Method for adjusting image brightness of photographic system

Abstract

The invention discloses a method for adjusting image brightness of a photographic system. The method comprises the following steps of: providing corresponding relation data; detecting position data of a moving object through a moving object detection device; obtaining a corresponding predetermined image coordinate area from the corresponding relation data according to the position data; obtaining a first image output by the image capturing device; calculating a first global exposure parameter of the first image, and calculating a first local exposure parameter of a first local image corresponding to the predetermined image coordinate area in the first image; obtaining another image output by the image capturing device, wherein a local image corresponding to the predetermined image coordinate area in the other image has a local exposure parameter; wherein the local exposure parameter is closer to an ideal exposure parameter than the first local exposure parameter; and outputting the other image as a grid of a film.

Description

Technical Field

[0001] The present invention relates to a photographic system; in particular, it relates to a method for adjusting the image brightness of a photographic system. Background Art

[0002] A traditional surveillance camera is installed in a place to be monitored, continuously captures images of the place, and stores the continuously captured images as a video. Since the traditional surveillance camera continuously stores videos, even if no moving object enters the place, it still continuously captures videos. Therefore, the file size of the video will be large, and more storage space is required to store the video. Another improved surveillance camera does not store images when capturing images, and only starts to store the captured images as a video until a moving object is judged to appear in the images. Therefore, the file size of the video can be smaller.

[0003] Whether it is a traditional surveillance camera or an improved surveillance camera, the distance between the moving object and the surveillance camera will change as the moving object moves. For example, when the moving object approaches the surveillance camera, the brightness on the surface of the moving object may increase as the distance decreases. If the brightness of the moving object itself is overexposed, the surveillance camera needs to adjust the gain value or exposure time of an image sensor of the surveillance camera according to the brightness in the image at any time. In the video recorded in this situation, viewers will find that the brightness of the moving object in the video will have a sudden change, such as sudden overexposure or underexposure. Summary of the Invention

[0004] In view of this, an object of the present invention is to provide a method for adjusting the image brightness of a photographic system, which can make the local image corresponding to the moving object in the video frame obtain better brightness.

[0005] To achieve the above object, a method for adjusting the image brightness of a photographic system provided by the present invention, wherein the photographic system includes an image capturing device, a moving object detecting device, and a processing device. The image capturing device has an imaging range, the moving object detecting device has a detecting range, and the imaging range and the detecting range partially overlap. The image brightness adjustment method includes the following steps:

[0006] A. Provide a correspondence data, which records a plurality of predetermined position data corresponding to a plurality of predetermined positions in the detecting range of the moving object detecting device. Each of the predetermined position data includes a predetermined image coordinate area corresponding to each of the predetermined positions;

[0007] B. Detect a position data of a moving object in the detecting range by the moving object detecting device;

[0008] C. The processing device obtains, according to the position data, a predetermined image coordinate area corresponding to the predetermined position data from the corresponding relationship data;

[0009] D. The processing device controls the image capturing device to obtain a first image output by the image capturing device;

[0010] E. The processing device calculates a first global exposure parameter of the whole of the first image, and calculates a first local exposure parameter of a first local image corresponding to the predetermined image coordinate area in the first image;

[0011] F. The processing device controls the image capturing device to obtain another image output by the image capturing device. The whole of the another image has a global exposure parameter, and a local image corresponding to the predetermined image coordinate area in the another image has a local exposure parameter; wherein, the local exposure parameter is closer to an ideal exposure parameter than the first local exposure parameter; and

[0012] G. The processing device outputs the another image as a frame of a video.

[0013] The effect of the present invention is that the brightness of the local image in the another image has been adjusted to a better brightness before being output as the frame. Therefore, sudden brightness changes of the local image corresponding to a moving object in the frames of the video can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of a photography system according to a first preferred embodiment of the present invention.

[0015] Figure 2 is a schematic diagram of the detection range of a moving object detection device and the imaging range of an image capturing device according to a first preferred embodiment of the present invention.

[0016] Figure 3 is a schematic diagram showing predetermined image coordinate areas corresponding to moving objects at different predetermined positions in an image according to a first preferred embodiment of the present invention.

[0017] Figure 4 is a schematic diagram showing predetermined positions of the detection range of a moving object detection device according to a first preferred embodiment of the present invention.

[0018] Figure 5 is a schematic diagram showing a corresponding relationship data according to a first preferred embodiment of the present invention.

