how to set hue value of some pixel with opencv

opencv hsv
Gianluca picture Gianluca · Apr 12, 2011 · Viewed 7.9k times · Source

I need to change the hue of some pixels of my image, but i don't know how to set them!

I converted the image in HSV with CV_BGR2HSV and now i'm cycling with a for by rows and cols...

how can I access each pixel's hue?

for setting RGB i'm using this code...

CvScalar s;
s=cvGet2D(imgRGB,i,j); // get the (i,j) pixel value
printf("B=%f, G=%f, R=%f\n",s.val[0],s.val[1],s.val[2]);
s.val[0]=240;
s.val[1]=100;
s.val[2]=100;
cvSet2D(imgRGB,i,j,s); // set the (i,j) pixel value

Answer

Simon picture Simon · Apr 13, 2011

You already converted your image to HSV, so the 3 layers of the image now correspond to Hue, Saturation and Value:

  • s.val[0] is the hue.
  • s.val[1] is the saturation.
  • s.val[2] is the value.

So go ahead and use exactly the same method as for your RGB images to get and set the pixel values.

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