iphone：从相机拍摄的图像改变方向

Question

I made an iphone app to capture image from camera and to set that image in next view. But the problem is that image is rotated. ie landscape image becomes potraite and protraite image becomes landscape. I have referred many codes but could not get solution.

My code is :

- (void)btnCapturePressed
{
 if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
        {

            picker=[[UIImagePickerController alloc] init];
            picker.delegate=self;

            [picker setAllowsEditing:YES];

            picker.sourceType=UIImagePickerControllerSourceTypeCamera;
            //[self.navigationController pushViewController:(UIViewController *)ipc animated:YES];
            [self presentModalViewController:picker animated:YES];
            [picker release];
      }
}

-(void) imagePickerController:(UIImagePickerController *) picker didFinishPickingMediaWithInfo :(NSDictionary *)info
{
           UIImage *imageToScale=[info objectForKey:UIImagePickerControllerOriginalImage];

            imgView = [[UIImageView alloc] initWithImage:imageToScale];

            [picker presentModalViewController:cropper animated:YES];
}

I have also refered the link . with same problem, but could not find the solution.

Please help me.

Thanks.

Answer 1

So for that at the time of image take store the orientation of the device and pass it to the method below as parameter Here just give any name to method and pass the parameter orientation

switch (orientation) {
            case UIDeviceOrientationPortrait:
                [featureLayer setAffineTransform:CGAffineTransformMakeRotation(DegreesToRadians(0.))];
                break;
            case UIDeviceOrientationPortraitUpsideDown:
                [featureLayer setAffineTransform:CGAffineTransformMakeRotation(DegreesToRadians(180.))];
                break;
            case UIDeviceOrientationLandscapeLeft:
                [featureLayer setAffineTransform:CGAffineTransformMakeRotation(DegreesToRadians(90.))];
                break;
            case UIDeviceOrientationLandscapeRight:
                [featureLayer setAffineTransform:CGAffineTransformMakeRotation(DegreesToRadians(-90.))];
                break;
            case UIDeviceOrientationFaceUp:
            case UIDeviceOrientationFaceDown:
            default:
                break; // leave the layer in its last known orientation
        }

and the macro I have used here DegreesToRadians() is as follow

static CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};

This will definitely works.

Happy Coding :)

EDIT

If the above code doesn't work well then use this one

@interface UIImage (RotationMethods)
- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees;
@end

@implementation UIImage (RotationMethods)

- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees 
{   
    // calculate the size of the rotated view's containing box for our drawing space
    UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.size.width, self.size.height)];
    CGAffineTransform t = CGAffineTransformMakeRotation(DegreesToRadians(degrees));
    rotatedViewBox.transform = t;
    CGSize rotatedSize = rotatedViewBox.frame.size;

    // Create the bitmap context
    UIGraphicsBeginImageContext(rotatedSize);
    CGContextRef bitmap = UIGraphicsGetCurrentContext();

    // Move the origin to the middle of the image so we will rotate and scale around the center.
    CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);

    //   // Rotate the image context
    CGContextRotateCTM(bitmap, DegreesToRadians(degrees));

    // Now, draw the rotated/scaled image into the context
    CGContextScaleCTM(bitmap, 1.0, -1.0);
    CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), [self CGImage]);

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;

}
@end

and then call the above function as below

switch (orientation) {
        case UIDeviceOrientationPortrait:
            image = [image imageRotatedByDegrees:0];
            break;
        case UIDeviceOrientationPortraitUpsideDown:
            image = [image imageRotatedByDegrees:180];
            break;
        case UIDeviceOrientationLandscapeLeft:
            image = [image imageRotatedByDegrees:-90];
            break;
        case UIDeviceOrientationLandscapeRight:
            image = [image imageRotatedByDegrees:90];
            break;
        case UIDeviceOrientationFaceUp:
        case UIDeviceOrientationFaceDown:
        default:
            break; // leave the layer in its last known orientation
    }   

If the image is not in required orientation then add 90 to all of the above imageRotatedByDegrees 's argument (ie if it is 0 then it will be 0+90) or as you required.

EDIT 1

UIDeviceOrientation curDeviceOrientation = [[UIDevice currentDevice] orientation];

Answer 2

I was struggling with this issue but found a much easier solution:

  AVCaptureConnection *vc = [self.snapper connectionWithMediaType:AVMediaTypeVideo];

  // THIS IS THE KEY LINE!!!!!!!!!!!!!!!!!!!!!
  [vc setVideoOrientation:[self interfaceToVideoOrientation]];

  [self.snapper captureStillImageAsynchronouslyFromConnection:vc
                                            completionHandler:
   ^(CMSampleBufferRef buf, NSError *err) {
     NSData* data = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:buf];
     UIImage* im = [UIImage imageWithData:data];
     // Do something with the image.
  }];


- (AVCaptureVideoOrientation)interfaceToVideoOrientation
{
  switch ([UIApplication sharedApplication].statusBarOrientation)
  {
    case UIInterfaceOrientationPortrait:
      return AVCaptureVideoOrientationPortrait;
    case UIInterfaceOrientationPortraitUpsideDown:
      return AVCaptureVideoOrientationPortraitUpsideDown;
    case UIInterfaceOrientationLandscapeRight:
      return AVCaptureVideoOrientationLandscapeRight;
    case UIInterfaceOrientationLandscapeLeft:
      return AVCaptureVideoOrientationLandscapeLeft;
    default:
      return AVCaptureVideoOrientationPortrait;
  }
}

Setting the video orientation before the capture has now fixed my issue with the image coming out with the wrong orientation.

