Identifying corners of a table top

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I'm experienced in multiple languages and have some simple image processing in my background, but I'm fairly new to OpenCV and advanced techniques. I'm trying to find a way to identify a kitchen table top trapezoid and get the four corner points X, Y in pixels.

The sample image would have a singular table (generally) that is of a different color than the rest of the area. Maybe it'd have a table cloth, or be granite, etc.. but it'd be different than the surroundings.

Example of what I'm trying to get:

(but I also need to get points + angles of the corners/lines)

Not looking for someone to do the work for me, but some examples and direction would be awesome.

Thanks!