DL-Art-School/codes/data/util.py

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2019-08-23 13:42:47 +00:00
import os
import math
import pickle
import random
import numpy as np
import glob
import torch
import cv2
####################
# Files & IO
####################
###################### get image path list ######################
IMG_EXTENSIONS = ['.jpg', '.JPG', '.jpeg', '.JPEG', '.png', '.PNG', '.ppm', '.PPM', '.bmp', '.BMP']
def is_image_file(filename):
return any(filename.endswith(extension) for extension in IMG_EXTENSIONS)
def _get_paths_from_images(path):
"""get image path list from image folder"""
assert os.path.isdir(path), '{:s} is not a valid directory'.format(path)
images = []
for dirpath, _, fnames in sorted(os.walk(path)):
for fname in sorted(fnames):
if is_image_file(fname):
img_path = os.path.join(dirpath, fname)
images.append(img_path)
assert images, '{:s} has no valid image file'.format(path)
return images
def _get_paths_from_lmdb(dataroot):
"""get image path list from lmdb meta info"""
meta_info = pickle.load(open(os.path.join(dataroot, 'meta_info.pkl'), 'rb'))
paths = meta_info['keys']
sizes = meta_info['resolution']
if len(sizes) == 1:
sizes = sizes * len(paths)
return paths, sizes
def get_image_paths(data_type, dataroot, weights=[]):
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"""get image path list
support lmdb or image files"""
paths, sizes = None, None
if dataroot is not None:
if data_type == 'lmdb':
paths, sizes = _get_paths_from_lmdb(dataroot)
elif data_type == 'img':
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if isinstance(dataroot, list):
paths = []
for i in range(len(dataroot)):
r = dataroot[i]
extends = 1
# Weights have the effect of repeatedly adding the paths from the given root to the final product.
if weights:
extends = weights[i]
for j in range(extends):
paths.extend(_get_paths_from_images(r))
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paths = sorted(paths)
else:
paths = sorted(_get_paths_from_images(dataroot))
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else:
raise NotImplementedError('data_type [{:s}] is not recognized.'.format(data_type))
return paths, sizes
def glob_file_list(root):
return sorted(glob.glob(os.path.join(root, '*')))
###################### read images ######################
def _read_img_lmdb(env, key, size):
"""read image from lmdb with key (w/ and w/o fixed size)
size: (C, H, W) tuple"""
with env.begin(write=False) as txn:
buf = txn.get(key.encode('ascii'))
img_flat = np.frombuffer(buf, dtype=np.uint8)
C, H, W = size
img = img_flat.reshape(H, W, C)
return img
def read_img(env, path, size=None):
"""read image by cv2 or from lmdb
return: Numpy float32, HWC, BGR, [0,1]"""
if env is None: # img
img = cv2.imread(path, cv2.IMREAD_UNCHANGED)
else:
img = _read_img_lmdb(env, path, size)
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if img is None:
print("Image error: %s" % (path,))
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img = img.astype(np.float32) / 255.
