问题
I have original image and I can cycle all pixels using @patrick-rutkowski answer here. Also I have this answer seems to create image with pixel data. But I can't understand how to combine these two answers. So the first task is get pixel and second is add it to another CGImage. For example if I want to extract all red pixels from the original image and add these red pixels to another image. I suppose it's way to go.
来源：https://stackoverflow.com/questions/28310186/create-new-image-using-just-some-pixels-data-from-the-source-image-based-on-them