Error regarding input node in vitis-ai-quantizer

Question

Im trying to quantize my model using vitis-ai tensoflow in the vitis ai docker image.But an error occurs sating my input node is wrong.I checked my input node via displaying using netron,but it is the only input node.why does this occur?

Quantization code is below.

MODEL_PATH='./trained_models/saved_model'
FROZEN_GRAPH='${MODEL_PATH}/frozen_graph.pb'
INPUT_NODES="input_1"
OUTPUT_NODES='unknown_134'
OUTPUT_DIR="./quantize_result"


vai_q_tensorflow quantize \
    --input_frozen_graph ${FROZEN_GRAPH} \
    --input_nodes ${INPUT_NODES} \
    --input_shapes ?,256,512,3 \
    --output_nodes ${OUTPUT_NODES} \
    --input_fn graph_input_fn.input_fn\
    --method 1 \
    --weight_bit 8 \
    --activation_bit 8 \
    --calib_iter 5\
    --simulate_dpu 1 \
    --output_dir ${OUTPUT_DIR} \
    --dump_float 0

Input node='input_1'(according to netron) error saying input_1 not found for frozen graph.