what are all the drawing tools a user would be given?
Basically just a finger or a simple tablet pen. Mostly just using a finger to draw.
how complex can a drawing become?
Like the ones shown above. Not much more complex. It is meant to be drawn on a mobile phone with your finger, so the drawings cant be too sophisticated. All the images will all be quite simple where most of the image will be whitespace.
do you only have raster data of the result, or vector data of the result
I have PNG images, so raster data. I dont have the vector data, and I dont plan to get that unless I really have to.
do you have complete information on every operation and stroke the user makes?
I guess I could manage to get all that information, but I want to avoid doing that as it would make my drawing program much more complicated.
I have PNG images, most images will be simple drawing similar to an elementary school or kindergarten drawing (see below for some examples). The pictures will (most of the time) not be very detailed, just some rough drawings you can make with your finger on a mobile phone that will be done in a couple of seconds or a couple of minutes at most.
Most of the background will be white/transparent as seen in the pictures above.
I am really unsure on how to proceed with this as most examples use real photos and that is not the type of images that I will use.
For example, here are four pictures. I want to match the hearts with each other (top left and top right), but the other two drawings on the bottom should hopefully not be a good match with any of the other drawings.
