2D drawing from black/white picture

Hi.

Basically I wanna do something pretty simple - to generate a model/2D drawing from a simple picture of a black and white pattern. So I am using the "image sampler" to extract values. My plan is then to "cull" all the values corresponding to white and then only have the coordinates for black values. Then hopefully be able to create a surface with holes where there is with on the image.

Any suggestions? Or ideas to obtain this? Right now the "culled" list of points just as a square in the bottom corner and not where the are supposed to be.

Best regards Rasmus