Automatic exposure adjustment method and apparatus, camera, and computer-readable storage medium

Abstract

The present disclosure relates to an automatic exposure adjustment method and device, a camera, and a computer-readable storage medium. The automatic exposure adjustment method includes a region division calculation step of dividing an image generated based on a subject image signal output from a sensor into a plurality of regions and calculating a brightness component of each of the regions, a dynamic range deficiency determination step of determining a dynamic range deficiency based on the brightness component of each of the regions, and an exposure value determination step of determining a plurality of exposure values ​​suitable for dynamic range expansion based on the dynamic range deficiency. [Effect] This makes it possible to automatically determine a plurality of exposure values ​​that are optimal for dynamic range expansion in order to obtain unique dynamic expansion results without relying on human experience, thereby making it possible to suppress variation between the results of dynamic range expansion and expected results.

Description

[Technical field]

[0001] The present disclosure relates to the field of digital imaging, and in particular to an automatic exposure adjustment method and apparatus, a camera, and a computer-readable storage medium. [Background technology]

[0002] In the field of digital images, the dynamic range is a very important concept, specifically representing the luminance difference between the darkest and brightest parts of an image. In many cases, it is necessary to achieve a better visual effect by expanding the dynamic range, that is, it is necessary to achieve the effect of obtaining an image that has good gradation from dark to bright parts and is close to the dynamic range of human vision by expanding the dynamic range of an image and suppressing white blowout and black crush of the subject image. Currently, various methods have been proposed for expanding the dynamic range by synthesizing multiple images with different exposure values. However, in these methods, the exposure value of the image used for synthesis is determined by a person based on experience, selecting and deciding the results of changing the exposure value and shooting, for example, by a person checking and selecting the excess or deficiency of the exposure value of multiple images by bracket shooting. When the dynamic range is expanded with such exposure values, there may be a variation between the results of the dynamic range expansion and the expected results. Summary of the Invention

[0003] In view of the above circumstances, the present disclosure proposes an automatic exposure adjustment method and device, a camera, and a computer-readable storage medium that automatically determine an exposure value suitable for dynamic range expansion without relying on human experience.

[0004] According to one aspect of the present disclosure, there is provided an automatic exposure adjustment method including: a region division calculation step of dividing an image generated based on a subject image signal output from a sensor into a plurality of regions and calculating a brightness component of each of the regions; a dynamic range deficiency determination step of determining a dynamic range deficiency based on the brightness component of each of the regions; and an exposure value determination step of determining a plurality of exposure values ​​suitable for dynamic range expansion based on the dynamic range deficiency.

[0005] According to another aspect of the present disclosure, there is provided an automatic exposure adjustment device including: a region division calculation unit that divides an image generated based on a subject image signal output from a sensor into a plurality of regions and calculates a brightness component of each of the regions; a dynamic range deficiency determination unit that determines a dynamic range deficiency based on the brightness component of each of the regions; and an exposure value determination unit that determines a plurality of exposure values ​​suitable for dynamic range expansion based on the dynamic range deficiency.

[0006] According to another aspect of the present disclosure, there is provided a camera including a processor and a memory unit for storing instructions executable by the processor, the processor being configured to perform the above-mentioned automatic exposure adjustment method when it executes the instructions stored in the memory unit.

[0007] According to another aspect of the present disclosure, there is provided a non-volatile computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, effectuate the automatic exposure adjustment method described above.

[0008] According to another aspect of the present disclosure, there is provided a computer program product including computer readable code or a non-volatile computer readable storage medium storing computer readable code, the computer readable code, when executed in a processor of an electronic device, causing the processor of the electronic device to perform the automatic exposure adjustment method described above.

[0009] According to the automatic exposure adjustment method and device, camera, and computer-readable storage medium of each aspect of the present disclosure, an image generated based on a subject image signal from a sensor is divided into multiple regions, a brightness component of each region is calculated, the brightness component of each region is statistically analyzed to calculate a dynamic range deficiency, and an exposure value suitable for dynamic range expansion is calculated based on the dynamic range deficiency. This makes it possible to automatically determine multiple exposure values ​​optimal for dynamic range expansion to obtain a unique result of dynamic range expansion without relying on human experience, to suppress the occurrence of variation between the result of dynamic range expansion and the expected result, and to achieve a good visual effect by automatically expanding the dynamic range.

