cooc_feature_matrix🔗
Short description🔗
cooc_feature_matrix — Calculate gray value features from a co-occurrence matrix.
Signature🔗
cooc_feature_matrix( image CoocMatrix, out real Energy, out real Correlation, out real Homogeneity, out real Contrast )
Description🔗
The operator cooc_feature_matrix calculates from a co-occurrence
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 (Measure for image homogeneity): \(\textrm{Energy} = \sum_{i,j=0}^{width}{c_{ij}^2}\)
-
Correlation (Measure for gray value dependencies): \(\textrm{Correlation} = \frac{\sum_{i,j=0}^{width} {{( i - u_{x} ) ( j - u_{y} ) c_{ij}}}}{s_{x} s_{y}}\)
-
Local homogeneity: \(\textrm{Homogeneity} = \sum_{i,j=0}^{width}{ \frac{1}{ 1 + ( i - j )^2} c_{ij}}\)
-
Contrast (Measure for the size of the intensity differences): \(\textrm{Contrast} = \sum_{i,j=0}^{width} {( i - j )^2 c_{ij}}\)
where
-
\(width =\) Width of
CoocMatrix, -
\(c_{ij}\) Entry of co-occurrence matrix,
-
\(u_{x} = \sum_{i,j=0}^{width}{ i *c_{ij}}\),
-
\(u_{y} = \sum_{i,j=0}^{width}{ j *c_{ij}}\),
-
\(s_{x}^2 = \sum_{i,j=0}^{width}{ (i - u_{x})^2 * c_{ij}}\),
-
\(s_{y}^2 = \sum_{i,j=0}^{width}{ (i - u_{y})^2 * c_{ij}}\).
Attention🔗
The region of the input image is disregarded.
Execution information🔗
Execution information
-
Multithreading type: reentrant (runs in parallel with non-exclusive operators).
-
Multithreading scope: global (may be called from any thread).
-
Automatically parallelized on tuple level.
Parameters🔗
CoocMatrix (input_object) singlechannelimage(-array) → object (real)
Co-occurrence matrix.
Energy (output_control) real → (real)
Homogeneity of the gray values.
Correlation (output_control) real → (real)
Correlation of gray values.
Homogeneity (output_control) real → (real)
Local homogeneity of gray values.
Contrast (output_control) real → (real)
Gray value contrast.
Result🔗
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.
Combinations with other operators🔗
Combinations
Possible predecessors
Alternatives
See also
Module🔗
Foundation