Patent ID: 7587458

Claim:
A method of transmitting a digital message from a first computing device to a second computing device by means of a. the first device identifying a standard codebook that can be associated with a digital message, said standard codebook being stored on both the first and second devices; b. the first device identifying a first set of data elements found in the digital message which are found in the standard codebook; c. the first device identifying a second set of data elements found in the digital message which are not found in the standard codebook but which could be more efficiently represented if they had been found; d. the first device generating a modified version of the said standard codebook including the second set of data elements; e. the first device generating a set of difference information from a comparison between the modified version of the standard codebook and the original standard codebook; f. the first device encoding the digital message by replacing both the first and the second sets of data elements with code vectors pointing to the identical data elements in the modified version of the codebook; g. the first device transmitting the said difference information together with supplementary data, said supplementary data including at least the encoded digital message; and h. the second device, on receiving the difference information and the supplementary data: i. constructing a modified version of the codebook by applying the set of differences to its copy of the standard codebook; and ii. replacing all code vectors in the encoded digital message with the corresponding data elements from the modified version of the codebook to reproduce the original digital message.