[0010] Other features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0011] The drawings, which form a part of the specification, illustrate exemplary embodiments, features and aspects of the present disclosure and, together with the specification, are used to interpret the principles of the present disclosure. [Figure 1] FIG. 1 shows a flowchart of the automatic exposure adjustment method according to this embodiment. [Diagram 2] FIG. 2 shows a flow chart of a first example of an automatic exposure adjustment method. [Diagram 3] FIG. 3 shows a flow chart of a second example of the automatic exposure adjustment method. [Figure 4] FIG. 4 is a block diagram of an automatic exposure adjustment device according to an exemplary embodiment. [Diagram 5] FIG. 5 shows an example of a sample image. [Figure 6] FIG. 6 shows the result of equally dividing the sample image shown in FIG. [Figure 7] FIG. 7 shows a visualization of the luminance of each region. [Figure 8]FIG. 8 shows an example of a histogram of the brightness component of each region and its normal distribution curve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Various exemplary embodiments, features, and aspects of the present disclosure will now be described in detail with reference to the drawings, in which like reference numerals represent elements of the same or similar function. While illustrating various aspects of the embodiments in the drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0013] The word "exemplary" herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or superior over other embodiments.

[0014] In addition, in order to better explain the present disclosure, many specific details are shown in the following specific embodiments. It should be understood by those skilled in the art that the present disclosure can be similarly implemented without any specific details. In some embodiments, in order to emphasize the gist of the present disclosure, detailed descriptions are not provided for methods, means, elements and circuits that are well known to those skilled in the art.

[0015] In the related art, multiple different exposure values ​​are determined by a person selecting and deciding the results of changing the exposure value and taking pictures based on experience, which creates a problem of variation between the results of dynamic range expansion and the expected results.

[0016] In order to solve this problem, the present disclosure has been achieved by considering a method for automatically calculating optimal multiple different exposure values ​​for synthesizing multiple images with different exposure values ​​and expanding the dynamic range without relying on human experience. In the present disclosure, the area of ​​an image generated based on a subject image signal output from a sensor is arbitrarily divided, the dynamic range of the subject is calculated, for example, by statistical analysis of the brightness components of the divided areas, and an exposure value suitable for expanding the dynamic range is automatically calculated based on the calculation result, thereby determining multiple different exposure values ​​for obtaining a unique result of dynamic expansion without relying on human experience, thereby solving the above problem.

[0017] In the present disclosure, as shown in FIG. 1, an automatic exposure adjustment method is proposed that is executed in a device product that calculates the exposure of a camera, such as a mobile phone, an industrial camera, a security camera, an automotive camera, a camera module, etc. The execution timing of the automatic exposure adjustment method of the present disclosure is not particularly limited. In one possible implementation form, the control method shown in FIG. 1 can be executed immediately after the device product is started. Of course, the device product may execute the control method of this embodiment when an execution condition is reached after a certain time has elapsed since the device product was started, or when execution is commanded by a user.

[0018] In the embodiment shown in FIG. 1, the automatic exposure adjustment method may include the following steps.

[0019] Step S110 (area division calculation step): An image generated based on a subject image signal output from a sensor is divided into a plurality of areas, and the brightness component of each area is calculated.

[0020] In this embodiment, a subject image signal is received from a sensor, an image is generated based on the received subject image signal, the generated image is divided into a plurality of regions, and the brightness component of each region is calculated.

[0021] In one possible implementation, the generated image is divided equally into multiple regions, preferably as many as possible, in order to increase the number of samples for statistical analysis and determine exposure values ​​that are more suitable for dynamic range expansion.

[0022] Although the above description has been given of a method for calculating the brightness component using an example in which the subject image signal is an RGB signal, those skilled in the art will understand that the present disclosure is not limited to this. In practice, the method for calculating the brightness component can be flexibly set according to the user's personal preferences and / or the actual application scene.

[0023] Step S120 (insufficient dynamic range determining step): Insufficient dynamic range is determined based on the brightness component of each region.

[0024] In this embodiment, the brightness component of each region is statistically analyzed, and the dynamic range that is insufficient can be determined based on the results of the statistical analysis. In general, the dynamic range that a sensor can expose is narrower than the dynamic range of human vision. Therefore, whiteout or blackout may occur in the captured image of the subject. The image of the subject in which whiteout or blackout occurs is defined as having an insufficient dynamic range. In this embodiment, the insufficient dynamic range refers to the amount of dynamic range expansion required to suppress whiteout or blackout.

