Disclosed is a method of compressing information for storage in a fixed
size memory. The data items (D(k)) that constitute the information are
divided into pieces (D(s,k)) of decreasing significance. For example, the
DCT blocks of an image are hierarchically quantized (3). The memory (5) is
organized in corresponding memory layers (501-504). Successive memory
layers have a decreasing number of memory locations. Every time a data
item is applied to the memory, its less significant data pieces will have
to compete with corresponding data pieces of previously stored data items.
Depending on its contribution to perceptual image quality, the applied
data piece is stored or the stored data piece is kept. Links (511-513,
521-522) are stored in the memory to identify the path along which a data
item is stored. Eventually, the image is automatically compressed so as to
exactly fit in the memory. FIG. 2.