keras-ocr Fine tunning recognizer IAM Handwriting dataset

Hello. I have a question about fine tunning using the IAM handwriting dataset. do I have to fine-tuning the detector too?

when I want to run the training process I get this error message.

Epoch 1/1000 2510/10257 [======>.......................] - ETA: 6:57 - loss: 11.6869

UnknownError Traceback (most recent call last) in () 10 validation_data=validation_gen, 11 callbacks=callbacks, ---> 12 epochs=1000, 13 )

10 frames /usr/local/lib/python3.6/dist-packages/tensorflow/python/eager/execute.py in quick_execute(op_name, num_outputs, inputs, attrs, ctx, name) 58 ctx.ensure_initialized() 59 tensors = pywrap_tfe.TFE_Py_Execute(ctx._handle, device_name, op_name, ---> 60 inputs, attrs, num_outputs) 61 except core._NotOkStatusException as e: 62 if name is not None:

UnknownError: 2 root error(s) found. (0) Unknown: error: OpenCV(4.4.0) /tmp/pip-req-build-qacpj5ci/opencv/modules/imgproc/src/color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cvtColor'

Traceback (most recent call last):

File "/usr/local/lib/python3.6/dist-packages/tensorflow/python/ops/script_ops.py", line 244, in call ret = func(*args)

File "/usr/local/lib/python3.6/dist-packages/tensorflow/python/autograph/impl/api.py", line 302, in wrapper return func(*args, **kwargs)

File "/usr/local/lib/python3.6/dist-packages/tensorflow/python/data/ops/dataset_ops.py", line 827, in generator_py_func values = next(generator_state.get_iterator(iterator_id))

File "/usr/local/lib/python3.6/dist-packages/tensorflow/python/keras/engine/data_adapter.py", line 814, in wrapped_generator for data in generator_fn():

File "/usr/local/lib/python3.6/dist-packages/keras_ocr/recognition.py", line 361, in get_batch_generator batch = [sample for sample, _ in zip(image_generator, range(batch_size))]

File "/usr/local/lib/python3.6/dist-packages/keras_ocr/recognition.py", line 361, in batch = [sample for sample, _ in zip(image_generator, range(batch_size))]

File "/usr/local/lib/python3.6/dist-packages/keras_ocr/datasets.py", line 395, in get_recognizer_image_generator cval=cval)

File "/usr/local/lib/python3.6/dist-packages/keras_ocr/tools.py", line 407, in read_and_fit image = read(filepath_or_array) if isinstance(filepath_or_array, str) else filepath_or_array

File "/usr/local/lib/python3.6/dist-packages/keras_ocr/tools.py", line 36, in read return cv2.cvtColor(image, cv2.COLOR_BGR2RGB)

cv2.error: OpenCV(4.4.0) /tmp/pip-req-build-qacpj5ci/opencv/modules/imgproc/src/color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cvtColor'

 [[{{node PyFunc}}]]
 [[IteratorGetNext]]

(1) Unknown: error: OpenCV(4.4.0) /tmp/pip-req-build-qacpj5ci/opencv/modules/imgproc/src/color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cvtColor'