From fbe70767b260570c37b3fb490d10171ede422921 Mon Sep 17 00:00:00 2001
From: Nicholas Scott <TalosOfCrete@protonmail.com>
Date: Tue, 2 Jun 2020 02:43:46 -0500
Subject: [PATCH] upload

---
 facelib/ResNet50.py            | 221 +++++++++++++++++++++
 facelib/RetinaFaceExtractor.py | 343 +++++++++++++++++++++++++++++++++
 facelib/box_utils.py           | 328 +++++++++++++++++++++++++++++++
 facelib/coord_conv.py          | 153 +++++++++++++++
 facelib/prior_box.py           |  34 ++++
 5 files changed, 1079 insertions(+)
 create mode 100644 facelib/ResNet50.py
 create mode 100644 facelib/RetinaFaceExtractor.py
 create mode 100644 facelib/box_utils.py
 create mode 100644 facelib/coord_conv.py
 create mode 100644 facelib/prior_box.py

diff --git a/facelib/ResNet50.py b/facelib/ResNet50.py
new file mode 100644
index 0000000..0060382
--- /dev/null
+++ b/facelib/ResNet50.py
@@ -0,0 +1,221 @@
+import torch
+import torch.nn as nn
+
+from pathlib import Path
+
+def conv3x3(in_planes, out_planes, stride=1, groups=1, dilation=1):
+    """3x3 convolution with padding"""
+    return nn.Conv2d(in_planes, out_planes, kernel_size=3, stride=stride,
+                     padding=dilation, groups=groups, bias=False, dilation=dilation)
+
+
+def conv1x1(in_planes, out_planes, stride=1):
+    """1x1 convolution"""
+    return nn.Conv2d(in_planes, out_planes, kernel_size=1, stride=stride, bias=False)
+
+
+class BasicBlock(nn.Module):
+    expansion = 1
+
+    def __init__(self, inplanes, planes, stride=1, downsample=None, groups=1,
+                 base_width=64, dilation=1, norm_layer=None):
+        super(BasicBlock, self).__init__()
+        if norm_layer is None:
+            norm_layer = nn.BatchNorm2d
+        if groups != 1 or base_width != 64:
+            raise ValueError('BasicBlock only supports groups=1 and base_width=64')
+        if dilation > 1:
+            raise NotImplementedError("Dilation > 1 not supported in BasicBlock")
+        # Both self.conv1 and self.downsample layers downsample the input when stride != 1
+        self.conv1 = conv3x3(inplanes, planes, stride)
+        self.bn1 = norm_layer(planes)
+        self.relu = nn.ReLU(inplace=True)
+        self.conv2 = conv3x3(planes, planes)
+        self.bn2 = norm_layer(planes)
+        self.downsample = downsample
+        self.stride = stride
+
+    def forward(self, x):
+        identity = x
+
+        out = self.conv1(x)
+        out = self.bn1(out)
+        out = self.relu(out)
+
+        out = self.conv2(out)
+        out = self.bn2(out)
+
+        if self.downsample is not None:
+            identity = self.downsample(x)
+
+        out += identity
+        out = self.relu(out)
+
+        return out
+
+
+class Bottleneck(nn.Module):
+    # Bottleneck in torchvision places the stride for downsampling at 3x3 convolution(self.conv2)
+    # while original implementation places the stride at the first 1x1 convolution(self.conv1)
+    # according to "Deep residual learning for image recognition"https://arxiv.org/abs/1512.03385.
+    # This variant is also known as ResNet V1.5 and improves accuracy according to
+    # https://ngc.nvidia.com/catalog/model-scripts/nvidia:resnet_50_v1_5_for_pytorch.
+
+    expansion = 4
+
+    def __init__(self, inplanes, planes, stride=1, downsample=None, groups=1,
+                 base_width=64, dilation=1, norm_layer=None):
+        super(Bottleneck, self).__init__()
+        if norm_layer is None:
+            norm_layer = nn.BatchNorm2d
+        width = int(planes * (base_width / 64.)) * groups
+        # Both self.conv2 and self.downsample layers downsample the input when stride != 1
+        self.conv1 = conv1x1(inplanes, width)
+        self.bn1 = norm_layer(width)
+        self.conv2 = conv3x3(width, width, stride, groups, dilation)
+        self.bn2 = norm_layer(width)
+        self.conv3 = conv1x1(width, planes * self.expansion)
+        self.bn3 = norm_layer(planes * self.expansion)
+        self.relu = nn.ReLU(inplace=True)
+        self.downsample = downsample
+        self.stride = stride
+
+    def forward(self, x):
+        identity = x
+
+        out = self.conv1(x)
+        out = self.bn1(out)
+        out = self.relu(out)
+
+        out = self.conv2(out)
+        out = self.bn2(out)
+        out = self.relu(out)
+
+        out = self.conv3(out)
+        out = self.bn3(out)
+
+        if self.downsample is not None:
+            identity = self.downsample(x)
+
+        out += identity
+        out = self.relu(out)
+
+        return out
+
+
+class ResNet(nn.Module):
+
+    def __init__(self, block, layers, num_classes=1000, zero_init_residual=False,
+                 groups=1, width_per_group=64, replace_stride_with_dilation=None,
+                 norm_layer=None):
+        super(ResNet, self).__init__()
+        if norm_layer is None:
+            norm_layer = nn.BatchNorm2d
+        self._norm_layer = norm_layer
+
+        self.inplanes = 64
+        self.dilation = 1
+        if replace_stride_with_dilation is None:
+            # each element in the tuple indicates if we should replace
+            # the 2x2 stride with a dilated convolution instead
+            replace_stride_with_dilation = [False, False, False]
+        if len(replace_stride_with_dilation) != 3:
+            raise ValueError("replace_stride_with_dilation should be None "
+                             "or a 3-element tuple, got {}".format(replace_stride_with_dilation))
+        self.groups = groups
+        self.base_width = width_per_group
+        self.conv1 = nn.Conv2d(3, self.inplanes, kernel_size=7, stride=2, padding=3,
+                               bias=False)
+        self.bn1 = norm_layer(self.inplanes)
+        self.relu = nn.ReLU(inplace=True)
+        self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
+        self.layer1 = self._make_layer(block, 64, layers[0])
+        self.layer2 = self._make_layer(block, 128, layers[1], stride=2,
+                                       dilate=replace_stride_with_dilation[0])
+        self.layer3 = self._make_layer(block, 256, layers[2], stride=2,
+                                       dilate=replace_stride_with_dilation[1])
+        self.layer4 = self._make_layer(block, 512, layers[3], stride=2,
+                                       dilate=replace_stride_with_dilation[2])
+        self.avgpool = nn.AdaptiveAvgPool2d((1, 1))
+        self.fc = nn.Linear(512 * block.expansion, num_classes)
+
+        for m in self.modules():
+            if isinstance(m, nn.Conv2d):
+                nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu')
+            elif isinstance(m, (nn.BatchNorm2d, nn.GroupNorm)):
+                nn.init.constant_(m.weight, 1)
+                nn.init.constant_(m.bias, 0)
+
+        # Zero-initialize the last BN in each residual branch,
+        # so that the residual branch starts with zeros, and each residual block behaves like an identity.
