thinning_seqthinning_seqThinningSeqThinningSeqthinning_seq (Operator)

Name

thinning_seqthinning_seqThinningSeqThinningSeqthinning_seq — Remove the result of a hit-or-miss operation from a region (sequential).

Warning

thinning_seqthinning_seqThinningSeqThinningSeqThinningSeqthinning_seq is obsolete and is only provided for reasons of backward compatibility.

Signature

thinning_seq(Region : RegionThin : GolayElement, Iterations : )

Description

thinning_seqthinning_seqThinningSeqThinningSeqThinningSeqthinning_seq calculates the sequential thinning of the input regions with a structuring element from the Golay alphabet (GolayElementGolayElementGolayElementGolayElementgolayElementgolay_element). To do so, thinning_seqthinning_seqThinningSeqThinningSeqThinningSeqthinning_seq calls the operator thinning_golaythinning_golayThinningGolayThinningGolayThinningGolaythinning_golay with all possible rotations of the structuring element IterationsIterationsIterationsIterationsiterationsiterations times. If IterationsIterationsIterationsIterationsiterationsiterations is chosen large enough, the operator calculates the skeleton of a region if the structuring elements 'l' or 'm' are used. For the element 'c' the background and foreground are exchanged in order to have an effect on the interior boundary of a region. If a very large value or 'maximal' is passed for IterationsIterationsIterationsIterationsiterationsiterations the iteration stops if no more changes occur. The following structuring elements are available:

'l': Skeleton, similar to skeletonskeletonSkeletonSkeletonSkeletonskeleton. This structuring element is also used in morph_skizmorph_skizMorphSkizMorphSkizMorphSkizmorph_skiz.
'm': A skeleton with many “hairs” and multiple (parallel) branches.
'd': A skeleton without multiple branches, but with many gaps, similar to morph_skeletonmorph_skeletonMorphSkeletonMorphSkeletonMorphSkeletonmorph_skeleton.
'c': Uniform erosion of the region.
'e': One pixel wide lines are shortened. This structuring element is also used in morph_skizmorph_skizMorphSkizMorphSkizMorphSkizmorph_skiz.
'i': Isolated points are removed. (Only IterationsIterationsIterationsIterationsiterationsiterations = 1 is useful.)
'f': Y-junctions are eliminated. (Only IterationsIterationsIterationsIterationsiterationsiterations = 1 is useful.)
'f2': One pixel long branches and corners are removed. (Only IterationsIterationsIterationsIterationsiterationsiterations = 1 is useful.)
'h': A kind of inner boundary, which, however, is thicker than the result of boundaryboundaryBoundaryBoundaryBoundaryboundary, is generated. (Only IterationsIterationsIterationsIterationsiterationsiterations = 1 is useful.)
'k': Junction points are eliminated, but also new ones are generated.

The Golay elements, together with all possible rotations, are described with the operator golay_elementsgolay_elementsGolayElementsGolayElementsGolayElementsgolay_elements.

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

RegionRegionRegionRegionregionregion (input_object) region(-array) → object

Regions to be processed.

RegionThinRegionThinRegionThinRegionThinregionThinregion_thin (output_object) region(-array) → object

Result of the thinning operator.

GolayElementGolayElementGolayElementGolayElementgolayElementgolay_element (input_control) string → (string)

Structuring element from the Golay alphabet.

Default value: 'l' "l" "l" "l" "l" "l"

List of values: 'c'"c""c""c""c""c", 'd'"d""d""d""d""d", 'e'"e""e""e""e""e", 'f'"f""f""f""f""f", 'f2'"f2""f2""f2""f2""f2", 'h'"h""h""h""h""h", 'i'"i""i""i""i""i", 'k'"k""k""k""k""k", 'l'"l""l""l""l""l", 'm'"m""m""m""m""m"

IterationsIterationsIterationsIterationsiterationsiterations (input_control) integer → (integer / string)

Number of iterations. For 'f', 'f2', 'h' and 'i' the only useful value is 1.

Default value: 20

Suggested values: 'maximal'"maximal""maximal""maximal""maximal""maximal", 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 50, 70, 100, 150, 200

Typical range of values: 1 ≤ Iterations Iterations Iterations Iterations iterations iterations (lin)

Minimum increment: 1

Recommended increment: 1

Complexity

Let F be the area of an input region. Then the runtime complexity for one region is:

Result

thinning_seqthinning_seqThinningSeqThinningSeqThinningSeqthinning_seq returns TRUE if all parameters are correct. The behavior in case of empty or no input region can be set via: