Image Texture and Fourier Analysis in a Polar Spatial Frequency System:
methods illustration
Abstract
Abstract
We illustrate the connection between image-texture and defined regions
in a polar spatial frequency coordinate system. This is provided within
the context of describing a non-parametric method for characterizing
two-dimensional
spectra of gray scaled images, described in part previously. The
spectrum is divided into concentric radial bands of fixed bandwidth.
Each band is summarized, producing a set of measures characterizing the
image as a function of radial spatial frequency. This set of measures
has a parallel multiscale description as texture in the image domain.
This approach was modified to capture texture with directional
attributes. This is a data reduction technique that gives a full
accounting of the image variance as function of image texture and
direction indexed to regions in the polar frequency plane. Application
examples include analyzing the summarized spectrum graphically, making
inter/intra image spectral comparisons, and evaluating spectral models.
Simulated noise images, an image of peppers, and a gray scale image with
well-defined linear structure were used to illustrate the principles.