+        # This improves the model by 0.2~0.3% according to https://arxiv.org/abs/1706.02677
+        if zero_init_residual:
+            for m in self.modules():
+                if isinstance(m, Bottleneck):
+                    nn.init.constant_(m.bn3.weight, 0)
+                elif isinstance(m, BasicBlock):
+                    nn.init.constant_(m.bn2.weight, 0)
+
+    def _make_layer(self, block, planes, blocks, stride=1, dilate=False):
+        norm_layer = self._norm_layer
+        downsample = None
+        previous_dilation = self.dilation
+        if dilate:
+            self.dilation *= stride
+            stride = 1
+        if stride != 1 or self.inplanes != planes * block.expansion:
+            downsample = nn.Sequential(
+                conv1x1(self.inplanes, planes * block.expansion, stride),
+                norm_layer(planes * block.expansion),
+            )
+
+        layers = []
+        layers.append(block(self.inplanes, planes, stride, downsample, self.groups,
+                            self.base_width, previous_dilation, norm_layer))
+        self.inplanes = planes * block.expansion
+        for _ in range(1, blocks):
+            layers.append(block(self.inplanes, planes, groups=self.groups,
+                                base_width=self.base_width, dilation=self.dilation,
+                                norm_layer=norm_layer))
+
+        return nn.Sequential(*layers)
+
+    def _forward_impl(self, x):
+        # See note [TorchScript super()]
+        x = self.conv1(x)
+        x = self.bn1(x)
+        x = self.relu(x)
+        x = self.maxpool(x)
+
+        x = self.layer1(x)
+        x = self.layer2(x)
+        x = self.layer3(x)
+        x = self.layer4(x)
+
+        x = self.avgpool(x)
+        x = torch.flatten(x, 1)
+        x = self.fc(x)
+
+        return x
+
+    def forward(self, x):
+        return self._forward_impl(x)
+        
+
+def _resnet(arch, block, layers, pretrained, **kwargs):
+    model = ResNet(block, layers, **kwargs)
+    if pretrained:
+        model_path = Path(__file__).parent / "resnet50-19c8e357.pth"
+        state_dict = torch.load(model_path)
+        model.load_state_dict(state_dict)
+    return model
+
+
+def resnet50(pretrained=True, **kwargs):
+    r"""ResNet-50 model from
+    `"Deep Residual Learning for Image Recognition" <https://arxiv.org/pdf/1512.03385.pdf>`_
+    Args:
+        pretrained (bool): If True, returns a model pre-trained on ImageNet
+    """
+    return _resnet('resnet50', Bottleneck, [3, 4, 6, 3], pretrained,
+                   **kwargs)
\ No newline at end of file
diff --git a/facelib/RetinaFaceExtractor.py b/facelib/RetinaFaceExtractor.py
new file mode 100644
index 0000000..9f02fc8
--- /dev/null
+++ b/facelib/RetinaFaceExtractor.py
@@ -0,0 +1,343 @@
+import operator
+from pathlib import Path
+
+import cv2
+import numpy as np
+
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+
+from facelib.nn_pt import nn as nn_pt
+
+import torchvision.models as models
+import torchvision.models.detection.backbone_utils as backbone_utils
+import torchvision.models._utils as _utils
+from torchvision.transforms import ToTensor
+
+from facelib.net import FPN as FPN
+from facelib.net import SSH as SSH
+
+from facelib.box_utils import decode
+from facelib.prior_box import PriorBox
+
+from facelib.ResNet50 import resnet50
+
+from facelib.config import cfg_re50
+"""Ported from https://github.com/biubug6/Pytorch_Retinaface/"""
+
+class RetinaFaceExtractor(object):
+    def __init__(self, place_model_on_cpu=False):
+        nn_pt.initialize()
+        
+        model_path = Path(__file__).parent / "RetinaFace-Resnet50.pth"
+        
+        if not model_path.exists():
+            raise Exception("Unable to load RetinaFace-Resnet50.pth")
+
+        class ClassHead(nn.Module):
+            def __init__(self,inchannels=512,num_anchors=3):
+                super(ClassHead,self).__init__()
+                self.num_anchors = num_anchors
+                self.conv1x1 = nn.Conv2d(inchannels,self.num_anchors*2,kernel_size=(1,1),stride=1,padding=0)
+
+            def forward(self,x):
+                out = self.conv1x1(x)
+                out = out.permute(0,2,3,1).contiguous()
+        
+                return out.view(out.shape[0], -1, 2)
+            
+
+        class BboxHead(nn.Module):
+            def __init__(self,inchannels=512,num_anchors=3):
+                super(BboxHead,self).__init__()
+                self.conv1x1 = nn.Conv2d(inchannels,num_anchors*4,kernel_size=(1,1),stride=1,padding=0)
+
+            def forward(self,x):
+                out = self.conv1x1(x)
+                out = out.permute(0,2,3,1).contiguous()
+
+                return out.view(out.shape[0], -1, 4)
+
