Best way to measure area using OpenCV

Question

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I'm trying to measure the orange-colored area in the image above using OpenCV. The orange area I mean here is the high temperature area. The scale on the right is the color scale of the temperature for this thermal camera imaging and my target area is from 250 degree Celcius and above.

I haven't actually coded yet, but from what I think the best way to measure this is using histogram computation for a certain range, thus getting the area.

Is there any better way to do this?

Any kind of help is very much appreciated.

Answer 1

Convert to grayscale 1 channel image, then blur and threshold. Also you may try growing region algorithm or watershed algorithm instead thresholding. Anyway, segmentation will give you mask of region, then use cv.countNonZero(), to get number of white pixels.