Data compression

A video encoder configured to send video data over a channel, the encoder comprising:

• a compressor configured to compress video data using an adjustable compression factor, and a transmitter configured to transmit constructed data packets over the channel, wherein the compressor is configured to:
• (a) receive an original data array to be compressed;
• (b) divide the original data array into blocks of one or more sizes;
• (c) determine a plurality of possible compressed encodings for each block of the array using a respective different compression technique for each encoding of the block, wherein each possible compressed encoding has a respective data size and a respective reconstruction error;
• (d) initialise a compressed encoding of the original data array which when uncompressed corresponds to a reference data array which is an initial approximation to the original data array, wherein the compressed encoding has a first data size and a first reconstruction error, representing a quantitative difference between the original data array and the reference data array;
• (e) generate a list of the plurality for compressed encodings and select that one of the plurality of compressed encodings from the list which, when uncompressed and added to the reference data array, provides the largest relative improvement in reconstruction error per unit increase in data size;
• (f) update the compressed encoding of the original data array by adding the selected compressed encoding, and updating the reference data array by adding the selected encoding in uncompressed form;
• and
• (g) recursively repeat steps (e) and (f) until a maximum data size is achieved for the compressed encoding of the original data array.

A non-transitory computer readable storage medium having a computer program stored thereon, the computer program comprising processor readable instructions that, when executed, direct a device to perform actions comprising:

• (a) providing an original data array to be compressed;
• (b) dividing the original data array into blocks of one or more sizes;
• (c) determining a plurality of possible compressed encodings for each block of the array using a respective different compression technique for each encoding of the block, wherein each possible compressed encoding has a respective data size and a respective reconstruction error;
• (d) initialising a compressed encoding of the original data array which when uncompressed corresponds to a reference data array which is an initial approximation to the original data array, wherein the compressed encoding has a first data size and a first reconstruction error, representing a quantitative difference between the original data array and the reference data array;
• (e) generating a list of the plurality of compressed encodings and selecting that one of the plurality of compressed encodings from the list which, when uncompressed and added to the reference data array, provides the largest relative improvement in reconstruction error per unit increase in data size;
• (f) updating the compressed encoding of the original data array by adding the selected compressed encoding, and updating the reference data array by adding the selected encoding in uncompressed form;
• and
• (g) recursively repeating steps (e) and (f) until a maximum data size is achieved for the compressed encoding of the original data array.