test_enhance_single_unalign.py

'''
This script enhance all faces in one image with PSFR-GAN and paste it back to the original place.
'''
import dlib
import os
import cv2
import numpy as np 
from tqdm import tqdm
from skimage import transform as trans
from skimage import io

import torch
from utils import utils
from options.test_options import TestOptions
from models import create_model


def detect_and_align_faces(img, face_detector, lmk_predictor, template_path, template_scale=2, size_threshold=999):
    align_out_size = (512, 512)
    ref_points = np.load(template_path) / template_scale
        
    # Detect landmark points
    face_dets = face_detector(img, 1)
    assert len(face_dets) > 0, 'No faces detected'

    aligned_faces = []
    tform_params = []
    for det in face_dets:
        if isinstance(face_detector, dlib.cnn_face_detection_model_v1):
            rec = det.rect # for cnn detector
        else:
            rec = det
        if rec.width() > size_threshold or rec.height() > size_threshold: 
            print('Face is too large')
            break
        landmark_points = lmk_predictor(img, rec) 
        single_points = []
        for i in range(5):
            single_points.append([landmark_points.part(i).x, landmark_points.part(i).y])
        single_points = np.array(single_points)
        tform = trans.SimilarityTransform()
        tform.estimate(single_points, ref_points)
        tmp_face = trans.warp(img, tform.inverse, output_shape=align_out_size, order=3)
        aligned_faces.append(tmp_face*255)
        tform_params.append(tform)
    return [aligned_faces, tform_params]


def def_models(opt):
    model = create_model(opt)
    model.load_pretrain_model()
    model.netG.to(opt.device)
    return model


def enhance_faces(LQ_faces, model):
    hq_faces = []
    lq_parse_maps = []
    for lq_face in tqdm(LQ_faces):
        with torch.no_grad():
            lq_tensor = torch.tensor(lq_face.transpose(2, 0, 1)) / 255. * 2 - 1
            lq_tensor = lq_tensor.unsqueeze(0).float().to(model.device)
            output_SR = model.netG(lq_tensor)
        hq_faces.append(utils.tensor_to_img(output_SR, normal=True))
    return hq_faces


def past_faces_back(img, hq_faces, tform_params, upscale=1):
    h, w = img.shape[:2]
    img = cv2.resize(img, (int(w*upscale), int(h*upscale)), interpolation=cv2.INTER_CUBIC)
    for hq_img, tform in tqdm(zip(hq_faces, tform_params), total=len(hq_faces)):
        tform.params[0:2,0:2] /= upscale
        back_img = trans.warp(hq_img/255., tform, output_shape=[int(h*upscale), int(w*upscale)], order=3) * 255
        
        # blur mask to avoid border artifacts
        mask = (back_img == 0) 
        mask = cv2.blur(mask.astype(np.float32), (5,5))
        mask = (mask > 0)
        img = img * mask + (1 - mask) * back_img 
    return img.astype(np.uint8)


def save_imgs(img_list, save_dir):
    for idx, img in enumerate(img_list):
        save_path = os.path.join(save_dir, '{:03d}.jpg'.format(idx))
        io.imsave(save_path, img.astype(np.uint8))

if __name__ == '__main__':
    opt = TestOptions().parse()
    #  face_detector = dlib.get_frontal_face_detector()
    face_detector = dlib.cnn_face_detection_model_v1('./pretrain_models/mmod_human_face_detector.dat')
    lmk_predictor = dlib.shape_predictor('./pretrain_models/shape_predictor_5_face_landmarks.dat')
    template_path = './pretrain_models/FFHQ_template.npy'

    print('======> Loading images, crop and align faces.')
    img_path = opt.test_img_path 
    img = dlib.load_rgb_image(img_path)
    aligned_faces, tform_params = detect_and_align_faces(img, face_detector, lmk_predictor, template_path)
    # Save aligned LQ faces
    save_lq_dir = os.path.join(opt.results_dir, 'LQ_faces') 
    os.makedirs(save_lq_dir, exist_ok=True)
    print('======> Saving aligned LQ faces to', save_lq_dir)
    save_imgs(aligned_faces, save_lq_dir)

    enhance_model = def_models(opt)
    hq_faces = enhance_faces(aligned_faces, enhance_model)
    # Save LQ parsing maps and enhanced faces
    save_hq_dir = os.path.join(opt.results_dir, 'HQ') 
    os.makedirs(save_hq_dir, exist_ok=True)
    print('======> Save the enhanced faces.')
    save_imgs(hq_faces, save_hq_dir)

    print('======> Paste the enhanced faces back to the original image.')
    hq_img = past_faces_back(img, hq_faces, tform_params, upscale=opt.test_upscale) 
    final_save_path = os.path.join(opt.results_dir, 'hq_final.jpg') 
    print('======> Save final result to', final_save_path)
    io.imsave(final_save_path, hq_img)