#!/usr/bin/env python # -*- coding:utf-8 -*- # Power by Zongsheng Yue 2021-11-24 16:54:19 import sys import cv2 import math import torch import random import numpy as np from scipy import fft from pathlib import Path from einops import rearrange from skimage import img_as_ubyte, img_as_float32 # --------------------------Metrics---------------------------- def ssim(img1, img2): C1 = (0.01 * 255)**2 C2 = (0.03 * 255)**2 img1 = img1.astype(np.float64) img2 = img2.astype(np.float64) kernel = cv2.getGaussianKernel(11, 1.5) window = np.outer(kernel, kernel.transpose()) mu1 = cv2.filter2D(img1, -1, window)[5:-5, 5:-5] # valid mu2 = cv2.filter2D(img2, -1, window)[5:-5, 5:-5] mu1_sq = mu1**2 mu2_sq = mu2**2 mu1_mu2 = mu1 * mu2 sigma1_sq = cv2.filter2D(img1**2, -1, window)[5:-5, 5:-5] - mu1_sq sigma2_sq = cv2.filter2D(img2**2, -1, window)[5:-5, 5:-5] - mu2_sq sigma12 = cv2.filter2D(img1 * img2, -1, window)[5:-5, 5:-5] - mu1_mu2 ssim_map = ((2 * mu1_mu2 + C1) * (2 * sigma12 + C2)) / ((mu1_sq + mu2_sq + C1) * (sigma1_sq + sigma2_sq + C2)) return ssim_map.mean() def calculate_ssim(im1, im2, border=0, ycbcr=False): ''' SSIM the same outputs as MATLAB's im1, im2: h x w x , [0, 255], uint8 ''' if not im1.shape == im2.shape: raise ValueError('Input images must have the same dimensions.') if ycbcr: im1 = rgb2ycbcr(im1, True) im2 = rgb2ycbcr(im2, True) h, w = im1.shape[:2] im1 = im1[border:h-border, border:w-border] im2 = im2[border:h-border, border:w-border] if im1.ndim == 2: return ssim(im1, im2) elif im1.ndim == 3: if im1.shape[2] == 3: ssims = [] for i in range(3): ssims.append(ssim(im1[:,:,i], im2[:,:,i])) return np.array(ssims).mean() elif im1.shape[2] == 1: return ssim(np.squeeze(im1), np.squeeze(im2)) else: raise ValueError('Wrong input image dimensions.') def calculate_psnr(im1, im2, border=0, ycbcr=False): ''' PSNR metric. im1, im2: h x w x , [0, 255], uint8 ''' if not im1.shape == im2.shape: raise ValueError('Input images must have the same dimensions.') if ycbcr: im1 = rgb2ycbcr(im1, True) im2 = rgb2ycbcr(im2, True) h, w = im1.shape[:2] im1 = im1[border:h-border, border:w-border] im2 = im2[border:h-border, border:w-border] im1 = im1.astype(np.float64) im2 = im2.astype(np.float64) mse = np.mean((im1 - im2)**2) if mse == 0: return float('inf') return 20 * math.log10(255.0 / math.sqrt(mse)) def batch_PSNR(img, imclean, border=0, ycbcr=False): if ycbcr: img = rgb2ycbcrTorch(img, True) imclean = rgb2ycbcrTorch(imclean, True) Img = img.data.cpu().numpy().clip(min=0., max=1.) Iclean = imclean.data.cpu().numpy().clip(min=0., max=1.) Img = img_as_ubyte(Img) Iclean = img_as_ubyte(Iclean) PSNR = 0 h, w = Iclean.shape[2:] for i in range(Img.shape[0]): PSNR += calculate_psnr(Iclean[i,:,].transpose((1,2,0)), Img[i,:,].transpose((1,2,0)), border) return PSNR def batch_SSIM(img, imclean, border=0, ycbcr=False): if ycbcr: img = rgb2ycbcrTorch(img, True) imclean = rgb2ycbcrTorch(imclean, True) Img = img.data.cpu().numpy() Iclean = imclean.data.cpu().numpy() Img = img_as_ubyte(Img) Iclean = img_as_ubyte(Iclean) SSIM = 0 for i in range(Img.shape[0]): SSIM += calculate_ssim(Iclean[i,:,].transpose((1,2,0)), Img[i,:,].transpose((1,2,0)), border) return SSIM def normalize_np(im, mean=0.5, std=0.5, reverse=False): ''' Input: im: h x w x c, numpy array Normalize: (im - mean) / std Reverse: im * std + mean ''' if not isinstance(mean, (list, tuple)): mean = [mean, ] * im.shape[2] mean = np.array(mean).reshape([1, 