从相机捕获的iphone图像自动旋转-90度

Question

我以编程方式从我的应用程序中的相机中获取了图像。 它已被很好地获取，但是当我切换到另一个视图并关闭该视图时，我的图像会自动旋转 -90 度。

并且这种变化仅发生在第一次之后，当我移动时没有变化发生意味着图像保持在 -90 度状态，这仅在我从相机捕获图像时发生。 当我从照片库中获取图像时，没有发现任何问题。

下图是我的原图

这是旋转的图像

我不知道为什么会发生这种变化。

Answer 1

您必须使用此功能来旋转相机拍摄的图像

 - (void)imagePickerController:(UIImagePickerController *)picker
                didFinishPickingImage:(UIImage *)image
                                    editingInfo:(NSDictionary *)editingInfo
{
    image = [self scaleAndRotateImage:image];
    [self useImage:image];
    [[picker parentViewController] dismissModalViewControllerAnimated:YES];
}


- (void)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();

    [self setRotatedImage:imageCopy];
    //return imageCopy;
}

Answer 2

解决此问题的最简单方法是在didFinishPickingImage委托中缩放图像。 您可以使用以下代码通过导入类“ UIImage+ImageScaling.h ”进行缩放。

theImage =[UIImage imageWithImage:image scaledToSizeWithSameAspectRatio:CGSizeMake(400, 300)]; // for iphone.

Answer 3

这个方法对我有用

- (UIImage*) rotateImageAppropriately:(UIImage*)imageToRotate
{
   UIImage* properlyRotatedImage;

   CGImageRef imageRef = [imageToRotate CGImage];

   if (imageToRotate.imageOrientation == 0)
   {
       properlyRotatedImage = imageToRotate;
   }
   else if (imageToRotate.imageOrientation == 3)
   {

       CGSize imgsize = imageToRotate.size;
       UIGraphicsBeginImageContext(imgsize);
       [imageToRotate drawInRect:CGRectMake(0.0, 0.0, imgsize.width, imgsize.height)];
       properlyRotatedImage = UIGraphicsGetImageFromCurrentImageContext();
       UIGraphicsEndImageContext();
   }
   else if (imageToRotate.imageOrientation == 1)
   {
       properlyRotatedImage = [UIImage imageWithCGImage:imageRef scale:1.0 orientation:1];
   }

   return properlyRotatedImage;
}

Answer 4

不良行为现在已在 13.4 中改变。 现在以准确的方向捕获图像。

Answer 5

如果您仍然需要一些解决方案，请参阅此链接，我在其中发布了我对此问题的答案，请参阅编辑和编辑 1 还请参阅最后 2 或 3 条评论以供进一步参考

Answer 6

试试这个属性

@property (nonatomic) CGAffineTransform cameraViewTransform

并以-90度旋转，然后捕获图像。 如果不起作用，请使用 Cocoa Matters 提供的代码。

Answer 7

这是由于您的图像方向。 所以保持原始图像方向。 您将在 UIImagePickerController 委托方法中获得图像方向

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

示例代码：

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

    UIImage *sourceImage = [info valueForKey:UIImagePickerControllerOriginalImage];

    NSData *data = UIImagePNGRepresentation(sourceImage);
    UIImage *tmp = [UIImage imageWithData:data];
    UIImage *afterFixingOrientation = [UIImage imageWithCGImage:tmp.CGImage
                                         scale:sourceImage.scale
                                   orientation:sourceImage.imageOrientation];

    [self.imagePickerController dismissViewControllerAnimated:YES completion:nil];
}