title: image_picker: compressing is not supported for type PNG. How to compress the image files with extension .png?
body: <p><strong>In order to compress .jpg file this code simply works.</strong> </p>
  
  <pre><code>  File pickedFile = await ImagePicker.pickImage(source: ImageSource.gallery);
    print('Size in kb: -&gt; ' + (pickedFile.lengthSync() / 1000).toString());
    File compressedFile = await ImagePicker.pickImage( source: ImageSource.gallery, imageQuality: 50);
    print('Size kb: -&gt; ' + (compressedFile.lengthSync() / 1000).toString());
  
    _uploadFile(compressedFile);
  </code></pre>
  
  <p><strong>But how to compress the image files which have the extension like .png ?</strong> </p>
  
  <p><strong>Error:</strong></p>
  
  <pre><code>D/ImageResizer( 6282): image_picker: compressing is not supported for type PNG. Returning the image with original quality
  W/ExifInterface( 6282): Invalid image: ExifInterface got an unsupported image format file(ExifInterface supports JPEG and some RAW image formats only) or a corrupted JPEG file to ExifInterface.
  </code></pre>