File size: 3,834 Bytes
0a2e9f2 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 | import numbers
import torch
import cv2
import numpy as np
import PIL
from PIL import Image
def _is_tensor_clip(clip):
return torch.is_tensor(clip) and clip.ndimension() == 4
def crop_clip(clip, min_h, min_w, h, w):
if isinstance(clip[0], np.ndarray):
cropped = [img[min_h:min_h + h, min_w:min_w + w, :] for img in clip]
elif isinstance(clip[0], PIL.Image.Image):
cropped = [
img.crop((min_w, min_h, min_w + w, min_h + h)) for img in clip
]
else:
raise TypeError('Expected numpy.ndarray or PIL.Image' +
'but got list of {0}'.format(type(clip[0])))
return cropped
def to_grayscale(img, num_output_channels=1):
"""Convert image to grayscale version of image.
Args:
img (PIL Image): Image to be converted to grayscale.
Returns:
PIL Image: Grayscale version of the image.
if num_output_channels = 1 : returned image is single channel
if num_output_channels = 3 : returned image is 3 channel with r = g = b
"""
if not isinstance(img,PIL.Image.Image):
raise TypeError('img should be PIL Image. Got {}'.format(type(img)))
if num_output_channels == 1:
img = img.convert('L')
elif num_output_channels == 3:
img = img.convert('L')
np_img = np.array(img, dtype=np.uint8)
np_img = np.dstack([np_img, np_img, np_img])
img = Image.fromarray(np_img, 'RGB')
else:
raise ValueError('num_output_channels should be either 1 or 3')
return img
def resize_clip(clip, size, interpolation='bilinear'):
if isinstance(clip[0], np.ndarray):
if isinstance(size, numbers.Number):
im_h, im_w, im_c = clip[0].shape
# Min spatial dim already matches minimal size
if (im_w <= im_h and im_w == size) or (im_h <= im_w
and im_h == size):
return clip
new_h, new_w = get_resize_sizes(im_h, im_w, size)
size = (new_w, new_h)
else:
size = size[1], size[0]
if interpolation == 'bilinear':
np_inter = cv2.INTER_LINEAR
else:
np_inter = cv2.INTER_NEAREST
scaled = [
cv2.resize(img, size, interpolation=np_inter) for img in clip
]
elif isinstance(clip[0], PIL.Image.Image):
if isinstance(size, numbers.Number):
im_w, im_h = clip[0].size
# Min spatial dim already matches minimal size
if (im_w <= im_h and im_w == size) or (im_h <= im_w
and im_h == size):
return clip
new_h, new_w = get_resize_sizes(im_h, im_w, size)
size = (new_w, new_h)
else:
size = size[1], size[0]
if interpolation == 'bilinear':
pil_inter = PIL.Image.NEAREST
else:
pil_inter = PIL.Image.BILINEAR
scaled = [img.resize(size, pil_inter) for img in clip]
else:
raise TypeError('Expected numpy.ndarray or PIL.Image' +
'but got list of {0}'.format(type(clip[0])))
return scaled
def get_resize_sizes(im_h, im_w, size):
if im_w < im_h:
ow = size
oh = int(size * im_h / im_w)
else:
oh = size
ow = int(size * im_w / im_h)
return oh, ow
def normalize(clip, mean, std, inplace=False):
if not _is_tensor_clip(clip):
raise TypeError('tensor is not a torch clip.')
if not inplace:
clip = clip.clone()
dtype = clip.dtype
mean = torch.as_tensor(mean, dtype=dtype, device=clip.device)
std = torch.as_tensor(std, dtype=dtype, device=clip.device)
clip.sub_(mean[:, None, None, None]).div_(std[:, None, None, None])
return clip
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