1, im.shape[2]]) if not isinstance(std, (list, tuple)): std = [std, ] * im.shape[2] std = np.array(std).reshape([1, 1, im.shape[2]]) if not reverse: out = (im.astype(np.float32) - mean) / std else: out = im.astype(np.float32) * std + mean return out def normalize_th(im, mean=0.5, std=0.5, reverse=False): ''' Input: im: b x c x h x w, torch tensor Normalize: (im - mean) / std Reverse: im * std + mean ''' if not isinstance(mean, (list, tuple)): mean = [mean, ] * im.shape[1] mean = torch.tensor(mean, device=im.device).view([1, im.shape[1], 1, 1]) if not isinstance(std, (list, tuple)): std = [std, ] * im.shape[1] std = torch.tensor(std, device=im.device).view([1, im.shape[1], 1, 1]) if not reverse: out = (im - mean) / std else: out = im * std + mean return out # ------------------------Image format-------------------------- def rgb2ycbcr(im, only_y=True): ''' same as matlab rgb2ycbcr Input: im: uint8 [0,255] or float [0,1] only_y: only return Y channel ''' # transform to float64 data type, range [0, 255] if im.dtype == np.uint8: im_temp = im.astype(np.float64) else: im_temp = (im * 255).astype(np.float64) # convert if only_y: rlt = np.dot(im_temp, np.array([65.481, 128.553, 24.966])/ 255.0) + 16.0 else: rlt = np.matmul(im_temp, np.array([[65.481, -37.797, 112.0 ], [128.553, -74.203, -93.786], [24.966, 112.0, -18.214]])/255.0) + [16, 128, 128] if im.dtype == np.uint8: rlt = rlt.round() else: rlt /= 255. return rlt.astype(im.dtype) def rgb2ycbcrTorch(im, only_y=True): ''' same as matlab rgb2ycbcr Input: im: float [0,1], N x 3 x H x W only_y: only return Y channel ''' # transform to range [0,255.0] im_temp = im.permute([0,2,3,1]) * 255.0 # N x H x W x C --> N x H x W x C # convert if only_y: rlt = torch.matmul(im_temp, torch.tensor([65.481, 128.553, 24.966], device=im.device, dtype=im.dtype).view([3,1])/ 255.0) + 16.0 else: rlt = torch.matmul(im_temp, torch.tensor([[65.481, -37.797, 112.0 ], [128.553, -74.203, -93.786], [24.966, 112.0, -18.214]], device=im.device, dtype=im.dtype)/255.0) + \ torch.tensor([16, 128, 128]).view([-1, 1, 1, 3]) rlt /= 255.0 rlt.clamp_(0.0, 1.0) return rlt.permute([0, 3, 1, 2]) def bgr2rgb(im): return cv2.cvtColor(im, cv2.COLOR_BGR2RGB) def rgb2bgr(im): return cv2.cvtColor(im, cv2.COLOR_RGB2BGR) def tensor2img(tensor, rgb2bgr=True, out_type=np.uint8, min_max=(0, 1)): """Convert torch Tensors into image numpy arrays. After clamping to [min, max], values will be normalized to [0, 1]. Args: tensor (Tensor or list[Tensor]): Accept shapes: 1) 4D mini-batch Tensor of shape (B x 3/1 x H x W); 2) 3D Tensor of shape (3/1 x H x W); 3) 2D Tensor of shape (H x W). Tensor channel should be in RGB order. rgb2bgr (bool): Whether to change rgb to bgr. out_type (numpy type): output types. If ``np.uint8``, transform outputs to uint8 type with range [0, 255]; otherwise, float type with range [0, 1]. Default: ``np.uint8``. min_max (tuple[int]): min and max values for clamp. Returns: (Tensor or list): 3D ndarray of shape (H x W x C) OR 2D ndarray of shape (H x W). The channel order is BGR. """ if not (torch.is_tensor(tensor) or (isinstance(tensor, list) and all(torch.is_tensor(t) for t in tensor))): raise TypeError(f'tensor or list of tensors expected, got {type(tensor)}') flag_tensor = torch.is_tensor(tensor) if flag_tensor: tensor = [tensor] result = [] for _tensor in tensor: _tensor = _tensor.squeeze(0).float().detach().cpu().clamp_(*min_max) _tensor = (_tensor - min_max[0]) / (min_max[1] - min_max[0]) n_dim = _tensor.dim() if n_dim == 4: img_np = make_grid(_tensor, nrow=int(math.sqrt(_tensor.size(0))), normalize=False).numpy() img_np = img_np.transpose(1, 2, 0) if rgb2bgr: img_np = cv2.cvtColor(img_np, cv2.COLOR_RGB2BGR) elif n_dim == 3: img_np = _tensor.numpy() img_np = img_np.transpose(1, 2, 0) if img_np.shape[2] == 1: # gray image img_np = np.squeeze(img_np, axis=2) else: if rgb2bgr: img_np = cv2.cvtColor(img_np, cv2.COLOR_RGB2BGR) elif n_dim == 2: img_np = _tensor.numpy() else: raise TypeError(f'Only support 4D, 3D or 2D tensor. But received with dimension: {n_dim}') if out_type == np.uint8: # Unlike MATLAB, numpy.unit8() WILL NOT round by default. img_np = (img_np * 255.0).round() img_np = img_np.astype(out_type) result.append(img_np) if len(result) == 1 and flag_tensor: result = result[0] return result def img2tensor(imgs, bgr2rgb=False, out_type=torch.float32): """Convert image numpy arrays into torch tensor. Args: imgs (Array or list[array]): Accept shapes: 3) list of numpy arrays 1) 3D numpy array of shape (H x W x 3/1); 2) 2D Tensor of shape (H x W). Tensor channel should be in RGB order. Returns: (array or list): 4D ndarray of shape (1 x C x H x W) """ def _img2tensor(img): if img.ndim == 2: tensor = torch.from_numpy(img[None, None,]).type(out_type) elif img.ndim == 3: if bgr2rgb: img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB) tensor = torch.from_numpy(rearrange(img, 'h w c -> c h w')).type(out_type).unsqueeze(0) else: raise TypeError(f'2D or 3D numpy array expected, got{img.ndim}D array') return tensor if not (isinstance(imgs, np.ndarray) or (isinstance(imgs, list) and all(isinstance(t, np.ndarray) for t in imgs))): raise TypeError(f'Numpy array or list of numpy array expected, got {type(imgs)}') flag_numpy = isinstance(imgs, np.ndarray) if flag_numpy: imgs = [imgs,] result = [] for _img in imgs: result.append(_img2tensor(_img)) if len(result) == 1 and flag_numpy: result = result[0] return result # ------------------------Image resize----------------------------- def imresize_np(img, scale, antialiasing=True): # Now the scale should be the same for H and W # input: img: Numpy, HWC or HW [0,1] # output: HWC or HW [0,1] w/o round img = torch.from_numpy(img) need_squeeze = True if img.dim() == 2 else False if need_squeeze: img.unsqueeze_(2) in_H, in_W, in_C = img.size() out_C, 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]) for j in range(out_C): out_1[i, :, j] = img_aug[idx:idx + kernel_width, :, j].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]) for j in range(out_C): out_2[:, i, j] = out_1_aug[:, idx:idx + kernel_width, j].mv(weights_W[i]) if need_squeeze: out_2.squeeze_() return out_2.numpy() 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) # 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)) # ------------------------Image I/O----------------------------- def imread(path, chn='rgb', dtype='float32', force_gray2rgb=True, force_rgba2rgb=False): ''' Read image. chn: 'rgb', 'bgr' or 'gray' out: im: h x w x c, numpy tensor ''' try: im = cv2.imread(str(path), cv2.IMREAD_UNCHANGED) # BGR, uint8 except: print(str(path)) if im is None: print(str(path)) if chn.lower() == 'gray': assert im.ndim == 2, f"{str(path)} has {im.ndim} channels!" else: if im.ndim == 2: if force_gray2rgb: im = np.stack([im, im, im], axis=2) else: raise ValueError(f"{str(path)} has {im.ndim} channels!") elif im.ndim == 4: if force_rgba2rgb: im = im[:, :, :3] else: raise ValueError(f"{str(path)} has {im.ndim} channels!") else: if chn.lower() == 'rgb': im = bgr2rgb(im) elif chn.lower() == 'bgr': pass if dtype == 'float32': im = im.astype(np.float32) / 255. elif dtype == 'float64': im = im.astype(np.float64) / 255. elif dtype == 'uint8': pass else: sys.exit('Please input corrected dtype: float32, float64 or uint8!') return im def imwrite(im_in, path, chn='rgb', dtype_in='float32', qf=None): ''' Save image. Input: im: h x w x c, numpy tensor path: the saving path chn: the channel order of the im, ''' im = im_in.copy() if isinstance(path, str): path = Path(path) if dtype_in != 'uint8': im = img_as_ubyte(im) if chn.lower() == 'rgb' and im.ndim == 3: im = rgb2bgr(im) if qf is not None and path.suffix.lower() in ['.jpg', '.jpeg']: flag = cv2.imwrite(str(path), im, [int(cv2.IMWRITE_JPEG_QUALITY), int(qf)]) else: flag = cv2.imwrite(str(path), im) return flag def jpeg_compress(im, qf, chn_in='rgb'): ''' Input: im: h x w x 3 array qf: compress factor, (0, 100] chn_in: 'rgb' or 'bgr' Return: Compressed Image with channel order: chn_in ''' # transform to BGR channle and uint8 data type im_bgr = rgb2bgr(im) if chn_in.lower() == 'rgb' else im if im.dtype != np.dtype('uint8'): im_bgr = img_as_ubyte(im_bgr) # JPEG compress flag, encimg = cv2.imencode('.jpg', im_bgr, [int(cv2.IMWRITE_JPEG_QUALITY), qf]) assert flag im_jpg_bgr = cv2.imdecode(encimg, 1) # uint8, BGR # transform back to original channel and the original data type im_out = bgr2rgb(im_jpg_bgr) if chn_in.lower() == 'rgb' else im_jpg_bgr if im.dtype != np.dtype('uint8'): im_out = img_as_float32(im_out).astype(im.dtype) return im_out # ------------------------Augmentation----------------------------- def data_aug_np(image, mode): ''' Performs data augmentation of the input image Input: image: a cv2 (OpenCV) image mode: int. Choice of transformation to apply to the image 0 - no transformation 1 - flip up and down 2 - rotate counterwise 90 degree 3 - rotate 90 degree and flip up and down 4 - rotate 180 degree 5 - rotate 180 degree and flip 6 - rotate 270 degree 7 - rotate 270 degree and flip ''' if mode == 0: # original out = image elif mode == 1: # flip up and down out = np.flipud(image) elif mode == 2: # rotate counterwise 90 degree out = np.rot90(image) elif mode == 3: # rotate 90 degree and flip up and down out = np.rot90(image) out = np.flipud(out) elif mode == 4: # rotate 180 degree out = np.rot90(image, k=2) elif mode == 5: # rotate 180 degree and flip out = np.rot90(image, k=2) out = np.flipud(out) elif mode == 6: # rotate 270 degree out = np.rot90(image, k=3) elif mode == 7: # rotate 270 degree and flip out = np.rot90(image, k=3) out = np.flipud(out) else: raise Exception('Invalid choice of image transformation') return out.copy() def inverse_data_aug_np(image, mode): ''' Performs inverse data augmentation of the input image ''' if mode == 0: # original out = image elif mode == 1: out = np.flipud(image) elif mode == 2: out = np.rot90(image, axes=(1,0)) elif mode == 3: out = np.flipud(image) out = np.rot90(out, axes=(1,0)) elif mode == 4: out = np.rot90(image, k=2, axes=(1,0)) elif mode == 5: out = np.flipud(image) out = np.rot90(out, k=2, axes=(1,0)) elif mode == 6: out = np.rot90(image, k=3, axes=(1,0)) elif mode == 7: # rotate 270 degree and flip out = np.flipud(image) out = np.rot90(out, k=3, axes=(1,0)) else: raise Exception('Invalid choice of image transformation') return out # ----------------------Visualization---------------------------- def imshow(x, title=None, cbar=False): import matplotlib.pyplot as plt plt.imshow(np.squeeze(x), interpolation='nearest', cmap='gray') if title: plt.title(title) if cbar: plt.colorbar() plt.show() def imblend_with_mask(im, mask, alpha=0.25): """ Input: im, mask: h x w x c numpy array, uint8, [0, 255] alpha: scaler in [0.0, 1.0] """ edge_map = cv2.Canny(mask, 100, 200).astype(np.float32)[:, :, None] / 255. assert mask.dtype == np.uint8 mask = mask.astype(np.float32) / 255. if mask.ndim == 2: mask = mask[:, :, None] back_color = np.array([159, 121, 238], dtype=np.float32).reshape((1,1,3)) blend = im.astype(np.float32) * alpha + (1 - alpha) * back_color blend = np.clip(blend, 0, 255) out = im.astype(np.float32) * (1 - mask) + blend * mask # paste edge out = out * (1 - edge_map) + np.array([0,255,0], dtype=np.float32).reshape((1,1,3)) * edge_map return out.astype(np.uint8) # -----------------------Covolution------------------------------ def imgrad(im, pading_mode='mirror'): ''' Calculate image gradient. Input: im: h x w x c numpy array ''' from scipy.ndimage import correlate # lazy import wx = np.array([[0, 0, 0], [-1, 1, 0], [0, 0, 0]], dtype=np.float32) wy = np.array([[0, -1, 0], [0, 1, 0], [0, 0, 0]], dtype=np.float32) if im.ndim == 3: gradx = np.stack( [correlate(im[:,:,c], wx, mode=pading_mode) for c in range(im.shape[2])], axis=2 ) grady = np.stack( [correlate(im[:,:,c], wy, mode=pading_mode) for c in range(im.shape[2])], axis=2 ) grad = np.concatenate((gradx, grady), axis=2) else: gradx = correlate(im, wx, mode=pading_mode) grady = correlate(im, wy, mode=pading_mode) grad = np.stack((gradx, grady), axis=2) return {'gradx': gradx, 'grady': grady, 'grad':grad} def imgrad_fft(im): ''' Calculate image gradient. Input: im: h x w x c numpy array ''' wx = np.rot90(np.array([[0, 0, 0], [-1, 1, 0], [0, 0, 0]], dtype=np.float32), k=2) gradx = convfft(im, wx) wy = np.rot90(np.array([[0, -1, 0], [0, 1, 0], [0, 0, 0]], dtype=np.float32), k=2) grady = convfft(im, wy) grad = np.concatenate((gradx, grady), axis=2) return {'gradx': gradx, 'grady': grady, 'grad':grad} def convfft(im, weight): ''' Convolution with FFT Input: im: h1 x w1 x c numpy array weight: h2 x w2 numpy array Output: out: h1 x w1 x c numpy array ''' axes = (0,1) otf = psf2otf(weight, im.shape[:2]) if im.ndim == 3: otf = np.tile(otf[:, :, None], (1,1,im.shape[2])) out = fft.ifft2(fft.fft2(im, axes=axes) * otf, axes=axes).real return out def psf2otf(psf, shape): """ MATLAB psf2otf function. Borrowed from https://github.com/aboucaud/pypher/blob/master/pypher/pypher.py. Input: psf : h x w numpy array shape : list or tuple, output shape of the OTF array Output: otf : OTF array with the desirable shape """ if np.all(psf == 0): return np.zeros_like(psf) inshape = psf.shape # Pad the PSF to outsize psf = zero_pad(psf, shape, position='corner') # Circularly shift OTF so that the 'center' of the PSF is [0,0] element of the array for axis, axis_size in enumerate(inshape): psf = np.roll(psf, -int(axis_size / 2), axis=axis) # Compute the OTF otf = fft.fft2(psf) # Estimate the rough number of operations involved in the FFT # and discard the PSF imaginary part if within roundoff error # roundoff error = machine epsilon = sys.float_info.epsilon # or np.finfo().eps n_ops = np.sum(psf.size * np.log2(psf.shape)) otf = np.real_if_close(otf, tol=n_ops) return otf # ----------------------Patch