Image Processing Toolbox Release Notes

Texture Analysis

The toolbox now supports a set of functions that you can use for texture analysis. These functions include

• entropy -- Calculates the entropy of an intensity image
• entropyfilt -- Calculates the local entropy of an intensity image
• graycomatrix -- Computes the gray-level co-occurrence matrix from an image
• graycoprops -- Extracts properties from a gray-level co-occurrence matrix
• rangefilt -- Calculates the local range of an image
• stdfilt -- Calculates the standard deviation of an image

Texture analysis refers to the characterization of regions in an image by their texture content. Texture analysis attempts to quantify intuitive qualities described by terms such as rough, silky, or bumpy in the context of an image. In this case, the roughness or bumpiness refers to variations in the brightness values or gray levels.

Some of the most commonly used texture measures are derived from the Grey Level Co-occurrence Matrix (GLCM). The GLCM is a tabulation of how often different combinations of pixel brightness values (gray levels) occur in a pixel pair in an image. You can use the graycomatrix function to create a GLCM and then use graycoprops to extract feature information (e.g., contrast, correlation, energy, and homogeneity) from the GLCM.

The texture analysis support also includes several new functions that filter using standard statistical measures, such as range, standard deviation, and entropy. (Entropy is a statistical measure of randomness.) To see an example of using these filtering functions, view the "Texture Segmentation Using Texture Filters" demo. Use the iptdemos function to access toolbox demos.

Hough Transform

New ICC Color Profile Export Function

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