Image collector based on JPEG2000 image compression standard

Abstract

The utility model provides an image collector based on a JPEG2000 image compression standard, and belongs to the technical field of image compression collection. The problems that the compression multiplying power of an existing image collector cannot be changed, and image signals are lost and discontinuous during transmission due to the fact that a standard interface is not adopted are solved. An external device inputs a PAL system image to an image collector, the PAL system image enters an image collection unit, a PAL analog image is converted into a digital image and line, field and odd-even signals, and the digital image is directly transmitted to an image compression unit; and the row, field and odd-even signals are transmitted to the FPGA for synchronization and shaping and then are output to the image compression unit. The image compression unit is used for compressing an input digital image signal according to row, field and odd-even synchronizing signals according to a JPEG2000 compression standard, and outputting compressed data in an RS485 serial format; the utility model is applied to telemetering image acquisition.

Description

TECHNICAL FIELD

[0001] The utility model provides a kind of image collector based on JPEG2000 image compression standard belongs to telemeter image signal acquisition compression technical field. BACKGROUND

[0002] At present, image signal acquisition and transmission function are involved in many wireless transmission fields, and image signal needs to be compressed due to the limitation of wireless transmission distance and transmission bandwidth during image acquisition and transmission. The existing image collector adopts a fixed compression ratio compression method. However, in actual process, image signal is always in a changing state, and the richness of image signal also changes accordingly. The size of data after image compression is related to the richness of image signal, and the richer the image is, the larger the data after compression is. If image compression is performed according to a fixed compression ratio, the rate of compressed image output by the image collector will change in real time. In actual environment, if image signal is relatively rich, the rate of compressed image output by the image collector is relatively large, and vice versa. If the richness of image signal increases to a certain degree, the output rate of the image collector may be too large to exceed the transmission bandwidth, resulting in image signal loss and discontinuity.

[0003] In addition, the existing image collector may not adopt a standard interface due to different use environments and transmission protocols, and an additional conversion interface needs to be used during actual use, which may cause inconvenience and affect data transmission. UTILITY MODEL CONTENT

[0004] The utility model discloses a kind of image collector based on JPEG2000 image compression standard to solve the problem that the compression ratio of existing image collector is not changeable and standard interface is not adopted, which can cause image signal loss and discontinuity during transmission. The purpose is to improve the circuit part of image acquisition unit, image compression unit and data transmission unit, and to compress image using JPEG2000 image compression standard. The rate of compressed image output by the image collector can adapt to synchronous mode and asynchronous mode, so as to adjust the output rate of compressed image.

[0005] The utility model discloses a technical scheme for: a kind of image collector based on JPEG2000 image compression standard, including shell, and power supply interface, the output interface of compressed image and the input interface of PAL system analog image are provided on shell, control circuit board is installed in shell interior, and power conversion circuit, image acquisition unit, image compression unit, main control unit and data transmission unit are integrated on control circuit board, the external power supply input of power supply interface is converted into multiple different voltage grades power supply by power conversion circuit, and the different components of control circuit board are powered, the input end of image acquisition unit is connected the input interface of PAL system analog image, for converting analog image into digital image and line, field, parity signal, the digital image output end of image acquisition unit is connected the digital image input end of image compression unit, the line, field, parity signal output end of image acquisition unit is connected main control unit, and main control unit is output to image compression unit after line, field, parity signal are synchronized, shaping, the output end of image compression unit is connected main control unit, and compressed image data is sent to main control unit, and the signal output end of main control unit is connected the output interface of compressed image by data transmission unit.

[0006] Further, the image compression unit adopts built-in JPEG2000 image compression standard to compress the image.

[0007] Further, the shell is provided with two external interfaces, one of which includes the functions of power supply and compressed image output.

[0008] Further, the image acquisition unit adopts an ADV7182A video decoder, and the image compression unit adopts an ADV212 JPEG2000 codec.

[0009] Further, the main control unit adopts a GW2A-LV55PG484 FPGA.

[0010] Further, the data transmission unit adopts a MAX3485 RS485 transceiver.

[0011] Further, both external interfaces adopt standard interfaces.

[0012] Further, the external interface for power supply and compressed image output adopts a J30J-21ZKP connector, and the external interface for PAL system analog image input adopts an SMA-KFD86 connector.

[0013] The advantages of this invention compared to existing technologies are as follows: The image acquisition device of this invention adopts an integrated design, featuring small size, light weight, and easy installation, making it suitable for environments with limited installation space. Furthermore, the image acquisition device uses a standardized interface design with conventional connectors for easy connection to other devices. The connectors also feature protruding surfaces and ergonomic design for convenient connection and installation.

