gen_cooc_matrix🔗
Short description🔗
gen_cooc_matrix — Calculate the co-occurrence matrix of a region in an image.
Signature🔗
gen_cooc_matrix( region Regions, image Image, out image Matrix, integer LdGray, integer Direction )
Description🔗
The operator gen_cooc_matrix determines from the input
regions how often the gray values \(i\) and \(j\) are located next to
each other in a certain direction (0, 45,
90, 135 degrees), stores this number in the
co-occurrence matrix at the locations \((i,j)\) and \((j,i)\) (the
matrix is symmetrical), and finally scales the matrix with the
number of entries. LdGray indicates the number of gray
values to be distinguished (namely \(2^{\textrm{LdGray}}\)).
Example: Input image with gray values (scaled with LdGray=2)
| 0 | 0 | 3 |
| 1 | 1 | 2 |
| 1 | 2 | 3 |
Co-occurrence matrix (not scaled):
textbf{0:} quad
| 2 | 0 | 0 | 1 |
| 0 | 2 | 2 | 0 |
| 0 | 2 | 0 | 1 |
| 1 | 0 | 1 | 0 |
qquad textbf{135:} quad
| 0 | 1 | 1 | 0 |
| 1 | 0 | 1 | 1 |
| 1 | 1 | 0 | 0 |
| 0 | 1 | 0 | 0 |
qquad textbf{90:} quad
| 0 | 2 | 0 | 0 |
| 2 | 2 | 1 | 0 |
| 0 | 1 | 0 | 2 |
| 0 | 0 | 2 | 0 |
qquad textbf{45:} quad
| 0 | 1 | 0 | 0 |
| 1 | 2 | 0 | 1 |
| 0 | 0 | 2 | 0 |
| 0 | 1 | 0 | 0 |
Attention🔗
Note that the operator gen_cooc_matrix only considers
the given Regions and ignores any previously set domain
of the input image Image.
Execution information🔗
Execution information
-
Multithreading type: reentrant (runs in parallel with non-exclusive operators).
-
Multithreading scope: global (may be called from any thread).
Parameters🔗
Regions (input_object) region(-array) → object
Region to be checked.
Image (input_object) singlechannelimage → object (byte)
Image providing the gray values.
Matrix (output_object) image(-array) → object (real)
Co-occurrence matrix (matrices).
LdGray (input_control) integer → (integer)
Number of gray values to be distinguished (\(2^{\textrm{LdGray}}\)).
Default: 6
List of values: 1, 2, 3, 4, 5, 6, 7, 8
Value range: LdGray (lin)
Minimum increment: 1
Recommended increment: 1
Direction (input_control) integer → (integer)
Direction of neighbor relation.
Default: 0
List of values: 0, 45, 90, 135
Result🔗
The operator gen_cooc_matrix returns the value 2 (H_MSG_TRUE) if
an image with defined gray values is entered 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>:),
the behavior in case of empty region is set via
set_system(::'empty_region_result',<Result>:).
If necessary an exception is raised.
Combinations with other operators🔗
Combinations
Possible predecessors
draw_region, gen_circle, gen_ellipse, gen_rectangle1, gen_rectangle2, threshold, erosion_circle, binomial_filter, gauss_filter, smooth_image, sub_image
Alternatives
See also
Module🔗
Foundation