Question

以编程方式我在我的应用程序中从相机中提取了图像。它取得了很好的效果，但是当我转移到另一个视图并在那时关闭那个视图时，我的图像会自动旋转-90度。

并且这种变化仅在我移位后第一次发生没有发生变化意味着图像保持在-90度状态，这只有在我从相机捕获图像时才会发生。当我从照片库中获取图像时，没有发现任何问题。

以下图片是我的原始图片

Original image

这是旋转图像

rotated image

我不知道为什么会发生这种变化。

Answer 1

您必须使用此功能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缩放didFinishPickingImage委托内的图像。您可以通过导入类“UIImage+ImageScaling.h”来使用以下代码进行缩放。

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

Answer 3

此方法适用于我，

- (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

试试这个属性

@property (nonatomic) CGAffineTransform cameraViewTransform

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

Answer 5

如果您仍然需要一些解决方案，请参阅我发布此问题答案的this链接，请参阅编辑和编辑1，另请参阅最后2或3条评论以供进一步参考

Answer 6

错误行为现已更改为13.4。现在可以以正确的方向捕获图像。

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];
}

从相机拍摄的iphone图像自动旋转-90度

7 个答案: