合并两个 UIImage
我有 imageA （取自用户 iPhone 相机）和 imageB，这是一张带有愚蠢边框（例如）的图像，带有大量透明的 alpha 空间。
我想做的是合并这两个图像，将 imageB 放在 imageA 上，然后将它们保存为 imageC 以进行其他工作。
有办法做到这一点吗？
干杯
，到目前为止，
-(void)merge
{
CGSize size = CGSizeMake(320, 480);
UIGraphicsBeginImageContext(size);
CGPoint thumbPoint = CGPointMake(0,0);
UIImage *imageA = imageView.image;
[imageA drawAtPoint:thumbPoint];
UIImage* starred = [UIImage imageNamed:@"imageB.png"];
CGPoint starredPoint = CGPointMake(0, 0);
[starred drawAtPoint:starredPoint];
UIImage *imageC = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
imageView.image = imageC;
}
我看不到/不知道我在这里做错了什么
I have imageA (taken from the users iPhone camera) and imageB, an image with a silly boarder (for eg) with plenty of transparent alpha space.
What I would like to to do is to merge these two images, laying imageB over imageA, and then saving them as imageC for other work.
Is there a way to do this?
Cheers
I've got this so far
-(void)merge
{
CGSize size = CGSizeMake(320, 480);
UIGraphicsBeginImageContext(size);
CGPoint thumbPoint = CGPointMake(0,0);
UIImage *imageA = imageView.image;
[imageA drawAtPoint:thumbPoint];
UIImage* starred = [UIImage imageNamed:@"imageB.png"];
CGPoint starredPoint = CGPointMake(0, 0);
[starred drawAtPoint:starredPoint];
UIImage *imageC = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
imageView.image = imageC;
}
I can't see/dont know what I'm doing wrong here
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评论（2）
该代码看起来是正确的（尽管我建议将其转换为使用创建的 CGBitmapContext 用于线程安全），但是
imageB应该是 JPEG 吗？ JPEG 不支持透明度，因此，为了使混合正常工作，它实际上应该是 PNG。That code looks correct (though I would recommend converting it to use a created CGBitmapContext for thread-safety), but is
imageBsupposed to be a JPEG? JPEGs don't support transparency, so, in order for the blending to work, it should really be a PNG.请注意，对于视网膜支持，您应该使用： UIGraphicsBeginImageContextWithOptions(size, YES, 0); // 0 表示让 iOS 为您处理缩放
Note that for retina support you should use:
UIGraphicsBeginImageContextWithOptions(size, YES, 0); // 0 means let iOS deal with scale for you