| 摘要 |
PROBLEM TO BE SOLVED: To efficiently generate color and monochromatic compressed image data.SOLUTION: When generating color and monochromatic compressed image data, a JPEG compression circuit 39 implements processing from input of block data to generation of encoded data using a common hardware circuit including a frequency conversion units 120, a quantization unit 130, a zigzag scan unit 140 and an encoding unit 150 as elements. The encoding unit 150 outputs a bit stream of encoded data obtained by performing entropy encoding on quantized data. On the other hand, identification signals capable of identifying a luminance region in the bit stream of the encoded data, a color difference region and regions of DC component data and AC component data requiring replacement of codes are outputted in parallel. On the basis of the identification signals, a color difference replacement unit 160 applies such code replacement as to change a color difference component into zero to the bit stream from the encoding unit 150. |
