Human visual sensitivity-weighted progressive image transmission using the lapped orthogonal transform

Abstract

Progressive transmission of images based on the lapped orthogonal transform (LOT), adaptive classification, and human visual sensitivity (HVS) weighting is proposed. HVS weighting for LOT basis functions is developed. This technique is quite general and can be applied to any orthogonal transform. The method is compared with discrete cosine transform (DCT)-based progressive image transmission (PIT). It is shown that LOT-based PIT yields subjectively improved images compared to those based on DCT. This is consistent with the reduction in block structure characteristic of LOT image coding.

Human Visual System Based Wavelet Decomposition for Image Compression

“…Log sensitivity approximation The maximum frequency in the original digital signal is given by f max = N 4 arctan ( 1 2 ) cycles/degree(5) where N is the number of samples and is the ratio of the distance of the viewer from the screen, l, to the screen width, w; = l=w 5]. The number of bits allocated to this signal is proportional to the area under the log sensitivity function between f 1 and f 2 .Area = log S(f 1 ) + log S(f 2 ) f 1 ):…”