CGImageRef oldImageRef=image.CGImage;
UIImage* newImage=[UIImage imageWithCGImage:oldImageRef];
注释：UIImage* newImage=[UIImage imageWithCGImage:oldImageRef scale:.1 orientation:UIImageOrientationRight];
使用上面的语句，可以将图像旋转90度变成我们需要的样子。NSData* data=UIImageJPEGRepresentation(image, 0);
NSLog(@"%lu",(unsigned long)data.length);
CGImageRef imageRef=image.CGImage;
CGImageRef newimage=CGImageCreateWithImageInRect(imageRef, rect);
- (UIImage *)image:(UIImage *)image rotation:(UIImageOrientation)orientation
{
long double rotate = 0.0;
CGRect rect;
float translateX = 0;
float translateY = 0;
float scaleX = 1.0;
float scaleY = 1.0;
switch (orientation) {
case UIImageOrientationLeft:
rotate = M_PI_2;
rect = CGRectMake(0, 0, image.size.height, image.size.width);
translateX = 0;
translateY = -rect.size.width;
scaleY = rect.size.width/rect.size.height;
scaleX = rect.size.height/rect.size.width;
break;
case UIImageOrientationRight:
rotate = 3 * M_PI_2;
rect = CGRectMake(0, 0, image.size.height, image.size.width);
translateX = -rect.size.height;
translateY = 0;
scaleY = rect.size.width/rect.size.height;
scaleX = rect.size.height/rect.size.width;
break;
case UIImageOrientationDown:
rotate = M_PI;
rect = CGRectMake(0, 0, image.size.width, image.size.height);
translateX = -rect.size.width;
translateY = -rect.size.height;
break;
default:
rotate = 0.0;
rect = CGRectMake(0, 0, image.size.width, image.size.height);
translateX = 0;
translateY = 0;
break;
}
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
//做CTM变换
CGContextTranslateCTM(context, 0.0, rect.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
CGContextRotateCTM(context, rotate);
CGContextTranslateCTM(context, translateX, translateY);
CGContextScaleCTM(context, scaleX, scaleY);
//绘制图片
CGContextDrawImage(context, CGRectMake(0, 0, rect.size.width, rect.size.height), image.CGImage);
UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();
return newPic;
}
结论：
这里的解决方案，就是对底层像素矩阵进行装换之后，在对里面数据截取一部分。可以解决截取部分内容的问题。
-------------------
2：解决方案二：就是对rect进行装换，根据数据底层，进行rect的转换。
IOS关于从照相机获取图片的问题，初步探究通过摄像头实现颜色与形状识别机制==,布布扣,bubuko.com
IOS关于从照相机获取图片的问题，初步探究通过摄像头实现颜色与形状识别机制==
原文：http://blog.csdn.net/alexzengxiaowu/article/details/22854209