1

我正在使用以下代码将图像发送到 Web 服务器。它有效，问题是图像在上传时由于某种原因被旋转。

这是我的上传方法： 

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

        [self dismissViewControllerAnimated:YES completion:nil];

        NSData *image = UIImageJPEGRepresentation([info objectForKey:UIImagePickerControllerOriginalImage], 0.1);

        // use token with url for json data from contents of url
        NSString *savedValue = [[NSUserDefaults standardUserDefaults]
                                stringForKey:@"token"];

        NSString *urlString = [NSString stringWithFormat:@"%@%@/photos?token=%@", kIDURLPhoto, listingId, savedValue];

        NSLog(@"urlstring for comment is %@",urlString);

        self.flUploadEngine = [[fileUploadEngine alloc] initWithHostName:urlString customHeaderFields:nil];

        NSMutableDictionary *postParams = [NSMutableDictionary dictionaryWithObjectsAndKeys: @"image", @"caption", nil];

        self.flOperation = [self.flUploadEngine postDataToServer:postParams path:nil];
        [self.flOperation addData:image forKey:@"picture" mimeType:@"image/jpeg" fileName:@"upload.jpg"];

        [self.flOperation addCompletionHandler:^(MKNetworkOperation* operation) {
            NSLog(@"%@", [operation responseString]);

    //         handle a successful 200 response

        [self.flUploadEngine enqueueOperation:self.flOperation];

        // for iOS7
        if ([self respondsToSelector:@selector(setNeedsStatusBarAppearanceUpdate)]) {

            [[UIApplication sharedApplication] setStatusBarHidden:YES];
        }

        [self forceReload];

    }
4

2 回答 2

12

Swift 5 扩展：

extension UIImage {
    /// Fix image orientaton to protrait up
    func fixedOrientation() -> UIImage? {
        guard imageOrientation != UIImage.Orientation.up else {
            // This is default orientation, don't need to do anything
            return self.copy() as? UIImage
        }

        guard let cgImage = self.cgImage else {
            // CGImage is not available
            return nil
        }

        guard let colorSpace = cgImage.colorSpace, let ctx = CGContext(data: nil, width: Int(size.width), height: Int(size.height), bitsPerComponent: cgImage.bitsPerComponent, bytesPerRow: 0, space: colorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue) else {
            return nil // Not able to create CGContext
        }

        var transform: CGAffineTransform = CGAffineTransform.identity

        switch imageOrientation {
        case .down, .downMirrored:
            transform = transform.translatedBy(x: size.width, y: size.height)
            transform = transform.rotated(by: CGFloat.pi)
        case .left, .leftMirrored:
            transform = transform.translatedBy(x: size.width, y: 0)
            transform = transform.rotated(by: CGFloat.pi / 2.0)
        case .right, .rightMirrored:
            transform = transform.translatedBy(x: 0, y: size.height)
            transform = transform.rotated(by: CGFloat.pi / -2.0)
        case .up, .upMirrored:
            break
        @unknown default:
            fatalError("Missing...")
            break
        }

        // Flip image one more time if needed to, this is to prevent flipped image
        switch imageOrientation {
        case .upMirrored, .downMirrored:
            transform = transform.translatedBy(x: size.width, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        case .leftMirrored, .rightMirrored:
            transform = transform.translatedBy(x: size.height, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        case .up, .down, .left, .right:
            break
        @unknown default:
            fatalError("Missing...")
            break
        }

        ctx.concatenate(transform)

        switch imageOrientation {
        case .left, .leftMirrored, .right, .rightMirrored:
            ctx.draw(cgImage, in: CGRect(x: 0, y: 0, width: size.height, height: size.width))
        default:
            ctx.draw(cgImage, in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
            break
        }

        guard let newCGImage = ctx.makeImage() else { return nil }
        return UIImage.init(cgImage: newCGImage, scale: 1, orientation: .up)
    }
}

目标 C 代码：

-(UIImage *)scaleAndRotateImage:(UIImage *)image{
        // No-op if the orientation is already correct
        if (image.imageOrientation == UIImageOrientationUp) return image;

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

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

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

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

            case UIImageOrientationLeftMirrored:
            case UIImageOrientationRightMirrored:
                transform = CGAffineTransformTranslate(transform, image.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, image.size.width, image.size.height,
                                                 CGImageGetBitsPerComponent(image.CGImage), 0,
                                                 CGImageGetColorSpace(image.CGImage),
                                                 CGImageGetBitmapInfo(image.CGImage));
        CGContextConcatCTM(ctx, transform);
        switch (image.imageOrientation) {
            case UIImageOrientationLeft:
            case UIImageOrientationLeftMirrored:
            case UIImageOrientationRight:
            case UIImageOrientationRightMirrored:
                // Grr...
                CGContextDrawImage(ctx, CGRectMake(0,0,image.size.height,image.size.width), image.CGImage);
                break;

            default:
                CGContextDrawImage(ctx, CGRectMake(0,0,image.size.width,image.size.height), image.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;
}

代码的使用

 UIImage *img=[info objectForKey:UIImagePickerControllerOriginalImage];

 img=[self scaleAndRotateImage:img];
 NSData *image = UIImageJPEGRepresentation(img, 0.1);
于 2013-10-21T12:42:38.980 回答
2

很可能您没有考虑 exif 数据，它们给出了相机的旋转，您应该将它们添加到图像 EXIF 字典中。这样，当您打开图像时，阅读软件可以相应地旋转图像。检查这个问题和相关答案，这会有所帮助

于 2013-10-21T11:29:51.783 回答