Patent attributes
An image is compressed according to a compression ratio selected based on a compression metric. In one embodiment, the compression metric is based on image characteristics indicative of the amount of image noise in an image, such as gain and lux. Greater compression ratios are used for image having compression metrics indicating a higher degree of noise. Because an image with higher image noise levels already has a reduced visual quality, the impact of higher compression is less significant as compared to the impact of compression on images having low image noise. In an embodiment, an image is divided into a number of regions, for each of which a compression metric and corresponding compression ratio is determined, so that regions of the image having high image noise may be compressed more than regions having low image noise.
