Image acquisition equipment and exposure control method and device

Abstract

The invention discloses image acquisition equipment and an exposure control method and device. The image acquisition equipment comprises a controller, a digital signal processor and at least one image sensor group, the image sensor group comprises a first image sensor and a second image sensor which are longitudinally adjacent and have an overlapping area. The controller determines the exposure time difference of the first image sensor and the second image sensor; and according to the exposure time difference, respectively sending a frame synchronization signal to the first image sensor and the second image sensor. The first image sensor and the second image sensor respectively perform exposure according to the exposure starting time received by the first image sensor and the second image sensor, convert the received ambient light signal into an electric signal, and send the electric signal to the digital signal processor; and the digital signal processor is used for generating an image according to the received electric signal. Compared with a longitudinal splicing scheme in the prior art, the method has the advantages that the continuity when the moving object passes through the whole image splicing seam is improved, and the image watching effect is improved.

Description

Technical Field

[0001] The present application relates to the field of security monitoring technology, and in particular to an image acquisition device, an exposure control method and a device. Background Art

[0002] In the field of security monitoring, in order to achieve a larger monitoring field of view, multiple image sensors are used for splicing and fusion to obtain a larger field of view. In order to control costs, such cameras generally use image sensors with lower cost rolling shutters.

[0003] The exposure principle of the rolling shutter image sensor is: the exposure time of the same row of each image sensor is the same or similar. For example, the exposure start time of the first row of image sensor 1 is the same or similar to the exposure start time of the first row of image sensor 2, the exposure start time of the second row of image sensor 1 is the same or similar to the exposure start time of the second row of image sensor 2, etc. There are differences in the exposure start time of each row in the image sensor. The difference in exposure start time is assumed to be t, which is related to the analog-to-digital AD conversion rate and pixel clock output inside the image sensor. For example, when the pixel clock is 74.25Mhz, the resolution of the image sensor is 1920 × 1080 (1920 pixels per row, a total of 1080 rows), and the readout time of that row is , about 25us, then the exposure time interval between the first and last lines is about , about 27ms.

[0004] The image sensor stitching methods in the prior art generally include horizontal stitching and vertical stitching. Figure 1 This is a schematic diagram of horizontal stitching. The first row and the first row of pixels of each image sensor are stitched. The characteristic of this stitching method is that the exposure time of all rows is the same or similar. When shooting a moving target, the imaging process of the moving object is complete and continuous. However, the problem with this stitching method is that the aspect ratio of the image is too large, and the viewing effect of the stitched image is poor. Figure 2 This is a diagram of vertical stitching. The first and last rows of pixels of adjacent image sensors are stitched together. The problem with this stitching method is that the exposure difference at the seam between the two image sensors, that is, the rows at different exposure times, will be stitched together. For example, at a 74.25MHZ pixel clock For the image sensor, the difference in exposure start time at the seam reaches 27ms. Therefore, when shooting a moving target, the object will be broken when passing through the seam due to the difference in exposure time, which also affects the viewing effect of the generated image. Summary of the invention

[0005] The present application provides an image acquisition device, an exposure control method and an apparatus, which are used to solve the problem in the prior art that when a moving object passes through the entire image seam, a break occurs, which affects the viewing effect of the image.

[0006] In a first aspect, the present application provides an image acquisition device, the image acquisition device comprising: a controller, a digital signal processor and at least one image sensor group; the image sensor group comprises a first image sensor and a second image sensor which are adjacent to each other in a longitudinal direction and have an overlapping area; The controller is configured to obtain and determine an exposure time difference between the first image sensor and the second image sensor according to an overlap area between the first image sensor and the second image sensor; and send frame synchronization signals to the first image sensor and the second image sensor respectively according to the exposure time difference, wherein the two frame synchronization signals respectively carry an exposure start time, and the time difference between the two exposure start times is the exposure time difference; The first image sensor and the second image sensor are respectively used for exposing according to the exposure start time received by themselves, converting the received ambient light signal into an electrical signal, and sending the electrical signal to the digital signal processor; The digital signal processor is used to generate an image according to the received electrical signal.

[0007] Further, the number of pixel rows included in the overlapped area of ​​the first image sensor and the second image sensor is a first number; the first time of exposing one frame of the first image sensor and the second image sensor is the same, the first image sensor and the second image sensor include the same pixel array; the number of pixel rows included in the pixel array is a second number; The controller is specifically used to determine the ratio of the first time to the second number, determine the product of the ratio and the first number, and determine the difference between the first time and the product as the exposure time difference.

