the degree of degradation.

[0093] Furthermore, the camera control device 20 estimates a short-term deterioration degree, which is the degree of deterioration in a first period, and a long-term deterioration degree, which is the degree of deterioration in a second period longer than the first period, and selects a program diagram based on the short-term deterioration degree and the long-term deterioration degree. This allows the camera control device 20 to select a suitable program diagram that matches both the degree of progression of deterioration in the first period and the degree of progression of deterioration in the second period.

[0094] Furthermore, the camera control device 20 increases the brightness of the image generated after the parameters related to the exposure amount to the image sensor 104 are controlled by the exposure control unit 23. This allows the camera control device 20 to output an image in which the necessary brightness is ensured while suppressing deterioration of the image sensor 104.

[0095] Furthermore, the camera control device 20 adjusts the gradation of an image generated after the parameters related to the amount of exposure to the image sensor 104 are controlled by the exposure control unit 23. This allows the camera control device 20 to output an image with suitably adjusted gradation while suppressing deterioration of the image sensor 104.

[0096] The exposure control unit 23 may switch the program diagram depending on whether the energy of the photons incident on the image sensor 104 belongs to the visible light region or the infrared region. This allows the exposure control unit 23 to select a suitable program diagram depending on whether the energy of the photons incident on the image sensor 104 belongs to the visible light region or the infrared region.

[0097] Furthermore, the exposure control unit 23 may switch the program chart based on whether or not flicker is present in the image generated using the image sensor 104. This allows the exposure control unit 23 to select a suitable program chart for when flicker is present in the image generated using the image sensor 104 or when flicker is not present in the image generated using the image sensor 104.

[0098] The present invention also includes the following inventions that appropriately combine the above-mentioned features.

[0099] (Configuration 1) A camera control device comprising: a deterioration level estimation means for estimating a deterioration level indicating the degree of deterioration of an image sensor that converts an image of a subject into an electrical signal; and an exposure control means for controlling a parameter related to the exposure amount to the image sensor so that the exposure amount to the image sensor is equal to or less than a predetermined exposure amount when the deterioration level satisfies a predetermined condition.

[0100] (Configuration 2) The camera control device according to configuration 1, further comprising a photon counting means that executes a photon number counting process that counts the number of photons incident on the image sensor or a photon number integration process that integrates the number of photons incident on the image sensor over a predetermined period, wherein the degradation degree estimation means estimates the degradation degree based on the number of photons counted by the photon number counting process or the number of photons integrated by the photon number integration process.

[0101] (Configuration 3) The camera control device according to configuration 2, wherein the photon counting means executes the photon number counting process or the photon number integration process for each area set on the light receiving surface of the image sensor, and the deterioration level estimation means estimates the deterioration level for each of the areas.

[0102] (Configuration 4) The camera control device according to any one of configurations 1 to 3, wherein the degradation level estimation means executes a luminance measurement process that measures the luminance of the image converted into an electrical signal by the imaging element, or a luminance integration process that integrates the luminance of the image converted into an electrical signal by the imaging element over a predetermined period, and estimates the degradation level based on the luminance measured by the luminance measurement process or the luminance integrated by the luminance integration process.

[0103] (Configuration 5) 5. The camera control device according to configuration 4, wherein the degradation level estimation means executes the luminance measurement process or the luminance integration process for each area set on the light receiving surface of the image sensor, and estimates the degradation level for each area.

[0104] (Configuration 6) The camera control device according to any one of configurations 1 to 5, wherein the deterioration level estimation means executes an evaluation value calculation process that calculates an evaluation value related to the brightness of the image converted into an electrical signal by the imaging element, or an evaluation value accumulation process that accumulates the evaluation value over a predetermined period, and estimates the deterioration level based on the evaluation value calculated by the evaluation value calculation process or the evaluation value accumulated by the evaluation value accumulation process.

