Sampling circuitry independently accesses channels of texture data that represent a set of pixels. One or more processing units separately compress the channels of the texture data and store compressed data representative of the channels of the texture data for the set of pixels. The channels can include a red channel, a blue channel, and a green channel that represent color values of the set of pixels and an alpha channel that represents degrees of transparency of the set of pixels. Storing the compressed data can include writing the compress data to portions of a cache. The processing units can identify a subset of the set of pixels that share a value of a first channel of the plurality of channels and represent the value of the first channel over the subset of the set of pixels using information representing the value, the first channel, and boundaries of the subset.