Creating TFRecord file causes UnicodeDecodeError when being read - tensorflow

Question

I'm following the directions to create a TFRecord file in this example for object detection:
https://github.com/tensorflow/models/blob/master/research/object_detection/g3doc/using_your_own_dataset.md
I have created a Jupyter Notebook with Python 3.6.4 and TensorFlow 1.6.0 with these instructions.
I changed the value assignment inside create_tf_example to enter the correct information from my example (which is a PIL Image):
def create_tf_example(example):
height = example.height
width = example.width
filename = tf.compat.as_bytes(example.filename)
# convert Image to bytes for TF
imgByteArr = io.BytesIO()
example.save(imgByteArr, format='PNG')
imgByteArr = imgByteArr.getvalue()
encoded_image_data = tf.compat.as_bytes(imgByteArr, encoding='utf-8') # Encoded image bytes
image_format = b'png'
xmins = [0]
xmaxs = [width]
ymins = [0]
ymaxs = [height]
classes_text = [b'Test']
classes = [1]
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_image_data),
'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),
}))
return tf_example
However, it will create the file without issue and when I try to read it again, I'm getting an error. This is the same error when I try to read the TFRecord file later with TensorFlow (label_map_util.load_labelmap(PATH_TO_LABELS)):
open('data/tfrecord/label_map.pbtxt').read()
---------------------------------------------------------------------------
UnicodeDecodeError Traceback (most recent call last)
<ipython-input-26-dfa57505da97> in <module>()
----> 1 open('data/tfrecord/label_map.pbtxt').read()
~/Documents/.../bin/../lib/python3.6/codecs.py in decode(self, input, final)
319 # decode input (taking the buffer into account)
320 data = self.buffer + input
--> 321 (result, consumed) = self._buffer_decode(data, self.errors, final)
322 # keep undecoded input until the next call
323 self.buffer = data[consumed:]
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xbe in position 10: invalid start byte
It isn't clear to me what I should be doing differently because of tf_example.SerializeToString() seems to be doing the encoding to a string in the example.
Here is the output if it helps from open('data/tfrecord/label_map.pbtxt', 'rb').read():
b'kX\x00\x00\x00\x00\x00\x00\x05#\xbe\xe0\n\xe7\xb0\x01\n\x15\n\x0bimage/width\x12\x06\x1a\x04\n\x02\x98\x03\n\x17\n\x0cimage/format\x12\x07\n\x05\n\x03png\n!\n\x18image/object/class/label\x12\x05\x1a\x03\n\x01\x01\n\x16\n\x0cimage/height\x12\x06\x1a\x04\n\x02\x98\x03\nM\n\x17image/object/class/text\x122\n0\n.Qma8oN1eQwAiKUQZJRXry1VD2yCwYWnZQ6rtQwsC8LzjDu\nR\n\x0fimage/source_id\x12?\n=\n;data/png/Qma8oN1eQwAiKUQZJRXry1VD2yCwYWnZQ6rtQwsC8LzjDu.png\n"\n\x16image/object/bbox/ymin\x12\x08\x12\x06\n\x04\x00\x00\x00\x00\n\xf2\xac\x01\n\rimage/encoded\x12\xdf\xac\x01\n\xdb\xac\x01\n\xd7\xac\x01\x89PNG\r\n
Thank you!