Image processor and image processing method

摘要

The speed of decoding processing for variable-length coded image data is improved. The image processor includes a variable-length decoding unit for variable-length decoding input data and outputting a pair of the run length of zero coefficients and a non-zero coefficient; an inverse quantization unit for subjecting the non-zero coefficient to inverse quantization and obtaining inverse quantized data to be output; an address setting unit for carrying out inverse scanning, obtaining an address for storing the inverse quantized data on the basis of the run length of zero coefficients and specifying the address in the data storage unit; a write information storage unit for setting a write flag in an address thereof corresponding to the specified address; and a data reading unit for reading data from the data storage unit, and on the basis of information stored in the write information storage unit, directly outputting data from the address specified by the address setting unit while substituting a predetermined value for data from an address other than the specified address to output the substituted value.