[0008] Furthermore, the pixel arrays included in the first image sensor and the second image sensor are both arranged in a forward direction; the pixel array includes n rows of pixels; wherein the pixels from the n-x+1th row to the nth row of pixels of the first image sensor overlap with the pixels from the 1st row to the xth row of pixels of the second image sensor; n is the second number, and x is the first number.

[0009] Furthermore, the controller is specifically used to send a first frame synchronization signal to the first image sensor, the first frame synchronization signal carrying a first exposure start time; send a second frame synchronization signal to the second image sensor, the second frame synchronization signal carrying a second exposure start time; the time difference between the second exposure start time and the first exposure start time is the exposure time difference.

[0010] Furthermore, the image acquisition device also includes: a third image sensor laterally adjacent to the first image sensor; the exposure start time of the third image sensor being the same as the exposure start time of the first image sensor; The third image sensor is used for exposing according to its own exposure start time, converting the received ambient light signal into an electrical signal, and sending the electrical signal to the digital signal processor.

[0011] Furthermore, the image acquisition device also includes: a fourth image sensor laterally adjacent to the second image sensor; the exposure start time of the fourth image sensor being the same as the exposure start time of the second image sensor; The fourth image sensor is used for exposing according to its own exposure start time, converting the received ambient light signal into an electrical signal, and sending the electrical signal to the digital signal processor.

[0012] In a second aspect, the present application provides an exposure control method based on a multi-path rolling shutter based on an image acquisition device, which is applied to a controller in the image acquisition device, and the method includes: Acquire and determine the exposure time difference between the first image sensor and the second image sensor according to the overlap area of ​​the first image sensor and the second image sensor; send frame synchronization signals to the first image sensor and the second image sensor respectively according to the exposure time difference, the two frame synchronization signals respectively carry the exposure start time, and the time difference between the two exposure start times is the exposure time difference; Among them, the first image sensor and the second image sensor are adjacent to each other vertically and have an overlapping area; the first image sensor and the second image sensor are exposed according to the exposure start time received by themselves, respectively, convert the received ambient light signal into an electrical signal, and send the electrical signal to a digital signal processor; the digital signal processor generates an image according to the received electrical signal.

[0013] Further, the process of determining the exposure time difference includes: If the number of pixel rows contained in the overlapping area of ​​the first image sensor and the second image sensor is a first number; the first time for exposing a frame of the first image sensor and the second image sensor is the same, the pixel arrays included in the first image sensor and the second image sensor are the same; the number of pixel rows included in the pixel array is a second number; determine the ratio of the first time to the second number, determine the product of the ratio and the first number, and determine the difference between the first time and the product as the exposure time difference.

[0014] Further, the process of sending the frame synchronization signal to the first image sensor and the second image sensor respectively includes: If the pixel arrays included in the first image sensor and the second image sensor are both arranged in a forward direction; the pixel arrays include n rows of pixels; wherein the pixels from the n-x+1th row to the nth row of pixels of the first image sensor overlap with the pixels from the 1st row to the xth row of pixels of the second image sensor; n is the second number, and x is the first number; a first frame synchronization signal is sent to the first image sensor, and the first frame synchronization signal carries a first exposure start time; a second frame synchronization signal is sent to the second image sensor, and the second frame synchronization signal carries a second exposure start time; the time difference between the second exposure start time and the first exposure start time is the exposure time difference.

[0015] In a third aspect, the present application provides an exposure control device based on a multi-channel rolling shutter, which is applied to a controller in an image acquisition device, and the device includes: A determination module, configured to obtain and determine an exposure time difference between the first image sensor and the second image sensor according to an overlap area of ​​the first image sensor and the second image sensor; a sending module, configured to send frame synchronization signals to the first image sensor and the second image sensor respectively according to the exposure time difference, wherein the two frame synchronization signals respectively carry exposure start times, and the time difference between the two exposure start times is the exposure time difference; Among them, the first image sensor and the second image sensor are adjacent to each other vertically and have an overlapping area; the first image sensor and the second image sensor are exposed according to the exposure start time received by themselves, respectively, convert the received ambient light signal into an electrical signal, and send the electrical signal to a digital signal processor; the digital signal processor generates an image according to the received electrical signal.

[0016] Furthermore, the determination module is specifically used to determine the ratio of the first time to the second number, determine the product of the ratio and the first number, and determine the difference between the first time and the product as the exposure time difference if the number of pixel rows contained in the overlapping area of ​​the first image sensor and the second image sensor is a first number; the first time of exposing one frame of the first image sensor and the second image sensor is the same, the pixel arrays included in the first image sensor and the second image sensor are the same; and the number of pixel rows included in the pixel array is a second number.

