utils.py

# Copyright 2020 NVIDIA
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import torch
import torchvision.transforms as transforms
import torch.nn.functional as F
import cv2
import PIL.Image
import numpy as np

mean = torch.Tensor([0.485, 0.456, 0.406]).cuda()
std = torch.Tensor([0.229, 0.224, 0.225]).cuda()

def preprocess(image):
    device = torch.device('cuda')
    image = PIL.Image.fromarray(image)
    image = transforms.functional.to_tensor(image).to(device)
    image.sub_(mean[:, None, None]).div_(std[:, None, None])
    return image[None, ...]