"""
Export ONNX model of MODNet with:
input shape: (batch_size, 3, height, width)
output shape: (batch_size, 1, height, width)
Arguments:
--ckpt-path: path of the checkpoint that will be converted
--output-path: path for saving the ONNX model
Example:
python export_onnx.py \
--ckpt-path=modnet_photographic_portrait_matting.ckpt \
--output-path=modnet_photographic_portrait_matting.onnx
"""
import os
import argparse
import torch
import torch.nn as nn
from torch.autograd import Variable
from onnx import modnet_onnx
if __name__ == '__main__':
# define cmd arguments
parser = argparse.ArgumentParser()
parser.add_argument('--ckpt-path', type=str, required=True, help='path of the checkpoint that will be converted')
parser.add_argument('--output-path', type=str, required=True, help='path for saving the ONNX model')
args = parser.parse_args()
# check input arguments
if not os.path.exists(args.ckpt_path):
print('Cannot find checkpoint path: {0}'.format(args.ckpt_path))
exit()
# define model & load checkpoint
modnet = modnet_onnx.MODNet(backbone_pretrained=False,hr_channels=16)
modnet = nn.DataParallel(modnet).cuda()
state_dict = torch.load(args.ckpt_path)
modnet.load_state_dict(state_dict)
modnet.eval()
# prepare dummy_input
batch_size = 1
height = 256
width = 256
##############单个输入######################
# dummy_inputImg = Variable(torch.randn(batch_size, 3, height, width)).cuda()
#
# # export to onnx model
# torch.onnx.export(
# modnet.module, dummy_inputImg, args.output_path, export_params=True,
# input_names=['inputImg'], output_names=['output'],
# # dynamic_axes = {'input': {0:'batch_size', 2:'height', 3:'width'}, 'output': {0: 'batch_size', 2: 'height', 3: 'width'}},opset_version=11)
# dynamic_axes={'inputImg': {0: 'batch_size', 2: 'height', 3: 'width'}, 'output': {0: 'batch_size', 2: 'height', 3: 'width'}}, opset_version=11)
##############多个输入######################
dummy_inputImg = Variable(torch.randn(batch_size, 3, height, width)).cuda()
dummy_inputMatte = Variable(torch.randn(batch_size, 1, height, width)).cuda()
# export to onnx model
torch.onnx.export(
modnet.module, (dummy_inputImg,dummy_inputMatte),args.output_path, export_params = True,
input_names = ['inputImg','inputMatte'], output_names = ['output'],
# dynamic_axes = {'input': {0:'batch_size', 2:'height', 3:'width'}, 'output': {0: 'batch_size', 2: 'height', 3: 'width'}},opset_version=11)
dynamic_axes = {'inputImg': {0: 'batch_size',2: 'height', 3: 'width'},'inputMatte': {0: 'batch_size',2: 'height', 3: 'width'},'output': {0: 'batch_size', 2: 'height', 3: 'width'}}, opset_version = 11)