[0017] Furthermore, the sending module is specifically used for: if the pixel arrays included in the first image sensor and the second image sensor are both arranged in the forward direction; the pixel array includes n rows of pixels; wherein the pixels from the n-x+1th row to the nth row of pixels of the first image sensor overlap with the pixels from the 1st row to the xth row of pixels of the second image sensor; n is the second number, and x is the first number; sending a first frame synchronization signal to the first image sensor, the first frame synchronization signal carrying a first exposure start time; sending a second frame synchronization signal to the second image sensor, the second frame synchronization signal carrying a second exposure start time; the time difference between the second exposure start time and the first exposure start time is the exposure time difference.

[0018] In a fourth aspect, the present application provides a controller, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus; Memory, used to store computer programs; The processor is used to implement the method when executing the program stored in the memory.

[0019] In a fifth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program implements the described method when executed by a processor.

[0020] In a sixth aspect, the present application provides a computer program product, wherein the computer program product comprises an executable program, and the executable program is executed by a processor to implement the described method.

[0021] The above technical solution has the following advantages or beneficial effects: In the present application, the image acquisition device includes: a controller, a digital signal processor and at least one image sensor group; the image sensor group includes a first image sensor and a second image sensor that are adjacent to each other in the longitudinal direction and have an overlap area. The controller obtains and determines the exposure time difference between the first image sensor and the second image sensor according to the overlap area of ​​the first image sensor and the second image sensor; according to the exposure time difference, a frame synchronization signal is sent to the first image sensor and the second image sensor respectively, and the two frame synchronization signals respectively carry the exposure start time, and the time difference between the two exposure start times is the exposure time difference. The first image sensor and the second image sensor are exposed according to the exposure start time received by themselves, respectively, and the received ambient light signal is converted into an electrical signal, and the electrical signal is sent to the digital signal processor; the digital signal processor is used to generate an image according to the received electrical signal. In the present application, the first image sensor and the second image sensor are arranged to overlap in the longitudinal direction, and the time difference of the exposure start time of the first image sensor and the second image sensor is determined according to the overlap area. Compared with the longitudinal phase stitching scheme of the prior art, the difference in exposure time at the seam of the first image sensor and the second image sensor is reduced, and the continuity of the moving object when passing through the entire image seam is improved. Therefore, the fracture phenomenon at the seams of the image generated by the present application is alleviated, thereby improving the viewing effect of the image. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of horizontal splicing of image sensors in the prior art; Figure 2 It is a schematic diagram of longitudinal splicing of image sensors in the prior art; Figure 3 A schematic diagram of the structure of the first image acquisition device provided in this application; Figure 4 A schematic diagram of the arrangement of the first image sensor and the second image sensor provided by the present application; Figure 5 A schematic diagram of the structure of the second image acquisition device provided in this application; Figure 6 A schematic diagram of an exposure control process based on a multi-channel rolling shutter based on an image acquisition device provided in this application; Figure 7 A schematic diagram of the process of determining the exposure time difference provided for this application; Figure 8 A schematic diagram of a process of sending a frame synchronization signal to a first image sensor and a second image sensor respectively provided in the present application; Fig. 9 A schematic diagram of a first frame synchronization signal and a second frame synchronization signal provided in this application; Fig.10 A schematic diagram of the structure of an exposure control device based on a multi-channel rolling shutter provided in this application; Fig.11 This is a schematic diagram of the controller structure provided for this application. DETAILED DESCRIPTION

[0024] In order to make the purpose and implementation method of the present application clearer, the exemplary implementation method of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0025] It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their common and usual meanings.

[0026] The terms "first", "second", "third", etc. in the specification and claims of this application and the above drawings are used to distinguish similar or similar objects or entities, and do not necessarily mean to limit a specific order or sequence, unless otherwise noted. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances.

[0027] The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to all the components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0028] The term "module" refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and / or software code that is capable of performing the functions associated with that element.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0030] For the convenience of explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations can be obtained. The selection and description of the above embodiments are to better explain the principles and practical applications, so that those skilled in the art can better use the embodiments and various different variations of the embodiments suitable for specific use considerations.

[0031] Figure 3 This is a schematic diagram of the structure of a first image acquisition device provided by the present application, the image acquisition device comprising: a controller 11, a digital signal processor 12 and at least one image sensor group 13; the image sensor group comprises a first image sensor 131 and a second image sensor 132 which are adjacent to each other in the longitudinal direction and have an overlapping area; The controller 11 is used to obtain and determine the exposure time difference between the first image sensor 131 and the second image sensor 132 according to the overlap area between the first image sensor 131 and the second image sensor 132; according to the exposure time difference, send frame synchronization signals to the first image sensor 131 and the second image sensor 132 respectively, the two frame synchronization signals respectively carry the exposure start time, and the time difference between the two exposure start times is the exposure time difference; The first image sensor 131 and the second image sensor 132 are respectively used for exposing according to the exposure start time received by themselves, converting the received ambient light signal into an electrical signal, and sending the electrical signal to the digital signal processor 12; The digital signal processor 12 is used to generate an image according to the received electrical signal.

