How to use InRange at Different Color Space and Range.

asked 2013-05-22 10:21:54 -0600

wuling

424 ●4 ●15 ●25

updated 2020-11-15 02:08:27 -0600

sturkmen

6772 ●3 ●48 ●79 https://github.com/stu...

Hi all, how to use InRange at different color space and Range. for example:in RGB space, 0<=R,G,B<=255, so,it's very easy to use:

inRange(const MatND& src, const Scalar& lowerb, const Scalar& upperb, MatND& dst)

But if i want the range out of the lowerb & upperb, for example: I want R color Range: 0<=R<=20, 100<=R<=255. like Aforge Color Filtering as picture. Also, in the other color space how to use InRange where the parameters out of the range. Thanks:)

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answered 2013-05-22 10:39:47 -0600

berak
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updated 2013-05-22 10:43:16 -0600

inRange() can't do that, but not all hope's lost:

split your image into channels:

Mat orig; // bgr, probably
Mat chan[3];
split(orig,chan);  // chan[0]==blue, chan[1]==green, ..

apply your own operator on the channels to binarize them:

Mat bin_red = (chan[2]<20)|(chan[2]>100);  // note: single '|'
Mat bin_grn = (chan[1]<72)|(chan[1]>155);
Mat bin_blu = (chan[0]<64)|(chan[1]>155);

Mat bin = bin_red & bin_grn & bin_blu;  // where all conditions were met