[0019] Figure 6 is a schematic diagram showing predetermined energy values of the corresponding relationship data according to a first preferred embodiment of the present invention.

[0020] Figure 7 Flowchart of the method for adjusting the image brightness according to the first preferred embodiment of the present invention.

[0021] Figure 8 A schematic diagram showing the first image and the first partial image according to the first preferred embodiment of the present invention.

[0022] Figure 9 A schematic diagram showing the change in the exposure value of the first image to the third image according to the first preferred embodiment of the present invention.

[0023] Figure 10 A schematic diagram showing the first image and the first partial image according to the second preferred embodiment of the present invention.

[0024] Figure 11 A schematic diagram showing the change in the exposure value of the first image and the third image according to the second preferred embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 1: Imaging system

[0027] 10: Image capture device

[0028] 10a: Imaging range

[0029] 102: Image sensor

[0030] 20: Moving object detection device

[0031] 20a: Detection range

[0032] 30: Processing device

[0033] 32: Microprocessor

[0034] 34: Image processor

[0035] 40: Storage module

[0036] 50: Light source module

[0037] 60: Ambient light sensor

[0038] 70: Image

[0039] 72: First image

[0040] 722: First partial image

[0041] 724: Occluder

[0042] 80: Corresponding relationship data

[0043] 100: Moving object

[0044] 100a: Personnel

[0045] DATA1 to DATA70: Predetermined position data

[0046] C0: Predetermined image coordinate area

[0047] C1, C2: Coordinate points

[0048] (x1 - 1, y1 - 1): Coordinate point

[0049] (x2 - 1, y2 - 1): Coordinate point

[0050] (x1 - 39, y1 - 39): Coordinate point

[0051] (x2 - 39, y2 - 39): Coordinate point

[0052] P1: Predetermined position

[0053] S11 to S19: Steps Detailed implementation manner

[0054] To more clearly illustrate the present invention, preferred embodiments are given below and described in detail in conjunction with the accompanying drawings. Please refer Figure 1 With Figure 2 As shown, a photography system 1 of a preferred embodiment of the present invention includes an image capturing device 10, a moving object detection device 20, and a processing device 30.

[0055] The image capturing device 10 has an imaging range 10a. The image capturing device 10 includes an image sensor 102. The image capturing device 10 can be controlled to start, and continuously capture and output a plurality of images corresponding to the imaging range 10a through the image sensor 102. In this embodiment, an angle of the imaging range 10a, that is, the viewing angle of the image capturing device 10, can be, for example, 120 degrees. The resolution of the images output by the image capturing device 10 can be, for example, in specifications such as HD, FullHD, 2K, 4K, or above 8K.

[0056] The moving object detection device 20 and the image capturing device 10 are located at the same position, for example, disposed in a housing (not shown). The moving object detection device 20 has a detection range 20a. When a moving object 100, such as a person 100a, enters the detection range 20a of the moving object detection device 20, the moving object detection device 20 detects the moving object 100 and generates corresponding position data. An angle of the detection range 20a can be, for example, 120 degrees, and a maximum distance (i.e., radius) of the detection range 20a can be, for example, 10 meters. The detection range 20a of the moving object detection device 20 partially overlaps with the imaging range 10a of the image capturing device 10. Preferably, the detection range 20a is located within the imaging range 10a, and the angle of the detection range 20a is less than or equal to the angle of the imaging range 10a.

[0057] In this embodiment, the moving object detection device 20 includes a radar, which can be, for example, a millimeter wave radar, but is not limited thereto, and can also be an ultrasonic radar or other types of radars. The position data generated by the radar includes a detection distance value, a detection angle value, and a detection energy value. The detection distance value is the distance between the moving object and the radar, the detection angle value is the relative angle between the moving object and the radar, and the detection energy value is the energy of a detection wave emitted by the radar reflected by the moving object. In an embodiment, in addition to using a radar, the moving object detection device can also use lidar or an infrared sensor (PIR).

