I'm implementing the feature where users can draw the diagram on canvas for the prepositional phrase. When the user done with the diagram then I convert and save the diagram as an Image. Now I want to find out whether the diagram drawn by the user is correct. For that, I'm comparing the user-drawn diagram with the correct diagram I have in my system. I've tried the pHash but the score isn't satisfying. Is there a way to do it in PHP/Javascript?
Below is the sample Image on which I want to perform the comparison.
Thank you.