Move the image work into the browser

Resizing, merging and censoring photos on a server means uploading the file, waiting, downloading it back and hoping the temporary copy really was temporary. Canvas does the same job on the device that already holds the pixels.

For the sizes people actually deal with (a form upload, a profile picture, a document scan) the browser wins on every count: it is faster, it costs nothing to run, and nothing leaves the machine.