[0058] The processing device 30 is electrically connected to the image capturing device 10 and the moving object detection device 20. The processing device 30 is configured to receive the position data of the moving object detection device 20 and control the image capturing device 10, and the processing device 30 receives the image output by the image capturing device 10. In this embodiment, the processing device 30 includes a microprocessor 32 and an image processor 34 that are electrically connected. Among them, the microprocessor 32 is electrically connected to the moving object detection device 20 to receive the position data generated by the moving object detection device 20. The image processor 34 is electrically connected to the microprocessor 32 and the image capturing device 10. The image processor 34 controls the image capturing device 10 to obtain the image output by the image sensor 102 of the image capturing device 10, and the image processor 34 can output the image output by the image sensor 102 of the image capturing device 10 as a frame. A plurality of the frames output by the image processor 34 can form a video. The image processor 34 is electrically connected to a storage module 40 and stores the video in the storage module 40. The storage module 40 can be, for example, a flash memory (such as micro SD, eMMC), a solid state drive, or a mechanical hard disk, etc.

[0059] Please cooperate with Figure 3 , taking the moving object 100 as an example of a person. When the same person is at different positions within the imaging range 10a of the imaging device 10, in the image 70 output by the imaging device 10, the closer the person is to the imaging device 10, the larger the area the person occupies in the image 70. Conversely, the farther the person is from the imaging device 10, the smaller the area the person occupies in the image 70.

[0060] Please cooperate with Figures 3 to 6 , the provider of the system can pre - establish a corresponding relationship data 80. The corresponding relationship data 80 includes a plurality of predetermined position data corresponding to a plurality of predetermined positions P1 ( Figure 5 for reference) within the detection range 20a of the moving object detection device 20. Each of the predetermined position data includes a predetermined image coordinate area C0 corresponding to each of the predetermined positions P1. In this embodiment, as Figure 4 shown, the plurality of predetermined position data is set corresponding to the plurality of predetermined positions P1 within the detection range 20a of the moving object detection device 20. The plurality of predetermined positions P1 within the detection range 20a are respectively located on the extension lines at intervals of 20 degrees and at positions every 1 meter; in Figure 4 , taking 70 predetermined positions P1 as an example, but not limited thereto. When the same person stands at each of the predetermined positions P1, an image is captured by the imaging device 10, and the range of the image occupied by the person in the captured image is estimated and set as each of the predetermined image coordinate areas C0. Among them, each predetermined image coordinate area C0 is composed of the range between two coordinate points C1, C2. As Figure 5 and Figure 6 shown, the corresponding relationship data can be, for example, a corresponding table or a data array. The corresponding relationship data 80 has 70 predetermined positions, and the predetermined position data corresponding to each of the predetermined positions are represented by DATA1 - DATA70.

[0061] In this embodiment, each predetermined position data further includes a predetermined distance value, a predetermined angle value, and a predetermined energy value. Each of the predetermined distance values is the distance between each of the predetermined positions and the moving object detection device 20. Each of the predetermined angle values is the angle of each of the predetermined positions relative to the moving object detection device. Each of the predetermined energy values is the detection energy value measured by the moving object detection device 20 when the same person is at each of the predetermined positions P1.

[0062] Taking Figure 3 , Figure 5 and Figure 6For example, in the predetermined position data DATA1, the predetermined image coordinate region C0 is the region from the coordinate point (x1 - 1, y1 - 1) to the coordinate point (x2 - 1, y2 - 1), the predetermined distance value is 10m, the predetermined angle value is 60°, and the predetermined energy value is 16dB. In the predetermined position data DATA39, the predetermined image coordinate region C0 is the region from the coordinate point (x1 - 39, y1 - 39) to the coordinate point (x2 - 39, y2 - 39), the predetermined distance value is 5m, the predetermined angle value is 0°, and the predetermined energy value is 33dB.

[0063] In addition, the supplier of the system can also set that the predetermined distance value of each of the predetermined position data has a corresponding predetermined distance range, the predetermined angle value of each of the predetermined position data has a corresponding predetermined angle range, and the predetermined energy value of each of the predetermined position data has a corresponding predetermined energy range. For example, the lower limit value of each predetermined distance range is the predetermined distance value - 0.4m, and the upper limit value is the predetermined distance value + 0.5m; the lower limit value of each predetermined angle range is the predetermined angle value - 9°, and the upper limit value is the predetermined angle value + 10°; the lower limit value of each predetermined energy range is the predetermined energy value - 3 to - 5dB, and hereinafter, taking the predetermined energy value - 3dB as an example, the upper limit value is the predetermined energy value + 3 to + 5dB, and hereinafter, each predetermined energy range takes the predetermined energy value + / - 3dB as an example. That is, in the predetermined position data DATA1, the predetermined distance range corresponding to the predetermined distance value (10m) is 9.6m to 10.5m, the predetermined angle range corresponding to the predetermined angle value (-60°) is -69° to -50°, and the predetermined energy range corresponding to the predetermined energy value (16dB) is 13dB to 19dB. In the predetermined position data DATA39, the predetermined distance range corresponding to the predetermined distance value (5m) is 4.6m to 5.5m, the predetermined angle range corresponding to the predetermined angle value (0°) is -9° to +10°, and the predetermined energy range corresponding to the predetermined energy value (33dB) is 30dB to 36dB.