+            
+        class LandmarkHead(nn.Module):
+            def __init__(self,inchannels=512,num_anchors=3):
+                super(LandmarkHead,self).__init__()
+                self.conv1x1 = nn.Conv2d(inchannels,num_anchors*10,kernel_size=(1,1),stride=1,padding=0)
+
+            def forward(self,x):
+                out = self.conv1x1(x)
+                out = out.permute(0,2,3,1).contiguous()
+
+                return out.view(out.shape[0], -1, 10)
+
+        class RetinaFace(nn.Module):
+            def __init__(self, cfg = cfg_re50):
+                super(RetinaFace,self).__init__()
+                backbone = resnet50(pretrained=cfg['pretrain'])
+
+                self.body = _utils.IntermediateLayerGetter(backbone, cfg['return_layers'])
+                in_channels_stage2 = cfg['in_channel']
+                in_channels_list = [in_channels_stage2 * 2,
+                                    in_channels_stage2 * 4,
+                                    in_channels_stage2 * 8,]
+                out_channels = cfg['out_channel']
+
+                self.fpn = FPN(in_channels_list,out_channels)
+                self.ssh1 = SSH(out_channels, out_channels)
+                self.ssh2 = SSH(out_channels, out_channels)
+                self.ssh3 = SSH(out_channels, out_channels)
+
+                self.ClassHead = self._make_class_head(fpn_num=3, inchannels=cfg['out_channel'])
+                self.BboxHead = self._make_bbox_head(fpn_num=3, inchannels=cfg['out_channel'])
+                self.LandmarkHead = self._make_landmark_head(fpn_num=3, inchannels=cfg['out_channel'])
+
+            def _make_class_head(self,fpn_num=3,inchannels=64,anchor_num=2):
+                classhead = nn.ModuleList()
+                for i in range(fpn_num):
+                    classhead.append(ClassHead(inchannels,anchor_num))
+                return classhead
+
+            def _make_bbox_head(self,fpn_num=3,inchannels=64,anchor_num=2):
+                bboxhead = nn.ModuleList()
+                for i in range(fpn_num):
+                    bboxhead.append(BboxHead(inchannels,anchor_num))
+                return bboxhead
+
+            def _make_landmark_head(self,fpn_num=3,inchannels=64,anchor_num=2):
+                landmarkhead = nn.ModuleList()
+                for i in range(fpn_num):
+                    landmarkhead.append(LandmarkHead(inchannels,anchor_num))
+                return landmarkhead
+
+
+            def forward(self,inputs):
+                out = self.body(inputs)
+
+                # FPN
+                fpn = self.fpn(out)
+
+                # SSH
+                feature1 = self.ssh1(fpn[0])
+                feature2 = self.ssh2(fpn[1])
+                feature3 = self.ssh3(fpn[2])
+                features = [feature1, feature2, feature3]
+
+                bbox_regressions = torch.cat([self.BboxHead[i](feature) for i, feature in enumerate(features)], dim=1)
+                classifications = torch.cat([self.ClassHead[i](feature) for i, feature in enumerate(features)],dim=1)
+                ldm_regressions = torch.cat([self.LandmarkHead[i](feature) for i, feature in enumerate(features)], dim=1)
+
+                output = (bbox_regressions, F.softmax(classifications, dim=-1), ldm_regressions)
+
+                return output
+                
+        def check_keys(model, pretrained_state_dict):
+            ckpt_keys = set(pretrained_state_dict.keys())
+            model_keys = set(model.state_dict().keys())
+            used_pretrained_keys = model_keys & ckpt_keys
+            unused_pretrained_keys = ckpt_keys - model_keys
+            missing_keys = model_keys - ckpt_keys
+            assert len(used_pretrained_keys) > 0, 'load NONE from pretrained checkpoint'
+            return True
+                
+        def remove_prefix(state_dict, prefix):
+            ''' Old style model is stored with all names of parameters sharing common prefix 'module.' '''
+            f = lambda x: x.split(prefix, 1)[-1] if x.startswith(prefix) else x
+            return {f(key): value for key, value in state_dict.items()}
+            
+        def load_model(model, pretrained_path, load_to_cpu):
+            if load_to_cpu:
+                pretrained_dict = torch.load(pretrained_path, map_location=lambda storage, loc: storage)
+            else:
+                device = torch.cuda.current_device()
+                pretrained_dict = torch.load(pretrained_path, map_location=lambda storage, loc: storage.cuda(device))
+            if "state_dict" in pretrained_dict.keys():
+                pretrained_dict = remove_prefix(pretrained_dict['state_dict'], 'module.')
+            else:
+                pretrained_dict = remove_prefix(pretrained_dict, 'module.')
