3D scatterplot of an image

Re:3D scatterplot of an image by tovacinni on Friday December 15, 2017 @02:11PM (#15934209)

Sorry if this is a stupid question, but can't you do this without converting the image into an RGB 3D space? (i.e. iterate through the pixels and count the ones within a certain range of what you want)

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Re:3D scatterplot of an image by kmill on Friday December 15, 2017 @07:07PM (#15936411)

You don't have to actually reify the conversion (as in, create a data structure that holds the new representation in memory). When they say that they converted the image into RGB 3D space, it was probably mainly conceptually, to give meaning to "nearness." I'd guess the only data they kept track of as the image streamed off the camera were two integer counts.

I wish I had more examples of algorithms where it is best explained as acting on a data structure that is not actually present, but all I can think of right now is using generators to represent a list.

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Re:3D scatterplot of an image by infinite8s on Friday December 15, 2017 @03:28PM (#15934802)

How would you determine if they were within the range? That's effectively converting it into a 3D space.

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Re:3D scatterplot of an image by thechao on Friday December 15, 2017 @07:54PM (#15936638)

A few plane equation evaluations—then a few ands, and a sum. Plenty of horsepower on a pentium pro to do that.

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Re:3D scatterplot of an image by infinite8s on Wednesday December 20, 2017 @10:21AM (#15970272)

Those plane equations are describing the pixel in 3D space.

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