Patent ID: 8934725
Filing Date: 2015-01-13
Classification: H04N

Abstract:
1. A method of coding bitplanes of data, the method comprising: determining a number P of consistent value bitplanes in a set of N bitplanes being coded, values in said P consistent value bitplanes being the same, P and N being integer values; generating a bitplane entropy coding control value P′ from a computation using the number P and a second control value as inputs, said second control value being a positive non-zero value, said generating including subtracting said second control value from P; identifying, using the bitplane entropy coding control value P′, a predetermined fixed number F of bitplanes of said set of N bitplanes, F, N, P and P′ all being integers; and subjecting the identified bitplanes to a first coding process to generate a first set of coded data; coding at least some remaining bitplanes of the set of N bitplanes using a second coding process to generate a second set of coded data, said second coding process being a second entropy coding process, said second entropy coding process being different from said first coding process, said remaining bitplanes being bitplanes which were not subjected to the first coding process; and generating a bitstream from said first and second sets of coded data and said value P′, said bitstream communicating the value P′.