在肖像模式下從iPhone點擊的圖像旋轉90度

Question

我上傳的圖像從iphone點擊從橫向和縱向模式。 橫向模式的圖像上傳正常，但問題是與肖像模式上傳的圖像。他們旋轉了90度。

其他圖片與肖像模式（不從iPhone單擊）工作正常。

任何想法爲什麼會發生這種情況？

Answer 1

在您的委託：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 

後你會得到你的UIImage從「信息」字典鍵「UIImagePickerControllerOriginalImage」，就可以看到imageOrientation財產的形象定位。如果不像你想在上傳之前旋轉你的圖片。

imageOrientation 
The orientation of the receiver’s image. (read-only) 

@property(nonatomic, readonly) UIImageOrientation imageOrientation 
Discussion 
Image orientation affects the way the image data is displayed when drawn. By default, images are displayed in the 「up」 orientation. If the image has associated metadata (such as EXIF information), however, this property contains the orientation indicated by that metadata. For a list of possible values for this property, see 「UIImageOrientation.」 

Availability 
Available in iOS 2.0 and later. 
Declared In 
UIImage.h 

UIImage Class Reference

UIImagePickerController Class Reference

UIImagePickerControllerDelegate Protocol Reference

第二個選項：

是允許用戶編輯您的圖像和獲取圖像 「UIImagePickerControllerEditedImage」;

將您的UIImagePickerController「allowsEditing」屬性設置爲Yes。

在您的代表中，您只需從「info」字典中獲取「UIImagePickerControllerEditedImage」密鑰的UIImage即可。

祝你好運。

Answer 2

我已經與這個問題摔跤了很久，我正在研究一個需要實際旋轉圖像的項目，就像重新排列像素以便我可以上傳它一樣。

您需要做的第一件事是確定方向，然後去掉那些煩人的元數據，然後旋轉圖像。

於是就把這裏面的didFinishPickingMediaWithInfo功能：

UIImage * img = [info objectForKey:@"UIImagePickerControllerOriginalImage"]; 

    if ([info objectForKey:@"UIImagePickerControllerMediaMetadata"]) { 
    //Rotate based on orientation 
    switch ([[[info objectForKey:@"UIImagePickerControllerMediaMetadata"] objectForKey:@"Orientation"] intValue]) { 
     case 3: 
      //Rotate image to the left twice. 
      img = [UIImage imageWithCGImage:[img CGImage]]; //Strip off that pesky meta data! 
      img = [rotateImage rotateImage:[rotateImage rotateImage:img withRotationType:rotateLeft] withRotationType:rotateLeft]; 
      break; 

     case 6: 
      img = [UIImage imageWithCGImage:[img CGImage]]; 
      img = [rotateImage rotateImage:img withRotationType:rotateRight]; 
      break; 

     case 8: 
      img = [UIImage imageWithCGImage:[img CGImage]]; 
      img = [rotateImage rotateImage:img withRotationType:rotateLeft]; 
      break; 

     default: 
      break; 
    } 
} 

這裏是調整大小功能：

+(UIImage*)rotateImage:(UIImage*)image withRotationType:(rotationType)rotation{ 
    CGImageRef imageRef = [image CGImage]; 
    CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(imageRef); 
    CGColorSpaceRef colorSpaceInfo = CGColorSpaceCreateDeviceRGB(); 

    if (alphaInfo == kCGImageAlphaNone) 
     alphaInfo = kCGImageAlphaNoneSkipLast; 

     CGContextRef bitmap; 

    bitmap = CGBitmapContextCreate(NULL, image.size.height, image.size.width, CGImageGetBitsPerComponent(imageRef), 4 * image.size.height/*CGImageGetBytesPerRow(imageRef)*/, colorSpaceInfo, alphaInfo); 
    CGColorSpaceRelease(colorSpaceInfo); 

    if (rotation == rotateLeft) { 
     CGContextTranslateCTM (bitmap, image.size.height, 0); 
     CGContextRotateCTM (bitmap, radians(90)); 
    } 
    else{ 
     CGContextTranslateCTM (bitmap, 0, image.size.width); 
     CGContextRotateCTM (bitmap, radians(-90)); 
    } 

    CGContextDrawImage(bitmap, CGRectMake(0, 0, image.size.width, image.size.height), imageRef); 
    CGImageRef ref = CGBitmapContextCreateImage(bitmap); 
    UIImage *result = [UIImage imageWithCGImage:ref]; 
    CGImageRelease(ref); 
    CGContextRelease(bitmap); 
    return result; 
} 

的img變量現在包含一個正確旋轉圖像。

Answer 3

好，更清潔的版本是：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 
{ 
    UIImage *img = [info valueForKey:UIImagePickerControllerOriginalImage]; 
    img = [UIImage imageWithCGImage:[img CGImage]]; 

    UIImageOrientation requiredOrientation = UIImageOrientationUp; 
    switch ([[[info objectForKey:@"UIImagePickerControllerMediaMetadata"] objectForKey:@"Orientation"] intValue]) 
    { 
     case 3: 
      requiredOrientation = UIImageOrientationDown; 
      break; 
     case 6: 
      requiredOrientation = UIImageOrientationRight; 
      break; 
     case 8: 
      requiredOrientation = UIImageOrientationLeft; 
      break; 
     default: 
      break; 
    } 

    UIImage *portraitImage = [[UIImage alloc] initWithCGImage:img.CGImage scale:1.0 orientation:requiredOrientation]; 

}