Patent ID: 7627180
Filing Date: 2009-12-01
Classification: H04N

Abstract:
1. An image compression apparatus comprising: downsampling region dividing means for dividing image data into downsampling regions each at a size that is an integer multiple of a block size; downsampling means for performing downsampling on at least a part of said downsampling regions to decrease the number of pixels thereof, and for generating reduced data each at a size that is an integer multiple of said block size; rearranging means for arranging two or more pieces of said reduced data in each of said downsampling regions subjected to said downsampling, for inserting fill data into each of pixels left in said downsampling region in which said reduced data is arranged, and for removing said downsampling regions in which said reduced data is not arranged; and data compressing means for dividing image data generated by said rearranging means into block regions each at said block size, and for performing a compression processing including an orthogonal transform and a quantization on each of said block regions, thereby generating compressed image data, wherein said downsampling region dividing means divides said image data into said downsampling regions having different sizes, and said downsampling means performs said downsampling at different compression rates according to said sizes of said downsampling regions, thereby generates said reduced data equal in size.