Wavelet Toolbox

Wavelet Decomposition of Indexed Images

The Wavelet Toolbox supports only indexed images with linear, monotonic colormaps. These images can be thought of as scaled intensity images, with matrix elements containing only integers from 1 to n, where n is the number of discrete shades in the image.

If the colormap is not provided, the graphical user interface tools display the image and processing results using a monotonic colormap with max(max(X))-min(min(X))+1 colors.

Since the image colormap is only used for display purposes, some indexed images may need to be preprocessed to achieve the correct results from the wavelet decomposition.

In general, color indexed images do not have linear, monotonic colormaps and need to be converted to the appropriate gray-scale indexed image before performing a wavelet decomposition.

How Decompositions Are Displayed

Note that the coefficients, approximations, and details produced by wavelet decomposition are not indexed image matrices.

To display these images in a suitable way, the graphical user interface tools follow these rules:

• Reconstructed approximations are displayed using the colormap map.
• The coefficients and the reconstructed details are displayed using the colormap map applied to a rescaled version of the matrices.

Indexed Images

Other Images

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