[0064] The aforementioned predetermined energy value and predetermined energy range are set for the moving object 100 being a human. When the energy detected by the radar is less than the lower limit value of the predetermined energy range, it is determined as a small non - human object, and when the energy detected by the radar is greater than the upper limit value of the predetermined energy range, it is determined as a large non - human object.

[0065] In this embodiment, the imaging system 1 optionally includes a light source module 50 and an ambient light sensor 60. The light source module 50 and the ambient light sensor 60 are electrically connected to the processing device 30, such as being electrically connected to the microprocessor 32. The light source module 50 can be controlled to change its light emission intensity, and the light emitted by the light source module 50 is directed towards the imaging range 10a. The ambient light sensor 60 detects an ambient illuminance of the environment where the imaging system is located. The microprocessor 32 of the processing device 30 determines whether to turn on the light source module 50 based on the ambient illuminance. For example, the light source is not turned on when the ambient illuminance is sufficient during the day. The microprocessor 32 of the processing device 30 can control the light emission intensity of the light source module 50 according to the position data of the moving object detection device 20 to adaptively adjust the light according to the distance of the moving object. The closer the moving object 100 is, the lower the light emission intensity; the farther the moving object 100 is, the higher the light emission intensity.

[0066] When the imaging system 1 is in the standby mode, the microprocessor 32 of the processing device 30, the image processor 34, and the image capture device 10 enter the standby state to save power consumption. Especially when the power source of the imaging system 1 is a battery, the power of the battery can be saved.

[0067] Through the above architecture, the image brightness adjustment method of this embodiment can be performed. The method includes Figure 7 the following steps shown.

[0068] Step S11: Provide the above-mentioned correspondence data 80. The correspondence data records the multiple predetermined position data corresponding to the multiple predetermined positions P1 in the detection range of the moving object detection device 20. Each predetermined position data includes the predetermined image coordinate area corresponding to each predetermined position. In this embodiment, the provider of the system can store the correspondence data 80 in a memory (not shown) of the processing device 30. The memory can be, for example, the built-in memory of the image processor 34 or an external memory connected to the image processor 34. Each predetermined position data further includes the predetermined distance value, the predetermined angle value, and the predetermined energy value, as well as the corresponding predetermined distance range, the predetermined angle range, and the predetermined energy range.

[0069] Step S12: Detect a position data of the moving object 100 in the detection range through the moving object detection device 20.

[0070] In this embodiment, when the moving object detection device 20 detects that the moving object 100 enters the detection range 20a, the microprocessor 32 is woken up by the moving object detection device 20. The moving object detection device 20 transmits the detected position data to the microprocessor 32. The position data includes the detection distance value, the detection angle value, and the detection energy value. The microprocessor 32 wakes up the image processor 34 and transmits the position data to the image processor 34.

[0071] In this embodiment, it may include an ambient illuminance detection step, which includes:

[0072] The ambient light sensor 60 detects the ambient illuminance and transmits the detected ambient illuminance to the microprocessor 32 of the processing device 30. The microprocessor 32 determines whether to control the light source module 50 to perform supplementary lighting according to the ambient illuminance. When the microprocessor 32 determines that the ambient illuminance is less than a predetermined illuminance, it represents that the current ambient illuminance is insufficient. The microprocessor 32 of the processing device 30 controls the light source module 50 to turn on and executes a light source control step.

[0073] The light source control step includes:

[0074] The processing device 30, such as the microprocessor 32, controls the light emission intensity of the light source module 50 according to the detection distance value, so that the light emission intensity of the light source module 50 is inversely proportional to the detection distance value. Therefore, appropriate supplementary lighting can be performed on the moving object 100 in the imaging range 10a, so that when the subsequent image capturing device 10 captures an image, an appropriate exposure value can be obtained for the moving object 100.

[0075] The above-mentioned ambient illuminance detection step and light source control step are not limited to being performed in step S12, and may also be performed before step S14, such as in step S13, or in both step S12 and step S13.

