Frame Buffer Compression without Color Information Loss

Due to the 60Hz or higher LCD refresh operations, display controller (DC) reads the pixels out from frame buffer at fixed rate. Accessing frame buffer consumes not only memory bandwidth, but power as well. Thus frame buffer compression (FBC) can contribute to alleviating both bandwidth and power consumption. A conceptual frame buffer compression model is proposed, and to the best of our knowledge, an arithmetic expression concerning the compression ratio and the read/update ratio of frame buffer is firstly presented, which reveals the correlation between frame buffer compression and target applications. Moreover, considering the linear access feature of frame buffer, we investigate a frame buffer compression without color information loss, named LFBC (Loss less Frame-Buffer Compression). LFBC defines new frame buffer compression data format, and employs run-length encoding (RLE) to implement the compression. For the applications suitable for frame buffer compression, LFBC reduces 50%90% bandwidth consumption and memory accesses caused by LCD refresh operations.