
Proceedings Paper
Visual-system-based polar quantization of local amplitude and local phase of orientation filter outputsFormat | Member Price | Non-Member Price |
---|---|---|
$17.00 | $21.00 |
Paper Abstract
Image decomposition via even- and odd-symmetric, size and orientation selective band-pass filters, as
suggested by the receptive field properties of visual cortical neurons, is well suited to image coding purposes.
Interpretation of the even/odd filter outputs as a complex ("analytic") signal offers the alternative of a polar
signal representation by a local amplitude and a local phase component. This is also indicated by our
measurement of a rotation symmetric shape of the two-dimensional probability density function (pdf) of the
even/odd filter outputs.
Our investigations into the properties of such a representation show that it provides an interesting separation of
the "amount of signal variation" (local amplitude) vs. the "type of signal variation" (local phase) . Furthermore
an efficient vector quantization procedure can be applied to the two-dimensional amplitude/phase vector. This
procedure divides the 2D signal space of the analytic signal into polar separable patches. Since phase
quantization errors are more tolerable at small amplitude levels local phase is quantized dependent on the
amplitude level. While typical pdf-optimized quantizers produce an increasingly higher amplitude resolution
towards very small amplitudes, human vision allows the application of an appropriate threshold which leads to an
"irrelevance zone" wherein obviously no phase information has to be coded. Using this coding scheme good
image quality can be obtained with about 0.8 bit/pixel.
Paper Details
Date Published: 1 October 1990
PDF: 12 pages
Proc. SPIE 1249, Human Vision and Electronic Imaging: Models, Methods, and Applications, (1 October 1990); doi: 10.1117/12.19680
Published in SPIE Proceedings Vol. 1249:
Human Vision and Electronic Imaging: Models, Methods, and Applications
Bernice E. Rogowitz; Jan P. Allebach, Editor(s)
PDF: 12 pages
Proc. SPIE 1249, Human Vision and Electronic Imaging: Models, Methods, and Applications, (1 October 1990); doi: 10.1117/12.19680
Show Author Affiliations
Bernhard Wegmann, Technische Univ. Muenchen (Germany)
Christoph Zetzsche, Technische Univ. Muenchen (Germany)
Published in SPIE Proceedings Vol. 1249:
Human Vision and Electronic Imaging: Models, Methods, and Applications
Bernice E. Rogowitz; Jan P. Allebach, Editor(s)
© SPIE. Terms of Use