[0076] Step S13: The processing device 30 obtains the predetermined image coordinate area corresponding to the position data from the corresponding relationship data 80 according to the position data.

[0077] The image processor 34 of the processing device 30 selects the predetermined position data corresponding to the detection distance value and the detection angle value from the corresponding relationship data 80 according to the detection distance value and the detection angle value of the position data, and then obtains the corresponding predetermined image coordinate area according to the selected predetermined position data.

[0078] For example, the position data measured by the moving object detection device 20 includes a detection distance value of 5 m and a detection angle value of 0°. After the image processor 34 receives the position data from the microprocessor 32, the image processor 34 selects the predetermined position data DATA39 corresponding to the predetermined distance value and the predetermined angle value from the corresponding relationship data 80 according to 5 m and 0°, and then obtains the corresponding predetermined image coordinate area C0 according to the selected predetermined position data DATA39, that is, the area from the coordinate point (x1-39, y1-39) to the coordinate point (x2-39, y2-39).

[0079] In the foregoing, taking the example that the detection distance value and the detection angle value of the moving object detection device 20 are exactly equal to the predetermined distance value and the predetermined angle value of the predetermined position data to obtain the corresponding predetermined position data DATA39. However, when the moving object 100 moves in the detection range 20a, it may also be located between two adjacent predetermined positions P1. At this time, the following method is used to obtain a predetermined position data corresponding to the predetermined position P1 closer to the moving object 100.

[0080] When the image processor 34 of the processing device 30 determines that the detection distance value of the position data is between the predetermined distance values of two adjacent predetermined position data, it selects the predetermined distance value corresponding to the predetermined distance range covering the detection distance value; when the image processor 34 of the processing device 30 determines that the detection angle value of the position data is between the predetermined angle values of two adjacent predetermined position data, it selects the predetermined angle value corresponding to the predetermined angle range covering the detection angle value. For example, the detection distance value of the position data is 4.2 m and the detection angle value is 3°. The image processor 34 selects the predetermined distance value 5 m corresponding to the predetermined distance range 4.6 m to 5.5 m covering 4.2 m, and selects the predetermined angle value 0° corresponding to the predetermined angle range of -9° to +10° covering 3°. Therefore, the predetermined image coordinate area of the predetermined position data DATA39 is obtained.

[0081] In addition, in this embodiment, after obtaining the predetermined position data, the image processor 34 of the processing device 30 obtains the corresponding predetermined energy range according to the selected predetermined position data DATA39, and determines whether the detection energy value of the moving object detection device 20 falls within the predetermined energy range (30 dB to 36 dB). For example, the detection energy value is 32 dB. When the image processor 34 of the processing device 30 determines that the detection energy value falls within the predetermined energy range, the image processor 34 regards the moving object 100 as a human, and then obtains the corresponding predetermined image coordinate area C0 according to the predetermined position data DATA39, and then proceeds to step S14. When the image processor 34 of the processing device 30 determines that the detection energy value is greater than or less than the predetermined energy range, the image processor 34 regards the moving object 100 as non-human and returns to step S12 for execution; alternatively, the image processor 34 first wakes up the image capturing device 10, controls the image capturing device 10 to capture an image, outputs the image as a frame of a video, and stores it in the storage module 40, and then returns to step S12 for execution.

[0082] Step S14: The processing device 30 controls the image capturing device 10 to obtain a first image 72 output by the image capturing device 10 ( Figure 8 Refer to). In this embodiment, the image processor 34 wakes up the image capturing device 10 and controls the image capturing device 10 to capture the first image 72 under a first exposure condition. The image capturing device 10 captures the first image 72 with weighted metering. The first image 72 is a static image output by the image sensor 102. The first exposure condition can be a preset exposure condition or determined according to the ambient illuminance sensed by the ambient light sensor 60.

[0083] Step S15: The processing device 30 calculates a first global exposure parameter of the whole of the first image 72, and calculates a first local exposure parameter of a first local image 722 corresponding to the predetermined image coordinate area C0 in the first image 72.

[0084] In this embodiment, after receiving the first image 72, the image processor performs operations on the first image 72 to calculate the first global exposure parameter. In this embodiment, the first global exposure parameter is taken as an example of a first global exposure value. The image processor 34 performs operations on the first local image 722 of the predetermined image coordinate area C0 to calculate the first local exposure parameter. In this embodiment, the first local exposure parameter is taken as an example of a first local exposure value. The algorithms for calculating the first global exposure parameter and the first local exposure parameter are existing image processing technologies and will not be elaborated herein.