if img.ndim == 2:
img = np.expand_dims(img, axis=2)
# some images have 4 channels
if img.shape[2] > 3:
img = img[:, :, :3]
return img
def read_img_seq(path):
"""Read a sequence of images from a given folder path
Args:
path (list/str): list of image paths/image folder path
Returns:
imgs (Tensor): size (T, C, H, W), RGB, [0, 1]
"""
if type(path) is list:
img_path_l = path
else:
img_path_l = sorted(glob.glob(os.path.join(path, '*')))
img_l = [read_img(None, v) for v in img_path_l]
# stack to Torch tensor
imgs = np.stack(img_l, axis=0)
imgs = imgs[:, :, :, [2, 1, 0]]
imgs = torch.from_numpy(np.ascontiguousarray(np.transpose(imgs, (0, 3, 1, 2)))).float()
return imgs
def index_generation(crt_i, max_n, N, padding='reflection'):
"""Generate an index list for reading N frames from a sequence of images
Args:
crt_i (int): current center index
max_n (int): max number of the sequence of images (calculated from 1)
N (int): reading N frames
padding (str): padding mode, one of replicate | reflection | new_info | circle
Example: crt_i = 0, N = 5
replicate: [0, 0, 0, 1, 2]
reflection: [2, 1, 0, 1, 2]
new_info: [4, 3, 0, 1, 2]
circle: [3, 4, 0, 1, 2]
Returns:
return_l (list [int]): a list of indexes
"""
max_n = max_n - 1
n_pad = N // 2
return_l = []
for i in range(crt_i - n_pad, crt_i + n_pad + 1):
if i < 0:
if padding == 'replicate':
add_idx = 0
elif padding == 'reflection':
add_idx = -i
elif padding == 'new_info':
add_idx = (crt_i + n_pad) + (-i)
elif padding == 'circle':
add_idx = N + i
else:
raise ValueError('Wrong padding mode')
elif i > max_n:
if padding == 'replicate':
add_idx = max_n
elif padding == 'reflection':
add_idx = max_n * 2 - i
elif padding == 'new_info':
add_idx = (crt_i - n_pad) - (i - max_n)
elif padding == 'circle':
add_idx = i - N
else:
raise ValueError('Wrong padding mode')
else:
add_idx = i
return_l.append(add_idx)
return return_l
####################
# image processing
# process on numpy image
####################
def augment(img_list, hflip=True, rot=True):
"""horizontal flip OR rotate (0, 90, 180, 270 degrees)"""
hflip = hflip and random.random() < 0.5
vflip = rot and random.random() < 0.5
rot90 = rot and random.random() < 0.5
def _augment(img):
if hflip:
img = img[:, ::-1, :]
if vflip:
img = img[::-1, :, :]
if rot90:
img = img.transpose(1, 0, 2)
return img
return [_augment(img) for img in img_list]
def augment_flow(img_list, flow_list, hflip=True, rot=True):
"""horizontal flip OR rotate (0, 90, 180, 270 degrees) with flows"""
hflip = hflip and random.random() < 0.5
vflip = rot and random.random() < 0.5
rot90 = rot and random.random() < 0.5
def _augment(img):
if hflip:
img = img[:, ::-1, :]
if vflip:
img = img[::-1, :, :]
if rot90:
img = img.transpose(1, 0, 2)
return img
def _augment_flow(flow):
if hflip:
flow = flow[:, ::-1, :]
flow[:, :, 0] *= -1
if vflip:
flow = flow[::-1, :, :]
flow[:, :, 1] *= -1
if rot90:
flow = flow.transpose(1, 0, 2)
flow = flow[:, :, [1, 0]]
return flow
rlt_img_list = [_augment(img) for img in img_list]
rlt_flow_list = [_augment_flow(flow) for flow in flow_list]
return rlt_img_list, rlt_flow_list
def channel_convert(in_c, tar_type, img_list):
"""conversion among BGR, gray and y"""
if in_c == 3 and tar_type == 'gray': # BGR to gray
gray_list = [cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) for img in img_list]
return [np.expand_dims(img, axis=2) for img in gray_list]
elif in_c == 3 and tar_type == 'y': # BGR to y
y_list = [bgr2ycbcr(img, only_y=True) for img in img_list]
return [np.expand_dims(img, axis=2) for img in y_list]
elif in_c == 1 and tar_type == 'RGB': # gray/y to BGR
return [cv2.cvtColor(img, cv2.COLOR_GRAY2BGR) for img in img_list]
else:
return img_list
def rgb2ycbcr(img, only_y=True):
"""same as matlab rgb2ycbcr
only_y: only return Y channel
Input:
uint8, [0, 255]
float, [0, 1]
"""
in_img_type = img.dtype
img.astype(np.float32)
if in_img_type != np.uint8:
img *= 255.
# convert
if only_y:
rlt = np.dot(img, [65.481, 128.553, 24.966]) / 255.0 + 16.0
else:
rlt = np.matmul(img, [[65.481, -37.797, 112.0], [128.553, -74.203, -93.786],
[24.966, 112.0, -18.214]]) / 255.0 + [16, 128, 128]
if in_img_type == np.uint8:
rlt = rlt.round()
else:
rlt /= 255.
return rlt.astype(in_img_type)
def bgr2ycbcr(img, only_y=True):
"""bgr version of rgb2ycbcr
only_y: only return Y channel
Input:
uint8, [0, 255]
float, [0, 1]
"""
in_img_type = img.dtype
img.astype(np.float32)
if in_img_type != np.uint8:
img *= 255.