[0025] In one possible implementation, the brightness components of each region are transformed into a uniform space and then statistically analyzed, preferably using a normal distribution for the statistical analysis.

[0026] Although the statistical analysis method has been described above using normal distribution as an example, those skilled in the art will understand that the present disclosure is not limited thereto. In practice, the statistical analysis method can be flexibly set according to the user's personal preferences and / or actual application scenarios, as long as it can determine the dynamic range that is lacking.

[0027] Step S130 (exposure value determination step): Based on the dynamic range deficiency, a plurality of exposure values ​​suitable for dynamic range expansion are determined.

[0028] In this embodiment, after determining the dynamic range deficiency based on the result of the statistical analysis, a plurality of exposure values ​​suitable for expanding the dynamic range are determined based on the dynamic range deficiency.

[0029] In one possible embodiment, a plurality of exposure values ​​are determined based on an exposure value when an object image signal is captured and a dynamic range that is insufficient. For example, a correspondence table or a calculation formula corresponding to the exposure value may be determined from a plurality of correspondence tables or a plurality of calculation formulas pre-stored in a storage unit based on an exposure value when an object image signal is captured, and an exposure value suitable for dynamic range expansion recorded in the determined correspondence table may be determined based on the dynamic range that is insufficient, or an exposure value suitable for dynamic range expansion may be calculated by the calculation formula based on the dynamic range that is insufficient. Also, an object image signal is captured at a predetermined exposure value, and an exposure value suitable for dynamic range expansion recorded in a correspondence table pre-stored in a storage unit may be determined based on the dynamic range that is insufficient, or an exposure value suitable for dynamic range expansion may be calculated by the calculation formula pre-stored in a storage unit based on the dynamic range that is insufficient.

[0030] In this way, an image generated based on a subject image signal from a sensor is divided into a plurality of regions, a brightness component of each region is calculated, the brightness component of each region is statistically analyzed to calculate a dynamic range deficiency, and an exposure value suitable for dynamic range expansion is calculated based on the dynamic range deficiency. According to the automatic exposure adjustment method of the above embodiment of the present disclosure, it is possible to automatically determine a plurality of exposure values ​​optimal for dynamic range expansion in order to obtain a unique dynamic range expansion result without relying on human experience, it is possible to suppress the occurrence of variation between the result of dynamic range expansion and the expected result, and it is possible to achieve a good visual effect by automatically expanding the dynamic range.

[0031] A first example of the automatic exposure adjustment method will be specifically described with reference to Fig. 2. As shown in Fig. 2, the automatic exposure adjustment method of the first example may include the following steps.

[0032] Step S210: A subject image signal captured at a predetermined exposure value is received, which is output from the sensor.

[0033] For example, an exposure value for acquiring a subject image signal is set in advance, and the camera captures an image of the subject at this exposure value and acquires the subject image signal by a sensor.

[0034] Step S220: An image is generated based on the received subject image signal.

[0035] Step S230: Divide the generated image into a plurality of regions.

[0036] In this embodiment, the area of ​​the generated image can be divided arbitrarily. For example, the sample image shown in FIG. 5 can be evenly divided into 32×32 areas as shown in FIG.

[0037] It is desirable to divide as many times as possible in order to increase the number of samples for statistical analysis and determine an exposure value that is more suitable for expanding the dynamic range. On the other hand, if the number of divisions is too large, it will take a lot of time and cost to calculate the brightness components and perform the statistical analysis. Therefore, it is considered to set the number of divisions appropriately according to actual needs.

[0038] Step S240: The brightness component of each region is calculated.

[0039] For example, if the subject image signal is an RGB signal, the pixel values ​​for each area and for each R, G, and B component are integrated, and the luminance Y obtained by converting from RGB to YUV can be used as the brightness component. The conversion formula for luminance Y based on BT.709 is as follows: Y=0.2126×R+0.7152×G+0.07222×B

[0040] FIG. 7 shows a visualization of the luminance Y of each region.

[0041] Step S250: The brightness component of each region is statistically analyzed, and the dynamic range deficiency is determined based on the result of the statistical analysis.