Cropping---------------------------- def random_crop(im, pch_size): ''' Randomly crop a patch from the give image. ''' h, w = im.shape[:2] # padding if necessary if h < pch_size or w < pch_size: pad_h = min(max(0, pch_size - h), h) pad_w = min(max(0, pch_size - w), w) im = cv2.copyMakeBorder(im, 0, pad_h, 0, pad_w, cv2.BORDER_REFLECT_101) h, w = im.shape[:2] if h == pch_size: ind_h = 0 elif h > pch_size: ind_h = random.randint(0, h-pch_size) else: raise ValueError('Image height is smaller than the patch size') if w == pch_size: ind_w = 0 elif w > pch_size: ind_w = random.randint(0, w-pch_size) else: raise ValueError('Image width is smaller than the patch size') im_pch = im[ind_h:ind_h+pch_size, ind_w:ind_w+pch_size,] return im_pch class ToTensor: def __init__(self, max_value=1.0): self.max_value = max_value def __call__(self, im): assert isinstance(im, np.ndarray) if im.ndim == 2: im = im[:, :, np.newaxis] if im.dtype == np.uint8: assert self.max_value == 255. out = torch.from_numpy(im.astype(np.float32).transpose(2,0,1) / self.max_value) else: assert self.max_value == 1.0 out = torch.from_numpy(im.transpose(2,0,1)) return out class RandomCrop: def __init__(self, pch_size, pass_crop=False): self.pch_size = pch_size self.pass_crop = pass_crop def __call__(self, im): if self.pass_crop: return im if isinstance(im, list) or isinstance(im, tuple): out = [] for current_im in im: out.append(random_crop(current_im, self.pch_size)) else: out = random_crop(im, self.pch_size) return out class ImageSpliterNp: def __init__(self, im, pch_size, stride, sf=1): ''' Input: im: h x w x c, numpy array, [0, 1], low-resolution image in SR pch_size, stride: patch setting sf: scale factor in image super-resolution ''' assert stride <= pch_size self.stride = stride self.pch_size = pch_size self.sf = sf if im.ndim == 2: im = im[:, :, None] height, width, chn = im.shape self.height_starts_list = self.extract_starts(height) self.width_starts_list = self.extract_starts(width) self.length = self.__len__() self.num_pchs = 0 self.im_ori = im self.im_res = np.zeros([height*sf, width*sf, chn], dtype=im.dtype) self.pixel_count = np.zeros([height*sf, width*sf, chn], dtype=im.dtype) def extract_starts(self, length): starts = list(range(0, length, self.stride)) if starts[-1] + self.pch_size > length: starts[-1] = length - self.pch_size return starts def __len__(self): return len(self.height_starts_list) * len(self.width_starts_list) def __iter__(self): return self def __next__(self): if self.num_pchs < self.length: w_start_idx = self.num_pchs // len(self.height_starts_list) w_start = self.width_starts_list[w_start_idx] * self.sf w_end = w_start + self.pch_size * self.sf h_start_idx = self.num_pchs % len(self.height_starts_list) h_start = self.height_starts_list[h_start_idx] * self.sf h_end = h_start + self.pch_size * self.sf pch = self.im_ori[h_start:h_end, w_start:w_end,] self.w_start, self.w_end = w_start, w_end self.h_start, self.h_end = h_start, h_end self.num_pchs += 1 else: raise StopIteration(0) return pch, (h_start, h_end, w_start, w_end) def update(self, pch_res, index_infos): ''' Input: pch_res: pch_size x pch_size x 3, [0,1] index_infos: (h_start, h_end, w_start, w_end) ''' if index_infos is None: w_start, w_end = self.w_start, self.w_end h_start, h_end = self.h_start, self.h_end else: h_start, h_end, w_start, w_end = index_infos self.im_res[h_start:h_end, w_start:w_end] += pch_res