[0032] In the present application, a solution is provided for the problem that when shooting a moving target, due to the difference in exposure time, the object will be broken when passing through the seam, which affects the viewing effect of the generated image.

[0033] In the present application, the image acquisition device includes: a controller, a digital signal processor and at least one image sensor group. The image sensor group includes a first image sensor and a second image sensor that are adjacent to each other in the longitudinal direction and have an overlapping area. The controller can be a central processing unit CPU, a microprocessor MCU, etc. The digital signal processor can be a DSP processor or a FPGA processor. Figure 3 An example in which an image acquisition device includes an image sensor group is used for schematic description. Figure 3The first image sensor is located at the top, the second image sensor is located at the bottom, and the pixels of a preset number of rows from bottom to top of the first image sensor overlap with the pixels of a preset number of rows from top to bottom of the second image sensor, and the overlapping part of the pixels is the overlapping area. It should be noted that if the image sensor also includes a third image sensor located below the second image sensor, the pixels of a preset number of rows from bottom to top of the second image sensor overlap with the pixels of a preset number of rows from top to bottom of the third image sensor. At this time, the second image sensor and the third image sensor constitute another image sensor group. The second image sensor in the image sensor group is equivalent to Figure 3 The first image sensor in the image sensor group shown; the third image sensor in the image sensor group is equivalent to Figure 3 The second image sensor in the image sensor group shown. The present application does not limit the number of image sensor groups. The image sensor in the present application includes a rolling shutter image sensor.

[0034] In the present application, the controller obtains the overlapping area of ​​the first image sensor and the second image sensor. Specifically, the number of pixel rows that overlap the first image sensor and the second image sensor is obtained. According to the overlapping area of ​​the first image sensor and the second image sensor, the exposure time difference between the first image sensor and the second image sensor is determined. Specifically, the exposure time difference between the first image sensor and the second image sensor is determined according to the number of pixel rows that overlap the first image sensor and the second image sensor. Optionally, the controller may pre-store the correspondence between the number of overlapping pixel rows and the exposure time difference, wherein the more the number of overlapping pixel rows, the smaller the exposure time difference. According to the number of overlapping pixel rows of the first image sensor and the second image sensor, and the above correspondence, the exposure time difference between the first image sensor and the second image sensor may be determined. Then, according to the exposure time difference, frame synchronization signals are sent to the first image sensor and the second image sensor respectively, and the two frame synchronization signals respectively carry the exposure start time, and the time difference between the two exposure start times is the exposure time difference. Optionally, as Figure 3 As shown, the first image sensor is located above the second image sensor, the exposure start time of the first image sensor is located before the exposure start time of the second image sensor, and the exposure start time of the first image sensor and the exposure start time of the second image sensor differ by an exposure time difference. The exposure start time of the first image sensor refers to the exposure start time of the first row of pixels of the first image sensor; the exposure start time of the second image sensor refers to the exposure start time of the first row of pixels of the second image sensor.

[0035] The first image sensor is exposed according to the exposure start time received by itself, converts the received ambient light signal into an electrical signal within the exposure time, and then sends the electrical signal to the digital signal processor. The digital signal processor generates an image captured by the first image sensor according to the received electrical signal; the second image sensor is exposed according to the exposure start time received by itself, converts the received ambient light signal into an electrical signal within the exposure time, and then sends the electrical signal to the digital signal processor. The digital signal processor generates an image captured by the second image sensor according to the received electrical signal. The digital signal processor splices the images captured by each image sensor to generate a final image. Optionally, the first image and the second image are spliced ​​according to the arrangement order and positional relationship of the first image sensor and the second image sensor. The image splicing process is not described in detail in this application.

