Texture compression can be applied to reduce memory usage at runtime.
Texture data is often the largest source of memory usage in a mobile application.
These features are: Given the above, most texture compression algorithms involve some form of fixed-rate lossy vector quantization of small fixed-size blocks of pixels into small fixed-size blocks of coding bits, sometimes with additional extra pre-processing and post-processing steps.
Block Truncation Coding is a very simple example of this family of algorithms.
OpenGL and OpenGL ES, as implemented on many video accelerator cards and mobile GPUs, can support multiple common kinds of texture compression - generally through the use of vendor extensions.