# convert
if only_y:
rlt = np.dot(img, [24.966, 128.553, 65.481]) / 255.0 + 16.0
else:
rlt = np.matmul(img, [[24.966, 112.0, -18.214], [128.553, -74.203, -93.786],
[65.481, -37.797, 112.0]]) / 255.0 + [16, 128, 128]
if in_img_type == np.uint8:
rlt = rlt.round()
else:
rlt /= 255.
return rlt.astype(in_img_type)
def ycbcr2rgb(img):
"""same as matlab ycbcr2rgb
Input:
uint8, [0, 255]
float, [0, 1]
"""
in_img_type = img.dtype
img.astype(np.float32)
if in_img_type != np.uint8:
img *= 255.
# convert
rlt = np.matmul(img, [[0.00456621, 0.00456621, 0.00456621], [0, -0.00153632, 0.00791071],
[0.00625893, -0.00318811, 0]]) * 255.0 + [-222.921, 135.576, -276.836]
if in_img_type == np.uint8:
rlt = rlt.round()
else:
rlt /= 255.
return rlt.astype(in_img_type)
def modcrop(img_in, scale):
"""img_in: Numpy, HWC or HW"""
img = np.copy(img_in)
if img.ndim == 2:
H, W = img.shape
H_r, W_r = H % scale, W % scale
img = img[:H - H_r, :W - W_r]
elif img.ndim == 3:
H, W, C = img.shape
H_r, W_r = H % scale, W % scale
img = img[:H - H_r, :W - W_r, :]
else:
raise ValueError('Wrong img ndim: [{:d}].'.format(img.ndim))
return img
####################
# Functions
####################
# matlab 'imresize' function, now only support 'bicubic'
def cubic(x):
absx = torch.abs(x)
absx2 = absx**2
absx3 = absx**3
return (1.5 * absx3 - 2.5 * absx2 + 1) * (
(absx <= 1).type_as(absx)) + (-0.5 * absx3 + 2.5 * absx2 - 4 * absx + 2) * ((
(absx > 1) * (absx <= 2)).type_as(absx))
def calculate_weights_indices(in_length, out_length, scale, kernel, kernel_width, antialiasing):
if (scale < 1) and (antialiasing):
# Use a modified kernel to simultaneously interpolate and antialias- larger kernel width
kernel_width = kernel_width / scale
# Output-space coordinates
x = torch.linspace(1, out_length, out_length)
# Input-space coordinates. Calculate the inverse mapping such that 0.5
# in output space maps to 0.5 in input space, and 0.5+scale in output
# space maps to 1.5 in input space.
u = x / scale + 0.5 * (1 - 1 / scale)
# What is the left-most pixel that can be involved in the computation?
left = torch.floor(u - kernel_width / 2)
# What is the maximum number of pixels that can be involved in the
# computation? Note: it's OK to use an extra pixel here; if the
# corresponding weights are all zero, it will be eliminated at the end
# of this function.
P = math.ceil(kernel_width) + 2
# The indices of the input pixels involved in computing the k-th output
# pixel are in row k of the indices matrix.
indices = left.view(out_length, 1).expand(out_length, P) + torch.linspace(0, P - 1, P).view(
1, P).expand(out_length, P)
# The weights used to compute the k-th output pixel are in row k of the
# weights matrix.
distance_to_center = u.view(out_length, 1).expand(out_length, P) - indices
# apply cubic kernel
if (scale < 1) and (antialiasing):
weights = scale * cubic(distance_to_center * scale)
else:
weights = cubic(distance_to_center)
# Normalize the weights matrix so that each row sums to 1.
weights_sum = torch.sum(weights, 1).view(out_length, 1)
weights = weights / weights_sum.expand(out_length, P)
