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import torch
import torch.nn as nn
from .layers import Decoder
from .layers_v2 import Decoder_v2
import torch.nn.functional as F
from bert.modeling_bert import BertModel
def dice_loss(inputs, targets):
"""
Compute the DICE loss, similar to generalized IOU for masks
Args:
inputs: A float tensor of arbitrary shape.
The predictions for each example.
targets: A float tensor with the same shape as inputs. Stores the binary
classification label for each element in inputs
(0 for the negative class and 1 for the positive class).
"""
inputs = inputs.sigmoid()
inputs = inputs.flatten(1)
targets = targets.flatten(1)
numerator = 2 * (inputs * targets).sum(1)
denominator = inputs.sum(-1) + targets.sum(-1)
loss = 1 - (numerator + 1) / (denominator + 1)
return loss.mean()
def sigmoid_focal_loss(inputs, targets, alpha: float = 0.25, gamma: float = 2):
"""
Loss used in RetinaNet for dense detection: https://arxiv.org/abs/1708.02002.
Args:
inputs: A float tensor of arbitrary shape.
The predictions for each example.
targets: A float tensor with the same shape as inputs. Stores the binary
classification label for each element in inputs
(0 for the negative class and 1 for the positive class).
alpha: (optional) Weighting factor in range (0,1) to balance
positive vs negative examples. Default = -1 (no weighting).
gamma: Exponent of the modulating factor (1 - p_t) to
balance easy vs hard examples.
Returns:
Loss tensor
"""
prob = inputs.sigmoid()
ce_loss = F.binary_cross_entropy_with_logits(inputs, targets, reduction="none")
p_t = prob * targets + (1 - prob) * (1 - targets)
loss = ce_loss * ((1 - p_t) ** gamma)
if alpha >= 0:
alpha_t = alpha * targets + (1 - alpha) * (1 - targets)
loss = alpha_t * loss
return loss.mean()
class CGFormer_sbert(nn.Module):
def __init__(self, backbone, args):
super(CGFormer_sbert, self).__init__()
self.backbone = backbone
self.mixup_lasttwo = args.mixup_lasttwo
if self.mixup_lasttwo :
self.decoder = Decoder_v2(args)
else :
self.decoder = Decoder(args)
self.text_encoder = BertModel.from_pretrained(args.bert)
self.text_encoder.pooler = None
self.args = args
self.filter_th = args.filter_threshold
# image, text, l_mask, target, hardpos, hp_emb
def forward(self, x, text, l_mask, mask=None, hp_bert_embs=None):
verb_masks, cl_masks = [], []
rows_to_filter, cols_to_filter = None, None
if self.training:
for i in range(len(hp_bert_embs)): # if hp exists in current idx
if ~torch.all(hp_bert_embs[i] == 0) :
verb_masks.extend([1, 1])
cl_masks.extend([1, 0]) # orig, hp
else:
verb_masks.extend([0])
cl_masks.extend([1])
# filtering with hp_mask
if hp_bert_embs.numel() > 0 and self.filter_th:
hp_mask = ~torch.all(hp_bert_embs == 0, dim=1)
hp_bert_embs = hp_bert_embs[hp_mask]
norms = torch.norm(hp_bert_embs, dim=-1, keepdim=True)
normed_embs = hp_bert_embs / norms
cosime_sim = torch.mm(normed_embs, normed_embs.T)
rows_to_filter, cols_to_filter = torch.where(cosime_sim > self.filter_th)
else:
verb_masks = [0] * len(text)
cl_masks = [1] * len(text)
verb_masks = torch.tensor(verb_masks, dtype=torch.bool).to(x.device)
cl_masks = torch.tensor(cl_masks, dtype=torch.bool).to(x.device)
# print("inside the model")
# print("x : ", x.shape)
# print("text : ", text.shape)
# print("l_mask : ", l_mask.shape)
# print("mask : ", mask.shape)
# print("hp_bert_embs : ", hp_bert_embs.shape)
# print("verb_masks : ", verb_masks)
# print("cl_masks : ", cl_masks)
input_shape = x.shape[-2:]
l_feats = self.text_encoder(text, attention_mask=l_mask)[0] # (6, 10, 768)
l_feats = l_feats.permute(0, 2, 1) # (B, 768, N_l) to make Conv1d happy
l_mask = l_mask.unsqueeze(dim=-1) # (batch, N_l, 1)
##########################
features = self.backbone(x, l_feats, l_mask)
x_c1, x_c2, x_c3, x_c4 = features
if self.mixup_lasttwo :
pred, maps, fq_fuse = self.decoder([x_c4, x_c3, x_c2, x_c1], l_feats, l_mask)
metric_tensor = F.adaptive_avg_pool2d(fq_fuse, (1, 1)).view(fq_fuse.shape[0], fq_fuse.shape[1])
# print(fq_fuse.shape, metric_tensor.shape)
else :
pred, maps = self.decoder([x_c4, x_c3, x_c2, x_c1], l_feats, l_mask)
metric_tensor = F.adaptive_avg_pool2d(x_c4, (1, 1)).view(x_c4.size(0), -1)
pred = F.interpolate(pred, input_shape, mode='bilinear', align_corners=True)
# loss
if self.training:
loss = 0.