[0042] For example, by calculating the logarithm to base 2 of the brightness components of each region based on APEX (The Additive System of Photographic Exposure) and converting them to a uniform space, it is possible to perform a calculation to make the brightness components of the dark side regions and the bright side regions have the same scale.

[0043] For example, one method of statistical analysis is estimation using normal distribution. The probability that an unknown sample will be distributed in the range of the mean ± N × standard deviation is determined by the size of N. If N = 3, the probability is 99.7%. By calculating the mean and standard deviation of the brightness component of the divided area, and setting the maximum and minimum values ​​of the brightness component of the divided area to the mean ± N × standard deviation, respectively, it is possible to estimate the missing dynamic range.

[0044] Figure 8 shows an example of a histogram of the brightness component (logarithmic value with base 2) of each region and its normal distribution curve. The insufficient dynamic range can be estimated from the results of comparing the histogram and normal distribution curve. For example, as shown in Figure 8, it can be seen that the subject image signal output from the sensor is dark and there is an insufficient dynamic range on the bright side.

[0045] Step S260: Based on the dynamic range deficiency, a number of exposure values ​​suitable for dynamic range expansion are determined.

[0046] For example, the storage unit may store in advance a correspondence table in which the insufficient dynamic range and the corresponding exposure value suitable for dynamic range expansion are recorded, or a calculation formula for calculating the exposure value suitable for dynamic range expansion using the insufficient dynamic range as a parameter. Depending on the insufficient dynamic range calculated in step S250, the corresponding exposure value suitable for dynamic range expansion is determined in the correspondence table, or the insufficient dynamic range calculated in step S250 is substituted into the calculation formula to calculate the exposure value suitable for dynamic range expansion. For example, the insufficient dynamic range and the exposure value suitable for expanding the dynamic range may be calculated using the following specific calculation formula.

number

[0047] Although the method of determining the exposure value has been described above using the correspondence table and the calculation example, a person skilled in the art would understand that the present disclosure is not limited to this. It is sufficient to determine a plurality of exposure values ​​suitable for expanding the dynamic range based on the insufficient dynamic range.

[0048] In this way, an image generated based on a subject image signal captured at a predetermined exposure value output from a sensor is divided into a plurality of regions, a brightness component of each region is calculated, the brightness component of each region is statistically analyzed to calculate a dynamic range deficiency, and an exposure value suitable for dynamic range expansion is calculated based on the dynamic range deficiency. According to the automatic exposure adjustment method of the above embodiment of the present disclosure, it is possible to automatically determine a plurality of exposure values ​​optimal for dynamic range expansion in order to obtain a unique dynamic range expansion result without relying on human experience, it is possible to suppress the occurrence of variation between the result of dynamic range expansion and the expected result, and it is possible to achieve a good visual effect by automatically expanding the dynamic range.

[0049] A second example of the automatic exposure adjustment method will be specifically described with reference to Fig. 3. As shown in Fig. 3, the automatic exposure adjustment method of the second example may include the following steps.

[0050] Step S310: A subject image signal output from the sensor is received, and an exposure value for capturing the subject image signal is determined.

[0051] For example, the camera photographs a subject at an arbitrary exposure value and obtains a subject image signal by a sensor. When the camera receives the subject image signal output from the sensor, it determines an exposure value for photographing the subject image signal. For example, the camera may receive the exposure value for photographing the subject image signal together with the subject image signal, or may transmit a request for obtaining the exposure value for photographing the subject image signal to the camera and obtain the exposure value for photographing the subject image signal.

[0052] Steps S320 to S350 are the same as steps S220 to S250, and therefore a description thereof will be omitted here.

[0053] Step S360: Based on the exposure value when capturing the subject image signal and the insufficient dynamic range, a plurality of exposure values ​​suitable for expanding the dynamic range are determined.

[0054] For example, the storage unit may store in advance a plurality of correspondence tables in which the insufficient dynamic range and the corresponding exposure value suitable for dynamic range expansion are recorded, or a calculation formula capable of calculating an exposure value suitable for dynamic range expansion using the insufficient dynamic range as a parameter. The correspondence table or calculation formula is stored in the storage unit as an exposure value when the subject image signal is captured. Based on the exposure value when the subject image signal is captured determined in step S310, the correspondence table or calculation formula corresponding to the exposure value is selected from the storage unit. Based on the insufficient dynamic range calculated in step S350, an exposure value suitable for dynamic range expansion corresponding to the selected correspondence table is determined, or the insufficient dynamic range calculated in step S350 is substituted into the selected calculation formula to calculate an exposure value suitable for dynamic range expansion.

