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