Looking for someone who may be able to help me with OpenCV.

I'm trying to utilize OpenCV for its template matching functionality, and going through the documentation is frustrating me as it's built for python and I'm not understanding what I need to know...

For example, looking at https://docs.opencv.org/trunk/df/dfb/group__imgproc__object.html#ga586ebfb0a7fb604b35a23d85391329be

It tells you how to call the function, then throw it into an undeclared variable because that's how python works.

It doesn't tell you the format that it returns, or more importantly what it returns when there is NOT a match.

If anyone is familiar with OpenCV, please enlighten me or assist me in understanding this.

I'm also wondering if there's a way to do template matching on a portion of a source, instead of cropping an image before hand then doing the template off the cropped image. (Eg. Doing template matching but within minX minY maxX maxY of an image).