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Open Inventor 9.9

Package com.openinventor.imageviz.engines.geometryandmatching.patternrecognition

This group provides a package of pattern recognition functions based on standard correlation.

See: Description

Package com.openinventor.imageviz.engines.geometryandmatching.patternrecognition Description

This group provides a package of pattern recognition functions based on standard correlation. Some tools to ease the exploitation of results are also included.


The correlation filters allow you to specify a correlation step.

The correlation filters allow the matching of rectangular or irregular patterns. Non-rectangular patterns are implemented with mask AOIs.

Use SoGrayscaleCorrelationProcessing2d for grayscale image correlation and SoBinaryCorrelationProcessing2d for binary image correlation.

SoGrayscaleCorrelationProcessing2d allows for local luminosity and / or contrast normalization. There are 4 different correlation types (see SoGrayscaleCorrelationProcessing2d.CorrelationMode) :

We perform the correlation between a input image, , and a kernel, . The output image is an floating point image, . The correlation coefficient at location is given by a local calculation between the model and a pattern extraction from the input image, . The pattern location is and its dimension is . The actual calculation depends on image type:

It also depends on the correlation normalization TYPE as shown below. When a part of the pattern lies beyond the edge of the image the correlation is not performed on the image border. SCorrelation filters provide a step parameter (see SoGrayscaleCorrelationProcessing2d.OffsetMode and SoBinaryCorrelationProcessing2d.OffsetMode) which speeds up the operation by calculating 1 value out of each step, as shown in Figure 1.

Figure 1: Standard CorrelationLuminosity and Contrast normalization

The luminosity and contrast normalization is controlled by one of the 4 correlation types:

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Open Inventor 9.9

Generated on January 29, 2020, Copyright Thermo Fisher Scientific. All rights reserved.