从服务器下载时iPhone图像旋转

Question

我正在尝试将相机图像从iPhone上传到我的Web服务器，但是当我从服务器下载图像时，图像会如何改变其方向。这仅在相机图像而不是从我的机器上载到设备的简单图像中发生。

我已经使用此条件在服务器端旋转图像：

// obj将在服务器上上传图像时传递方向，其值为1或3或6或8

switch ((ushort)obj)
               {
                   case 1: //up
                       return 0;
                   case 3: //down
                       return 180;
                   case 6: //left
                       return 90;
                   case 8: //right
                       return 270;
                   default:
                       return 0;
               }

但是我仍然遇到同样的问题

这是我上传图片的代码：

-(void)uploadSingleFile
{
    if(!self.objWebServices.bSyncWasOn)
    {
        NSLog(@"STOP upload Single File RETURN");
        [self Call_SaveSyncedImageID];
        return;
    }
    SyncItem* item = [arrSelSyncItemIDS objectAtIndex:nSyncItemIndex];

    if(item.nType == SYNC_STATUS_NOT_SELECTED || item.nType == SYNC_STATUS_SYNC_DONE)
    {
        nSyncItemIndex = nSyncItemIndex + 1;
        if([arrSelSyncItemIDS count] > nSyncItemIndex)
        {
            NSLog(@"Called uploadSingleFile");
            [self uploadSingleFile];
            return;
        }
        else
        {
            //[self LoadImages:!bShowHideSyncImages];
            [SVProgressHUD dismiss];
            [BtnStopSync setTitle:@"Start sync" forState:UIControlStateNormal];
            self.objWebServices.bSyncWasOn = NO;
            self.objWebServices.isFileUpload = NO;

            if( [[NSUserDefaults standardUserDefaults] boolForKey:@"Notification_State"] ) // Setting Switch Bool
            {
                UIAlertView *Alert = [[UIAlertView alloc] initWithTitle:@"winkflash" message:@"*** Sync completed successfully." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                [Alert show];
            }
        }
    }
    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
    NSString *srtprefSessionId = [NSString stringWithFormat:@"%@",[prefs objectForKey:@"prefSessionId"]];

    BOOL isTrash = FALSE;   
    NSString *StrPath = @"/Pictures/";      //Change 
    ALAsset* temp = item.itemAsset;
    NSDate* assetDate = (NSDate*)[temp valueForProperty:@"ALAssetPropertyDate"];

    NSString* strID = @"";
    strID = [[temp valueForProperty:@"ALAssetPropertyURLs"] description];
    strID = [strID stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

    NSString* strImageType = @"";
    if ([strID rangeOfString:@"jpg"].location != NSNotFound || [strID rangeOfString:@"JPG"].location != NSNotFound ){
        strImageType = @"jpg";
    }
    else if ([strID rangeOfString:@"png"].location != NSNotFound || [strID rangeOfString:@"PNG"].location != NSNotFound )
        strImageType = @"png";


    NSDateFormatter* df = [[NSDateFormatter alloc]init];
    [df setDateFormat:@"MM/dd/yyyy"];
    NSString *result = [df stringFromDate:assetDate];

    NSTimeInterval timeInterval = [assetDate timeIntervalSince1970];
    ALAssetRepresentation *rep = [temp defaultRepresentation];

    //------------------ metadata -------------------------------------------------------
    NSDictionary *imageMetadata = [rep metadata];
    NSString *strOrt=[NSString stringWithFormat:@"%@",[imageMetadata valueForKey:@"Orientation"]];
    NSString *strOrientation;

    if([strOrt isEqualToString:@"6"])
    {
        strOrientation=@"1";
    }
    if([strOrt isEqualToString:@"8"])
    {
        strOrientation=@"3";
    }
    if([strOrt isEqualToString:@"3"])
    {
        strOrientation=@"6";
    }
    if([strOrt isEqualToString:@"1"])
    {
        strOrientation=@"8";
    }
    NSLog(@"print strOrientation:%@",strOrientation);
    //-----------------------------------------------------------------------------------

    StrPath = [StrPath stringByAppendingFormat:@"%d.%@",(int)timeInterval,strImageType];
    UIImage *image = [UIImage imageWithCGImage:[rep fullResolutionImage]];
    NSData *dataObj = nil;
    dataObj = UIImagePNGRepresentation(image);
    NSString* StrFileData = [Base64 encode:dataObj];
    NSString* strFileHash = [dataObj md5Test];