[0014] In terms of electrical design, an adaptive output bandwidth design is adopted, which solves the problem of image signal loss and discontinuity caused by excessive image signal. The actual acquired image signal is stable, continuous, and clear. Simultaneously, this image acquisition unit can operate in both synchronous and asynchronous output modes. In synchronous mode, it can participate in the entire wireless system, dynamically changing the compressed image output rate in real time according to the wireless system's synchronization commands. In asynchronous mode, it can output compressed image data at a preset fixed rate, providing flexible application modes to meet different usage environments.

[0015] This image acquisition device has been widely used in wireless image transmission environments, especially in narrow bandwidth transmission systems such as telemetry systems, achieving excellent image acquisition results and improving the quality of narrow bandwidth image transmission. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings:

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 for Figure 1 Top view;

[0019] Figure 3 for Figure 1 The front view;

[0020] Figure 4 This is a schematic diagram of the circuit structure of this utility model;

[0021] Figure 5 This is a circuit diagram of the image acquisition, compression, and transmission section of this utility model;

[0022] Figure 6 This is the circuit schematic of a power conversion circuit. Detailed Implementation

[0023] like Figures 1 to 6 As shown, this utility model provides an image acquisition device based on the JPEG2000 image compression standard, including a housing. The front of the housing has two external interfaces, such as... Figures 1-3As shown, the maximum size of the shell is 80mm*100mm*15mm, and the external interface is composed of two connectors, the left connector is J30J-21ZKP used for 28V power supply voltage input and compressed image signal output of the device, and the right connector is SMA-KFD86 used for inputting PAL system analog image signal.

[0024] The internal circuit composition diagram of the device is shown as Figure 4 The device is mainly composed of a power conversion circuit, an image acquisition unit, an image compression unit, a main control unit and a data transmission unit 5. The image acquisition unit selects an ADV7182A image analog-digital conversion chip, the image compression unit selects an ADV212 compression chip, the main control unit selects a domestic Gaoyun GW2A-LV55PG484 type FPGA, and the data transmission unit selects a MAX3485 type RS485 chip. The detailed circuit diagram is shown as Figure 5

[0025] The external device inputs the PAL system image to the image acquisition encoder, the PAL image enters the ADV7182A image acquisition unit, the PAL analog image is converted into a digital image and line, field and parity signals in YCrCb 4:2:2 format, the digital image is directly transmitted to the ADV212 image compression unit, the line, field and parity signals are transmitted to the main control unit FPGA for synchronization and shaping, and then output to the ADV212 image compression unit. The ADV212 image compression unit compresses the input digital image signal according to the line, field and parity synchronization signals according to the compression standard of JPEG2000, and outputs the compressed image data in RS485 serial format after compression. The output compressed data code rate can be dynamically configured.

[0026] The principle of dynamic configuration of the compressed data code rate is that the device of the utility model can work in synchronous output mode and asynchronous output mode. When working in synchronous output mode, the synchronous instruction input by the external device can be received, and the image compression data output is performed according to the beat of the synchronous instruction, and the code rate of the compressed image output is dynamically adjusted. When working in active output mode, the code rate of data output can be preset through the RS485 interface, and the compressed image is output according to the set code rate.

[0027] The dynamic configuration of the image data code rate will be described below according to specific embodiments.

[0028] Embodiment 1: synchronous output mode

[0029] ​When the image collector works in the synchronous output mode, the image output code rate varies with the frequency of the external synchronization signal. When the frequency of the external synchronization signal increases, the image output code rate increases; when the frequency of the external synchronization signal decreases, the image output code rate decreases.

[0030] After the image collector is powered on, the initial work of the image acquisition unit, the image compression unit and the data transmission unit is first completed. The initialization work is completed by the FPGA internal virtual MCU soft core. The image acquisition unit is responsible for converting the PAL system image into an 8-bit ITU-R BT.656 YCrCb 4:2:2 format digital image, the image compression unit is responsible for compressing the digital image according to the format of JPEG2000 (the compression ratio is specified according to the actual situation), and the data transmission unit is responsible for receiving the external synchronization signal and outputting the image compression data. After initialization, the external synchronization signal is valid, and when the external synchronization signal is valid, the data is sent according to the beat of the synchronization signal. The number of data sent in each beat is included in the synchronization beat instruction. The baud rate of the synchronization signal is 3686400bps, the transmission period is 100Hz, and the transmission length of each synchronization instruction is 7 bytes. The 3rd-4th byte represents the synchronization instruction length, and the big-end transmission mode is used. The 5th-6th byte represents the number of output compression data per packet, and the big-end transmission mode is used. The output data is 1024 (0400H) bytes per packet. According to the output code rate calculation formula, R=100*1024*8=819200bps. At this time, the synchronization signal transmission period changes from 100Hz to 200Hz, and the other remains unchanged. After calculation, R=200*1024*8=1638400bps. The synchronization transmission instruction is shown in Table 1.

