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terraref / extractors-stereo-rgb

Scripts and code relevant to the 8MP RGB stereo 3D cameras.
BSD 3-Clause "New" or "Revised" License
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Make texture analysis compute textures #15

Closed dlebauer closed 6 years ago

dlebauer commented 6 years ago

Following discussion in https://github.com/terraref/reference-data/issues/172

Question: There is a an option to compute multiple 'scales' of Haralick metrics. The default is to compute scales 1 and 2, but can apparently be any integer vector. I've hard-coded this to compute only scale 1. What is a scale in this context, and is 1 the appropriate scale to compute by default? (this ? cross posted in https://github.com/aoles/EBImage/issues/24)

(note: reverts terraref/extractors-stereo-rgb#14 that reverted terraref/extractors-stereo-rgb#13, which was prematurely merged)

kevin05jan commented 6 years ago

The explanation is found here: https://support.bioconductor.org/p/90366/

Haralick features evaluates co-occurrences of gray value pairs of two adjacent image pixels and computes/derives probabilistic features from the co-occurrence matrix. As repeating texture pattern can have different scale, the "adjacent" pixel can be >1 pixel away. By downscaling the image it is easier and faster to compute the co-occ matrix, vs using a co-occ search window with <x,y> offset parameters.

Also a good reference is this: http://earlglynn.github.io/RNotes/package/EBImage/Haralick-Textural-Features.html

Hope this helps

dlebauer commented 6 years ago

Which scales are useful? Is 1 the appropriate scale?

kevin05jan commented 6 years ago

That depends on the image and the texture property.

As for now I suggest to use 1 and perform a data analysis.

-- Kevin Nagel, Ph.D. Bioinformatician

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Which scales are useful? Is 1 the appropriate scale?

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