title: How to edit EXIF, IPTC and XMP metadata in cocoa?
body: <p>I want to read and edit EXIF, IPTC and XMP metadata of an images using cocoa.</p>
  
  <p>I can read the EXIF metadata using </p>
  
  <pre><code>NSBitmapImageRep * imageTest = [NSBitmapImageRep imageRepWithContentsOfFile:filePath] ;
    NSLog(@"Exif Data in %@ : %@",fileName, [imageTest valueForProperty:@"NSImageEXIFData"]) ;
  </code></pre>
  
  <p>How can I modify this data?</p>
  
  <p>Thanks
  Saurabh</p>