Send image to server as binary data

Question

I want to make an iPhone application to send an image to my server.

I want to draw something in iPhone (ex: a signature) as an image to POST binary image to my ser

Answer 1

Firstly you can get an NSData object containing either a PNG or JPEG representation of the image data using the UIImagePNGRepresentation and UIImageJPEGRepresentation functions.

// To get the data from a PNG file
NSData *dataForPNGFile = UIImagePNGRepresentation(yourImage);

// To get the data from a JPEG file
NSData *dataForPNGFile = UIImageJPEGRepresentation(yourImage, 0.9f);

(for more information see: UIImage Class Reference)

To finish to upload data from your iPhone to your server you can do this:

- (void)sendImage {
       NSData *postData = [nsdata from your original image];
       NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

       // Init and set fields of the URLRequest
       NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
       [request setHTTPMethod:@"POST"];
       [request setURL:[NSURL URLWithString:[NSString stringWithString:@"http://yoururl.domain"]]];
       [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
       [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
       [request setHTTPBody:postData];

       NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
       if (connection) {
          // Return data of the request
          NSData *receivedData = [[NSMutableData data] retain];
       }
       [request release];
 }

Answer 2

Use the drawrect method to do signatures on an UIImage. For that you have to use a UITouch delegate

and use the following to convert your UIImage object to NSData

// To get the data from a PNG file

NSData *dataForPNGFile = UIImagePNGRepresentation(yourImage);

// To get the data from a JPEG file

NSData *dataForPNGFile = UIImageJPEGRepresentation(yourImage, 0.9f);