+            check_keys(model, pretrained_dict)
+            model.load_state_dict(pretrained_dict, strict=False)
+            return model
+        
+        try:
+            torch.set_grad_enabled(False)
+            self.model = RetinaFace(cfg=cfg_re50)
+            self.model = load_model(self.model, model_path, place_model_on_cpu)
+            self.model.eval()
+        
+            self.device = torch.device("cpu" if place_model_on_cpu else "cuda")
+            self.model = self.model.to(self.device)
+            
+        except:
+            self.model = None
+            print("Could not load RetinaFace")
+        
+        
+
+        
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type=None, exc_value=None, traceback=None):
+        return False #pass exception between __enter__ and __exit__ to outter level
+
+    def extract (self, input_image, is_bgr=True, is_remove_intersects=False):
+        
+        cfg = cfg_re50
+        
+        if is_bgr:
+            input_image = input_image[:,:,::-1]
+            is_bgr = False
+
+        (h, w, ch) = input_image.shape
+
+        d = max(w, h)
+        scale_to = 640 if d >= 1280 else d / 2
+        scale_to = max(64, scale_to)
+
+        input_scale = d / scale_to
+        input_image = cv2.resize (input_image, ( int(w/input_scale), int(h/input_scale) ), interpolation=cv2.INTER_LINEAR)
+
+        (h, w, ch) = input_image.shape
+        
+        with torch.no_grad():
+            
+            input_image = ToTensor()(input_image)
+            input_image = input_image.to(self.device)
+        
+            loc, conf, landmarks = self.model( input_image[None,...]  )
+        
+            priorbox = PriorBox(cfg, image_size=(h, w))
+            priors = priorbox.forward()
+            priors = priors.to(self.device)
+            prior_data = priors.data
+        
+            boxes = decode(loc.data.squeeze(0), prior_data, cfg['variance'])
+            boxes = np.float32(boxes.cpu().numpy())
+            scores = np.float32(conf.squeeze(0).data.cpu().numpy()[:, 1])
+        
+            inds = np.where(scores > 0.05)[0]
+            boxes = boxes[inds]
+            scores = scores[inds]
+        
+            dets = np.hstack((boxes, scores[:, np.newaxis])).astype(np.float32, copy=False)
+            
+        keep = self.refine_nms(dets, 0.3)
+        dets = dets[keep, :]
+        
+        dets = dets.tolist()
+        dets = [ x[:-1].astype(np.int) for x in dets if x[-1] >= 0.5 ]
+        
+        
+
+        detected_faces = []
+        
+        for ltrb in dets:
+            # l,t,r,b = [ x for x in ltrb]
+            l,t,r,b = [ x*input_scale for x in ltrb]
+            bt = b-t
+            if min(r-l,bt) < 40: #filtering faces < 40pix by any side
+                continue
+            b += bt*0.1 #enlarging bottom line a bit for 2DFAN-4, because default is not enough covering a chin
+            detected_faces.append ( [int(x) for x in (l,t,r,b) ] )
+
+        #sort by largest area first
+        detected_faces = [ [(l,t,r,b), (r-l)*(b-t) ]  for (l,t,r,b) in detected_faces ]
+        detected_faces = sorted(detected_faces, key=operator.itemgetter(1), reverse=True )
+        detected_faces = [ x[0] for x in detected_faces]
+
+        if is_remove_intersects:
+            for i in range( len(detected_faces)-1, 0, -1):
+                l1,t1,r1,b1 = detected_faces[i]
+                l0,t0,r0,b0 = detected_faces[i-1]
+
+                dx = min(r0, r1) - max(l0, l1)
+                dy = min(b0, b1) - max(t0, t1)
+                if (dx>=0) and (dy>=0):
+                    detected_faces.pop(i)
+
+        return detected_faces 
+            
+        
+
+    def refine(self, olist):
+        bboxlist = []
+        for i, ((ocls,), (oreg,)) in enumerate (  ):
+            stride = 2**(i + 2)    # 4,8,16,32,64,128
+            s_d2 = stride / 2
+            s_m4 = stride * 4
+
+            for hindex, windex in zip(*np.where(ocls[...,1] > 0.05)):
+                score = ocls[hindex, windex, 1]
+                loc   = oreg[hindex, windex, :]
+                priors = np.array([windex * stride + s_d2, hindex * stride + s_d2, s_m4, s_m4])
+                priors_2p = priors[2:]
+                box = np.concatenate((priors[:2] + loc[:2] * 0.1 * priors_2p,
+                                      priors_2p * np.exp(loc[2:] * 0.2)) )
+                box[:2] -= box[2:] / 2
+                box[2:] += box[:2]
+
+                bboxlist.append([*box, score])
+
+        bboxlist = np.array(bboxlist)
+        if len(bboxlist) == 0:
+            bboxlist = np.zeros((1, 5))
+
+        bboxlist = bboxlist[self.refine_nms(bboxlist, 0.3), :]
+        bboxlist = [ x[:-1].astype(np.int) for x in bboxlist if x[-1] >= 0.5]
+        return bboxlist
+        
+    def refine_nms2(self, dets, thresh):
+        keep = list()
+        if len(dets) == 0:
+            return keep
+
+        x_1, y_1, x_2, y_2, scores = dets[:, 0], dets[:, 1], dets[:, 2], dets[:, 3], dets[:, 4]
+        areas = (x_2 - x_1 + 1) * (y_2 - y_1 + 1)
+        order = scores.argsort()[::-1]
+
+        keep = []
+        while order.size > 0:
+            i = order[0]
+            keep.append(i)
+            xx_1, yy_1 = np.maximum(x_1[i], x_1[order[1:]]), np.maximum(y_1[i], y_1[order[1:]])
+            xx_2, yy_2 = np.minimum(x_2[i], x_2[order[1:]]), np.minimum(y_2[i], y_2[order[1:]])
+
+            width, height = np.maximum(0.0, xx_2 - xx_1 + 1), np.maximum(0.0, yy_2 - yy_1 + 1)
+            ovr = width * height / (areas[i] + areas[order[1:]] - width * height)
+
+            inds = np.where(ovr <= thresh)[0]
+            order = order[inds + 1]
+        return keep
+        
+
+    def refine_nms(self, dets, thresh):
+        """Pure Python NMS baseline."""
+        x1 = dets[:, 0]
+        y1 = dets[:, 1]
+        x2 = dets[:, 2]
+        y2 = dets[:, 3]
+        scores = dets[:, 4]
+
+        areas = (x2 - x1 + 1) * (y2 - y1 + 1)
+        order = scores.argsort()[::-1]
+
+        keep = []
+        while order.size > 0:
+            i = order[0]
+            keep.append(i)
+            xx1 = np.maximum(x1[i], x1[order[1:]])
+            yy1 = np.maximum(y1[i], y1[order[1:]])
+            xx2 = np.minimum(x2[i], x2[order[1:]])
+            yy2 = np.minimum(y2[i], y2[order[1:]])
+
+            w = np.maximum(0.0, xx2 - xx1 + 1)
+            h = np.maximum(0.0, yy2 - yy1 + 1)
+            inter = w * h
+            ovr = inter / (areas[i] + areas[order[1:]] - inter)
+
+            inds = np.where(ovr <= thresh)[0]
+            order = order[inds + 1]
+
+        return keep
diff --git a/facelib/box_utils.py b/facelib/box_utils.py
new file mode 100644
index 0000000..daea71b
--- /dev/null
+++ b/facelib/box_utils.py
@@ -0,0 +1,328 @@
+import torch
+import numpy as np
+
+
+def point_form(boxes):
+    """ Convert prior_boxes to (xmin, ymin, xmax, ymax)
+    representation for comparison to point form ground truth data.
