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Two-Dimensional Hermite Filters Simplify the Description of High-Order Statistics of Natural Images.

TitleTwo-Dimensional Hermite Filters Simplify the Description of High-Order Statistics of Natural Images.
Publication TypeJournal Article
Year of Publication2016
AuthorsHu Q, Victor JD
JournalSymmetry (Basel)
Volume8
Issue9
Date Published2016 Sep
ISSN2073-8994
Abstract

Natural image statistics play a crucial role in shaping biological visual systems, understanding their function and design principles, and designing effective computer-vision algorithms. High-order statistics are critical for conveying local features, but they are challenging to study - largely because their number and variety is large. Here, via the use of two-dimensional Hermite (TDH) functions, we identify a covert symmetry in high-order statistics of natural images that simplifies this task. This emerges from the structure of TDH functions, which are an orthogonal set of functions that are organized into a hierarchy of ranks. Specifically, we find that the shape (skewness and kurtosis) of the distribution of filter coefficients depends only on the projection of the function onto a 1-dimensional subspace specific to each rank. The characterization of natural image statistics provided by TDH filter coefficients reflects both their phase and amplitude structure, and we suggest an intuitive interpretation for the special subspace within each rank.

DOI10.3390/sym8090098
Alternate JournalSymmetry (Basel)
PubMed ID27713838
PubMed Central IDPMC5050006
Grant ListR01 EY007977 / EY / NEI NIH HHS / United States
R01 EY009314 / EY / NEI NIH HHS / United States
/ / United States NEI / United States