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Open Inventor 10.3

Package com.openinventor.imageviz.engines.mathematicalmorphology.hitormissandskeleton

The Hit-or-miss and Skeleton category contains engines used to produce simplified representations of the objects in an image, while preserving their geometrical structure.

See: Description

Package com.openinventor.imageviz.engines.mathematicalmorphology.hitormissandskeleton Description

The Hit-or-miss and Skeleton category contains engines used to produce simplified representations of the objects in an image, while preserving their geometrical structure. The representations may then be used to calculate length, direction, etc. or to detect special topological structures such as end or triple points (number of crossings).

Morphological LUT

A morphological LUT (Look Up Table) allows to move in a binary image some predefined configurations of neighborhood and apply a criteria when this configuration matches or not. Creating a morphological LUT

First a kernel has to be defined to test if a given pixel matches a criteria or not. The kernel is made of classical binary pixel values : 0, 1 and a specific one: 2 which means 'don't care'.

For example:

A LUT to convert a binary image from an 8 neighbors connexity to 4 neighbors connexity can be defined testing if a given pixel has a neighbour in the north east, north west, south west and south east directions.

These kernels have to be added one by one to build the LUT, using the addKernel method. The first kernel has to be inserted with the mode NEW, that indicates the LUT has to be reset before to add this kernel inside. Other kernels have to be ineserted with the mode OR to indicate to look for this kernels or one of the previous.

For example : to change the connexity from 8 neighbors connexity to 4 , if the pixel matches the criteria the output value has to be forced to 0 and if it does not it has to be let unchanged. Therefore flagTrue = OUTPUT_ZERO and flagFalse = OUPUT_UNCHANGE.

Thinning, thickening and hit-or-miss operation with Morphological LUT

As a consequence morphological LUT's can be used to perform classical neighborhood operations such as thinning, thickening and hit-or-miss :

Skeletonization

A skeletonization is a transformation based on the thinning of connected components until a line is achieved. A skeleton is obtained by successive thinnings until convergence, using the L configuration and rotating it. The structuring element is: where means "don't care".

Point detectors

Once a skeleton is computed it may be useful to detect specific configurations of points. The point detectors uses hit-or-miss transforms (HMT) to select target points. The following engines are point detectors : SoEndPointsProcessing2d, SoInteriorPointsProcessing2d, SoIsolatedPointsProcessing2d.

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Open Inventor 10.3

Generated on September 13, 2019, Copyright Thermo Fisher Scientific. All rights reserved. http://www.openinventor.com