How to deal with "Unsupported operation _Cast"?


I have an ssd and I converted the pb file to uff,and the log goes like this:

2021-06-30 16:41:16.029792: I tensorflow/stream_executor/platform/default/] Successfully opened dynamic library
WARNING:tensorflow:Deprecation warnings have been disabled. Set TF_ENABLE_DEPRECATION_WARNINGS=1 to re-enable them.
Loading frozen_inference_graph.pb
WARNING:tensorflow:From /home/machine/.local/lib/python3.6/site-packages/uff/bin/…/…/uff/converters/tensorflow/ The name tf.gfile.GFile is deprecated. Please use instead.

NOTE: UFF has been tested with TensorFlow 1.15.0.
WARNING: The version of TensorFlow installed on this system is not guaranteed to work with UFF.
UFF Version 0.6.9
=== Automatically deduced input nodes ===
[name: “Input”
op: “Placeholder”
input: “Cast”
attr {
key: “dtype”
value {
type: DT_FLOAT
attr {
key: “shape”
value {
shape {
dim {
size: 1
dim {
size: 3
dim {
size: 300
dim {
size: 300

Using output node NMS
Converting to UFF graph
Warning: No conversion function registered for layer: NMS_TRT yet.
Converting NMS as custom op: NMS_TRT
WARNING:tensorflow:From /home/machine/.local/lib/python3.6/site-packages/uff/bin/…/…/uff/converters/tensorflow/ The name tf.AttrValue is deprecated. Please use tf.compat.v1.AttrValue instead.

Warning: No conversion function registered for layer: Cast yet.
Converting Cast as custom op: Cast
Warning: No conversion function registered for layer: FlattenConcat_TRT yet.
Converting concat_box_conf as custom op: FlattenConcat_TRT
Warning: No conversion function registered for layer: GridAnchor_TRT yet.
Converting GridAnchor as custom op: GridAnchor_TRT
Warning: No conversion function registered for layer: FlattenConcat_TRT yet.
Converting concat_box_loc as custom op: FlattenConcat_TRT
DEBUG [/home/machine/.local/lib/python3.6/site-packages/uff/bin/…/…/uff/converters/tensorflow/] Marking [‘NMS’] as outputs
No. nodes: 774
UFF Output written to frozen_inference_graph.uff

And then I run it with sampleUffSSD, and it goes wrong and say “Unsupported Operation _Cast”.
Now I wonder how it happened and how to make it correct. Thanks.


TensorRT 7: tensorRT 7.15
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Hi @2845590432,

UFF and Caffe Parser have been deprecated from TensorRT 7 onwards, hence request you to try ONNX parser.
Please check the below link for the same.

Also we recommend you to please try on latest TensorRT version 8.0 EA. Please let us know if you still face the issue.


Please refer to the installation steps from the below link if in case you are missing on anything
However suggested approach is to use TRT NGC containers to avoid any system dependency related issues.

In order to run python sample, make sure TRT python packages are installed while using NGC container.

In case, if you are trying to run custom model, please share your model and script with us, so that we can assist you better.