Comparison between the effective pictorial information capacities of JPEG 6b and 2000

The evaluation of the Modulation Transfer Function of JPEG compression provides significant challenges because of its non-linear and non-stationary nature. Previous works have documented the calculation of the First Order Wiener Kernel to estimate the linear portion of the Modulation Transfer Function of JPEG 6b and 2000 and compared that to measurements made using ISO 12233 and traditional edge techniques. The First Order Weiner Kernel was argued as representing the overall pictorial effect of the compression techniques more closely than measurement procedures relying on a small portion of the field of view. This work directly compares the results for JPEG 6b and 2000. Additional work attempts to calculate an 'effective' Point Spread Function based on the estimated MTF for the compression systems. These results are then combined with estimates of RMS noise to produce an approximation for the effective pictorial information capacity (EPIC) of the system. It is shown that there is a good degree of correlation between the actual bit rate used to encode the image and the system EPIC for monochrome images. This correlation breaks down when red, green or blue channels are analyzed individually.