[0036] In the present application, the image acquisition device includes: a controller, a digital signal processor and at least one image sensor group; the image sensor group includes a first image sensor and a second image sensor that are adjacent to each other in the longitudinal direction and have an overlap area. The controller obtains and determines the exposure time difference between the first image sensor and the second image sensor according to the overlap area of ​​the first image sensor and the second image sensor; according to the exposure time difference, a frame synchronization signal is sent to the first image sensor and the second image sensor respectively, and the two frame synchronization signals respectively carry the exposure start time, and the time difference between the two exposure start times is the exposure time difference. The first image sensor and the second image sensor are exposed according to the exposure start time received by themselves, respectively, and the received ambient light signal is converted into an electrical signal, and the electrical signal is sent to the digital signal processor; the digital signal processor is used to generate an image according to the received electrical signal. In the present application, the first image sensor and the second image sensor are arranged to overlap in the longitudinal direction, and the time difference of the exposure start time of the first image sensor and the second image sensor is determined according to the overlap area. Compared with the longitudinal phase stitching scheme of the prior art, the difference in exposure time at the seam of the first image sensor and the second image sensor is reduced, and the continuity of the moving object when passing through the entire image seam is improved. Therefore, the fracture phenomenon at the seams of the image generated by the present application is alleviated, thereby improving the viewing effect of the image.

[0037] In the present application, in order to further improve the viewing effect of the image, the number of pixel rows included in the overlapping area of ​​the first image sensor and the second image sensor is a first number; the first time of exposing one frame of the first image sensor and the second image sensor is the same, the first image sensor and the second image sensor include the same pixel array; the number of pixel rows included in the pixel array is a second number; The controller is specifically used to determine the ratio of the first time to the second number, determine the product of the ratio and the first number, and determine the difference between the first time and the product as the exposure time difference.

[0038] The first image sensor and the second image sensor provided in the present application include the same pixel array, and the arrangement direction of the pixel array is the same. The pixel array includes row 1, row 2, ..., row n. The same arrangement direction of the pixel array means that the pixel array of the first image sensor is row 1 to row n from top to bottom, and the pixel array of the second image sensor is also row 1 to row n from top to bottom. The first time for exposing a frame of the first image sensor and the second image sensor is the same. In the present application, the number of pixel rows contained in the overlapping area of ​​the first image sensor and the second image sensor is taken as the first number, and the number of pixel rows contained in the pixel array is taken as the second number.

[0039] The controller determines the ratio of the first time to the second quantity, determines the product of the ratio and the first quantity, and determines the difference between the first time and the product as the exposure time difference. For example, the ratio of the first time to the second quantity is determined, the product of the ratio and the first quantity is tx, and the first time of exposing one frame is t. Then the exposure time difference is determined to be t-tx. The exposure start time of the second image sensor is t1, and the exposure start time of the first image sensor is the time t-tx before t1. The application provides a method for determining the exposure time difference, and then sending frame synchronization signals to the first image sensor and the second image sensor respectively according to the exposure time difference, the two frame synchronization signals respectively carry the exposure start time, and the time difference between the two exposure start times is the exposure time difference; the first image sensor and the second image sensor are respectively used to expose according to the exposure start time received by themselves, convert the received ambient light signal into an electrical signal, and send the electrical signal to the digital signal processor; the digital signal processor is used to generate an image according to the received electrical signal. In this way, the exposure time of the pixel rows in the overlapped part of the first image sensor and the second image sensor can be the same, thereby minimizing the difference in exposure time at the seam between the first image sensor and the second image sensor, and improving the continuity of the moving object passing through the entire image seam. Therefore, the viewing effect of the image is further improved.

[0040] Figure 4 A schematic diagram of the arrangement of the first image sensor and the second image sensor provided in this application, such as Figure 4As shown, the pixel arrays included in the first image sensor and the second image sensor are both arranged in a forward direction; the pixel array includes n rows of pixels; wherein the pixels from the n-x+1th row to the nth row of pixels of the first image sensor overlap with the pixels from the 1st row to the xth row of pixels of the second image sensor; n is the second number, and x is the first number. The forward arrangement of the pixel array means that the pixel array is arranged from the 1st row to the nth row from top to bottom. The pixels from the n-x+1th row to the nth row of pixels of the first image sensor overlap with the pixels from the 1st row to the xth row of pixels of the second image sensor, that is, the first image sensor is located above the second image sensor.

[0041] In the present application, the controller is specifically used to send a first frame synchronization signal to the first image sensor, the first frame synchronization signal carrying a first exposure start time; send a second frame synchronization signal to the second image sensor, the second frame synchronization signal carrying a second exposure start time; the time difference between the second exposure start time and the first exposure start time is the exposure time difference.

[0042] Figure 5 This is a schematic diagram of the structure of a second image acquisition device provided in this application, wherein the image acquisition device further includes: a third image sensor 14 laterally adjacent to the first image sensor 131; the exposure start time of the third image sensor 14 is the same as the exposure start time of the first image sensor 131; The third image sensor 14 is used for exposing according to its own exposure start time, converting the received ambient light signal into an electrical signal, and sending the electrical signal to the digital signal processor.

