Method and device for transcoding N-bit words into M-bit words with M smaller N

1. Method for transcoding a N bits word into a M bits word, N>M, wherein it comprises the following steps:

breaking down the N bits word into an exponent part and a mantissa part having each a size which varies according to the value of said N bits word, the size of the mantissa part increasing with the value of said N bits word, and

encoding the exponent part of the N bits word into a variable number of bits A and removing, if need be, least significant bits of the mantissa part in order to obtain a mantissa with a variable number of bits B, with A+B=M.

2. Device for transcoding a N bits word into a M bits word, N>M, comprising

means for breaking down the N bits word into an exponent part and a mantissa part having each a size which varies according to the value of said N bits word, the size of the mantissa part increasing with the value of said N bits word, and

means for encoding the exponent part of the N bits word into a variable number of bits A and removing, if need be, least significant bits of the mantissa part in order to obtain a mantissa with a variable number of bits B, with A+B=M.

3. Plasma display panel comprising:

a degamma means for applying a degamma function to video input data and delivering N bits data;

a transcoding device for transcoding said N bits data into M bits data, with N>M, and

a mapping memory for remapping the M bits data, wherein said transcoding device is a transcoding device according to claim 2 .