UIImage掩盖问题iOS 7

Question

我有大量借用(标准)代码,它将灰度UIImage掩码应用于UIImage.

- (void) maskImage:(UIImage *)image withMask:(UIImage *)maskImage {

    CGImageRef imageRef = image.CGImage;  // main UIImage
    CGImageRef maskRef = maskImage.CGImage;  // grayscale UIImage mask

    CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef),
                                    CGImageGetHeight(maskRef),
                                    CGImageGetBitsPerComponent(maskRef),
                                    CGImageGetBitsPerPixel(maskRef),
                                    CGImageGetBytesPerRow(maskRef),
                                    CGImageGetDataProvider(maskRef), NULL, false);

    CGImageRef masked = CGImageCreateWithMask(imageRef, mask);

    maskedImage = [UIImage imageWithCGImage:masked];
    CGImageRelease(mask);
    CGImageRelease(masked);

    imageView.image = maskedImage;

}

然后我将imageView.image保存到文件中.代码就像iOS 6和6.1中的魅力一样; 保存的图像包含应用了蒙版的主UIImage.但是,我注意到此代码在iOS 7(iPhone)中的执行方式不同.在iOS 7中,保存的图像仅包含未应用蒙版的主UIImage.我不确定问题是在CGImageCreateWithMask()方法还是其他地方.

任何见解将不胜感激.非常感谢你提前.

Answer 1

我在我的应用程序上也发现了这个问题,我通过以下代码解决了它.

- (UIImage*)image:(UIImage*)image withMask:(UIImage*)maskImage
{
    CGImageRef maskRef = maskImage.CGImage;
    CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef),
                                    CGImageGetHeight(maskRef),
                                    CGImageGetBitsPerComponent(maskRef),
                                    CGImageGetBitsPerPixel(maskRef),
                                    CGImageGetBytesPerRow(maskRef),
                                    CGImageGetDataProvider(maskRef), NULL, false);

    CGImageRef maskedImageRef = CGImageCreateWithMask([handledImage CGImage], mask);
    CGImageRelease(mask);

    // Under iOS 7, UIImage with mask no longer applied mask when saving it.
    // We draw the image to context and obtain image from context to get the image applied mask
    CGContextRef context = CGBitmapContextCreate(nil,
                                                 CGImageGetWidth(maskedImageRef),
                                                 CGImageGetHeight(maskedImageRef),
                                                 CGImageGetBitsPerComponent(maskedImageRef),
                                                 CGImageGetBytesPerRow(maskedImageRef),
                                                 CGImageGetColorSpace(maskedImageRef),
                                                 CGImageGetBitmapInfo(maskedImageRef));

    CGRect imageRect = CGRectMake(0, 0, CGImageGetWidth(maskedImageRef), CGImageGetHeight(maskedImageRef));
    CGContextDrawImage(context, imageRect, maskedImageRef);
    CGImageRef imageRef = CGBitmapContextCreateImage(context);
    UIImage *maskedImage = [UIImage imageWithCGImage:imageRef];

    CFRelease(imageRef);
    CGContextRelease(context);
    CGImageRelease(maskedImageRef);

    return maskedImage;
}

Answer 2

上面的代码很好地说明了如何处理问题(在上下文中绘图)但对我不起作用.以下代码适用于IOS 7和以前的版本(IOS 6.x).

+(UIImage*)maskImageExt:(UIImage *)image withMask:(UIImage *)maskImage {
    CGImageRef maskRef = maskImage.CGImage;
    CGImageRef imageRef = image.CGImage;

    CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef),
                                        CGImageGetHeight(maskRef),
                                        CGImageGetBitsPerComponent(maskRef),
                                        CGImageGetBitsPerPixel(maskRef),
                                        CGImageGetBytesPerRow(maskRef),
                                        CGImageGetDataProvider(maskRef), NULL, true);

    CGImageRef maskImageRef = CGImageCreateWithMask([image CGImage], mask);

    CGContextRef context = CGBitmapContextCreate(nil,
                                                 CGImageGetWidth(imageRef),
                                                 CGImageGetHeight(imageRef),
                                                 CGImageGetBitsPerComponent(imageRef),
                                                 CGImageGetBytesPerRow(imageRef),
                                                 CGImageGetColorSpace(imageRef),
                                                 CGImageGetBitmapInfo(imageRef));
    CGRect imageRect = CGRectMake(0, 0, CGImageGetWidth(imageRef), CGImageGetHeight(imageRef));
    CGContextDrawImage(context, imageRect, maskImageRef);
    CGImageRef maskedImageRef = CGBitmapContextCreateImage(context);
    UIImage *maskedImage = [UIImage imageWithCGImage:maskedImageRef];

    CGImageRelease(mask);
    CGContextRelease(context);
    CGImageRelease(maskedImageRef);

    return maskedImage;
}