Patent ID: 7554557

Claim:
An image compression device, comprising: a floating-point texture-loading unit for receiving raw image data that comprises N number of RGB pixels (N is a positive integer); a shader for receiving the raw image data and shading the N number of RGB pixels to generate shaded image data; a RGB to YCrCb compressor for receiving the shaded image data and calculating the brightness/chroma value of each of the RGB pixels, wherein the chroma value of the RGB pixel having the smallest brightness value among all the RGB pixels is selected as a common chroma value for all the RGB pixels; and a parameter adjusting unit for receiving and adjusting N number of brightness values of the RGB pixels and the common chroma value and storing the N number of brightness values and the common chroma value in a form of compressed image data into a memory; wherein the raw image data and the compressed image data are represented as floating-numbers, and wherein the RGB to YCrCb compressor comprises: a RGB to YCrCb conversion unit for receiving the shaded image data and calculating the brightness/chroma value of each of the RGB pixels; and a chroma downsampler for selecting the chroma value of the RGB pixel having the smallest brightness value among all the RGB pixels as the common chroma value.