[0085] For example, please cooperate with Figure 9 , the first global exposure value of the first image 72 is -1.2 EV, and the first local exposure value of the first local image 722 is -2.5 EV. That is to say, the first local image is darker than the first image.

[0086] Step S16: The processing device 30 controls the image capturing device 10 according to the first global exposure parameter to obtain a second image output by the image capturing device 10. The whole of the second image has a second global exposure parameter. Wherein, the second global exposure parameter is an ideal exposure parameter, and a second local image corresponding to the predetermined image coordinate area C0 in the second image has a second local exposure parameter.

[0087] In this embodiment, the second global exposure parameter is taken as an example of a second global exposure value, and the ideal exposure parameter is taken as an example of an ideal exposure value. The ideal exposure value can be, for example, 0 EV.

[0088] The image processor controls a second exposure condition of the image capturing device 10 according to the first global exposure value calculated in step S15. Preferably, a difference obtained by subtracting the first global exposure value from the ideal exposure value is used to control the second exposure condition of the image capturing device 10 to capture the second image, so that the second global exposure value of the whole second image is equal to the ideal exposure value. The second image is a static image output by the image sensor 102. In other words, the purpose of step S16 is to enable the image capturing device 10 to obtain a second image whose overall exposure value is equal to the ideal exposure value.

[0089] For example, please cooperate with Figure 9 , the difference obtained by the image processor 34 subtracting the first global exposure value (-1.2 EV) from the ideal exposure value (0 EV) is +1.2 EV. The image processor 34 controls the second exposure condition of the image capturing device 10 with the difference (+1.2 EV). For example, the image capturing device 10 captures the second image by weighted metering plus the difference (+1.2 EV). In this way, the second global exposure value of the whole second image can be made equal to the ideal exposure value (0 EV), and the second local exposure value of the second local image in the second image is -1.3 EV, that is, equal to the first local exposure value (-2.5 EV) plus the difference (+1.2 EV).

[0090] Step S17: The processing device 30 controls the image capturing device 10 to obtain a third image output by the image capturing device 10. The whole of the third image has a third global exposure parameter, and a third partial image corresponding to the predetermined image coordinate region C0 in the third image has a third partial exposure parameter. Wherein, the third partial exposure parameter is closer to the ideal exposure parameter than the first partial exposure parameter. In the foregoing, the third image, the third global exposure parameter, the third partial image, and the third partial exposure parameter are respectively another image, a global exposure parameter, a partial image, and a partial exposure parameter defined in the present invention.

[0091] In this embodiment, the processing device 30 controls the image capturing device 10 to obtain the third image output by the image capturing device 10 according to a difference between the second global exposure parameter and the second partial exposure parameter. Wherein, the third partial exposure parameter is closer to the ideal exposure parameter than the second partial exposure parameter and the first partial exposure parameter. The third image is a static image output by the image sensor 102.

[0092] For example, the difference obtained by subtracting the second partial exposure (-1.3EV) from the second global exposure value (0EV) by the image processor 34 is +1.3EV. The image processor controls a third exposure condition of the image capturing device 10 according to the difference (+1.3EV). In this way, the third partial exposure value closer to the ideal exposure parameter (0EV) than the second partial exposure value (-1.3EV) can be obtained. More specifically, the image processor 34 multiplies the difference (+1.3EV) by a ratio to obtain an adjustment value. The ratio can be between 5 and 100%, and the user can select the desired ratio by himself. For example, if the ratio is selected to be 30%, the adjustment value is +0.39EV (i.e., +1.3EV×30%). The image processor 34 controls the third exposure condition of the image capturing device 10 according to the adjustment value (+0.39EV) to capture the third image, so that the third global exposure value is equal to the adjustment value (+0.39EV), and the third partial exposure value (-0.91EV) differs from the second partial exposure value (-1.3EV) by the adjustment value (+0.39EV). For example, the image capturing device 10 captures the third image with weighted metering plus the adjustment value (+0.39EV). At this time, the third global exposure value of the overall third image is slightly higher than the ideal exposure value.

[0093] If the selected ratio is 100%, the adjustment value is +1.3 EV (i.e., +1.3 EV × 100%). The image processor 34 controls the third exposure condition of the image capturing device 10 according to the adjustment value (+1.3 EV) to capture the third image, so that the third global exposure value is equal to the adjustment value (+1.3 EV), and the third local exposure value is (0 EV). In other words, at this time, the third local exposure value is equal to the ideal exposure value (0 EV), and the third global exposure value of the overall third image is higher than the ideal exposure value.