[0043] The controller sends a first frame synchronization signal to the first image sensor, and the first frame synchronization signal carries a first exposure start time; the controller sends a third frame synchronization signal to the third image sensor, and the third frame synchronization signal carries a third exposure start time; wherein the first exposure start time and the third exposure start time are the same.

[0044] like Figure 5 As shown, the image acquisition device also includes: a fourth image sensor 15 laterally adjacent to the second image sensor 132; the exposure start time of the fourth image sensor 15 is the same as the exposure start time of the second image sensor 132; The fourth image sensor 15 is used for exposing according to its own exposure start time, converting the received ambient light signal into an electrical signal, and sending the electrical signal to the digital signal processor.

[0045] The controller sends a second frame synchronization signal to the second image sensor, and the second frame synchronization signal carries a second exposure start time. The controller sends a fourth frame synchronization signal to the fourth image sensor, and the fourth frame synchronization signal carries a fourth exposure start time. The second exposure start time and the fourth exposure start time are the same.

[0046] Figure 6 A schematic diagram of an exposure control process based on a multi-channel rolling shutter based on an image acquisition device provided in the present application, which is applied to a controller in the image acquisition device, comprises the following steps: S101: Acquire and determine, according to an overlap area of ​​a first image sensor and a second image sensor, an exposure time difference between the first image sensor and the second image sensor; S102: According to the exposure time difference, frame synchronization signals are sent to the first image sensor and the second image sensor respectively, the two frame synchronization signals respectively carry exposure start times, and the time difference between the two exposure start times is the exposure time difference; wherein, the first image sensor and the second image sensor are adjacent to each other vertically and have an overlapping area; the first image sensor and the second image sensor are exposed according to the exposure start times received by themselves respectively, convert the received ambient light signals into electrical signals, and send the electrical signals to a digital signal processor; the digital signal processor generates an image according to the received electrical signals.

[0047] Figure 7 The process schematic diagram of determining the exposure time difference provided for this application includes the following steps: S201: If the number of pixel rows included in the overlapped area of ​​the first image sensor and the second image sensor is a first number; the first exposure time of the first image sensor and the second image sensor is the same, the first image sensor and the second image sensor include the same pixel array; the number of pixel rows included in the pixel array is a second number; S202: Determine a ratio of a first time to a second number, determine a product of the ratio and the first number, and determine a difference between the first time and the product as the exposure time difference.

[0048] Figure 8 The schematic diagram of the process of sending a frame synchronization signal to a first image sensor and a second image sensor respectively provided in the present application includes the following steps: S301: If the pixel arrays included in the first image sensor and the second image sensor are both arranged in a forward direction; the pixel arrays include n rows of pixels; wherein the pixels from the n-x+1th row to the nth row of pixels of the first image sensor overlap with the pixels from the 1st row to the xth row of pixels of the second image sensor; n is the second number, and x is the first number; S302: Sending a first frame synchronization signal to the first image sensor, where the first frame synchronization signal carries a first exposure start time; S303: Send a second frame synchronization signal to the second image sensor, where the second frame synchronization signal carries a second exposure start time; a time difference between the second exposure start time and the first exposure start time is the exposure time difference.

[0049] Fig. 9 A schematic diagram of a first frame synchronization signal and a second frame synchronization signal provided in this application, such as Figure 8 As shown, Framevalid1 represents the first frame synchronization signal, Frame valid2 represents the second frame synchronization signal; t represents the exposure time for one frame, and the exposure time for one frame is the exposure time for valid pixels of the image sensor; ta is the exposure time for invalid pixels, and t-tx is the exposure time difference; Active Rows represents valid pixels, and Blank Rows represents invalid pixels.

[0050] The present application provides an image acquisition device and an exposure control method. Instead of changing the direction of the image sensor, the exposure timing is adjusted to ensure the consistency of the exposure time at the joint, so as to ensure the stitching effect of the moving target. In order to ensure the continuity of the image at the joint, the method of overlapping pixel rows is adopted, and then the images of the two vertically adjacent image sensors are coordinate transformed and finally fused. Assuming that the number of rows that the two image sensors need to overlap is x rows, in order to further ensure the continuity of the image at the joint, the present application aims to ensure that the exposure times of these overlapping rows are also simultaneous, so that when calculating the pixel overlap rate in scenes with moving targets, it has a better effect. The present application adopts the following method: Fig. 9 As shown in the figure, "exposure misalignment overlap" is performed. Assuming that the exposure time for one frame is t and the time of the overlapping area is tx, the two adjacent image sensors are synchronized by using frame synchronization signals with a difference of t-tx. Then, within the overlapping x rows, the exposure moments of the two image sensors are the same, ensuring that in motion scenes, the overlapping pixels will be as many as possible.

