Is it possible to use templateMatch with binary images? I have an error

Question

Is it possible to templateMatch binary images? I've tried it and nothing helps. I always get an error :

cv2.error: OpenCV(3.4.5) C:\projects\opencv-python\opencv\modules\imgproc\src\templmatch.cpp:1107: error: (-215:Assertion failed) (depth == CV_8U || depth == CV_32F) && type == _templ.type() && _img.dims() <= 2 in function 'cv::matchTemplate'

I've tried using astype(np.uint8) but it doesn't help either.

//template is already binary
//edited: all the code
img = cv2.imread('img/img.png')
template = cv2.imread('template-match/template.png')
img_roi=img[310:1060,510:1430]
img_gray = cv2.cvtColor(img_roi,cv2.COLOR_BGR2GRAY)
afterEnhance = cv2.GaussianBlur(img_gray, (7, 7), 0)
afterEnhance=cv2.equalizeHist(afterEnhance)
_,th1=cv2.threshold(afterEnhance,55,255,cv2.THRESH_BINARY)
result = cv2.matchTemplate(th1, template,cv2.TM_CCOEFF)

That is possible. Can you add the code where you input both images? — J.D., May 21 '19 at 14:30
Can you please tell the value `template.shape` is returning. — Vardan Agarwal, May 21 '19 at 15:02
@VardanAgarwal I got it now. template.shape was returning (708, 862,3) I did template=template[:,:,1] to lower the dimensions. Maybe this will help but for now I am working on it. — user9753084, May 21 '19 at 15:16
I would like to thank everyone for help. It works. Probably it was the fact that binary image was loaded with as 3 dimensional ndarray. — user9753084, May 21 '19 at 17:11

score 1 · Answer 1 · answered May 21 '19 at 16:02

1

Seems you figured it out: the template has 3 color channels, whereas img is converted to grayscale and has only one channel.
You can load the template-image as grayscale directly using
template = cv2.imread('template-match/template.png',0)

answered May 21 '19 at 16:02

J.D.

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Is it possible to use templateMatch with binary images? I have an error

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