Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

fix: Fixed Resize transfo in PyTorch when aspect ratio matches the target #357

Merged
merged 2 commits into from
Jul 6, 2021
Merged

fix: Fixed Resize transfo in PyTorch when aspect ratio matches the target #357

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
434cded
fix: Fixed edge case of torch resize
fg-mindee Jul 6, 2021
6cb0734
test: Added unittest to ensure correct behaviour
fg-mindee Jul 6, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 8 additions & 6 deletions doctr/transforms/modules/pytorch.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,32 +22,34 @@ def __init__(
preserve_aspect_ratio: bool = False,
symmetric_pad: bool = False,
) -> None:
super().__init__(size[::-1], interpolation)
super().__init__(size, interpolation)
self.preserve_aspect_ratio = preserve_aspect_ratio
self.symmetric_pad = symmetric_pad

def forward(self, img: torch.Tensor) -> torch.Tensor:
target_ratio = self.size[1] / self.size[0]
target_ratio = self.size[0] / self.size[1]
actual_ratio = img.shape[-2] / img.shape[-1]
if not self.preserve_aspect_ratio or (target_ratio == actual_ratio):
return super().forward(img)
else:
# Resize
if actual_ratio > target_ratio:
tmp_size = (self.size[1], int(self.size[1] / actual_ratio))
tmp_size = (self.size[0], int(self.size[0] / actual_ratio))
else:
tmp_size = (int(self.size[0] * actual_ratio), self.size[0])
tmp_size = (int(self.size[1] * actual_ratio), self.size[1])

# Scale image
img = F.resize(img, tmp_size, self.interpolation)
# Pad (inverted in pytorch)
_pad = (0, self.size[0] - img.shape[-1], 0, self.size[1] - img.shape[-2])
_pad = (0, self.size[1] - img.shape[-1], 0, self.size[0] - img.shape[-2])
if self.symmetric_pad:
half_pad = (math.ceil(_pad[1] / 2), math.ceil(_pad[3] / 2))
_pad = (half_pad[0], _pad[1] - half_pad[0], half_pad[1], _pad[3] - half_pad[1])
return pad(img, _pad)

def __repr__(self) -> str:
interpolate_str = self.interpolation.value
_repr = f"output_size={self.size[::-1]}, interpolation='{interpolate_str}'"
_repr = f"output_size={self.size}, interpolation='{interpolate_str}'"
if self.preserve_aspect_ratio:
_repr += f", preserve_aspect_ratio={self.preserve_aspect_ratio}, symmetric_pad={self.symmetric_pad}"
return f"{self.__class__.__name__}({_repr})"
6 changes: 6 additions & 0 deletions test/pytorch/test_transforms_pt.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -40,6 +40,12 @@ def test_resize():
assert not torch.all(out == 1)
assert out.shape[-2:] == output_size

# Same aspect ratio
output_size = (32, 128)
transfo = Resize(output_size, preserve_aspect_ratio=True)
out = transfo(torch.ones((3, 16, 64), dtype=torch.float32))
assert out.shape[-2:] == output_size


@pytest.mark.parametrize(
"rgb_min",
Expand Down