[0051] This application combines the exposure characteristics of the rolling shutter image sensor and adopts a staggered arrangement and splicing method of the upper and lower image sensors to ensure that the exposure time of the rows to be overlapped and fused is the same, especially when shooting moving objects, to ensure a higher pixel overlap rate. In the image splicing system, the exposure time difference at the seam is minimized, ensuring the continuity of the image when the moving object passes through the entire image without the occurrence of a fault phenomenon.

[0052] Fig.10The schematic diagram of the structure of the exposure control device based on the multi-way rolling shutter provided in the present application is applied to the controller in the image acquisition device, and the device includes: A determination module 21, configured to obtain and determine an exposure time difference between the first image sensor and the second image sensor according to an overlap area between the first image sensor and the second image sensor; A sending module 22, configured to send frame synchronization signals to the first image sensor and the second image sensor respectively according to the exposure time difference, wherein the two frame synchronization signals respectively carry exposure start times, and the time difference between the two exposure start times is the exposure time difference; Among them, the first image sensor and the second image sensor are adjacent to each other vertically and have an overlapping area; the first image sensor and the second image sensor are exposed according to the exposure start time received by themselves, respectively, convert the received ambient light signal into an electrical signal, and send the electrical signal to a digital signal processor; the digital signal processor generates an image according to the received electrical signal.

[0053] The determination module 21 is specifically used to determine the ratio of the first time to the second number, determine the product of the ratio and the first number, and determine the difference between the first time and the product as the exposure time difference if the number of pixel rows contained in the overlapping area of ​​the first image sensor and the second image sensor is a first number; the first time of exposing a frame of the first image sensor and the second image sensor are the same, the pixel arrays included in the first image sensor and the second image sensor are the same; and the number of pixel rows included in the pixel array is a second number.

[0054] The sending module 22 is specifically used for when the pixel arrays included in the first image sensor and the second image sensor are both arranged in the forward direction; the pixel arrays include n rows of pixels; wherein the pixels from the n-x+1th row to the nth row of pixels of the first image sensor overlap with the pixels from the 1st row to the xth row of pixels of the second image sensor; n is the second number, and x is the first number; sending a first frame synchronization signal to the first image sensor, the first frame synchronization signal carrying a first exposure start time; sending a second frame synchronization signal to the second image sensor, the second frame synchronization signal carrying a second exposure start time; the time difference between the second exposure start time and the first exposure start time is the exposure time difference.

[0055] The present application also provides a controller, such as Fig.11 As shown, it includes: a processor 31, a communication interface 32, a memory 33 and a communication bus 34, wherein the processor 31, the communication interface 32, and the memory 33 communicate with each other through the communication bus 34; The memory 33 stores a computer program, and when the program is executed by the processor 31, the processor 31 executes any one of the above method steps.

[0056] The communication bus mentioned in the above controller can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0057] The communication interface 32 is used for communication between the controller and other devices.

[0058] The memory may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0059] The above-mentioned processor can be a general-purpose processor, including a central processing unit, a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc.

[0060] The present application also provides a computer storage readable storage medium, wherein the computer readable storage medium stores a computer program executable by a controller, and when the program runs on the controller, the controller implements any of the above method steps when executing.

[0061] The present application provides a computer program product, wherein the computer program product comprises an executable program, and when the executable program is executed by a processor, the method described above is implemented.

[0062] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0063] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An image acquisition device, characterized in that: The image acquisition device comprises: a controller, a digital signal processor and at least one image sensor group; the image sensor group comprises a first image sensor and a second image sensor which are adjacent to each other in the longitudinal direction and have an overlapping area; The controller is configured to obtain and determine an exposure time difference between the first image sensor and the second image sensor according to an overlap area between the first image sensor and the second image sensor; and send frame synchronization signals to the first image sensor and the second image sensor respectively according to the exposure time difference, wherein the two frame synchronization signals respectively carry an exposure start time, and the time difference between the two exposure start times is the exposure time difference; The first image sensor and the second image sensor are respectively used for exposing according to the exposure start time received by themselves, converting the received ambient light signal into an electrical signal, and sending the electrical signal to the digital signal processor; The digital signal processor is used to generate an image according to the received electrical signal.

