This is how I process my pony drawings for view. This is a new app called CamScanner, it lets you scan pictures and documents without the use of a scanner, but with your own mobile device.
 
This is a little behind the scenes of how I create my images.
 
Before scanning the picture, I draw my pony, then I scan it using my phone. I save it onto my gallery as a picture, then going into Adobe Photoshop on my iPad, I use the cut out feature, select the “smart tool”, and erase the background. I save it back onto my device, then upload it here to Derpibooru.