Varying the depth of quadtree within the image

Your code is working just as you have described it. However, I was looking to perform quadtree-compression on the objects present in an image. So let's say if an image consists of a table and a chair, and I would like to perform quadtree-compression such that the depth for chair is less than the depth for table, is there a way to do it?
Presently, the code you have written allows to change the depth of complete image. Can you share a script that would allow to choose the specific pixels with in the image for performing quadtree-compression with a depth value of our choice?