Operators |
cooc_feature_matrix — Calculate gray value features from a co-occurrence matrix.
cooc_feature_matrix(CoocMatrix : : : Energy, Correlation, Homogeneity, Contrast)
The operator calculates from a co-occurence matrix (CoocMatrix) the energy (Energy), correlation (Correlation), local homogeneity (Homogeneity) and contrast (Contrast).
The operator cooc_feature_matrix calculates the gray value features from the part of the input matrix generated by gen_cooc_matrix corresponding to the direction matrix indicated by the parameters LdGray and Direction according to the following formulae:
Energy: width width ---- ---- \ \ Energy = / / cij * cij ---- ---- i=0 j=0 (Measure for image homogeneity) Correlation: width width ---- ---- \ \ / / (i - ux) * (j - uy) * cij ---- ---- i=0 j=0 Correlation = ----------------------------------------- sx * sy (Measure for gray value dependencies) Local homogeneity: width width ---- ---- \ \ 1 Homogeneity = / / ------------- * cij ---- ---- 1 + (i - j)^2 i=0 j=0 Contrast: width width ---- ---- \ \ Contrast = / / (i - j)^2 * cij ---- ---- i=0 j=0 (Measure for the size of the intensity differences) where width 2^LdGray - 1 cij Entry of co-occurrence matrix width width ---- ---- \ \ ux / / i * cij ---- ---- i=0 j=0 width width ---- ---- \ \ uy / / j * cij ---- ---- i=0 j=0 width width ---- ---- \ \ sx^2 / / (i - ux)^2 * cij ---- ---- i=0 j=0 width width ---- ---- \ \ sy^2 / / (i - uy)^2 * cij ---- ---- i=0 j=0
The region of the input image is disregarded.
Co-occurrence matrix.
Homogeneity of the gray values.
Correlation of gray values.
Local homogeneity of gray values.
Gray value contrast.
The operator cooc_feature_matrix returns the value 2 (H_MSG_TRUE) if an image with defined gray values is passed and the parameters are correct. The behavior in case of empty input (no input images available) is set via the operator set_system(::'no_object_result',<Result>:). If necessary an exception is raised.
intensity, min_max_gray, entropy_gray, select_gray
Foundation
Operators |