I’m trying to fine-tune VGG16 model for object detection. I’ve added a few dense layers and freezed the convolutional layers. There are 2 outputs of the model (bounding boxes and class labels) and the input is 512*512 images.
The error seems to occur during evaluation by the metric.
I have checked the model output shape and the training data’s ‘y’ shape.
The label and annotations have the shape: (6, 4) (6, 3)
The model outputs have the same shape:
<KerasTensor shape=(None, 6, 4), dtype=float32, sparse=False, name=keras_tensor_24>,
<KerasTensor shape=(None, 6, 3), dtype=float32, sparse=False, name=keras_tensor_30>

tf version – 2.16.0, python version – 3.10.11

The error I see is (the file path is edited):

Traceback (most recent call last):
File “train.py”, line 163, in
history = model.fit(
File “libsite-packageskerassrcutilstraceback_utils.py”, line 122, in error_handler
raise e.with_traceback(filtered_tb) from None
File “libsite-packagestensorflowpythoneagerexecute.py”, line 53, in quick_execute
tensors = pywrap_tfe.TFE_Py_Execute(ctx._handle, device_name, op_name,
tensorflow.python.framework.errors_impl.InvalidArgumentError: Graph execution error:

Detected at node ScatterNd defined at (most recent call last):
File “train.py”, line 163, in

File “libsite-packageskerassrcutilstraceback_utils.py”, line 117, in error_handler

File “libsite-packageskerassrcbackendtensorflowtrainer.py”, line 318, in fit

File “libsite-packageskerassrcbackendtensorflowtrainer.py”, line 121, in one_step_on_iterator

File “libsite-packageskerassrcbackendtensorflowtrainer.py”, line 108, in one_step_on_data

File “libsite-packageskerassrcbackendtensorflowtrainer.py”, line 77, in train_step

File “libsite-packageskerassrctrainerstrainer.py”, line 444, in compute_metrics

File “libsite-packageskerassrctrainerscompile_utils.py”, line 330, in update_state

File “libsite-packageskerassrctrainerscompile_utils.py”, line 17, in update_state

File “libsite-packageskerassrcmetricsiou_metrics.py”, line 129, in update_state

File “libsite-packageskerassrcmetricsmetrics_utils.py”, line 682, in confusion_matrix

File “libsite-packageskerassrcopscore.py”, line 237, in scatter

File “libsite-packageskerassrcbackendtensorflowcore.py”, line 354, in scatter

indices[0] = [286, 0] does not index into shape [3,3]
[[{{node ScatterNd}}]] [Op:__inference_one_step_on_iterator_4213]

I saw similar questions asked on this, found 2 solutions – ensure equal number of classes and number of units in output layer; change the loss functions and/or metrics.
I’m using Categorical accuracy and meanIoU as metrics and categorical crossentropy and MSE as loss functions for the two outputs. Also tried mean Average Precesion but it didn’t work.

Please help with any other solutions for this error!