[0105] (Configuration 7) 7. The camera control device according to configuration 6, wherein the degradation level estimation means executes the evaluation value calculation process or the evaluation value accumulation process for each area set on the light receiving surface of the imaging element, and estimates the degradation level for each area.

[0106] (Configuration 8) 8. The camera control device according to configuration 7, wherein the exposure control means controls a parameter relating to the amount of exposure to the image sensor based on the brightness of the area where the degree of degradation is equal to or greater than a predetermined degree of degradation.

[0107] (Configuration 9) The camera control device according to any one of configurations 1 to 8, wherein the exposure control means controls a parameter related to the amount of exposure to the image sensor based on a program diagram related to the amount of exposure to the image sensor, the program diagram being selected based on the degree of deterioration.

[0108] (Configuration 10) The camera control device according to configuration 9, wherein the exposure control means, when the degree of deterioration does not satisfy the predetermined condition, selects as the program diagram a normal program diagram that makes the image quality of the image converted into an electrical signal by the image sensor at a predetermined level or higher, and controls parameters related to the amount of exposure to the image sensor based on the normal program diagram.

[0109] (Configuration 11) The camera control device described in configuration 10, wherein the exposure control means selects the normal program diagram and then switches to a degradation suppression program diagram that sets the exposure amount to the image sensor to a predetermined exposure amount or less when the degradation level is estimated to be a first degradation level.

[0110] (Configuration 12) The camera control device described in configuration 9, wherein the exposure control means, when the degree of deterioration satisfies the predetermined condition, selects as the program diagram a deterioration suppression program diagram that sets the exposure amount to the image sensor to a predetermined exposure amount or less, and controls parameters related to the exposure amount to the image sensor based on the deterioration suppression program diagram.

[0111] (Configuration 13) The camera control device described in configuration 12, wherein the exposure control means, after selecting the degradation suppression program chart, switches to a normal program chart that makes the image quality of the image converted into an electrical signal by the image sensor at a predetermined level or above when the degradation level is estimated to be a second degradation level that is higher than the first degradation level.

[0112] (Configuration 14) The camera control device according to any one of configurations 9 to 13, wherein the deterioration level estimation means estimates a short-term deterioration level, which is the deterioration level in a first period, and a long-term deterioration level, which is the deterioration level in a second period that is longer than the first period, and the exposure control means selects the program diagram based on at least one of the short-term deterioration level and the long-term deterioration level.

[0113] (Configuration 15) The camera control device according to any one of configurations 9 to 14, wherein the exposure control means switches the program diagram depending on whether the energy of photons incident on the image sensor belongs to a visible light region or an infrared region.

[0114] (Configuration 16) 16. The camera control device according to any one of configurations 9 to 15, wherein the exposure control means switches the program chart based on whether or not flicker is included in an image generated using the imaging element.

[0115] (Configuration 17) 17. The camera control device according to any one of configurations 1 to 16, wherein the exposure control means controls at least one of a shutter speed, an aperture value, a filter transmittance, and a gain.

[0116] (Configuration 18) The camera control device according to any one of configurations 1 to 17, further comprising a brightness adjustment means for increasing the brightness of an image generated after a parameter related to the amount of exposure to the image sensor is controlled by the exposure control means.

[0117] (Configuration 19) 19. The camera control device according to any one of configurations 1 to 18, further comprising a gradation adjustment means for adjusting the gradation of an image generated after a parameter related to the amount of exposure to the image sensor is controlled by the exposure control means.

[0118] (Program 1) A camera control program that estimates a degree of deterioration that indicates the degree of deterioration of an image sensor that converts an image of a subject into an electrical signal, and, if the degree of deterioration satisfies a predetermined condition, controls a parameter related to the exposure amount to the image sensor so that the exposure amount to the image sensor is equal to or less than a predetermined exposure amount.

[0119] (Method 1) A camera control method comprising: estimating a degree of deterioration that indicates the degree of deterioration of an image sensor that converts an image of a subject into an electrical signal; and, if the degree of deterioration satisfies a predetermined condition, controlling a parameter related to the exposure amount to the image sensor so that the exposure amount to the image sensor is equal to or less than a predetermined exposure amount.

