How to stretch a skewed shape to document edge or to a square

Hello! I have dozens of photos of various stages of a square painting and the camera wasn't perfectly perpendicular to the painting as I took pictures. I am trying to stretch these odd shapes to each be square. I know I can use the polygonal lasso tool to select the edge of the painting, and then use the Transform:Distort tool to stretch each corner to the edge of the square Photoshop document. This will take ages. If I can select the painting using the polygonal lasso tool and then initiate an Action that automatically puts the four corners of my odd shape in the corners of my square document OR automatically makes the odd shape a specific square size, that would save me hours over the course of editing each image. Any ideas? Thanks!