mask = mask.unsqueeze(1).float()
for m, lam in zip(maps, [0.001,0.01,0.1]):
m = m[:,1].unsqueeze(1)
if m.shape[-2:] != mask.shape[-2:]:
mask_ = F.interpolate(mask, m.shape[-2:], mode='nearest').detach()
# loss += dice_loss(m, mask_, cl_masks) * lam
loss += dice_loss(m[cl_masks], mask_[cl_masks]) * lam
loss += dice_loss(pred[cl_masks], mask[cl_masks]) + sigmoid_focal_loss(pred[cl_masks], mask[cl_masks], alpha=-1, gamma=0)
metric_loss = 0.
if hp_bert_embs.numel() > 0:
metric_loss = self.compute_metric_loss(metric_tensor, verb_masks, rows_to_filter, cols_to_filter, self.args)
loss += metric_loss * self.args.metric_loss_weight
return pred.detach(), mask, loss
else:
return pred.detach(), maps
def compute_metric_loss(self, metric_tensor, positive_verbs, rows_to_filter, cols_to_filter, args) :
if args.loss_option == "ACL_verbonly" :
raise ValueError("ACL_verbonly is not supported in CGFormer")
elif args.loss_option == "ACE_verbonly" :
metric_loss = self.UniAngularLogitContrastLoss(metric_tensor, positive_verbs, rows_to_filter, cols_to_filter, m=args.margin_value, tau=args.temperature, verbonly=True, args=args)
return metric_loss
def return_mask(self, emb_distance, verb_mask=None, rows_to_filter=None, cols_to_filter=None):
B_, B_ = emb_distance.shape
positive_mask = torch.zeros_like(emb_distance)
positive_mask.fill_diagonal_(1) # Set diagonal elements to 1 for all cases
if B_ < len(verb_mask):
# If B_ equals to 2*K (double the number of verb phrase)
for i in range(B_ // 2):
positive_mask[2 * i, 2 * i + 1] = 1
positive_mask[2 * i + 1, 2 * i] = 1
else:
# Process the case where we have a mix of sentences with and without verbs
i = 0
while i < B_:
if verb_mask[i] == 1:
positive_mask[i, i + 1] = 1
positive_mask[i + 1, i] = 1
i += 2
else:
i += 1
negative_mask = torch.ones_like(emb_distance) - positive_mask
negative_mask = negative_mask.clone()
if rows_to_filter is not None and cols_to_filter is not None :
for row, col in zip(rows_to_filter, cols_to_filter):
negative_mask[row * 2, col * 2] = 0
negative_mask[row * 2, col * 2 + 1] = 0
negative_mask[row * 2 + 1, col * 2] = 0
negative_mask[row * 2 + 1, col * 2 + 1] = 0
return positive_mask, negative_mask
def UniAngularLogitContrastLoss(self, total_fq, verb_mask, rows_to_filter, cols_to_filter, alpha=0.5, verbonly=True, m=0.5, tau=0.05, args=None):
_, HW = total_fq.shape
if verbonly :
emb = total_fq[verb_mask]
assert emb.shape[0] % 2 == 0, f"Embedding count {emb.shape[0]} is not divisible by 2."
else :
emb = torch.mean(total_fq, dim=-1)
B_ = emb.shape[0]
emb_i = emb.unsqueeze(1).repeat(1, B_, 1) # (B_, B_, C)
emb_j = emb.unsqueeze(0).repeat(B_, 1, 1) # (B_, B_, C)
sim = nn.CosineSimilarity(dim=-1, eps=1e-6)
sim_matrix = sim(emb_i, emb_j).reshape(B_, B_) # (B_, B_)
sim_matrix = torch.clamp(sim_matrix, min=-0.999, max=0.999)
# print("sim matrix : ", sim_matrix)
margin_in_radians = m / 57.2958 # Convert degrees to radians
# print("sim_matrix : ", sim_matrix)
theta_matrix = (torch.pi / 2) - torch.acos(sim_matrix)
# print("theta_matrix : ", theta_matrix)
positive_mask, negative_mask = self.return_mask(sim_matrix, verb_mask, rows_to_filter, cols_to_filter)
# print("? `positive_mask` requires_grad:", positive_mask.requires_grad, positive_mask.device)
# print("? `negative_mask` requires_grad:", negative_mask.requires_grad, negative_mask.device)
# print("positive_mask : ", positive_mask)
# print("negative_mask : ", negative_mask)
# print("? `positive_mask` requires_grad:", positive_mask.requires_grad,
# "device:", positive_mask.device, "dtype:", positive_mask.dtype)
# print("? `negative_mask` requires_grad:", negative_mask.requires_grad,
# "device:", negative_mask.device, "dtype:", negative_mask.dtype)
theta_with_margin = theta_matrix.clone()
theta_with_margin[positive_mask.bool()] -= margin_in_radians
logits = theta_with_margin / tau # Scale with temperature
exp_logits = torch.exp(logits)
pos_exp_logits = exp_logits * positive_mask
pos_exp_logits = pos_exp_logits.sum(dim=-1)
neg_exp_logits = exp_logits * negative_mask
neg_exp_logits = neg_exp_logits.sum(dim=-1)
total_exp_logits = pos_exp_logits + neg_exp_logits
positive_loss = -torch.log(pos_exp_logits/ total_exp_logits)
angular_loss = positive_loss.mean()
# print("angular_loss : ", angular_loss)
return angular_loss |