Reputation: 9883
I'm creating a mask based on DeviceGray color space based image.
What basically I want to do is to change all sorts of gray (beside black) pixels into white and leave black pixels as they are.
So I want my image to be consisted with black and white pixels.
Any idea how to achieve that using CoreGraphics means ?
Please dont offer running all over the pixels in the loop
Upvotes: 0
Views: 881
Reputation: 8944
Use CGImageCreateWithMaskingColors
and CGContextSetRGBFillColor
together like this:
CGImageRef myMaskedImage;
const CGFloat myMaskingColors[6] = { 0, 124, 0, 68, 0, 0 };
myColorMaskedImage = CGImageCreateWithMaskingColors (image,
myMaskingColors);
CGContextSetRGBFillColor (myContext, 0.6373,0.6373, 0, 1);
CGContextFillRect(context, rect);
CGContextDrawImage(context, rect, myColorMaskedImage);
By the way, the fill color is mentioned at the CGImageCreateWithMaskingColors discussion.
Upvotes: 2