Separate triplet loss from model

4 files changed, 71 insertions, 29 deletions

diff --git a/models/auto_encoder.py b/models/auto_encoder.py
index 2d715db..1ef7494 100644
--- a/models/auto_encoder.py
+++ b/models/auto_encoder.py
@@ -171,7 +171,7 @@ class AutoEncoder(nn.Module):
 
             return (
                 (f_a_c1_t2_, f_c_c1_t2_, f_p_c1_t2_),
-                (xrecon_loss, cano_cons_loss, pose_sim_loss * 10)
+                torch.stack((xrecon_loss, cano_cons_loss, pose_sim_loss * 10))
             )
         else:  # evaluating
             return f_c_c1_t2_, f_p_c1_t2_
diff --git a/models/model.py b/models/model.py
index 82d6461..5aa6436 100644
--- a/models/model.py
+++ b/models/model.py
@@ -18,6 +18,7 @@ from utils.configuration import DataloaderConfiguration, \
     SystemConfiguration
 from utils.dataset import CASIAB, ClipConditions, ClipViews, ClipClasses
 from utils.sampler import TripletSampler
+from utils.triplet_loss import JointBatchAllTripletLoss
 
 
 class Model:
@@ -67,6 +68,7 @@ class Model:
         self._dataset_sig: str = 'undefined'
 
         self.rgb_pn: Optional[RGBPartNet] = None
+        self.ba_triplet_loss: Optional[JointBatchAllTripletLoss] = None
         self.optimizer: Optional[optim.Adam] = None
         self.scheduler: Optional[optim.lr_scheduler.StepLR] = None
         self.writer: Optional[SummaryWriter] = None
@@ -140,7 +142,8 @@ class Model:
         dataset = self._parse_dataset_config(dataset_config)
         dataloader = self._parse_dataloader_config(dataset, dataloader_config)
         # Prepare for model, optimizer and scheduler
-        model_hp = self.hp.get('model', {})
+        model_hp: dict = self.hp.get('model', {}).copy()
+        triplet_margins = model_hp.pop('triplet_margins', (0.2, 0.2))
         optim_hp: dict = self.hp.get('optimizer', {}).copy()
         start_iter = optim_hp.pop('start_iter', 0)
         ae_optim_hp = optim_hp.pop('auto_encoder', {})
@@ -150,6 +153,9 @@ class Model:
         sched_hp = self.hp.get('scheduler', {})
         self.rgb_pn = RGBPartNet(self.in_channels, self.in_size, **model_hp,
                                  image_log_on=self.image_log_on)
+        self.ba_triplet_loss = JointBatchAllTripletLoss(
+            self.rgb_pn.hpm_num_parts, triplet_margins
+        )
         # Try to accelerate computation using CUDA or others
         self.rgb_pn = self.rgb_pn.to(self.device)
         self.optimizer = optim.Adam([
@@ -193,10 +199,18 @@ class Model:
             # forward + backward + optimize
             x_c1 = batch_c1['clip'].to(self.device)
             x_c2 = batch_c2['clip'].to(self.device)
+            feature, ae_losses, images = self.rgb_pn(x_c1, x_c2)
             y = batch_c1['label'].to(self.device)
             # Duplicate labels for each part
-            y = y.unsqueeze(1).repeat(1, self.rgb_pn.num_total_parts)
-            losses, images = self.rgb_pn(x_c1, x_c2, y)
+            y = y.repeat(self.rgb_pn.num_total_parts, 1)
+            triplet_loss = self.ba_triplet_loss(feature, y)
+            losses = torch.cat((
+                ae_losses,
+                torch.stack((
+                    triplet_loss[:self.rgb_pn.hpm_num_parts].mean(),
+                    triplet_loss[self.rgb_pn.hpm_num_parts:].mean()
+                ))
+            ))
             loss = losses.sum()
             loss.backward()
             self.optimizer.step()
diff --git a/models/rgb_part_net.py b/models/rgb_part_net.py
index 67acac3..408bca0 100644
--- a/models/rgb_part_net.py
+++ b/models/rgb_part_net.py
@@ -4,7 +4,6 @@ import torch.nn as nn
 from models.auto_encoder import AutoEncoder
 from models.hpm import HorizontalPyramidMatching
 from models.part_net import PartNet
-from utils.triplet_loss import BatchAllTripletLoss
 
 
 class RGBPartNet(nn.Module):
@@ -25,7 +24,6 @@ class RGBPartNet(nn.Module):
             tfa_squeeze_ratio: int = 4,
             tfa_num_parts: int = 16,
             embedding_dims: int = 256,
-            triplet_margins: tuple[float, float] = (0.2, 0.2),
             image_log_on: bool = False
     ):
         super().__init__()
@@ -50,17 +48,13 @@ class RGBPartNet(nn.Module):
                                out_channels, embedding_dims)
         self.fc_mat = nn.Parameter(empty_fc)
 