Answer 3

I refer the discussion over apple's forum ( https://discussions.apple.com/thread/1537011?start=0&tstart=0 ) and found the following solution; It worked perfectly for me; I just copy paste it and it worked like gem;

-(UIImage *) scaleAndRotateImage(UIImage *)image
{
 int kMaxResolution = 320; // Or whatever

 CGImageRef imgRef = image.CGImage;

 CGFloat width = CGImageGetWidth(imgRef);
 CGFloat height = CGImageGetHeight(imgRef);


 CGAffineTransform transform = CGAffineTransformIdentity;
 CGRect bounds = CGRectMake(0, 0, width, height);
 if (width > kMaxResolution || height > kMaxResolution) {
 CGFloat ratio = width/height;
 if (ratio > 1) {
 bounds.size.width = kMaxResolution;
 bounds.size.height = bounds.size.width / ratio;
 }
 else {
 bounds.size.height = kMaxResolution;
 bounds.size.width = bounds.size.height * ratio;
 }
 }

 CGFloat scaleRatio = bounds.size.width / width;
 CGSize imageSize = CGSizeMake(CGImageGetWidth(imgRef), CGImageGetHeight(imgRef));
 CGFloat boundHeight;
 UIImageOrientation orient = image.imageOrientation;
 switch(orient) {

 case UIImageOrientationUp: //EXIF = 1
 transform = CGAffineTransformIdentity;
 break;

 case UIImageOrientationUpMirrored: //EXIF = 2
 transform = CGAffineTransformMakeTranslation(imageSize.width, 0.0);
 transform = CGAffineTransformScale(transform, -1.0, 1.0);
 break;

 case UIImageOrientationDown: //EXIF = 3
 transform = CGAffineTransformMakeTranslation(imageSize.width, imageSize.height);
 transform = CGAffineTransformRotate(transform, M_PI);
 break;

 case UIImageOrientationDownMirrored: //EXIF = 4
 transform = CGAffineTransformMakeTranslation(0.0, imageSize.height);
 transform = CGAffineTransformScale(transform, 1.0, -1.0);
 break;

 case UIImageOrientationLeftMirrored: //EXIF = 5
 boundHeight = bounds.size.height;
 bounds.size.height = bounds.size.width;
 bounds.size.width = boundHeight;
 transform = CGAffineTransformMakeTranslation(imageSize.height, imageSize.width);
 transform = CGAffineTransformScale(transform, -1.0, 1.0);
 transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
 break;

 case UIImageOrientationLeft: //EXIF = 6
 boundHeight = bounds.size.height;
 bounds.size.height = bounds.size.width;
 bounds.size.width = boundHeight;
 transform = CGAffineTransformMakeTranslation(0.0, imageSize.width);
 transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
 break;

 case UIImageOrientationRightMirrored: //EXIF = 7
 boundHeight = bounds.size.height;
 bounds.size.height = bounds.size.width;
 bounds.size.width = boundHeight;
 transform = CGAffineTransformMakeScale(-1.0, 1.0);
 transform = CGAffineTransformRotate(transform, M_PI / 2.0);
 break;

 case UIImageOrientationRight: //EXIF = 8
 boundHeight = bounds.size.height;
 bounds.size.height = bounds.size.width;
 bounds.size.width = boundHeight;
 transform = CGAffineTransformMakeTranslation(imageSize.height, 0.0);
 transform = CGAffineTransformRotate(transform, M_PI / 2.0);
 break;

 default:
 [NSException raise:NSInternalInconsistencyException format:@"Invalid image orientation"];

 }

 UIGraphicsBeginImageContext(bounds.size);

 CGContextRef context = UIGraphicsGetCurrentContext();

 if (orient == UIImageOrientationRight || orient == UIImageOrientationLeft) {
 CGContextScaleCTM(context, -scaleRatio, scaleRatio);
 CGContextTranslateCTM(context, -height, 0);
 }
 else {
 CGContextScaleCTM(context, scaleRatio, -scaleRatio);
 CGContextTranslateCTM(context, 0, -height);
 }

 CGContextConcatCTM(context, transform);

 CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, width, height), imgRef);
 UIImage *imageCopy = UIGraphicsGetImageFromCurrentImageContext();
 UIGraphicsEndImageContext();

 return imageCopy;
}

Answer 4

I had same problem and this helped for me.Hope it would help you too. It took me 2min to fix this issue. http://xcodetipss.blogspot.com/2012/04/image-rotated-when-taken-from-camera.html