Getting a Black and White UIImage (Not Grayscale)

Question

I need to get a pure black and white UIImage from another UIImage (not grayscale). Anyone can help me?

Thanks for reading.

EDITED:

Here

Answer 1

While it may be overkill for your purposes, I do just that for live video from the iPhone camera in my sample application here. That application takes a color and a sensitivity, and can turn all pixels white that are within that threshold and transparent if not. I use OpenGL ES 2.0 programmable shaders for this in order to get realtime responsiveness. The whole thing is described in this post here.

Again, this is probably overkill for what you want. In the case of a simple UIImage that you want to convert to black and white, you can probably read in the raw pixels, iterate through them, and apply the same sort of thresholding I did to output the final image. This won't be as fast as the shader approach, but it will be much simpler to code.