title: Question on the TensorFlow object detection api and image/format that is not jpeg(eg dicom or numpy array)
body: <p>I like to use the object detection api from tensorflow with dicom images instead of jpg.</p>
  <p>In the documentation:
  <a href="https://tensorflow-object-detection-api-tutorial.readthedocs.io/en/latest/training.html#create-tensorflow-records" rel="nofollow noreferrer">https://tensorflow-object-detection-api-tutorial.readthedocs.io/en/latest/training.html#create-tensorflow-records</a>
  I find the following code</p>
  <pre><code>    # ...
      encoded_jpg_io = io.BytesIO(encoded_jpg)
      # ...
  
      image_format = b'jpg'
      # ...
  
      tf_example = tf.train.Example(features=tf.train.Features(feature={
          'image/height': dataset_util.int64_feature(height),
          'image/width': dataset_util.int64_feature(width),
          'image/filename': dataset_util.bytes_feature(filename),
          'image/source_id': dataset_util.bytes_feature(filename),
          'image/encoded': dataset_util.bytes_feature(encoded_jpg),
          'image/format': dataset_util.bytes_feature(image_format),
          'image/object/bbox/xmin': dataset_util.float_list_feature(xmins),
          'image/object/bbox/xmax': dataset_util.float_list_feature(xmaxs),
          'image/object/bbox/ymin': dataset_util.float_list_feature(ymins),
          'image/object/bbox/ymax': dataset_util.float_list_feature(ymaxs),
          'image/object/class/text': dataset_util.bytes_list_feature(classes_text),
          'image/object/class/label': dataset_util.int64_list_feature(classes),
      }))
  
  </code></pre>
  <p>I have successfully saved a tfrecord with the above format, where encoded_jpg is a bytestring of a numpy array of the dicom file.</p>
  <ol>
  <li>However I ask myself how to set image_format and whether this is needed and where it is documented ?</li>
  <li>Furthermore I would like to know if it is in general possible to use the tensorflow objection api with dicom files or if the tensorflow object detection api is restricted to jpg.</li>
  </ol>
  <p>@j2abro
  I want explicitly not to convert my dicom images to jpeg, because jpeg as far as understood have 8 bit per pixel and my dicom files have 12 bit per pixel. I want to use the lossless version of my data.</p>