OpenCV Template Matching: Restrict search area

Question

I have working OpenCV template matching code made with python. Now I am searching for a way to tell OpenCV to search only in a supplied area (x, y, w, h), is that possible?

Regards, Philip

score 5 · Accepted Answer · answered Dec 19 '13 at 14:03

5

roi = image[y:y+h , x:x+w]

cv2.matchTemplate(roi, templ, ...

answered Dec 19 '13 at 14:03

berak

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So technically I just create a new image out of the original and then search in it? – plaetzchen Dec 19 '13 at 14:16
it's just a subrect of the original image ( so, not a copy, if you were asking this ) – berak Dec 19 '13 at 14:24
Problem is I get a NameError: global name 'y' is not defined – plaetzchen Dec 19 '13 at 14:38
hey, ofc. you've got to replace x,y,w,h with your numbers there – berak Dec 19 '13 at 14:41
I don't get it. So I if I have a image called template that is made with cv2.imread() I just do roi = template[10,10,10,10] and then I have a 10x10 sized chunk starting at coordinates X:10 and Y:10? – plaetzchen Dec 19 '13 at 14:45
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make it: template[10:20, 10:20] then – berak Dec 19 '13 at 14:47
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Please, complete your answer with a full formula and ideally a working example. – Yohan Obadia Mar 08 '17 at 14:52

OpenCV Template Matching: Restrict search area

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