[0094] Through the above step S17, the third local image in the predetermined image coordinate area C0 in the third image can be adjusted to obtain better brightness.

[0095] Subsequently, the processing device 30 can execute step S18.

[0096] Step S18: The processing device 30 outputs the third image as a frame of a video. The frame can be stored in the storage module 40. Since the brightness of the third local image has been adjusted before outputting as a frame, sudden brightness changes in the third local image corresponding to the moving object 100 in the video can be avoided.

[0097] In this embodiment, after step S18, it further includes step S19: Repeat steps S12 to S18 multiple times to form the video with multiple frames.

[0098] In this embodiment, when the moving object detection device 20 detects that the moving object 100 continuously stays within the detection range, it continuously performs step S19 to continuously record the video of the moving object 100 in the imaging range 10a. When the moving object detection device 20 does not detect the moving object 100 within the detection range, it means that the moving object 100 has left the detection range 20a, and then step H ends.

[0099] Therefore, by the moving object detection device 20 detecting the multiple position data of the moving object 100 within the detection range and obtaining the corresponding predetermined image coordinate area C0, no matter whether the moving object approaches or moves away from the image capturing device 10, the third local image corresponding to each frame (i.e., each third image) of the moving object 100 in the video can obtain better brightness. Even if the image capturing device 10 is in a backlight state, or there is a large-area occlusion 724 ( Figure 10 Refer to) in the image captured by the image capturing device 10, the third local image in the third image can still obtain better brightness.

[0100] In a second embodiment of the present invention, step S16 may also be omitted. That is, after step S15, step S17 is directly executed: the processing device 30 controls the image capturing device 10 to obtain the third image output by the image capturing device 10, so that the third local exposure parameter in the third image is closer to the ideal exposure parameter than the first local exposure parameter.

[0101] For example, please refer to Figure 11 , the difference obtained by subtracting the first local exposure value (-2.5EV) from the ideal exposure value (0EV) by the image processor 34 is +2.5EV. The image processor 34 controls the third exposure condition of the image capturing device 10 according to the difference (+2.5EV). For example, the image capturing device 10 captures the third image by using weighted metering plus the difference (+2.5EV). In this way, the third local exposure value in the third image can be made equal to the ideal exposure value (0EV).

[0102] Alternatively, the image processor 34 multiplies the difference (+2.5EV) by a ratio to obtain an adjustment value, and controls the third exposure condition of the image capturing device 10 according to the adjustment value. The ratio may be, for example, between 5 and 100%. Therefore, the third local exposure parameter in the third image can also be made closer to the ideal exposure parameter than the first local exposure parameter.

[0103] It should be noted that the examples in the above first embodiment Figure 9 and the second embodiment Figure 11 are described by taking the global exposure value being greater than the local exposure value as an example. In practice, there may also be a case where the local exposure value is greater than the global exposure value. However, the steps of brightness adjustment are the same. The only difference is that the adjusted third local exposure value is less than the first local exposure value and / or the second local exposure value, and the adjusted third global exposure value is less than the first global exposure value and / or the second global exposure value.

[0104] The above are only the preferred and feasible embodiments of the present invention. All equivalent changes made by applying the description and claims of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for adjusting the image brightness of a photographic system, wherein, The described photographic system includes an image capturing device, a moving object detecting device, and a processing device. The image capturing device has an imaging range, and the moving object detecting device has a detection range. The imaging range and the detection range partially overlap. The method for adjusting the image brightness includes the following steps: A. Provide a correspondence data, which records a plurality of predetermined position data corresponding to a plurality of predetermined positions in the detection range of the moving object detecting device. Each of the predetermined position data includes a predetermined image coordinate area corresponding to each of the predetermined positions. B. Detect a position data of a moving object in the detection range by the moving object detecting device. C. The processing device obtains the predetermined image coordinate area of the predetermined position data corresponding to the position data from the correspondence data according to the position data. D. The processing device controls the image capturing device to obtain a first image output by the image capturing device. E. The processing device calculates a first global exposure parameter of the whole of the first image, and calculates a first local exposure parameter of a first local image corresponding to the predetermined image coordinate area in the first image. F. The processing device controls the image capturing device to obtain another image output by the image capturing device. The whole of the another image has a global exposure parameter, and a local image corresponding to the predetermined image coordinate area in the another image has a local exposure parameter. Wherein, the local exposure parameter is closer to an ideal exposure parameter than the first local exposure parameter. G. The processing device outputs the another image as a frame of a video.