[0031]

[0032] Table 1.

[0033] Example 2: Asynchronous output mode

[0034] When the image collector works in the asynchronous output mode, the output code rate of the compressed image can be set through the external serial bus. The pre-set code rate parameters are composed of two sub-parameters, which are the synchronization instruction period n (Hz) and the number of data output per packet m (Byte). For example, to set the code rate to 1638400bps, the formula R=m*n*8 can be used for calculation, and m and n can be flexibly combined, which can be m=1024, n=200, or m=2048, n=100.

[0035] The image collector is powered on first to complete the device initialization, including the initialization of the image acquisition unit, the image compression unit and the data transmission unit (the transmission baud rate is 3686400bps), and reading the preset code rate (m=2048, n=100). After the initialization is completed, the code rate parameter is loaded, and the image collector outputs the image compression data according to the loaded code rate, with a period of 100Hz and 2048 bytes of data per packet.

[0036] It should be noted that the connection relationship between the components and modules of the utility model is determined and can be realized. Except for the special description in the embodiments, the specific connection relationship can bring corresponding technical effects. Based on the premise of not relying on the corresponding software program execution, the technical problems proposed by the utility model are solved. The model, connection mode, and conventional use method of the components, modules, and specific components in the utility model, and the anticipated technical effects brought by the above technical features, except for the specific description, belong to the public content disclosed in the patents, journal papers, technical manuals, technical dictionaries, textbooks, and other existing technologies obtained by the technical personnel in the field before the application date. They do not need to be described in detail. The technical scheme provided in the case is clear, complete, and can be realized, and the corresponding entity product can be reproduced or obtained according to the technical means.

[0037] Finally, it should be noted that: the above embodiments are only used to illustrate the technical scheme of the utility model, but not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical scheme recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical scheme deviate from the scope of the technical scheme of the embodiments of the utility model.

Claims

1. An image capture device based on the JPEG2000 image compression standard comprising a housing characterised in that: The shell is provided with a power supply interface, an output interface of compressed images and an input interface of PAL system analog images, and a control circuit board is installed in the shell, the control circuit board is integrated with a power conversion circuit, an image acquisition unit, an image compression unit, a main control unit and a data transmission unit, the power conversion circuit converts external power input from the power supply interface into power of multiple different voltage levels to supply different components on the control circuit board, the input end of the image acquisition unit is connected with the input interface of PAL system analog images to convert analog images into digital images and line, field and parity signals, the digital image output end of the image acquisition unit is connected with the digital image input end of the image compression unit, the line, field and parity signal output end of the image acquisition unit is connected with the main control unit, the main control unit synchronizes and shapes the line, field and parity signals and then outputs them to the image compression unit, the output end of the image compression unit is connected with the main control unit to send compressed image data to the main control unit, and the signal output end of the main control unit is connected with the output interface of compressed images through the data transmission unit.

2. An image acquirer based on JPEG2000 image compression standard according to claim 1, characterized in that: The image compression unit adopts built-in JPEG2000 image compression standard to compress images.

3. An image acquirer based on JPEG2000 image compression standard according to claim 1, characterized in that: The shell is provided with two external interfaces, one of which has the functions of power supply and output of compressed images.

4. The image acquirer based on JPEG 2000 image compression standard according to claim 1, characterized in that: The image acquisition unit adopts a video decoder of ADV7182A type, and the image compression unit adopts a JPEG2000 codec of ADV212 type.

5. The image acquirer based on JPEG 2000 image compression standard according to claim 1, characterized in that: The main control unit adopts a FPGA of GW2A-LV55PG484 type.

6. The image acquirer based on JPEG 2000 image compression standard according to claim 1, characterized in that: The data transmission unit adopts an RS485 transceiver of MAX3485 type.

7. An image acquirer based on JPEG2000 image compression standard according to claim 2, characterized in that: Both of the two external interfaces adopt standard interfaces.

8. An image acquirer based on JPEG2000 image compression standard according to claim 7, characterized in that: The external interface for power supply and output of compressed images adopts a connector of J30J-21ZKP type, and the external interface for input of PAL system analog images adopts a connector of SMA-KFD86 type.

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