The HTML5 Canvas let you draw graphics on the fly. So if you want to collect drawing in Drupal, the Canvas Field could help.
1. Download and enable the module.
4. By default, the canvas image will be saved on the server @ /sites/default/files/.png. But if you want to put them in a single folder, you need to manually create the folder on the server first. Let say i want to save all the canvas images in /sites/default/files/canvas/. First i need to create the canvas directory on /sites/default/files/. And then set the file directory to canvas.
This module is quite interesting and there are many more canvas features could be added to the canvas.