2. The method for adjusting the image brightness of the photographic system according to claim 1, wherein between steps E and F, it further includes: The processing device controls the image capturing device according to the first global exposure parameter to obtain a second image output by the image capturing device, and the whole of the second image has a second global exposure parameter, wherein, The second global exposure parameter is the ideal exposure parameter, and a second local image corresponding to the predetermined image coordinate area in the second image has a second local exposure parameter. Wherein, in step F, the processing device controls the image capturing device to obtain the another image output by the image capturing device according to a difference between the second global exposure parameter and the second local exposure parameter. Wherein, the local exposure parameter is closer to the ideal exposure parameter than the second local exposure parameter.

3. The method for adjusting the image brightness of the photographic system according to claim 2, wherein in step F, the processing device multiplies the difference by a ratio to obtain an adjustment value, and controls the image capturing device to obtain the another image output by the image capturing device according to the adjustment value, so that the local exposure parameter differs from the second local exposure parameter by the adjustment value.

4. The method for adjusting the image brightness of the photographic system according to claim 3, wherein the ratio ranges from 5 to 100%.

5. The method for adjusting the image brightness of the photographic system according to claim 1, wherein, After step G, it further includes: H. Repeat steps B to G multiple times to form the video with a plurality of the frames.

6. The method for adjusting the image brightness of the photographic system according to claim 5, further includes: When the moving object detection device fails to detect the moving object within the detection range, step H ends.

7. The method for adjusting the image brightness of the photographic system according to claim 1, wherein the photographic system includes a light source module; Among them, In step B, the position data includes a detection distance value; Before step D, there is a light source control step, and the light source control step includes: The processing device controls the light emission intensity of the light source module according to the detection distance value, so that the light emission intensity of the light source module is inversely proportional to the detection distance value.

8. The method for adjusting the image brightness of the photographic system according to claim 7, wherein the photographic system includes an ambient light sensor; Before step D, it includes: Detect an ambient illuminance through the ambient light sensor. When the ambient illuminance is less than a predetermined illuminance, the processing device controls the light source module to turn on and executes the light source control step.

9. The method for adjusting the image brightness of the photographic system according to claim 1, wherein in step A, each of the predetermined position data of the corresponding relationship data includes a predetermined distance value and a predetermined angle value; in step B, the position data includes a detection distance value and a detection angle value; Wherein in step C, the processing device selects the predetermined position data corresponding to the detection distance value and the detection angle value from the corresponding relationship data according to the detection distance value and the detection angle value of the position data, and then obtains the corresponding predetermined image coordinate area according to the selected predetermined position data.

10. The method for adjusting the image brightness of the photographic system according to claim 9, wherein in step A, the predetermined distance value of each of the predetermined position data of the corresponding relationship data has a corresponding predetermined distance range, and the predetermined angle value of each of the predetermined position data has a corresponding predetermined angle range; Wherein in step C, when the processing device determines that the detection distance value of the position data is between the predetermined distance values of two adjacent predetermined position data, it selects the predetermined distance value corresponding to the predetermined distance range covering the detection distance value; when the processing device determines that the detection angle value of the position data is between the predetermined angle values of two adjacent predetermined position data, it selects the predetermined angle value corresponding to the predetermined angle range covering the detection angle value.

11. The method for adjusting the image brightness of the photographic system according to claim 9, wherein in step A, each of the predetermined position data of the corresponding relationship data further includes a predetermined energy value, and the predetermined energy value has a corresponding predetermined energy range; In step B, the position data further includes a detection energy value; In step C, the processing device selects the predetermined position data corresponding to the detected distance value and the detected angle value from the corresponding relationship data according to the detected distance value and the detected angle value of the position data, and obtains the corresponding predetermined energy range according to the selected predetermined position data; when the processing device determines that the detected energy value falls within the predetermined energy range, the processing device obtains the corresponding predetermined image coordinate area according to the selected predetermined position data, and then proceeds to step D.

12. The method for adjusting the image brightness of the imaging system according to claim 11, wherein when the processing device determines that the detected energy value is higher than or lower than the predetermined energy range, the image capturing device is controlled to obtain an image output by the image capturing device, and the image is output as a frame of the video.

Images