Luke, you may give a try to [SharinPix][1]

This specialized app for salesforce could be used to achieve so like this : 

Adding an album to the objects


 - Take picture to the camera under Salesforce1 adding image to the album
 - Choose this image in the album and the menu command (Add To Rich Text)
 - It makes a call to salesforce code (then you can do your magic here)
 - it provides an URL for the image to be inserted with the wanted metrics (resolution, width, height, ...)

Coud that help?

  [1]: http://sharinpix.com