[0120] <Other embodiments> The present invention can also be realized by supplying a program that realizes one or more of the functions of the above-described embodiments to a system or device via a network or a recording medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit that realizes one or more of the functions, such as an ASIC (Application Specific Integrated Circuit).

[0121] The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments. In other words, the present invention includes embodiments in which various modifications have been made based on the spirit of the present invention, and these embodiments are not excluded from the scope of the present invention. [Explanation of symbols]

[0122] 1: Camera 10: Imaging unit 20: Camera control device 21: Image generation unit 22: Deterioration degree estimation part 23: Exposure control unit 24: Brightness adjustment section 25: Gradation adjustment section 26: Output section

Claims

1. a photon counting means for performing a photon counting process for counting the number of photons incident on an image sensor that converts light from a subject into an electrical signal to generate an image, or a photon number integrating process for integrating the number of photons incident on the image sensor over a predetermined period of time; a degradation level estimation means for estimating a degradation level indicating a degree of degradation of the image sensor based on the number of photons counted by the photon number counting process or the number of photons integrated by the photon number integration process; an exposure control means for controlling, when the degree of deterioration is greater than a predetermined value, a parameter relating to the amount of exposure to the image sensor so that the amount of exposure to the image sensor is smaller than when the degree of deterioration is equal to or less than the predetermined value; A camera control device comprising:

2. the photon counting means executes the photon number counting process or the photon number integrating process for each area set on the light receiving surface of the image sensor, the deterioration level estimation means estimates the deterioration level for each of the regions; The camera control device according to claim 1 .

3. a deterioration level estimation means for estimating a deterioration level indicating a degree of deterioration of an image pickup element that generates an image by converting light from a subject into an electrical signal; an exposure control means for controlling a parameter relating to the amount of exposure to the image sensor when the degree of deterioration is greater than a predetermined value so that the amount of exposure to the image sensor is smaller than when the degree of deterioration is equal to or less than the predetermined value; the deterioration level estimation means executes a luminance measurement process for measuring the luminance of the image converted into an electrical signal by the imaging element, or a luminance integration process for integrating the luminance of the image converted into an electrical signal by the imaging element over a predetermined period, and estimates the deterioration level based on the luminance measured by the luminance measurement process or the luminance integrated by the luminance integration process. A camera control device comprising:

4. the deterioration level estimation means executes the luminance measurement process or the luminance integration process for each region set on the light receiving surface of the image sensor, and estimates the deterioration level for each region. The camera control device according to claim 3 .

5. 4. The camera control device according to claim 3, further comprising a photon counting unit that executes a photon counting process for counting the number of photons incident on the image sensor or a photon number integrating process for integrating the number of photons incident on the image sensor over a predetermined period of time.

6. a deterioration level estimation means for estimating a deterioration level indicating a degree of deterioration of an image pickup element that generates an image by converting light from a subject into an electrical signal; an exposure control means for controlling a parameter relating to the amount of exposure to the image sensor when the degree of deterioration is greater than a predetermined value so that the amount of exposure to the image sensor is smaller than when the degree of deterioration is equal to or less than the predetermined value; the deterioration level estimation means executes an evaluation value calculation process for calculating an evaluation value relating to the brightness of the image converted into an electrical signal by the imaging element, or an evaluation value accumulation process for accumulating the evaluation value over a predetermined period, and estimates the deterioration level based on the evaluation value calculated by the evaluation value calculation process or the evaluation value accumulated by the evaluation value accumulation process. A camera control device comprising:

7. the deterioration level estimation means executes the evaluation value calculation process or the evaluation value accumulation process for each region set on the light receiving surface of the imaging element, and estimates the deterioration level for each region. The camera control device according to claim 6 .