2. The image acquisition device according to claim 1, characterized in that: The number of pixel rows included in the overlapped area of ​​the first image sensor and the second image sensor is a first number; the first time of exposing one frame of the first image sensor and the second image sensor is the same, the first image sensor and the second image sensor include the same pixel array; the number of pixel rows included in the pixel array is a second number; The controller is specifically used to determine the ratio of the first time to the second number, determine the product of the ratio and the first number, and determine the difference between the first time and the product as the exposure time difference.

3. The image acquisition device according to claim 2, characterized in that: The pixel arrays included in the first image sensor and the second image sensor are both arranged in a forward direction; the pixel array includes n rows of pixels; wherein the pixels from the n-x+1th row to the nth row of pixels of the first image sensor overlap with the pixels from the 1st row to the xth row of pixels of the second image sensor; n is the second number, and x is the first number.

4. The image acquisition device according to claim 3, characterized in that: The controller is specifically configured to send a first frame synchronization signal to the first image sensor, wherein the first frame synchronization signal carries a first exposure start time; and send a second frame synchronization signal to the second image sensor, wherein the second frame synchronization signal carries a second exposure start time; The time difference between the second exposure start time and the first exposure start time is the exposure time difference.

5. The image acquisition device according to claim 1, characterized in that: The image acquisition device also includes: a third image sensor laterally adjacent to the first image sensor; the exposure start time of the third image sensor being the same as the exposure start time of the first image sensor; The third image sensor is used for exposing according to its own exposure start time, converting the received ambient light signal into an electrical signal, and sending the electrical signal to the digital signal processor.

6. The image acquisition device according to claim 1, characterized in that: The image acquisition device also includes: a fourth image sensor laterally adjacent to the second image sensor; the exposure start time of the fourth image sensor being the same as the exposure start time of the second image sensor; The fourth image sensor is used for exposing according to its own exposure start time, converting the received ambient light signal into an electrical signal, and sending the electrical signal to the digital signal processor.

7. An exposure control method based on a multi-channel rolling shutter based on the image acquisition device according to any one of claims 1 to 6, characterized in that: A controller applied to the image acquisition device, the method comprising: Acquire and determine the exposure time difference between the first image sensor and the second image sensor according to the overlap area of ​​the first image sensor and the second image sensor; send frame synchronization signals to the first image sensor and the second image sensor respectively according to the exposure time difference, the two frame synchronization signals respectively carry the exposure start time, and the time difference between the two exposure start times is the exposure time difference; Among them, the first image sensor and the second image sensor are adjacent to each other vertically and have an overlapping area; the first image sensor and the second image sensor are exposed according to the exposure start time received by themselves, respectively, convert the received ambient light signal into an electrical signal, and send the electrical signal to a digital signal processor; the digital signal processor generates an image according to the received electrical signal.

8. The method according to claim 7, characterized in that The process of determining the exposure time difference includes: If the number of pixel rows contained in the overlapping area of ​​the first image sensor and the second image sensor is a first number; the first time for exposing a frame of the first image sensor and the second image sensor is the same, the pixel arrays included in the first image sensor and the second image sensor are the same; the number of pixel rows included in the pixel array is a second number; determine the ratio of the first time to the second number, determine the product of the ratio and the first number, and determine the difference between the first time and the product as the exposure time difference.

9. The method according to claim 8, characterized in that The process of sending a frame synchronization signal to the first image sensor and the second image sensor respectively includes: If the pixel arrays included in the first image sensor and the second image sensor are both arranged in a forward direction; the pixel arrays include n rows of pixels; wherein the pixels from the n-x+1th row to the nth row of pixels of the first image sensor overlap with the pixels from the 1st row to the xth row of pixels of the second image sensor; n is the second number, and x is the first number; a first frame synchronization signal is sent to the first image sensor, and the first frame synchronization signal carries a first exposure start time; a second frame synchronization signal is sent to the second image sensor, and the second frame synchronization signal carries a second exposure start time; the time difference between the second exposure start time and the first exposure start time is the exposure time difference.

10. An exposure control device based on a multi-way rolling shutter, characterized in that: A controller used in an image acquisition device, the device comprising: A determination module, configured to obtain and determine an exposure time difference between the first image sensor and the second image sensor according to an overlap area of ​​the first image sensor and the second image sensor; a sending module, configured to send frame synchronization signals to the first image sensor and the second image sensor respectively according to the exposure time difference, wherein the two frame synchronization signals respectively carry exposure start times, and the time difference between the two exposure start times is the exposure time difference; Among them, the first image sensor and the second image sensor are adjacent to each other vertically and have an overlapping area; the first image sensor and the second image sensor are exposed according to the exposure start time received by themselves, respectively, convert the received ambient light signal into an electrical signal, and send the electrical signal to a digital signal processor; the digital signal processor generates an image according to the received electrical signal.

Images