Cropping an image before sending to the server on iOS

Question

I'm trying to crop an image before sending to the server and I'm having issues.

I'm was trying to do this:

imageUploadReq.photo = [self encodeToBase64String:[UIImage imageWithData:UIImageJPEGRepresentation(fileData, 0.07f)]];

But Xcode is complaining that "Incompatible pointer types passing NSData * to parameter type UIImage". I tried to cast it, but it wouldn't work either.

Here is the code:

- (void)uploadPhoto {

   NSData *fileData;

   if (self.image != nil) {
       UIImage *newImage = [self resizeImage:self.image toWidth:320.0f andHeight:480.0f];
       fileData = UIImageJPEGRepresentation(newImage, 0.07f);
   }

    WUTModelImageUploadReq *imageUploadReq = [[WUTModelImageUploadReq alloc]init];

    // I'm trying to set the first parameter of UIImageJPEGRepresentation to fileData 
    imageUploadReq.photo = [self encodeToBase64String:[UIImage imageWithData:UIImageJPEGRepresentation(self.viewControllerPost.imageForPost, 0.07f)]];
    imageUploadReq.extension = @"jpg";


    void (^wsSuccessHandler)(AFHTTPRequestOperation *operation, NSDictionary* responseObject) = ^(AFHTTPRequestOperation *operation, id responseObject){
    NSLog(@"Pull Feed responseObject %@",responseObject);

    NSError *error;
    WUTModelPostImageResponse *wsResponse = [[WUTModelPostImageResponse alloc]initWithDictionary:(NSDictionary *)responseObject error:&error];

    if (error) {
        errorMessage = @"Failure to upload image.";
        [self postExecuteFail];
    }else{
        if (wsResponse.success) {
            WUTModelImage *imageTemp = [wsResponse.data firstObject];
            [postItem setObject:imageTemp.photo forKey:@"photo"];
            [self uploadPostFeed];

        }else{
            errorMessage = @"Failure to upload image.";
            [self postExecuteFail];
        }
     }
  };

    void (^wsErrorHandler)(AFHTTPRequestOperation *operation, NSError *error) = ^(AFHTTPRequestOperation *operation, NSError *error){
    if ([error.localizedDescription rangeOfString:@"401"].location != NSNotFound)
        errorMessage = @"It seems that your login session get expire, Please relogin after logged out.";
    else
        errorMessage = @"Failure to upload image.";
    [self postExecuteFail];
  };

  AFHTTPRequestOperation *op = [WUTCommonWebServices WebServicePostCallWithAccessTokenForEndPoint:WS_UploadImage WithJson:imageUploadReq ForSuccess:wsSuccessHandler ForFailure:wsErrorHandler];
  [op start];

}

What's `WUTModelImageUploadReq`, especially it's property `photo`? What's `encodeToBase64String:`? — Larme, Jul 28 '15 at 16:18
I'm cropping it here `UIImage *newImage = [self resizeImage:self.image toWidth:320.0f andHeight:480.0f];` — Paul, Jul 28 '15 at 16:54
It's still unclear. photo is a UIImage? a NSString? What's the definition of `encodeToBase64String:`? — Larme, Jul 29 '15 at 08:47
@Larme photo has a property and is a NSString. This is the helper method for encodeToBase64String: `- (NSString *)encodeToBase64String:(UIImage *)image { return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength]; }` — Paul, Jul 29 '15 at 15:59
@Larme Sorry, but Xcode throws an error. Error is: Use of undeclared identifier 'newImage' — Paul, Jul 29 '15 at 16:11
imageUploadReq.photo = [self encodeToBase64String:[UIImage imageWithData:fileData]]; — Larme, Jul 29 '15 at 16:12
@Larme It didn't work. The photo didn't upload to the server in the app. — Paul, Jul 29 '15 at 16:23
@Larme I tried putting in the `NSLog(@"Error: %@", error);` but Xcode didn't spit anything out in the logs when it failed. — Paul, Jul 29 '15 at 17:37

Bhanupriya · Answer 1 · 2015-07-30T05:21:22.943

0

I think, you need this:

+(UIImage*)imageWithImage:(UIImage*)image scaledToSize:(CGSize)newSize{
UIGraphicsBeginImageContext( newSize );
[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

return newImage;    }

You just need to pass original image and your desired size and it will return your expected image.

Call the method like:

UIImage *originalImage = [info valueForKey:UIImagePickerControllerOriginalImage]; // here originalImage is image taken from camera or you can use whatever you want

UIImage * image = [GlobalFunction imageWithImage:originalImage scaledToSize:CGSizeMake(200, 200)]; // GlobalFunction is class where I have defined this method and it returns UIImage of size (200, 200)

edited Jul 30 '15 at 05:21

answered Jul 29 '15 at 05:26

Bhanupriya

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Thanks. Is this a category or a helper method? – Paul Jul 29 '15 at 16:01
Its a helper method. Just pass your original image and expected size and it will return cropped image with your expected size. If this is what you needed, then accept the answer. – Bhanupriya Jul 30 '15 at 04:35
How do I pass an image using this helper method? Like this? https://gist.github.com/lumierephoto/04664b705b80b63d8cb4 – Paul Jul 30 '15 at 05:12

Cropping an image before sending to the server on iOS

1 Answers1