8. the exposure control means controls a parameter relating to the amount of exposure to the image sensor based on the brightness of the area where the degree of deterioration is equal to or greater than a predetermined degree of deterioration. The camera control device according to claim 7 .

9. 7. The camera control device according to claim 6, further comprising a photon counting unit that executes a photon counting process for counting the number of photons incident on the image sensor or a photon number integrating process for integrating the number of photons incident on the image sensor over a predetermined period of time.

10. the exposure control means controls a parameter relating to the amount of exposure to the image sensor based on a program diagram relating to the amount of exposure to the image sensor, the program diagram being selected based on the degree of deterioration. The camera control device according to claim 1 .

11. when the degree of deterioration is less than a predetermined threshold, the exposure control means selects, as the program chart, a normal program chart that makes the image quality of the image converted into an electrical signal by the image sensor at a predetermined level or higher, and controls parameters related to the amount of exposure to the image sensor based on the normal program chart. The camera control device according to claim 10.

12. the exposure control means selects the normal program chart, and then switches to a deterioration suppression program chart that sets the exposure amount to the image sensor to a predetermined exposure amount or less at a point in time when the deterioration level is estimated to be a first deterioration level. The camera control device according to claim 11 .

13. the exposure control means, when the degree of deterioration is equal to or greater than a predetermined threshold, selects, as the program diagram, a deterioration suppression program diagram that sets the amount of exposure to the image sensor to a predetermined amount or less, and controls a parameter related to the amount of exposure to the image sensor based on the deterioration suppression program diagram. The camera control device according to claim 10.

14. the deterioration level estimation means estimates a short-term deterioration level, which is the deterioration level in a first period, and a long-term deterioration level, which is the deterioration level in a second period that is longer than the first period; the exposure control means selects the program diagram based on at least one of the short-term deterioration degree and the long-term deterioration degree. The camera control device according to claim 10.

15. the exposure control means switches the program diagram depending on whether the energy of the photons incident on the image sensor is in the visible light region or in the infrared region. The camera control device according to claim 10.

16. the exposure control means switches the program chart based on whether or not flicker is present in the image generated using the image sensor. The camera control device according to claim 10.

17. the exposure control means controls at least one of a shutter speed, an aperture value, and a filter transmittance; a brightness adjusting unit that adjusts a gain so as to correct brightness of the image that changes in response to control of at least one of the shutter speed, the aperture value, and the transmittance of the filter; The camera control device according to claim 1 .

18. a brightness adjusting unit that increases the brightness of an image generated after a parameter related to the amount of exposure to the image sensor is controlled by the exposure control unit; The camera control device according to claim 1 .

19. further comprising a gradation adjustment unit that adjusts the gradation of an image generated after a parameter related to the amount of exposure to the image sensor is controlled by the exposure control unit; The camera control device according to claim 1 .

20. a photon number counting process for counting the number of photons incident on an image sensor that converts light from a subject into an electrical signal to generate an image, or a photon number integrating process for integrating the number of photons incident on the image sensor over a predetermined period of time; estimating a degree of deterioration of the image sensor based on the number of photons counted by the photon counting process or the number of photons integrated by the photon number integration process; When the degree of deterioration is greater than a predetermined value, a parameter related to the amount of exposure to the image sensor is controlled so that the amount of exposure to the image sensor is smaller than when the degree of deterioration is equal to or less than the predetermined value. Camera control program.

21. a photon number counting process for counting the number of photons incident on an image sensor that converts light from a subject into an electrical signal to generate an image, or a photon number integrating process for integrating the number of photons incident on the image sensor over a predetermined period of time; estimating a degree of deterioration of the image sensor based on the number of photons counted by the photon counting process or the number of photons integrated by the photon number integration process; When the degree of deterioration is greater than a predetermined value, a parameter related to the amount of exposure to the image sensor is controlled so that the amount of exposure to the image sensor is smaller than when the degree of deterioration is equal to or less than the predetermined value. Camera control method.

Images