    //----------------------------------------------------
    NSMutableDictionary *DictRequest = [[NSMutableDictionary alloc]init];
    [DictRequest setObject:srtprefSessionId forKey:@"SessionId"];
    [DictRequest setObject:StrPath forKey:@"Path"];
    [DictRequest setValue:[NSNumber numberWithBool:isTrash] forKey:@"UploadDirectlyToTrashbin"];
    [DictRequest setObject:StrFileData forKey:@"FileData"];
    [DictRequest setObject:strFileHash forKey:@"FileHash"];
    [DictRequest setObject:result forKey:@"DateCreated"];

    BOOL isNULL = [self stringIsEmpty:strOrientation];
    if(!isNULL)
    {
        [DictRequest setObject:strOrientation forKey:@"Orientation"];
    }


    NSString *jsonString = [DictRequest JSONRepresentation];
    NSString *strUrl=[NSString stringWithFormat:@"%@",FileUpload_URL];
    NSURL *url1=[NSURL URLWithString:strUrl];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url1];
    [request setTimeoutInterval:60.0];
    [request setHTTPMethod:@"POST"];
    NSData *postData = [jsonString dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
    NSString *postLength = [NSString stringWithFormat:@"%d",[postData length]];
    [request setHTTPBody:postData];
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
    [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];


    if(theConnection)
        [self Set2Defaults];

    theConnection = [[NSURLConnection alloc]initWithRequest:request delegate:self];

    [SVProgressHUD dismiss];

    if(theConnection)
        webData = [NSMutableData data];
    else
        NSLog(@"Connection Failed !!!");
}

Answer 1

这是因为方向存储在UIImage中的方式。

我在UIImage的类别内使用此函数。

- (UIImage *)fixOrientation {

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

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

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

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

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

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

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

从imagePicker获取图像时只需运行此命令。

然后，当您上传和下载时，它将保持方向。

Answer 2

尝试这个：

UIImage *sourceImage = ... // Our image
CGRect selectionRect = CGRectMake(100.0, 100.0, 300.0, 400.0);
CGImageRef resultImageRef = CGImageCreateWithImageInRect(sourceImage.CGImage,
selectionRect);
UIImage *resultImage = [[UIImage alloc] initWithCGImage:resultImageRef];

和

CGRect TransformCGRectForUIImageOrientation(CGRect source, UIImageOrientation orientation, CGSize imageSize) {
switch (orientation) {
case UIImageOrientationLeft: { // EXIF #8
  CGAffineTransform txTranslate = CGAffineTransformMakeTranslation(imageSize.height, 0.0);
  CGAffineTransform txCompound = CGAffineTransformRotate(txTranslate,M_PI_2);
  return CGRectApplyAffineTransform(source, txCompound);
}
case UIImageOrientationDown: { // EXIF #3
  CGAffineTransform txTranslate = CGAffineTransformMakeTranslation(imageSize.width, imageSize.height);
  CGAffineTransform txCompound = CGAffineTransformRotate(txTranslate,M_PI);
  return CGRectApplyAffineTransform(source, txCompound);
}
case UIImageOrientationRight: { // EXIF #6
  CGAffineTransform txTranslate = CGAffineTransformMakeTranslation(0.0, imageSize.width);
  CGAffineTransform txCompound = CGAffineTransformRotate(txTranslate,M_PI + M_PI_2);
  return CGRectApplyAffineTransform(source, txCompound);
}
case UIImageOrientationUp: // EXIF #1 - do nothing
  default: // EXIF 2,4,5,7 - ignore
  return source;
}
}
  ...
UIImage *sourceImage = ... // Our image
 CGRect selectionRect = CGRectMake(100.0, 100.0, 300.0, 400.0);
CGRect transformedRect = TransformCGRectForUIImageOrientation(selectionRect,  sourceImage.imageOrientation, sourceImage.size);
CGImageRef resultImageRef = CGImageCreateWithImageInRect(sourceImage.CGImage, transformedRect);
UIImage *resultImage = [[UIImage alloc] initWithCGImage:resultImageRef];