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SegmentImage_Gray_Linear

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Module: FoundationPro

Segments an image into blobs examining differences between pixels values.

Applications

Detection of objects of undefined shape, but characterized by uniform brightness and good contrast to the background.
Name Type Range Description
inImage Image Input image
inRoi Region* Range of pixels to be processed
inMergingMethod BlobMergingMethod Defines a criterion by which two pixels can be merged into one blob
inConnectivity RegionConnectivity Defines if pixels can be merged only horizontally and vertically, or also diagonally
inMaxDifference Integer 0 - Maximal tonal difference that allows two pixels to be merged into one blob
inHysteresis Integer Total change of MaxDifference during all image passes
inPassCount Integer 1 - 5 Number of iterations in which the entire image is scanned for pixels that can be merged
inDirectional Bool When 'True' the filter can segment results of GradientDirAndPresenceImage
inMinArea Integer 0 - Minimal area of a blob that may be accepted
inMaxArea Integer* Minimal area of a blob that may be accepted
outBlobs RegionArray

Requirements

For input inImage only pixel formats are supported: 1⨯uint8, 1⨯int8, 1⨯uint16, 1⨯int16, 1⨯int32, 1⨯real, 3⨯uint8, 3⨯int8, 3⨯uint16, 3⨯int16, 3⨯int32, 3⨯real.

Read more about pixel formats in Image documentation.

Description

The filter segments the inImage image into blobs of pixels which gray values do not differ too much. The classification is different depending on the inMergingMethod input:

  • Neighbor – two adjacent pixels are considered to belong to the same blob when their values differ by at most inMaxDifference
  • NeighborVerified – as above, but an additional verification is performed to avoid undersegmentation
  • Mean – pixel is considered to belong to an adjacent blob when its value differs by at most inMaxDifference from the mean value of this blob's pixels
  • MeanSorted – not implemented in this filter

Examples

SegmentImage_Gray_Linear performed on the sample image with inMaxDifference = 55, inMergingMethod = MeanLinear and inMinArea = 50.

Errors

This filter can throw an exception to report error. Read how to deal with errors in Error Handling.

List of possible exceptions:

Error type Description
DomainError Directional method only supports single-channel images.
DomainError Directional method only supports UInt8 images.
DomainError Two- and four-channel images are not supported in SegmentImage_Gray.
DomainError Not supported inImage pixel format in SegmentImage_Gray_Linear.

Complexity Level

This filter is available on Advanced Complexity Level.

Filter Group

This filter is member of SegmentImage filter group.

See Also

  • SegmentImage_Gray_Tiled – Segments an image into blobs examining differences between pixels values, first pass is tiled.