+    Args:
+        boxes: (tensor) center-size default boxes from priorbox layers.
+    Return:
+        boxes: (tensor) Converted xmin, ymin, xmax, ymax form of boxes.
+    """
+    return torch.cat((boxes[:, :2] - boxes[:, 2:]/2,     # xmin, ymin
+                     boxes[:, :2] + boxes[:, 2:]/2), 1)  # xmax, ymax
+
+
+def center_size(boxes):
+    """ Convert prior_boxes to (cx, cy, w, h)
+    representation for comparison to center-size form ground truth data.
+    Args:
+        boxes: (tensor) point_form boxes
+    Return:
+        boxes: (tensor) Converted xmin, ymin, xmax, ymax form of boxes.
+    """
+    return torch.cat((boxes[:, 2:] + boxes[:, :2])/2,  # cx, cy
+                     boxes[:, 2:] - boxes[:, :2], 1)  # w, h
+
+
+def intersect(box_a, box_b):
+    """ We resize both tensors to [A,B,2] without new malloc:
+    [A,2] -> [A,1,2] -> [A,B,2]
+    [B,2] -> [1,B,2] -> [A,B,2]
+    Then we compute the area of intersect between box_a and box_b.
+    Args:
+      box_a: (tensor) bounding boxes, Shape: [A,4].
+      box_b: (tensor) bounding boxes, Shape: [B,4].
+    Return:
+      (tensor) intersection area, Shape: [A,B].
+    """
+    A = box_a.size(0)
+    B = box_b.size(0)
+    max_xy = torch.min(box_a[:, 2:].unsqueeze(1).expand(A, B, 2),
+                       box_b[:, 2:].unsqueeze(0).expand(A, B, 2))
+    min_xy = torch.max(box_a[:, :2].unsqueeze(1).expand(A, B, 2),
+                       box_b[:, :2].unsqueeze(0).expand(A, B, 2))
+    inter = torch.clamp((max_xy - min_xy), min=0)
+    return inter[:, :, 0] * inter[:, :, 1]
+
+
+def jaccard(box_a, box_b):
+    """Compute the jaccard overlap of two sets of boxes.  The jaccard overlap
+    is simply the intersection over union of two boxes.  Here we operate on
+    ground truth boxes and default boxes.
+    E.g.:
+        A ∩ B / A ∪ B = A ∩ B / (area(A) + area(B) - A ∩ B)
+    Args:
+        box_a: (tensor) Ground truth bounding boxes, Shape: [num_objects,4]
+        box_b: (tensor) Prior boxes from priorbox layers, Shape: [num_priors,4]
+    Return:
+        jaccard overlap: (tensor) Shape: [box_a.size(0), box_b.size(0)]
+    """
+    inter = intersect(box_a, box_b)
+    area_a = ((box_a[:, 2]-box_a[:, 0]) *
+              (box_a[:, 3]-box_a[:, 1])).unsqueeze(1).expand_as(inter)  # [A,B]
+    area_b = ((box_b[:, 2]-box_b[:, 0]) *
+              (box_b[:, 3]-box_b[:, 1])).unsqueeze(0).expand_as(inter)  # [A,B]
+    union = area_a + area_b - inter
+    return inter / union  # [A,B]
+
+
+def matrix_iou(a, b):
+    """
+    return iou of a and b, numpy version for data augenmentation
+    """
+    lt = np.maximum(a[:, np.newaxis, :2], b[:, :2])
+    rb = np.minimum(a[:, np.newaxis, 2:], b[:, 2:])
+
+    area_i = np.prod(rb - lt, axis=2) * (lt < rb).all(axis=2)
+    area_a = np.prod(a[:, 2:] - a[:, :2], axis=1)
+    area_b = np.prod(b[:, 2:] - b[:, :2], axis=1)
+    return area_i / (area_a[:, np.newaxis] + area_b - area_i)
+
+
+def matrix_iof(a, b):
+    """
+    return iof of a and b, numpy version for data augenmentation
+    """
+    lt = np.maximum(a[:, np.newaxis, :2], b[:, :2])
+    rb = np.minimum(a[:, np.newaxis, 2:], b[:, 2:])
+
+    area_i = np.prod(rb - lt, axis=2) * (lt < rb).all(axis=2)
+    area_a = np.prod(a[:, 2:] - a[:, :2], axis=1)
+    return area_i / np.maximum(area_a[:, np.newaxis], 1)
+
+
+def match(threshold, truths, priors, variances, labels, landms, loc_t, conf_t, landm_t, idx):
+    """Match each prior box with the ground truth box of the highest jaccard
+    overlap, encode the bounding boxes, then return the matched indices
+    corresponding to both confidence and location preds.
+    Args:
+        threshold: (float) The overlap threshold used when mathing boxes.
+        truths: (tensor) Ground truth boxes, Shape: [num_obj, 4].
+        priors: (tensor) Prior boxes from priorbox layers, Shape: [n_priors,4].
+        variances: (tensor) Variances corresponding to each prior coord,
+            Shape: [num_priors, 4].
+        labels: (tensor) All the class labels for the image, Shape: [num_obj].
+        landms: (tensor) Ground truth landms, Shape [num_obj, 10].
+        loc_t: (tensor) Tensor to be filled w/ endcoded location targets.
+        conf_t: (tensor) Tensor to be filled w/ matched indices for conf preds.
+        landm_t: (tensor) Tensor to be filled w/ endcoded landm targets.
+        idx: (int) current batch index
+    Return:
+        The matched indices corresponding to 1)location 2)confidence 3)landm preds.
