def __call__(self, tensor):
"""
Args:
tensor (Tensor): Tensor image of size (C, H, W) to be normalized.
Returns:
Tensor: Normalized Tensor image.
"""
return F.normalize(tensor, self.mean, self.std)
def transform_test(imgs,
short=416,
max_size=1024,
stride=1,
mean=(0.485, 0.456, 0.406),
std=(0.229, 0.224, 0.225)):
"""A util function to transform all images to tensors as network input by applying
normalizations. This function support 1 NDArray or iterable of NDArrays.
Parameters
----------
imgs : PIL.Image or iterable of PIL.Image
Image(s) to be transformed.
short : int, default=416
Resize image short side to this `short` and keep aspect ratio. Note that yolo network
max_size : int, optional
Maximum longer side length to fit image.
This is to limit the input image shape. Aspect ratio is intact because we
support arbitrary input size in our YOLO implementation.
stride : int, optional, default is 1
The stride constraint due to precise alignment of bounding box prediction module.
Image's width and height must be multiples of `stride`. Use `stride = 1` to
relax this constraint.
mean : iterable of float
Mean pixel values.
std : iterable of float
Standard deviations of pixel values.
Returns
-------
(Tensor, numpy.array) or list of such tuple
A (1, 3, H, W) mxnet NDArray as input to network, and a numpy ndarray as
original un-normalized color image for display.
If multiple image names are supplied, return two lists. You can use
`zip()`` to collapse it.
"""
if isinstance(imgs, np.ndarray):
imgs = [imgs]
for im in imgs:
assert isinstance(im, np.ndarray), "Expect NDArray, got {}".format(
type(im))
tensors = []
origs = []
for img in imgs:
img = timage.resize_short_within(img,
short,
max_size,
mult_base=stride)
orig_img = img.astype('uint8')
img = vf.to_tensor(img)
img = vf.normalize(img, mean=mean, std=std)
tensors.append(img.unsqueeze(0))
origs.append(orig_img)
if len(tensors) == 1:
return tensors[0], origs[0]
return tensors, origs
def __call__(self, src, label):
"""Apply transform to validation image/label."""
# resize
h, w, _ = src.shape
img = timage.imresize(src, self._width, self._height, interp=9)
bbox = tbbox.resize(label, in_size=(w, h), out_size=(self._width, self._height))
img = vf.to_tensor(img)
img = vf.normalize(img, mean=self._mean, std=self._std)
return img, bbox.astype(type_map[img.dtype])
def __call__(self, src, label):
"""Apply transform to training image/label."""
# random color jittering
img = eximage.random_color_distort(src)
# random expansion with prob 0.5
if np.random.uniform(0, 1) > 0.5:
img, expand = timage.random_expand(
img, fill=[m * 255 for m in self._mean])
bbox = tbbox.translate(label,
x_offset=expand[0],
y_offset=expand[1])
else:
img, bbox = img, label
# random cropping
h, w, _ = img.shape
bbox, crop = exbbox.random_crop_with_constraints(bbox, (w, h))
x0, y0, w, h = crop
img = timage.fixed_crop(img, x0, y0, w, h)
# resize with random interpolation
h, w, _ = img.shape
interp = np.random.randint(0, 5)
img = timage.imresize(img, self._width, self._height, interp=interp)
bbox = tbbox.resize(bbox, (w, h), (self._width, self._height))
# random horizontal flip
h, w, _ = img.shape
img, flips = timage.random_flip(img, px=0.5)
bbox = tbbox.flip(bbox, (w, h), flip_x=flips[0])
# to tensor
img = vf.to_tensor(img / 255)
img = vf.normalize(img, mean=self._mean, std=self._std)
if self._target_generator is None:
return img, bbox.astype(img.dtype)
# generate training target so cpu workers can help reduce the workload on gpu
gt_bboxes = torch.from_numpy(bbox[np.newaxis, :, :4])
gt_ids = torch.from_numpy(bbox[np.newaxis, :, 4:5])
if self._mixup:
gt_mixratio = torch.from_numpy(bbox[np.newaxis, :, -1:])
else:
gt_mixratio = None
objectness, center_targets, scale_targets, weights, class_targets = self._target_generator(
self._height, self._width, self._feat_maps, self._anchors,
self._offsets, gt_bboxes, gt_ids, gt_mixratio)
return (img, objectness[0], center_targets[0], scale_targets[0],
weights[0], class_targets[0], gt_bboxes[0])
def transform_test(imgs,
short=600,
max_size=1000,
mean=(0.485, 0.456, 0.406),
std=(0.229, 0.224, 0.225)):
"""A util function to transform all images to tensors as network input by applying
normalizations. This function support 1 NDArray or iterable of NDArrays.
Parameters
----------
imgs : NDArray or iterable of NDArray
Image(s) to be transformed.
short : int, optional, default is 600
Resize image short side to this `short` and keep aspect ratio.
max_size : int, optional, default is 1000
Maximum longer side length to fit image.
This is to limit the input image shape, avoid processing too large image.
mean : iterable of float
Mean pixel values.
std : iterable of float
Standard deviations of pixel values.
Returns
-------
(mxnet.NDArray, numpy.ndarray) or list of such tuple
A (1, 3, H, W) mxnet NDArray as input to network, and a numpy ndarray as
original un-normalized color image for display.
If multiple image names are supplied, return two lists. You can use
`zip()`` to collapse it.
"""
if isinstance(imgs, np.ndarray):
imgs = [imgs]
for im in imgs:
assert isinstance(im, np.ndarray), "Expect NDArray, got {}".format(
type(im))
tensors = []
origs = []
for img in imgs:
img = timage.resize_short_within(img, short, max_size)
orig_img = img.astype('uint8')
img = vf.to_tensor(img)
img = vf.normalize(img, mean=mean, std=std)
tensors.append(img.unsqueeze(0))
origs.append(orig_img)
if len(tensors) == 1:
return tensors[0], origs[0]
return tensors, origs
def __call__(self, src, label, mask):
"""Apply transform to validation image/label."""
# resize shorter side but keep in max_size
h, _, _ = src.shape
img = timage.resize_short_within(src,
self._short,
self._max_size,
interp=1)
# no scaling ground-truth, return image scaling ratio instead
im_scale = float(img.shape[0]) / h
img = vf.to_tensor(img)
img = vf.normalize(img, mean=self._mean, std=self._std)
return img, torch.tensor([img.shape[-2], img.shape[-1], im_scale],
dtype=torch.float32)
def __call__(self, src, label):
"""Apply transform to validation image/label."""
# resize shorter side but keep in max_size
h, w, _ = src.shape
img = timage.resize_short_within(src,
self._short,
self._max_size,
interp=1)
# no scaling ground-truth, return image scaling ratio instead
bbox = tbbox.resize(label, (w, h), (img.shape[1], img.shape[0]))
im_scale = h / float(img.shape[0])
img = vf.to_tensor(img)
img = vf.normalize(img, mean=self._mean, std=self._std)
return img, bbox.astype('float32'), torch.tensor([im_scale],
dtype=torch.float32)
