video_inference.py

import argparse
import datetime
import random
import time
from pathlib import Path
from tqdm import tqdm

import torch
import torchvision.transforms as standard_transforms
import numpy as np

from PIL import Image
import cv2
from crowd_datasets import build_dataset
from engine import *
from models import build_model
import os
import warnings
warnings.filterwarnings('ignore')

def get_args_parser():
    parser = argparse.ArgumentParser('Set parameters for P2PNet evaluation', add_help=False)
    
    # * Backbone
    parser.add_argument('--backbone', default='vgg16_bn', type=str,
                        help="name of the convolutional backbone to use")
    
    parser.add_argument('--input_video', default='../Video-tests/test1.mp4', type=str,
                        help="address of input video file")

    parser.add_argument('--row', default=2, type=int,
                        help="row number of anchor points")
    parser.add_argument('--line', default=2, type=int,
                        help="line number of anchor points")

    parser.add_argument('--output_dir', default='./logs/',
                        help='path where to save')
    parser.add_argument('--weight_path', default='./weights/SHTechA.pth',
                        help='path where the trained weights saved')

    parser.add_argument('--gpu_id', default=0, type=int, help='the gpu used for evaluation')

    return parser

def load_model(args):
    os.environ["CUDA_VISIBLE_DEVICES"] = '{}'.format(args.gpu_id)

    print(args)
    device = torch.device('cpu')
    # get the P2PNet
    model = build_model(args)
    # move to GPU
    model.to(device)
    # load trained model
    if args.weight_path is not None:
        checkpoint = torch.load(args.weight_path, map_location='cpu')
        model.load_state_dict(checkpoint['model'])
    # convert to eval mode
    model.eval()
    # create the pre-processing transform
    transform = standard_transforms.Compose([
        standard_transforms.ToTensor(), 
        standard_transforms.Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]),
    ])
    return model, transform, device
def video_reader(videoFile):
    cap = cv2.VideoCapture(videoFile)
    while(cap.isOpened()):
        ret,cv2_im = cap.read()
        if ret:
            converted = cv2.cvtColor(cv2_im,cv2.COLOR_BGR2RGB)
            pil_im = Image.fromarray(converted)
            yield pil_im
                    
        elif not ret:
            break
    cap.release()


def main(args, debug=False):
    result = []
    model, transform, device = load_model(args)
    for frame in tqdm(video_reader(args.input_video)):
        img_raw = frame
        # round the size
        width, height = img_raw.size
        new_width = width // 128 * 128
        new_height = height // 128 * 128
        img_raw = img_raw.resize((new_width, new_height), Image.ANTIALIAS)
        frames_size = (new_width, new_height)
        # pre-proccessing
        img = transform(img_raw)

        samples = torch.Tensor(img).unsqueeze(0)
        samples = samples.to(device)
        # run inference
        outputs = model(samples)
        outputs_scores = torch.nn.functional.softmax(outputs['pred_logits'], -1)[:, :, 1][0]

        outputs_points = outputs['pred_points'][0]

        threshold = 0.5
        # filter the predictions
        points = outputs_points[outputs_scores > threshold].detach().cpu().numpy().tolist()
        predict_cnt = int((outputs_scores > threshold).sum())

        outputs_scores = torch.nn.functional.softmax(outputs['pred_logits'], -1)[:, :, 1][0]

        outputs_points = outputs['pred_points'][0]
        # draw the predictions
        size = 10
        img_to_draw = cv2.cvtColor(np.array(img_raw), cv2.COLOR_RGB2BGR)
        for p in points:
            img_to_draw = cv2.circle(img_to_draw, (int(p[0]), int(p[1])), size, (0, 0, 255), -1)
        # save the visualized image
        # cv2.imwrite(os.path.join(args.output_dir, 'pred{}.jpg'.format(predict_cnt)), img_to_draw)
        # break
        if result:
            result.write(img_to_draw)
        else:
            result = cv2.VideoWriter(f'{args.output_dir}pred_{args.input_video}.avi', 
                         cv2.VideoWriter_fourcc(*'MJPG'),
                         10, frames_size)    
            result.write(img_to_draw)
    result.release()

if __name__ == '__main__':
    parser = argparse.ArgumentParser('P2PNet evaluation script', parents=[get_args_parser()])
    args = parser.parse_args()
    main(args)