基于文本的图像压缩在LED显示屏中的应用

Implementation of document images compression in LED screen

LED显示屏主要用来显示文字信息,它的控制系统多为单片机控制,通信方式为rs232或者低速的以太网。考虑到单片机的处理能力和控制系统成本的原因,一般控制系统都没有设置字库,所以LED显示屏上显示的文字一般都用位图点阵信息表示。但基于文本的位图数据量很大,且控制系统的通讯传输速度低下,在发送大量显示画面时位图数据的压缩就非常重要。由于控制系统单片机的处理能力有限J,PEG、GIF等图像压缩算法难以实现。基于行程编码图像压缩算法计算量小、适合单片机处理,而且对于文字位图的压缩率较高。

The LED screen used mainly to display text information. Mostly control system is Micro-processor and communication pattern is RS232 or low speed Ethernet. Because Micro-processor ability and cost that control system of LED screen is not install fonts library, text information is convert to dot-matrix bitrnap to display, but size ofbitmap file is too large and communication speed is lower, so it is necessary to images compression when send lot of text pictures to control system. For ability of Micro-processor, it is too difficulty to use JPEG or GIF algorithms. Based on RLE （run-length encoding） document images compression algorithms is less compute scale, and suit to Micro-processor, and same time the algorithms have high compression rate for document images.