Question

I am working on a simple coloring book for children with physical limitations.
Teachers will be able to insert a picture in the program composed of only closed areas.
I then need to analyze the image and find all closed areas (the places the child will be able to color).
I need to do this because all areas that can be painted will glow up one after the other.
I think I can accomplish this with a floodfill so I need a point (X,Y coordinate) inside every closed area.

Anyone ever did something like this?
Some tips or source code available?

Many thanks!

Answer 1

I don’t have much experience with WPF per se, but I would probably use an algorithm like this:

First, I am assuming the image is strictly monochrome. That is, there are only pure black (line) and pure white (colourable area) pixels.

1. Convert the image to true-colour
2. Examine the Top-Left pixel.
3. If this pixel is white, do a flood fill with a new unique colour
4. Move one-pixel to the right (if out of bounds, move down one and all the way to the left)
5. Go to 3

Now, every area in the image has a different colour.