从UIImage返回子图像 [英] Return a subimage from a UIImage
本文介绍了从UIImage返回子图像的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想从UIImage中获取一个子图像。我四处寻找类似的问题,但无济于事。
I want to grab a subimage from a UIImage. I've looked around for a similar question, to no avail.
我知道我想要抓取的像素范围 - 如何从现有图像中返回此子图像?
I know the range of pixels I want to grab - how can I return this subimage, from an existing image?
推荐答案
这应该有所帮助: http://iphonedevelopment.blogspot.com/2010/11/drawing-part-of-uiimage.html
此代码段创建了一个 UIImage
的类别,但代码应该很容易修改,无需作为类别。
This code snippet is creating a category of UIImage
but the code should be easily modified to work without it being a category.
执行相同操作的更简单方法如下:
A shorter way of doing the same thing is the following:
CGRect fromRect = CGRectMake(0, 0, 320, 480); // or whatever rectangle
CGImageRef drawImage = CGImageCreateWithImageInRect(image.CGImage, fromRect);
UIImage *newImage = [UIImage imageWithCGImage:drawImage];
CGImageRelease(drawImage);
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