# If a column in weights is all zero, get rid of it. only consider the first and last column.
weights_zero_tmp = torch.sum((weights == 0), 0)
if not math.isclose(weights_zero_tmp[0], 0, rel_tol=1e-6):
indices = indices.narrow(1, 1, P - 2)
weights = weights.narrow(1, 1, P - 2)
if not math.isclose(weights_zero_tmp[-1], 0, rel_tol=1e-6):
indices = indices.narrow(1, 0, P - 2)
weights = weights.narrow(1, 0, P - 2)
weights = weights.contiguous()
indices = indices.contiguous()
sym_len_s = -indices.min() + 1
sym_len_e = indices.max() - in_length
indices = indices + sym_len_s - 1
return weights, indices, int(sym_len_s), int(sym_len_e)
def imresize(img, scale, antialiasing=True):
# Now the scale should be the same for H and W
# input: img: CHW RGB [0,1]
# output: CHW RGB [0,1] w/o round
in_C, in_H, in_W = img.size()
_, out_H, out_W = in_C, math.ceil(in_H * scale), math.ceil(in_W * scale)
kernel_width = 4
kernel = 'cubic'
# Return the desired dimension order for performing the resize. The
# strategy is to perform the resize first along the dimension with the
# smallest scale factor.
# Now we do not support this.
# get weights and indices
weights_H, indices_H, sym_len_Hs, sym_len_He = calculate_weights_indices(
in_H, out_H, scale, kernel, kernel_width, antialiasing)
weights_W, indices_W, sym_len_Ws, sym_len_We = calculate_weights_indices(
in_W, out_W, scale, kernel, kernel_width, antialiasing)
# process H dimension
# symmetric copying
img_aug = torch.FloatTensor(in_C, in_H + sym_len_Hs + sym_len_He, in_W)
img_aug.narrow(1, sym_len_Hs, in_H).copy_(img)
sym_patch = img[:, :sym_len_Hs, :]
inv_idx = torch.arange(sym_patch.size(1) - 1, -1, -1).long()
sym_patch_inv = sym_patch.index_select(1, inv_idx)
img_aug.narrow(1, 0, sym_len_Hs).copy_(sym_patch_inv)
sym_patch = img[:, -sym_len_He:, :]
inv_idx = torch.arange(sym_patch.size(1) - 1, -1, -1).long()
sym_patch_inv = sym_patch.index_select(1, inv_idx)
img_aug.narrow(1, sym_len_Hs + in_H, sym_len_He).copy_(sym_patch_inv)
out_1 = torch.FloatTensor(in_C, out_H, in_W)
kernel_width = weights_H.size(1)
for i in range(out_H):
idx = int(indices_H[i][0])
out_1[0, i, :] = img_aug[0, idx:idx + kernel_width, :].transpose(0, 1).mv(weights_H[i])
out_1[1, i, :] = img_aug[1, idx:idx + kernel_width, :].transpose(0, 1).mv(weights_H[i])
out_1[2, i, :] = img_aug[2, idx:idx + kernel_width, :].transpose(0, 1).mv(weights_H[i])
# process W dimension
# symmetric copying
out_1_aug = torch.FloatTensor(in_C, out_H, in_W + sym_len_Ws + sym_len_We)
out_1_aug.narrow(2, sym_len_Ws, in_W).copy_(out_1)
sym_patch = out_1[:, :, :sym_len_Ws]
inv_idx = torch.arange(sym_patch.size(2) - 1, -1, -1).long()
sym_patch_inv = sym_patch.index_select(2, inv_idx)
out_1_aug.narrow(2, 0, sym_len_Ws).copy_(sym_patch_inv)
sym_patch = out_1[:, :, -sym_len_We:]
inv_idx = torch.arange(sym_patch.size(2) - 1, -1, -1).long()
sym_patch_inv = sym_patch.index_select(2, inv_idx)
out_1_aug.narrow(2, sym_len_Ws + in_W, sym_len_We).copy_(sym_patch_inv)
out_2 = torch.FloatTensor(in_C, out_H, out_W)
kernel_width = weights_W.size(1)
for i in range(out_W):
idx = int(indices_W[i][0])
out_2[0, :, i] = out_1_aug[0, :, idx:idx + kernel_width].mv(weights_W[i])
out_2[1, :, i] = out_1_aug[1, :, idx:idx + kernel_width].mv(weights_W[i])
out_2[2, :, i] = out_1_aug[2, :, idx:idx + kernel_width].mv(weights_W[i])
return out_2
def imresize_np(img, scale, antialiasing=True):
# Now the scale should be the same for H and W
# input: img: Numpy, HWC BGR [0,1]
# output: HWC BGR [0,1] w/o round
img = torch.from_numpy(img)
in_H, in_W, in_C = img.size()
_, out_H, out_W = in_C, math.ceil(in_H * scale), math.ceil(in_W * scale)
kernel_width = 4
kernel = 'cubic'