+    """
+    # jaccard index
+    overlaps = jaccard(
+        truths,
+        point_form(priors)
+    )
+    # (Bipartite Matching)
+    # [1,num_objects] best prior for each ground truth
+    best_prior_overlap, best_prior_idx = overlaps.max(1, keepdim=True)
+
+    # ignore hard gt
+    valid_gt_idx = best_prior_overlap[:, 0] >= 0.2
+    best_prior_idx_filter = best_prior_idx[valid_gt_idx, :]
+    if best_prior_idx_filter.shape[0] <= 0:
+        loc_t[idx] = 0
+        conf_t[idx] = 0
+        return
+
+    # [1,num_priors] best ground truth for each prior
+    best_truth_overlap, best_truth_idx = overlaps.max(0, keepdim=True)
+    best_truth_idx.squeeze_(0)
+    best_truth_overlap.squeeze_(0)
+    best_prior_idx.squeeze_(1)
+    best_prior_idx_filter.squeeze_(1)
+    best_prior_overlap.squeeze_(1)
+    best_truth_overlap.index_fill_(0, best_prior_idx_filter, 2)  # ensure best prior
+    # TODO refactor: index  best_prior_idx with long tensor
+    # ensure every gt matches with its prior of max overlap
+    for j in range(best_prior_idx.size(0)):     # 判别此anchor是预测哪一个boxes
+        best_truth_idx[best_prior_idx[j]] = j
+    matches = truths[best_truth_idx]            # Shape: [num_priors,4] 此处为每一个anchor对应的bbox取出来
+    conf = labels[best_truth_idx]               # Shape: [num_priors]      此处为每一个anchor对应的label取出来
+    conf[best_truth_overlap < threshold] = 0    # label as background   overlap<0.35的全部作为负样本
+    loc = encode(matches, priors, variances)
+
+    matches_landm = landms[best_truth_idx]
+    landm = encode_landm(matches_landm, priors, variances)
+    loc_t[idx] = loc    # [num_priors,4] encoded offsets to learn
+    conf_t[idx] = conf  # [num_priors] top class label for each prior
+    landm_t[idx] = landm
+
+
+def encode(matched, priors, variances):
+    """Encode the variances from the priorbox layers into the ground truth boxes
+    we have matched (based on jaccard overlap) with the prior boxes.
+    Args:
+        matched: (tensor) Coords of ground truth for each prior in point-form
+            Shape: [num_priors, 4].
+        priors: (tensor) Prior boxes in center-offset form
+            Shape: [num_priors,4].
+        variances: (list[float]) Variances of priorboxes
+    Return:
+        encoded boxes (tensor), Shape: [num_priors, 4]
+    """
+
+    # dist b/t match center and prior's center
+    g_cxcy = (matched[:, :2] + matched[:, 2:])/2 - priors[:, :2]
+    # encode variance
+    g_cxcy /= (variances[0] * priors[:, 2:])
+    # match wh / prior wh
+    g_wh = (matched[:, 2:] - matched[:, :2]) / priors[:, 2:]
+    g_wh = torch.log(g_wh) / variances[1]
+    # return target for smooth_l1_loss
+    return torch.cat([g_cxcy, g_wh], 1)  # [num_priors,4]
+
+def encode_landm(matched, priors, variances):
+    """Encode the variances from the priorbox layers into the ground truth boxes
+    we have matched (based on jaccard overlap) with the prior boxes.
+    Args:
+        matched: (tensor) Coords of ground truth for each prior in point-form
+            Shape: [num_priors, 10].
+        priors: (tensor) Prior boxes in center-offset form
+            Shape: [num_priors,4].
+        variances: (list[float]) Variances of priorboxes
+    Return:
+        encoded landm (tensor), Shape: [num_priors, 10]
+    """
+
+    # dist b/t match center and prior's center
+    matched = torch.reshape(matched, (matched.size(0), 5, 2))
+    priors_cx = priors[:, 0].unsqueeze(1).expand(matched.size(0), 5).unsqueeze(2)
+    priors_cy = priors[:, 1].unsqueeze(1).expand(matched.size(0), 5).unsqueeze(2)
+    priors_w = priors[:, 2].unsqueeze(1).expand(matched.size(0), 5).unsqueeze(2)
+    priors_h = priors[:, 3].unsqueeze(1).expand(matched.size(0), 5).unsqueeze(2)
+    priors = torch.cat([priors_cx, priors_cy, priors_w, priors_h], dim=2)
+    g_cxcy = matched[:, :, :2] - priors[:, :, :2]
+    # encode variance
+    g_cxcy /= (variances[0] * priors[:, :, 2:])
+    # g_cxcy /= priors[:, :, 2:]
+    g_cxcy = g_cxcy.reshape(g_cxcy.size(0), -1)
+    # return target for smooth_l1_loss
+    return g_cxcy
+
+
+# Adapted from https://github.com/Hakuyume/chainer-ssd
+def decode(loc, priors, variances):
+    """Decode locations from predictions using priors to undo
+    the encoding we did for offset regression at train time.
+    Args:
+        loc (tensor): location predictions for loc layers,
+            Shape: [num_priors,4]
+        priors (tensor): Prior boxes in center-offset form.
+            Shape: [num_priors,4].
+        variances: (list[float]) Variances of priorboxes
+    Return:
+        decoded bounding box predictions
+    """
+
+    boxes = torch.cat((
+        priors[:, :2] + loc[:, :2] * variances[0] * priors[:, 2:],
+        priors[:, 2:] * torch.exp(loc[:, 2:] * variances[1])), 1)
+    boxes[:, :2] -= boxes[:, 2:] / 2
+    boxes[:, 2:] += boxes[:, :2]
+    return boxes
+
+def decode_landm(pre, priors, variances):
+    """Decode landm from predictions using priors to undo
+    the encoding we did for offset regression at train time.
+    Args:
+        pre (tensor): landm predictions for loc layers,
+            Shape: [num_priors,10]
+        priors (tensor): Prior boxes in center-offset form.
+            Shape: [num_priors,4].
