用于二维码解码的图像传感器接口模块设计

Design of image sensor interface module for 2D code decoding

针对嵌入式二维码识别系统中对图像处理的需求,本文设计了一款基于高性能总线(AHB)的图像传感器接口IP(硅知识产权核)。该IP作为CMOS图像传感器和二维码解码系统的其他模块之间的一个接口,主要实现采集、处理与缓存图像传感器数据的功能,支持图像RGB565(红色分量R为5比特,绿色分量G为6比特,蓝色分量B为5比特)和YCbCr422(4字节的数据里面包含2字节的亮度分量Y,1字节的蓝色度分量Cb和1字节的红色色度分量Cr)的数据格式,支持直接存储器(DMA)接口,支持图像窗口裁剪功能。设计采用自顶向下的方法来划分和设计每个子模块的,并在基于现场可编程门阵列(FPGA)的二维码解码系统中进行了仿真和验证,结果表明,图像可以被无失真的捕获和传输。

For the demand of image processing in embedded QR code recognition system,this paper designs an image sensor interface IP(Silicon Intellectual Property)based on Advanced High performance Bus(AHB).The IP serves as an interface between CMOS image sensors and other modules in the QR code decoding system,mainly implements the function of capturing,processing and caching data from the image sensor.Supports RGB565(5 bits for red component R,6 bits for green component G,and 5 bits for blue component B)and YCbCr422(4 bytes of data containing 2 bytes of luminance component Y,1 byte of blue chrominance component Cb,and 1 byte of red chrominance component Cr)data formats,Direct Memory Access(DMA)interface,and image window cropping function.The design uses a top-down approach to divide and design each submodule,and is simulated and verified in a Field Programmable Gate Array(FPGA)based 2D code decoding system.The results show that images can be captured and transmitted without distortion.