Abstract: An apparatus and method are provided for Z-buffer compression and decompression. The memory requirements for Z-buffer are reduced with a slight loss of image quality. When coupled with over-sampling, the Z-buffer compression algorithm of the present invention decreases the memory requirements for over-sampled images with negligible loss of image quality. In one embodiment, once a block of h Z-values has been accumulated in the memory, it is compressed by an encoder. Next, the minimum (MIN) and maximum (MAX) values are recorded. Thereafter, the range between MIN and MAX is divided into a number of intervals (L). Instead of storing each of the 32-bit samples, an index ki is used to represent each sample. The index ki is calculated for i equals 1 to h, using the following equation: ki=(Zi−MIN)*L/(MAX−MIN). This formula will yield a number between 0 and the number of intervals. Next the compressed Z-values are transferred to a Z-buffer.