How to merge transparent PNG Image with color

Question

I tried with drawInRect and CGContextDrawImage but it is applying to the whole image.

I want it to apply to the image part only, not to the transparent part. Does anyone know how to do it?

Answer 1

Thanks for the help...i tried this code it worked for me finally.

UIGraphicsBeginImageContext(firstImage.size);

CGContextRef context = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(context, 0, firstImage.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
CGRect rect = CGRectMake(0, 0, firstImage.size.width, firstImage.size.height);
// draw black background to preserve color of transparent pixels
CGContextSetBlendMode(context, kCGBlendModeNormal);
[[UIColor whiteColor] setFill];
CGContextFillRect(context, rect);
// draw original image
CGContextSetBlendMode(context, kCGBlendModeNormal);
CGContextDrawImage(context, rect, firstImage.CGImage);
// tint image (loosing alpha) - the luminosity of the original image is preserved
CGContextSetBlendMode(context, kCGBlendModeDarken);
[[UIColor colorWithPatternImage:secondImage] setFill];
CGContextFillRect(context, rect);
// mask by alpha values of original image
CGContextSetBlendMode(context, kCGBlendModeDestinationIn);
CGContextDrawImage(context, rect, firstImage.CGImage);
//[firstImage drawInRect:rect];

// image drawing code here
UIImage *coloredImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();