+        variances: (list[float]) Variances of priorboxes
+    Return:
+        decoded landm predictions
+    """
+    landms = torch.cat((priors[:, :2] + pre[:, :2] * variances[0] * priors[:, 2:],
+                        priors[:, :2] + pre[:, 2:4] * variances[0] * priors[:, 2:],
+                        priors[:, :2] + pre[:, 4:6] * variances[0] * priors[:, 2:],
+                        priors[:, :2] + pre[:, 6:8] * variances[0] * priors[:, 2:],
+                        priors[:, :2] + pre[:, 8:10] * variances[0] * priors[:, 2:],
+                        ), dim=1)
+    return landms
+
+
+def log_sum_exp(x):
+    """Utility function for computing log_sum_exp while determining
+    This will be used to determine unaveraged confidence loss across
+    all examples in a batch.
+    Args:
+        x (Variable(tensor)): conf_preds from conf layers
+    """
+    x_max = x.data.max()
+    return torch.log(torch.sum(torch.exp(x-x_max), 1, keepdim=True)) + x_max
+
+
+# Original author: Francisco Massa:
+# https://github.com/fmassa/object-detection.torch
+# Ported to PyTorch by Max deGroot (02/01/2017)
+def nms(boxes, scores, overlap=0.5, top_k=200):
+    """Apply non-maximum suppression at test time to avoid detecting too many
+    overlapping bounding boxes for a given object.
+    Args:
+        boxes: (tensor) The location preds for the img, Shape: [num_priors,4].
+        scores: (tensor) The class predscores for the img, Shape:[num_priors].
+        overlap: (float) The overlap thresh for suppressing unnecessary boxes.
+        top_k: (int) The Maximum number of box preds to consider.
+    Return:
+        The indices of the kept boxes with respect to num_priors.
+    """
+
+    keep = torch.Tensor(scores.size(0)).fill_(0).long()
+    if boxes.numel() == 0:
+        return keep
+    x1 = boxes[:, 0]
+    y1 = boxes[:, 1]
+    x2 = boxes[:, 2]
+    y2 = boxes[:, 3]
+    area = torch.mul(x2 - x1, y2 - y1)
+    v, idx = scores.sort(0)  # sort in ascending order
+    # I = I[v >= 0.01]
+    idx = idx[-top_k:]  # indices of the top-k largest vals
+    xx1 = boxes.new()
+    yy1 = boxes.new()
+    xx2 = boxes.new()
+    yy2 = boxes.new()
+    w = boxes.new()
+    h = boxes.new()
+
+    # keep = torch.Tensor()
+    count = 0
+    while idx.numel() > 0:
+        i = idx[-1]  # index of current largest val
+        # keep.append(i)
+        keep[count] = i
+        count += 1
+        if idx.size(0) == 1:
+            break
+        idx = idx[:-1]  # remove kept element from view
+        # load bboxes of next highest vals
+        torch.index_select(x1, 0, idx, out=xx1)
+        torch.index_select(y1, 0, idx, out=yy1)
+        torch.index_select(x2, 0, idx, out=xx2)
+        torch.index_select(y2, 0, idx, out=yy2)
+        # store element-wise max with next highest score
+        xx1 = torch.clamp(xx1, min=x1[i])
+        yy1 = torch.clamp(yy1, min=y1[i])
+        xx2 = torch.clamp(xx2, max=x2[i])
+        yy2 = torch.clamp(yy2, max=y2[i])
+        w.resize_as_(xx2)
+        h.resize_as_(yy2)
+        w = xx2 - xx1
+        h = yy2 - yy1
+        # check sizes of xx1 and xx2.. after each iteration
+        w = torch.clamp(w, min=0.0)
+        h = torch.clamp(h, min=0.0)
+        inter = w*h
+        # IoU = i / (area(a) + area(b) - i)
+        rem_areas = torch.index_select(area, 0, idx)  # load remaining areas)
+        union = (rem_areas - inter) + area[i]
+        IoU = inter/union  # store result in iou
+        # keep only elements with an IoU <= overlap
+        idx = idx[IoU.le(overlap)]
+    return keep, count
\ No newline at end of file
diff --git a/facelib/coord_conv.py b/facelib/coord_conv.py
new file mode 100644
index 0000000..f5c9400
--- /dev/null
+++ b/facelib/coord_conv.py
@@ -0,0 +1,153 @@
+import torch
+import torch.nn as nn
+
+
+class AddCoordsTh(nn.Module):
+    def __init__(self, x_dim=64, y_dim=64, with_r=False, with_boundary=False):
+        super(AddCoordsTh, self).__init__()
+        self.x_dim = x_dim
+        self.y_dim = y_dim
+        self.with_r = with_r
+        self.with_boundary = with_boundary
+
+    def forward(self, input_tensor, heatmap=None):
+        """
+        input_tensor: (batch, c, x_dim, y_dim)
+        """
+        batch_size_tensor = input_tensor.shape[0]
+
+        xx_ones = torch.ones([1, self.y_dim], dtype=torch.int32)#.cuda()
+        xx_ones = xx_ones.unsqueeze(-1)
+
+        xx_range = torch.arange(self.x_dim, dtype=torch.int32).unsqueeze(0)#.cuda()
+        xx_range = xx_range.unsqueeze(1)
+
+        xx_channel = torch.matmul(xx_ones.float(), xx_range.float())
+        xx_channel = xx_channel.unsqueeze(-1)
+
+
+        yy_ones = torch.ones([1, self.x_dim], dtype=torch.int32)#.cuda()
+        yy_ones = yy_ones.unsqueeze(1)
+
+        yy_range = torch.arange(self.y_dim, dtype=torch.int32).unsqueeze(0)#.cuda()
+        yy_range = yy_range.unsqueeze(-1)
+
+        yy_channel = torch.matmul(yy_range.float(), yy_ones.float())
+        yy_channel = yy_channel.unsqueeze(-1)
+
+        xx_channel = xx_channel.permute(0, 3, 2, 1)
+        yy_channel = yy_channel.permute(0, 3, 2, 1)
+
+        xx_channel = xx_channel / (self.x_dim - 1)
+        yy_channel = yy_channel / (self.y_dim - 1)
+
+        xx_channel = xx_channel * 2 - 1
+        yy_channel = yy_channel * 2 - 1
+
+        xx_channel = xx_channel.repeat(batch_size_tensor, 1, 1, 1)
+        yy_channel = yy_channel.repeat(batch_size_tensor, 1, 1, 1)
+
+        if self.with_boundary and type(heatmap) != type(None):
+            boundary_channel = torch.clamp(heatmap[:, -1:, :, :],
+                                        0.0, 1.0)
+
+            zero_tensor = torch.zeros_like(xx_channel)
+            xx_boundary_channel = torch.where(boundary_channel>0.05,
+                                              xx_channel, zero_tensor)
+            yy_boundary_channel = torch.where(boundary_channel>0.05,
+                                              yy_channel, zero_tensor)
+        if self.with_boundary and type(heatmap) != type(None):
+            xx_boundary_channel = xx_boundary_channel#.cuda()
+            yy_boundary_channel = yy_boundary_channel#.cuda()
+        ret = torch.cat([input_tensor, xx_channel, yy_channel], dim=1)
+
+
+        if self.with_r:
+            rr = torch.sqrt(torch.pow(xx_channel, 2) + torch.pow(yy_channel, 2))
+            rr = rr / torch.max(rr)
+            ret = torch.cat([ret, rr], dim=1)
+
+        if self.with_boundary and type(heatmap) != type(None):
+            ret = torch.cat([ret, xx_boundary_channel,
+                             yy_boundary_channel], dim=1)
+        return ret
+
+
+class CoordConvTh(nn.Module):
+    """CoordConv layer as in the paper."""
