制作黑白图像？

Question

我有另一个石英2d(iphone)问题:

如何将ImageView的所有颜色更改为黑白并仅留下红色???

DD

Answer 1

UIImage *originalImage = [info objectForKey:UIImagePickerControllerOriginalImage];  this image we get from UIImagePickerController

    CGColorSpaceRef colorSapce = CGColorSpaceCreateDeviceGray();
    CGContextRef context = CGBitmapContextCreate(nil, originalImage.size.width, originalImage.size.height, 8, originalImage.size.width, colorSapce, kCGImageAlphaNone);
    CGContextSetInterpolationQuality(context, kCGInterpolationHigh);
    CGContextSetShouldAntialias(context, NO);
    CGContextDrawImage(context, CGRectMake(0, 0, originalImage.size.width, originalImage.size.height), [originalImage CGImage]);

    CGImageRef bwImage = CGBitmapContextCreateImage(context);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSapce);

    UIImage *resultImage = [UIImage imageWithCGImage:bwImage]; // This is result B/W image.
    CGImageRelease(bwImage);

这是我在其他论坛上发现的东西,它看起来工作!!!