-        (hpm_margin, pn_margin) = triplet_margins
-        self.hpm_ba_trip = BatchAllTripletLoss(hpm_margin)
-        self.pn_ba_trip = BatchAllTripletLoss(pn_margin)
-
     def fc(self, x):
         return x @ self.fc_mat
 
-    def forward(self, x_c1, x_c2=None, y=None):
+    def forward(self, x_c1, x_c2=None):
         # Step 1: Disentanglement
         # n, t, c, h, w
-        ((x_c, x_p), losses, images) = self._disentangle(x_c1, x_c2)
+        ((x_c, x_p), ae_losses, images) = self._disentangle(x_c1, x_c2)
 
         # Step 2.a: Static Gait Feature Aggregation & HPM
         # n, c, h, w
@@ -77,15 +71,7 @@ class RGBPartNet(nn.Module):
         x = self.fc(x)
 
         if self.training:
-            y = y.T
-            hpm_ba_trip = self.hpm_ba_trip(
-                x[:self.hpm_num_parts], y[:self.hpm_num_parts]
-            )
-            pn_ba_trip = self.pn_ba_trip(
-                x[self.hpm_num_parts:], y[self.hpm_num_parts:]
-            )
-            losses = torch.stack((*losses, hpm_ba_trip, pn_ba_trip))
-            return losses, images
+            return x, ae_losses, images
         else:
             return x.unsqueeze(1).view(-1)
 
diff --git a/utils/triplet_loss.py b/utils/triplet_loss.py
index 954def2..0df2188 100644
--- a/utils/triplet_loss.py
+++ b/utils/triplet_loss.py
@@ -11,6 +11,25 @@ class BatchAllTripletLoss(nn.Module):
     def forward(self, x, y):
         p, n, c = x.size()
 
+        dist = self._batch_distance(x)
+        positive_negative_dist = self._hard_distance(dist, y, p, n)
+        all_loss = F.relu(self.margin + positive_negative_dist).view(p, -1)
+        parted_loss_mean = self._none_zero_parted_mean(all_loss)
+
+        return parted_loss_mean
+
+    @staticmethod
+    def _hard_distance(dist, y, p, n):
+        hard_positive_mask = y.unsqueeze(1) == y.unsqueeze(2)
+        hard_negative_mask = y.unsqueeze(1) != y.unsqueeze(2)
+        all_hard_positive = dist[hard_positive_mask].view(p, n, -1, 1)
+        all_hard_negative = dist[hard_negative_mask].view(p, n, 1, -1)
+        positive_negative_dist = all_hard_positive - all_hard_negative
+
+        return positive_negative_dist
+
+    @staticmethod
+    def _batch_distance(x):
         # Euclidean distance p x n x n
         x_squared_sum = torch.sum(x ** 2, dim=2)
         x1_squared_sum = x_squared_sum.unsqueeze(2)
@@ -20,17 +39,40 @@ class BatchAllTripletLoss(nn.Module):
             F.relu(x1_squared_sum - 2 * x1_times_x2_sum + x2_squared_sum)
         )
 
-        hard_positive_mask = y.unsqueeze(1) == y.unsqueeze(2)
-        hard_negative_mask = y.unsqueeze(1) != y.unsqueeze(2)
-        all_hard_positive = dist[hard_positive_mask].view(p, n, -1, 1)
-        all_hard_negative = dist[hard_negative_mask].view(p, n, 1, -1)
-        positive_negative_dist = all_hard_positive - all_hard_negative
-        all_loss = F.relu(self.margin + positive_negative_dist).view(p, -1)
+        return dist
 
+    @staticmethod
+    def _none_zero_parted_mean(all_loss):
         # Non-zero parted mean
         non_zero_counts = (all_loss != 0).sum(1)
         parted_loss_mean = all_loss.sum(1) / non_zero_counts
         parted_loss_mean[non_zero_counts == 0] = 0
 
-        loss = parted_loss_mean.mean()
-        return loss
+        return parted_loss_mean
+
+
+class JointBatchAllTripletLoss(BatchAllTripletLoss):
+    def __init__(
+            self,
+            hpm_num_parts: int,
+            margins: tuple[float, float] = (0.2, 0.2)
+    ):
+        super().__init__()
+        self.hpm_num_parts = hpm_num_parts
+        self.margin_hpm, self.margin_pn = margins
+
+    def forward(self, x, y):
+        p, n, c = x.size()
+
+        dist = self._batch_distance(x)
+        positive_negative_dist = self._hard_distance(dist, y, p, n)
+        hpm_part_loss = F.relu(
+            self.margin_hpm + positive_negative_dist[:self.hpm_num_parts]
+        ).view(self.hpm_num_parts, -1)
+        pn_part_loss = F.relu(
+            self.margin_pn + positive_negative_dist[self.hpm_num_parts:]
+        ).view(p - self.hpm_num_parts, -1)
+        all_loss = torch.cat((hpm_part_loss, pn_part_loss)).view(p, -1)
+        parted_loss_mean = self._none_zero_parted_mean(all_loss)
+
+        return parted_loss_mean