+    def __init__(self, x_dim, y_dim, with_r, with_boundary,
+                 in_channels, first_one=False, *args, **kwargs):
+        super(CoordConvTh, self).__init__()
+        self.addcoords = AddCoordsTh(x_dim=x_dim, y_dim=y_dim, with_r=with_r,
+                                    with_boundary=with_boundary)
+        in_channels += 2
+        if with_r:
+            in_channels += 1
+        if with_boundary and not first_one:
+            in_channels += 2
+        self.conv = nn.Conv2d(in_channels=in_channels, *args, **kwargs)
+
+    def forward(self, input_tensor, heatmap=None):
+        ret = self.addcoords(input_tensor, heatmap)
+        last_channel = ret[:, -2:, :, :]
+        ret = self.conv(ret)
+        return ret, last_channel
+
+
+'''
+An alternative implementation for PyTorch with auto-infering the x-y dimensions.
+'''
+class AddCoords(nn.Module):
+
+    def __init__(self, with_r=False):
+        super().__init__()
+        self.with_r = with_r
+
+    def forward(self, input_tensor):
+        """
+        Args:
+            input_tensor: shape(batch, channel, x_dim, y_dim)
+        """
+        batch_size, _, x_dim, y_dim = input_tensor.size()
+
+        xx_channel = torch.arange(x_dim).repeat(1, y_dim, 1)
+        yy_channel = torch.arange(y_dim).repeat(1, x_dim, 1).transpose(1, 2)
+
+        xx_channel = xx_channel / (x_dim - 1)
+        yy_channel = yy_channel / (y_dim - 1)
+
+        xx_channel = xx_channel * 2 - 1
+        yy_channel = yy_channel * 2 - 1
+
+        xx_channel = xx_channel.repeat(batch_size, 1, 1, 1).transpose(2, 3)
+        yy_channel = yy_channel.repeat(batch_size, 1, 1, 1).transpose(2, 3)
+
+        if input_tensor.is_cuda:
+            xx_channel = xx_channel#.cuda()
+            yy_channel = yy_channel#.cuda()
+
+        ret = torch.cat([
+            input_tensor,
+            xx_channel.type_as(input_tensor),
+            yy_channel.type_as(input_tensor)], dim=1)
+
+        if self.with_r:
+            rr = torch.sqrt(torch.pow(xx_channel - 0.5, 2) + torch.pow(yy_channel - 0.5, 2))
+            if input_tensor.is_cuda:
+                rr = rr#.cuda()
+            ret = torch.cat([ret, rr], dim=1)
+
+        return ret
+
+
+class CoordConv(nn.Module):
+
+    def __init__(self, in_channels, out_channels, with_r=False, **kwargs):
+        super().__init__()
+        self.addcoords = AddCoords(with_r=with_r)
+        self.conv = nn.Conv2d(in_channels + 2, out_channels, **kwargs)
+
+    def forward(self, x):
+        ret = self.addcoords(x)
+        ret = self.conv(ret)
+        return ret
\ No newline at end of file
diff --git a/facelib/prior_box.py b/facelib/prior_box.py
new file mode 100644
index 0000000..e20e443
--- /dev/null
+++ b/facelib/prior_box.py
@@ -0,0 +1,34 @@
+import torch
+from itertools import product as product
+import numpy as np
+from math import ceil
+
+
+class PriorBox(object):
+    def __init__(self, cfg, image_size=None, phase='test'):
+        super(PriorBox, self).__init__()
+        self.min_sizes = cfg['min_sizes']
+        self.steps = cfg['steps']
+        self.clip = cfg['clip']
+        self.image_size = image_size
+        self.feature_maps = [[ceil(self.image_size[0]/step), ceil(self.image_size[1]/step)] for step in self.steps]
+        self.name = "s"
+
+    def forward(self):
+        anchors = []
+        for k, f in enumerate(self.feature_maps):
+            min_sizes = self.min_sizes[k]
+            for i, j in product(range(f[0]), range(f[1])):
+                for min_size in min_sizes:
+                    s_kx = min_size / self.image_size[1]
+                    s_ky = min_size / self.image_size[0]
+                    dense_cx = [x * self.steps[k] / self.image_size[1] for x in [j + 0.5]]
+                    dense_cy = [y * self.steps[k] / self.image_size[0] for y in [i + 0.5]]
+                    for cy, cx in product(dense_cy, dense_cx):
+                        anchors += [cx, cy, s_kx, s_ky]
+
+        # back to torch land
+        output = torch.Tensor(anchors).view(-1, 4)
+        if self.clip:
+            output.clamp_(max=1, min=0)
+        return output
\ No newline at end of file