چکیده (انگلیسی):

An extension of the standard JPEG image compression known as JPEG-3 allows rescaling of the
quantization matrix to achieve a certain image output quality. Recently, Tchebichef Moment Transform
(TMT) has been introduced in the field of image compression. TMT has been shown to perform better than the
standard JPEG image compression. This study presents an adaptive TMT image compression. This task is
obtained by generating custom quantization tables for low, medium and high image output quality levels based
on a psychovisual model. A psychovisual model is developed to approximate visual threshold on Tchebichef
moment from image reconstruction error. The contribution of each moment will be investigated and analyzed
in a quantitative experiment. The sensitivity of TMT basis functions can be measured by evaluating their
contributions to image reconstruction for each moment order. The psychovisual threshold model allows a
developer to design several custom TMT quantization tables for a user to choose from according to his or her
target output preference. Consequently, these quantization tables produce lower average bit length of Huffman
code while still retaining higher image quality than the extended JPEG scaling scheme.