Method for entropically transcoding a first data stream into a second compressed binary data stream, and corresponding computer program and image recording device

An image capture device comprising:

• a pixel reader which reads values of pixels of an image;
• and
• an encoder which block encodes the values for supplying a first sequence of binary data of words to transcode into a second compressed sequence of binary data through use of a predetermined entropic code involving a variable-length of the encoded words to transcode each word of the first sequence of binary data into a transcoded word,
• wherein the encoder:
• subdivides the word into first and second subwords, wherein the first subword comprises B low-order bits of the word, and the second subword comprises other high-order bits of the word, through load of the bits of the word in cells of a first cell shift register linked to a first short-circuiter which short-circuits a first part of the first cell shift register, the first short-circuiter being defined on the basis of the value of a number B of low-order bits considered as representative of a noise level of the words of the first sequence of binary data;
• applies the predetermined entropic code to the second subword to obtain a second transcoded subword, through the load of bits in the cells of a second cell shift register arranged in series with the first shift register and further linked to a second short-circuiter which short-circuits a second part of the second cell shift register, the cells of the second shift register being loaded with bits at an equal predetermined value, with a bit at a complementary value different from the predetermined value and with a bit at a value defined as a function of a sign bit of the word;
• and
• obtains the transcoded word by concatenation of the first subword and of the second transcoded subword, the concatenation being obtained through a sequential reading of values of the non short-circuited cells of the first and second cell shift registers arranged in series.

A non-transitory computer readable medium comprising program executable code instructions for execution of a method when executed on a computer, said method for entropic transcoding of a first sequence of binary data words to transcode into a second compressed sequence of binary data through use of a predetermined entropic code involving a variable-length of the encoded words to transcode each word of the first sequence of binary data into a transcoded word, wherein, on basis of a predetermined number B of low-order bits considered as representative of a noise level of the words of the first sequence of binary data, the method comprising, in application to each word of the first sequence of binary data:

• subdividing the word into first and second subwords, wherein the first subword comprises the B low-order bits of the word, and the second subword comprises other high-order bits of the word, through load of the bits of the word in cells of a first cell shift register linked to a first short-circuiter which short-circuits a first part of the first cell shift register, the first short-circuiter being defined on the basis of the value of number B;
• applying the predetermined entropic code to the second subword to obtain a second transcoded subword, through the load of bits in the cells of a second cell shift register arranged in series with the first shift register and further linked to a second short-circuiter which short-circuits a second part of the second cell shift register, the cells of the second shift register being loaded with bits at an equal predetermined value, with a bit at a complementary value different from the predetermined value and with a bit at a value defined as a function of a sign bit of the word;
• and
• obtaining the transcoded word by concatenation of the first subword and of the second transcoded subword, the concatenation being obtained through a sequential reading of values of the non short-circuited cells of the first and second cell shift registers arranged in series.