[0055] Furthermore, the storage unit pre-stores a calculation formula for calculating an exposure value suitable for expanding the dynamic range, using the exposure value when capturing the subject image signal and the insufficient dynamic range as parameters. The exposure value when capturing the subject image signal determined in step S310 and the insufficient dynamic range calculated in step S350 may be substituted into this calculation formula to calculate the exposure value suitable for expanding the dynamic range.

[0056] In this way, an image generated based on a subject image signal from a sensor is divided into a plurality of regions, a brightness component of each region is calculated, the brightness component of each region is statistically analyzed to calculate a dynamic range deficiency, and an exposure value suitable for dynamic range expansion is calculated based on the exposure value when capturing the subject image signal and the dynamic range deficiency. According to the automatic exposure adjustment method of the above embodiment of the present disclosure, it is possible to automatically determine a plurality of exposure values ​​optimal for dynamic range expansion in order to obtain a unique result of dynamic range expansion without relying on human experience, and it is possible to suppress the occurrence of variation between the result of dynamic range expansion and the expected result.

[0057] Fig. 4 is a block diagram of an automatic exposure adjusting device according to an exemplary embodiment. As shown in Fig. 4, the automatic exposure adjusting device may include an area division calculation unit 410 that divides an image generated based on a subject image signal output from a sensor into a plurality of areas and calculates a brightness component of each area, a dynamic range deficiency determination unit 420 that determines a dynamic range deficiency based on the brightness component of each area, and an exposure value determination unit 430 that determines a plurality of exposure values ​​suitable for dynamic range expansion based on the dynamic range deficiency.

[0058] In one possible implementation, the region division calculation unit 410 evenly divides an image generated based on the subject image signal output from the sensor into a plurality of regions.

[0059] In one possible implementation, the deficit dynamic range determiner 420 converts the luminance component of each region into a uniform space and then performs statistical analysis on the luminance component of each region.

[0060] In one possible implementation, the statistical analysis utilizes a normal distribution.

[0061] In one possible implementation, the exposure value determination unit 430 determines a plurality of exposure values ​​suitable for dynamic range expansion based on an exposure value when the subject image signal is captured and a dynamic range that is insufficient. For example, based on an exposure value when the subject image signal is captured, a correspondence table or a calculation formula corresponding to the exposure value may be determined from a plurality of correspondence tables or a plurality of calculation formulas pre-stored in the storage unit, and based on the dynamic range that is insufficient, an exposure value suitable for dynamic range expansion recorded in the determined correspondence table may be determined, or based on the dynamic range that is insufficient, an exposure value suitable for dynamic range expansion may be calculated by the calculation formula. Also, the subject image signal is captured at a predetermined exposure value, and based on the dynamic range that is insufficient, an exposure value suitable for dynamic range expansion recorded in a correspondence table pre-stored in the storage unit may be determined, or based on the dynamic range that is insufficient, an exposure value suitable for dynamic range expansion may be calculated by the calculation formula pre-stored in the storage unit.

[0062] Regarding the apparatus in the above-mentioned embodiment, the specific method by which each unit performs an operation is described in detail in the embodiment related to the method, and therefore a detailed description thereof will be omitted here.

[0063] In comparison with the conventional technology in which a person changes the exposure value based on experience, selects the results of shooting, and determines the exposure value of an image to be used for synthesis, the present disclosure divides an image generated based on a subject image signal from a sensor into multiple regions, calculates the brightness component of each region, statistically analyzes the brightness component of each region to calculate the dynamic range deficiency, and calculates an exposure value suitable for dynamic range expansion based on the dynamic range deficiency. This makes it possible to automatically determine multiple exposure values ​​optimal for dynamic range expansion to obtain a unique result of dynamic range expansion without relying on human experience, suppress the occurrence of variation between the result of dynamic range expansion and the expected result, and achieve a good visual effect by automatically expanding the dynamic range.

[0064] In some embodiments, the functions or modules of the apparatus according to the embodiments of the present disclosure are used to perform the methods described in the above method embodiments. Specific implementations will be apparent from the description of the above method embodiments, and detailed descriptions will be omitted for brevity.

