CGImageRef oldImageRef=image.CGImage;
UIImage* newImage=[UIImage imageWithCGImage:oldImageRef];
注釋:UIImage* newImage=[UIImage imageWithCGImage:oldImageRef scale:.1 orientation:UIImageOrientationRight];
使用上面的語句,可以將圖像旋轉90度變成我們需要的樣子。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變換 CGContextTranslateCTM(context, 0.0, rect.size.height); CGContextScaleCTM(context, 1.0, -1.0); CGContextRotateCTM(context, rotate); CGContextTranslateCTM(context, translateX, translateY); CGContextScaleCTM(context, scaleX, scaleY); //繪制圖片 CGContextDrawImage(context, CGRectMake(0, 0, rect.size.width, rect.size.height), image.CGImage); UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext(); return newPic; }
結論:
這裡的解決方案,就是對底層像素矩陣進行裝換之後,在對裡面數據截取一部分。可以解決截取部分內容的問題。
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2:解決方案二:就是對rect進行裝換,根據數據底層,進行rect的轉換。