iphone - 以错误的方向保存图像

Question

我正在使用 AGImagepickerContoller，它可以从相机胶卷中保存多个图像，我在 successBlock 中以这种方式保存:

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory,    NSUserDomainMask ,YES );
    NSString *documentsDir = [paths objectAtIndex:0];
    NSString *savedImagePath = [documentsDir stringByAppendingPathComponent:[NSString stringWithFormat:@"oneSlotImages%u.png", i]];

    ALAssetRepresentation *rep = [[info objectAtIndex: i] defaultRepresentation];
    UIImage *image = [UIImage imageWithCGImage:[rep fullResolutionImage]];

    //----resize the images
    image = [self imageByScalingAndCroppingForSize:image toSize:CGSizeMake(256,256*image.size.height/image.size.width)];

    NSData *imageData = UIImagePNGRepresentation(image);
    [imageData writeToFile:savedImagePath atomically:YES];

我的问题是在保存时，并在我的预览中使用加载。它看起来像这样:

我想要的是在预览中有这样的效果:

我读过这个iOS UIImagePickerController result image orientation after upload .

但我不太明白我应该把它放在我的代码中的什么地方。希望有人能指导我的问题。谢谢。

Answer 1

这是方法，传递任何方向的 UIImage 它将返回肖像图像

-(UIImage*)rotateUIImage:(UIImage*)src {

    // No-op if the orientation is already correct
    if (src.imageOrientation == UIImageOrientationUp) return src ;

    // We need to calculate the proper transformation to make the image upright.
    // We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
    CGAffineTransform transform = CGAffineTransformIdentity;

    switch (src.imageOrientation) {
        case UIImageOrientationDown:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, src.size.width, src.size.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;

        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
            transform = CGAffineTransformTranslate(transform, src.size.width, 0);
            transform = CGAffineTransformRotate(transform, M_PI_2);
            break;

        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, 0, src.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        case UIImageOrientationUp:
        case UIImageOrientationUpMirrored:
            break;
    }

    switch (src.imageOrientation) {
        case UIImageOrientationUpMirrored:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, src.size.width, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;

        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, src.size.height, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
        case UIImageOrientationUp:
        case UIImageOrientationDown:
        case UIImageOrientationLeft:
        case UIImageOrientationRight:
            break;
    }

    // Now we draw the underlying CGImage into a new context, applying the transform
    // calculated above.
    CGContextRef ctx = CGBitmapContextCreate(NULL, src.size.width, src.size.height,
                                             CGImageGetBitsPerComponent(src.CGImage), 0,
                                             CGImageGetColorSpace(src.CGImage),
                                             CGImageGetBitmapInfo(src.CGImage));
    CGContextConcatCTM(ctx, transform);
    switch (src.imageOrientation) {
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            // Grr...
            CGContextDrawImage(ctx, CGRectMake(0,0,src.size.height,src.size.width), src.CGImage);
            break;

        default:
            CGContextDrawImage(ctx, CGRectMake(0,0,src.size.width,src.size.height), src.CGImage);
            break;
    }

    // And now we just create a new UIImage from the drawing context
    CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
    UIImage *img = [UIImage imageWithCGImage:cgimg];
    CGContextRelease(ctx);
    CGImageRelease(cgimg);
    return img;
}