基于FPGA的图像压缩与编码算法设计

高帧频相机需要较长时间记录目标状态的图像信息,由于记录介质的存储容量所限,需要对图像进行实时压缩、记录与传输。EZW和SPIHT两种编码方法速度慢,不易在FPGA上实现,且对缓存要求较高。根据小波变换后小波系数的冗余及分布特性,提出一种新的编码算法,通过直接对系数大小做比较,然后结合数值特性和分布特性对小波系统进行动态分组,用较少的存储空间记录图像系数信息。该算法适合在FPGA上实现,实验结果验证了方法的可行性。

Design of Image Compression and Encoding Algorithm Based on FPGA

It takes a long time for high speed frame cameras to record image information of target states. The images need to be compressed, recorded and transmitted in real time for limited storage capacity of record medium. The speed of EZW and SPIHT coding methods are both too slow to work out on field-programmable gate array (FPGA) and they need high quality buffer storage. A new coding algorithm has been proposed based on redundancy and distribution characteristics of wavelet coefficients after wavelet transformation. Wavelet systems are grouped dynamically by directly comparing with magnitude of coefficients and incorporating characteristics of numbers and distributions. Less memory space is used to record coefficient information of images. The algorithm is suitable for FPGA. The feasibility of the method is verified by experiments.