from detection.sfd import sfd_detector
def pgd_attack(model, input_data, eps=0.03, alpha=0.01, attack_steps=1, device='cpu'):
ta = input_data.requires_grad_(True).to(device)
perturbation = torch.zeros_like(input_data,requires_grad=True).to(device)
for step in range(attack_steps):
pred_result = model.detect_from_image((input_data + perturbation).clamp(0, 255))
pred_box, pred_conf = [], []
for result in pred_result:
pred_box.append(result[:4])
pred_conf.append(result[4])
pred_conf = torch.tensor(pred_conf, dtype=torch.float32, device=device)
potential_true_index,potential_false_index=classify_index_by_iou(pred_box,ground_truth_box,thresh_IOU=0.3)
loss = loss_function(pred_conf,potential_true_index,potential_false_index)
loss.backward()
grad = perturbation.grad.data
have this error: RuntimeError: element 0 of tensors does not require grad and does not have a grad_fn
related code(sfd_detector.py)
models_urls = {
's3fd': 'https://www.adrianbulat.com/downloads/python-fan/s3fd-619a316812.pth',
}
class SFDDetector(FaceDetector):
def __init__(self, device, path_to_detector=None, verbose=False, filter_threshold=0.5):
super(SFDDetector, self).__init__(device, verbose)
# Initialise the face detector
if path_to_detector is None:
model_weights = load_url(models_urls['s3fd'])
else:
model_weights = torch.load(path_to_detector)
self.fiter_threshold = filter_threshold
self.face_detector = s3fd()
self.face_detector.load_state_dict(model_weights)
self.face_detector.to(device)
self.face_detector.eval()
def _filter_bboxes(self, bboxlist):
if len(bboxlist) > 0:
keep = nms(bboxlist, 0.3)
bboxlist = bboxlist[keep, :]
bboxlist = [x for x in bboxlist if x[-1] > self.fiter_threshold]
return bboxlist
# def detect_from_image(self, tensor_or_path):
def detect_from_image(self, image):
# image = self.tensor_or_path_to_ndarray(tensor_or_path)
# bboxlist = detect(self.face_detector, image, device=self.device)[0]
bboxlist = batch_detect(self.face_detector, image, device=self.device)[0]
bboxlist = self._filter_bboxes(bboxlist)
return bboxlist
def detect_from_batch(self, tensor):
bboxlists = batch_detect(self.face_detector, tensor, device=self.device)
new_bboxlists = []
for i in range(bboxlists.shape[0]):
bboxlist = bboxlists[i]
bboxlist = self._filter_bboxes(bboxlist)
new_bboxlists.append(bboxlist)
return new_bboxlists
detect.py
def batch_detect(net, img_batch, device):
"""
Inputs:
- img_batch: a torch.Tensor of shape (Batch size, Channels, Height, Width)
"""
if 'cuda' in device:
torch.backends.cudnn.benchmark = True
batch_size = img_batch.size(0)
img_batch = img_batch.to(device, dtype=torch.float32)
img_batch = img_batch.flip(-3) # RGB to BGR
img_batch = img_batch - torch.tensor([104.0, 117.0, 123.0], device=device).view(1, 3, 1, 1)
# with torch.no_grad():
olist = net(img_batch) # patched uint8_t overflow error
for i in range(len(olist) // 2):
olist[i * 2] = F.softmax(olist[i * 2], dim=1)
olist = [oelem.data.cpu().numpy() for oelem in olist]
bboxlists = get_predictions(olist, batch_size)
return bboxlists
def get_predictions(olist, batch_size):
bboxlists = []
variances = [0.1, 0.2]
for i in range(len(olist) // 2):
ocls, oreg = olist[i * 2], olist[i * 2 + 1]
stride = 2**(i + 2) # 4,8,16,32,64,128
poss = zip(*np.where(ocls[:, 1, :, :] > 0.05))
for Iindex, hindex, windex in poss:
axc, ayc = stride / 2 + windex * stride, stride / 2 + hindex * stride
priors = np.array([[axc / 1.0, ayc / 1.0, stride * 4 / 1.0, stride * 4 / 1.0]])
score = ocls[:, 1, hindex, windex][:,None]
loc = oreg[:, :, hindex, windex].copy()
boxes = decode(loc, priors, variances)
bboxlists.append(np.concatenate((boxes, score), axis=1))
if len(bboxlists) == 0: # No candidates within given threshold
bboxlists = np.array([[] for _ in range(batch_size)])
else:
bboxlists = np.stack(bboxlists, axis=1)
return bboxlists
all of function code
def calculate_iou(box1, box2):
x_left = max(box1[0], box2[0])
y_top = max(box1[1], box2[1])
x_right = min(box1[2], box2[2])
y_bottom = min(box1[3], box2[3])
if x_right < x_left or y_bottom < y_top:
return 0.0 # 没有交集
intersection_area = (x_right - x_left) * (y_bottom - y_top)
box1_area = (box1[2] - box1[0]) * (box1[3] - box1[1])
box2_area = (box2[2] - box2[0]) * (box2[3] - box2[1])
# 并集面积
union_area = box1_area + box2_area - intersection_area
iou = intersection_area / union_area
return iou
def classify_index_by_iou(pred_box,ground_truth_box,thresh_IOU = 0.3):
potential_true_index = []
potential_false_index = []
for i,pred in enumerate(pred_box):
match_found=False
for truth in ground_truth_box:
if calculate_iou(pred,truth)>thresh_IOU:
potential_true_index.append(i)
match_found=True
break
if not match_found:
potential_false_index.append(i)
return potential_true_index,potential_false_index
def loss_function(pred_conf, potential_true_index, potential_false_index, threshold_false_box=1000):
true_detection_loss = torch.tensor(0.0, dtype=torch.float32, device='cpu')
false_detection_loss = torch.tensor(0.0, dtype=torch.float32, device='cpu')
# true_detection_loss=torch.log(1-pred_conf[potential_true_index]).sum()
# false_detection_loss=torch.log(pred_conf[potential_false_index[:threshold_false_box]]).sum()
for i in potential_true_index:
true_detection_loss -= torch.log(1 - pred_conf[i])
for j in potential_false_index[:threshold_false_box]:
false_detection_loss -= torch.log(pred_conf[j])
loss = torch.add(true_detection_loss,false_detection_loss)
print(loss)
return loss
I just want to get grad.data information properly... i really don't know what is the problem.did i need to change all of numpy function to pytorch? i'm stuck in this problem for 1week,plz help,thx
check if the loss before loss.backward() requires grad by printing loss.requires_grad. If not you should check in the loss calculation function if:
pred_conf[i] requires grad?From what I see, your function in detect.py convert tensor to numpy and python, which break the gradient chain. That should be why your loss doesn't require grad.