The invention discloses a
JPEG2000 self-adapting
rate control system and a method based on pre-assignment of
code rate, mainly solving the problem of large calculation amount and large memory size of
JPEG2000 encoding method. The code block of the original image after pretreatment,
wavelet transformation and quantification is output by two lines, one line directly enters the
bit plane and MQ coder; for the other line, the entropy of each code block is estimated by the entropy estimate module, sent to the
code rate assignment module to assign
code rate, and the code rate of each code block is feed back to the
bit plane and MQ coder through the encoding depth control module, after the code blocks are encoded by the
bit plane, further feed back to the encoding depth control module to determine the output code
stream of each encoded code block, and the output code
stream is under optimal interception and code
stream organization to output the ultimate code stream. At the same time, the invention can change the threshold value of the encoding depth control coefficient as required, to flexibly control the encoding depth in order to improve the
image compression quality. The invention has the advantages of
low complexity and easiness for hardware implementation, and is suitable for various
JPEG2000 image real-
time compression systems.