[0065] An embodiment of the present disclosure further provides a computer readable storage medium having computer program instructions stored thereon, the computer program instructions, when executed by a processor, causing the computer to implement the above-mentioned automatic exposure adjustment method. The computer readable storage medium may be a volatile or non-volatile computer readable storage medium.

[0066] An embodiment of the present disclosure further provides a camera including a processor and a memory unit for storing instructions executable by the processor, the processor being configured to perform the above-mentioned automatic exposure adjustment method when it executes the instructions stored in the memory unit.

[0067] An embodiment of the present disclosure further provides a computer program product including computer readable code or a non-volatile computer readable storage medium having computer readable code stored thereon, the computer readable code, when executed in a processor of an electronic device, causing the processor of the electronic device to perform the automatic exposure adjustment method described above.

[0068] Although the embodiments of the present disclosure have been described above, the above description is merely illustrative and not exhaustive, and is not limited to the embodiments disclosed. Various modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The terms selected in this specification are intended to appropriately interpret the principles, practical applications, or improvements to existing technology of the embodiments, or to allow other skilled in the art to understand the embodiments disclosed in the text.

Claims

1. an area division calculation step of dividing an image generated based on a subject image signal output from a sensor into a plurality of areas and calculating a brightness component of each of the areas; a dynamic range deficiency determination step of determining a dynamic range deficiency based on the brightness component of each of the regions; and determining a plurality of exposure values ​​suitable for expanding the dynamic range based on the insufficient dynamic range. The step of determining a dynamic range deficiency includes: performing a statistical analysis of the brightness components of each of the regions in a uniform space to determine the dynamic range deficiency; 23. An automatic exposure adjustment method comprising:

2. 2. The automatic exposure adjustment method according to claim 1, wherein in said region division calculation step, said image is divided equally into a plurality of regions.

3. 2. The method of claim 1, wherein the statistical analysis utilizes a normal distribution.

4. 4. The automatic exposure adjustment method according to claim 1, wherein in the exposure value determination step, the plurality of exposure values ​​are determined based on an exposure value when the subject image signal is captured and the insufficient dynamic range.

5. The exposure value determination step includes: determining a correspondence table corresponding to the exposure value from among a plurality of correspondence tables pre-stored in a storage unit based on the exposure value when the subject image signal is captured, and determining an exposure value suitable for dynamic range expansion recorded in the corresponding correspondence table based on the insufficient dynamic range; or 5. The automatic exposure adjustment method according to claim 4, further comprising a step of determining a calculation formula corresponding to the exposure value from among a plurality of calculation formulas pre-stored in a storage unit based on the exposure value when the subject image signal is captured, and calculating an exposure value suitable for dynamic range expansion using the corresponding calculation formula based on the insufficient dynamic range.

6. The subject image signal is captured at a predetermined exposure value, The automatic exposure adjustment method according to any one of claims 1 to 3, characterized in that the exposure value determination step includes a step of determining an exposure value suitable for dynamic range expansion recorded in a correspondence table pre-stored in a storage unit based on the insufficient dynamic range, or a step of calculating an exposure value suitable for dynamic range expansion by a calculation formula pre-stored in a storage unit based on the insufficient dynamic range.

7. an area division calculation unit that divides an image generated based on a subject image signal output from a sensor into a plurality of areas and calculates a brightness component of each of the areas; a dynamic range deficiency determination unit that determines a dynamic range deficiency based on the brightness component of each of the regions; an exposure value determination unit that determines a plurality of exposure values ​​suitable for expanding a dynamic range based on the insufficient dynamic range; The dynamic range deficiency determination unit is A luminance component of each of the regions is statistically analyzed in a uniform space to determine the dynamic range deficiency. An automatic exposure adjustment device characterized by:

8. A processor; a memory unit for storing instructions executable by a processor; A camera, characterized in that the processor is configured to perform the automatic exposure adjustment method according to any one of claims 1 to 3 when executing instructions stored in the memory unit.

9. A non-volatile computer readable storage medium having stored thereon computer program instructions, the computer program instructions being characterized in that, when executed by a processor, the computer program instructions cause an automatic exposure adjustment method according to any one of claims 1 to 3 to be implemented.

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