def forward(self, x, augment=False, profile=False):
if augment:
img_size = x.shape[-2:] # height, width
s = [1, 0.83, 0.67] # scales
f = [None, 3, None] # flips (2-ud, 3-lr)
y = [] # outputs
for si, fi in zip(s, f):
xi = scale_img(x.flip(fi) if fi else x, si, gs=int(self.stride.max()))
yi = self.forward_once(xi)[0] # forward
# cv2.imwrite(f'img_{si}.jpg', 255 * xi[0].cpu().numpy().transpose((1, 2, 0))[:, :, ::-1]) # save
yi[..., :4] /= si # de-scale
if fi == 2:
yi[..., 1] = img_size[0] - yi[..., 1] # de-flip ud
elif fi == 3:
yi[..., 0] = img_size[1] - yi[..., 0] # de-flip lr
y.append(yi)
return torch.cat(y, 1), None # augmented inference, train
else:
return self.forward_once(x, profile) # single-scale inference, train
def forward_once(self, x, augment=False, verbose=False):
img_size = x.shape[-2:] # height, width
yolo_out, out = [], []
if verbose:
print('0', x.shape)
str = ''
# Augment images (inference and test only)
if augment: # https://github.com/ultralytics/yolov3/issues/931
nb = x.shape[0] # batch size
s = [0.83, 0.67] # scales
x = torch.cat(
(
x,
torch_utils.scale_img(x.flip(3),
s[0]), # flip-lr and scale
torch_utils.scale_img(x, s[1]), # scale
),
0)
for i, module in enumerate(self.module_list):
name = module.__class__.__name__
if name in [
'WeightedFeatureFusion', 'FeatureConcat', 'FeatureConcat2',
'FeatureConcat3', 'FeatureConcat_l'
]: # sum, concat
if verbose:
l = [i - 1] + module.layers # layers
sh = [list(x.shape)
] + [list(out[i].shape)
for i in module.layers] # shapes
str = ' >> ' + ' + '.join(
['layer %g %s' % x for x in zip(l, sh)])
x = module(x, out) # WeightedFeatureFusion(), FeatureConcat()
elif name == 'YOLOLayer':
yolo_out.append(module(x, out))
else: # run module directly, i.e. mtype = 'convolutional', 'upsample', 'maxpool', 'batchnorm2d' etc.
x = module(x)
out.append(x if self.routs[i] else [])
if verbose:
print('%g/%g %s -' % (i, len(self.module_list), name),
list(x.shape), str)
str = ''
if self.training: # train
return yolo_out
elif ONNX_EXPORT: # export
x = [torch.cat(x, 0) for x in zip(*yolo_out)]
return x[0], x[1], torch.cat(
x[2:4], 1) # scores, cls, boxes: 3780x80, 3780x4
else: # inference or test
x, p = zip(*yolo_out) # inference output, training output
x = torch.cat(x, 1) # cat yolo outputs
if augment: # de-augment results
x = torch.split(x, nb, dim=0)
x[1][..., :4] /= s[0] # scale
x[1][..., 0] = img_size[1] - x[1][..., 0] # flip lr
x[2][..., :4] /= s[1] # scale
x = torch.cat(x, 1)
return x, p