我正在对UIImageView
进行旋转,然后尝试裁切一部分并将其另存为UIImage
。 UIImageView
旋转,但是它总是裁切照片的相同部分。因此,裁剪未考虑图像旋转。我究竟做错了什么?
//rotate image
CGRect new = CGRectMake(0, 0, 100, 50);
CGAffineTransform rotation = CGAffineTransformMakeRotation(5);
[photo setTransform:rotation];
// crop image
CGImageRef imageRef = CGImageCreateWithImageInRect([photo.image CGImage], new);
UIImage *croppedImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
// display crop bounds
UIView* faceBounds = [[UIView alloc] initWithFrame:new];
faceBounds.layer.borderWidth = 2;
faceBounds.layer.borderColor = [[UIColor redColor] CGColor];
最佳答案
使用以下代码片段旋转图像数据。
输入数据为inAngle
(弧度角)和inImage
(UIImage
实例)。
这样做会创建一个图像上下文,对其应用转换,然后将原始图像绘制到该上下文中。生成的图像数据现在将存储在resultImage
中。
前三行处理边界结果图像帧的计算。
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, inImage.size.width, inImage.size.height)];
rotatedViewBox.transform = CGAffineTransformMakeRotation(inAngle);
CGSize rotatedSize = rotatedViewBox.frame.size;
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(bitmap, rotatedSize.width / 2.0f, rotatedSize.height / 2.0f);
CGContextRotateCTM(bitmap, inAngle);
CGContextScaleCTM(bitmap, 1.0f, -1.0f);
CGContextDrawImage(bitmap, CGRectMake(-inImage.size.width / 2.0f,
-inImage.size.height / 2.0f,
inImage.size.width,
inImage.size.height),
inImage.CGImage);
UIImage *resultImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
关于iphone - 旋转和裁剪图像IOS,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12061691/