# Return the desired dimension order for performing the resize. The
# strategy is to perform the resize first along the dimension with the
# smallest scale factor.
# Now we do not support this.
# get weights and indices
weights_H, indices_H, sym_len_Hs, sym_len_He = calculate_weights_indices(
in_H, out_H, scale, kernel, kernel_width, antialiasing)
weights_W, indices_W, sym_len_Ws, sym_len_We = calculate_weights_indices(
in_W, out_W, scale, kernel, kernel_width, antialiasing)
# process H dimension
# symmetric copying
img_aug = torch.FloatTensor(in_H + sym_len_Hs + sym_len_He, in_W, in_C)
img_aug.narrow(0, sym_len_Hs, in_H).copy_(img)
sym_patch = img[:sym_len_Hs, :, :]
inv_idx = torch.arange(sym_patch.size(0) - 1, -1, -1).long()
sym_patch_inv = sym_patch.index_select(0, inv_idx)
img_aug.narrow(0, 0, sym_len_Hs).copy_(sym_patch_inv)
sym_patch = img[-sym_len_He:, :, :]
inv_idx = torch.arange(sym_patch.size(0) - 1, -1, -1).long()
sym_patch_inv = sym_patch.index_select(0, inv_idx)
img_aug.narrow(0, sym_len_Hs + in_H, sym_len_He).copy_(sym_patch_inv)
out_1 = torch.FloatTensor(out_H, in_W, in_C)
kernel_width = weights_H.size(1)
for i in range(out_H):
idx = int(indices_H[i][0])
out_1[i, :, 0] = img_aug[idx:idx + kernel_width, :, 0].transpose(0, 1).mv(weights_H[i])
out_1[i, :, 1] = img_aug[idx:idx + kernel_width, :, 1].transpose(0, 1).mv(weights_H[i])
out_1[i, :, 2] = img_aug[idx:idx + kernel_width, :, 2].transpose(0, 1).mv(weights_H[i])
# process W dimension
# symmetric copying
out_1_aug = torch.FloatTensor(out_H, in_W + sym_len_Ws + sym_len_We, in_C)
out_1_aug.narrow(1, sym_len_Ws, in_W).copy_(out_1)
sym_patch = out_1[:, :sym_len_Ws, :]
inv_idx = torch.arange(sym_patch.size(1) - 1, -1, -1).long()
sym_patch_inv = sym_patch.index_select(1, inv_idx)
out_1_aug.narrow(1, 0, sym_len_Ws).copy_(sym_patch_inv)
sym_patch = out_1[:, -sym_len_We:, :]
inv_idx = torch.arange(sym_patch.size(1) - 1, -1, -1).long()
sym_patch_inv = sym_patch.index_select(1, inv_idx)
out_1_aug.narrow(1, sym_len_Ws + in_W, sym_len_We).copy_(sym_patch_inv)
out_2 = torch.FloatTensor(out_H, out_W, in_C)
kernel_width = weights_W.size(1)
for i in range(out_W):
idx = int(indices_W[i][0])
out_2[:, i, 0] = out_1_aug[:, idx:idx + kernel_width, 0].mv(weights_W[i])
out_2[:, i, 1] = out_1_aug[:, idx:idx + kernel_width, 1].mv(weights_W[i])
out_2[:, i, 2] = out_1_aug[:, idx:idx + kernel_width, 2].mv(weights_W[i])
return out_2.numpy()
if __name__ == '__main__':
# test imresize function
# read images
img = cv2.imread('test.png')
img = img * 1.0 / 255
img = torch.from_numpy(np.transpose(img[:, :, [2, 1, 0]], (2, 0, 1))).float()
# imresize
scale = 1 / 4
import time
total_time = 0
for i in range(10):
start_time = time.time()
rlt = imresize(img, scale, antialiasing=True)
use_time = time.time() - start_time
total_time += use_time
print('average time: {}'.format(total_time / 10))
import torchvision.utils
torchvision.utils.save_image((rlt * 255).round() / 255, 'rlt.png', nrow=1, padding=0,
normalize=False)