Title :
Hexagonal sub-band coding for images
Author :
Mahesh, Balaskrishnan ; Pearlman, William A.
Author_Institution :
Dept. of Electr., Comput., & Syst. Eng., Rensselaer Polytech. Inst., Troy, NY, USA
Abstract :
An image coding system is proposed in which hexagonally sampled images are decomposed into subbands that are selective in both frequency and orientation. Nine high-frequency bands each of one octave and 60 degrees of angular orientation are built on a pyramidal structure along with one low-frequency band. Bits are then allocated optimally to the subbands under a mean-squared-error distortion measure. Optimal quantizers are designed for each subband for entropy coding under a Laplacian distribution assumption. An adaptive version of the coding scheme is also implemented, and the results are compared at rates of 0.5 and 1.0 bits per pixel
Keywords :
data compression; encoding; picture processing; Laplacian distribution; adaptive coding; entropy coding; hexagonal subband coding; hexagonally sampled images; image coding; mean-squared-error distortion measure; optimal quantisers; pyramidal structure; Distortion measurement; Filtering; Filters; Frequency; Image coding; Image reconstruction; Image sampling; Kernel; Mirrors; Sampling methods;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 1989. ICASSP-89., 1989 International Conference on
Conference_Location :
Glasgow
DOI :
10.1109/ICASSP.1989.266839
