ios – 相机图像旋转问题

我在这里遇到一个非常奇怪的问题.当我以纵向模式单击图像并上传它然后再次获取它时,显示逆时针旋转90度.但是当我在相机胶卷中看到它时,它会以正确的方向显示.我已经尝试了几乎所有可能的链接/代码来解决这个问题,但似乎没有任何帮助.我以JPEG格式保存图像.请帮助这个人.
提前致谢！！

解决方法

解决方法是在UI Image上创建一个类别,并根据其元数据EXIF缩放和旋转图像.

这是一段神奇的代码：

- (UIImage *)scaleAndRotateImage:(UIImage *)image {

    int kMaxResolution = 640; // Or whatever

    CGImageRef imgRef = image.CGImage;

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


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

    CGContextConcatCTM(context,transform);

    CGContextDrawImage(UIGraphicsGetCurrentContext(),CGRectMake(0,height),imgRef);
    UIImage *imagecopy = UIGraphicsGetimageFromCurrentimageContext();
    UIGraphicsEndImageContext();

    return imagecopy;
}