self.pixel_count[h_start:h_end, w_start:w_end] += 1 def gather(self): assert np.all(self.pixel_count != 0) return self.im_res / self.pixel_count class ImageSpliterTh: def __init__(self, im, pch_size, stride, sf=1, extra_bs=1): ''' Input: im: n x c x h x w, torch tensor, float, low-resolution image in SR pch_size, stride: patch setting sf: scale factor in image super-resolution pch_bs: aggregate pchs to processing, only used when inputing single image ''' assert stride <= pch_size self.stride = stride self.pch_size = pch_size self.sf = sf self.extra_bs = extra_bs bs, chn, height, width= im.shape self.true_bs = bs self.height_starts_list = self.extract_starts(height) self.width_starts_list = self.extract_starts(width) self.starts_list = [] for ii in self.height_starts_list: for jj in self.width_starts_list: self.starts_list.append([ii, jj]) self.length = self.__len__() self.count_pchs = 0 self.im_ori = im self.im_res = torch.zeros([bs, chn, height*sf, width*sf], dtype=im.dtype, device=im.device) self.pixel_count = torch.zeros([bs, chn, height*sf, width*sf], dtype=im.dtype, device=im.device) def extract_starts(self, length): if length <= self.pch_size: starts = [0,] else: starts = list(range(0, length, self.stride)) for ii in range(len(starts)): if starts[ii] + self.pch_size > length: starts[ii] = length - self.pch_size starts = sorted(set(starts), key=starts.index) return starts def __len__(self): return len(self.height_starts_list) * len(self.width_starts_list) def __iter__(self): return self def __next__(self): if self.count_pchs < self.length: index_infos = [] current_starts_list = self.starts_list[self.count_pchs:self.count_pchs+self.extra_bs] for ii, (h_start, w_start) in enumerate(current_starts_list): w_end = w_start + self.pch_size h_end = h_start + self.pch_size current_pch = self.im_ori[:, :, h_start:h_end, w_start:w_end] if ii == 0: pch = current_pch else: pch = torch.cat([pch, current_pch], dim=0) h_start *= self.sf h_end *= self.sf w_start *= self.sf w_end *= self.sf index_infos.append([h_start, h_end, w_start, w_end]) self.count_pchs += len(current_starts_list) else: raise StopIteration() return pch, index_infos def update(self, pch_res, index_infos): ''' Input: pch_res: (n*extra_bs) x c x pch_size x pch_size, float index_infos: [(h_start, h_end, w_start, w_end),] ''' assert pch_res.shape[0] % self.true_bs == 0 pch_list = torch.split(pch_res, self.true_bs, dim=0) assert len(pch_list) == len(index_infos) for ii, (h_start, h_end, w_start, w_end) in enumerate(index_infos): current_pch = pch_list[ii] self.im_res[:, :, h_start:h_end, w_start:w_end] += current_pch self.pixel_count[:, :, h_start:h_end, w_start:w_end] += 1 def gather(self): assert torch.all(self.pixel_count != 0) return self.im_res.div(self.pixel_count) # ----------------------Patch Cliping---------------------------- class Clamper: def __init__(self, min_max=(-1, 1)): self.min_bound, self.max_bound = min_max[0], min_max[1] def __call__(self, im): if isinstance(im, np.ndarray): return np.clip(im, a_min=self.min_bound, a_max=self.max_bound) elif isinstance(im, torch.Tensor): return torch.clamp(im, min=self.min_bound, max=self.max_bound) else: raise TypeError(f'ndarray or Tensor expected, got {type(im)}') # ----------------------Interpolation---------------------------- class Bicubic: def __init__(self, scale=None, out_shape=None, activate_matlab=True, resize_back=False): self.scale = scale self.activate_matlab = activate_matlab self.out_shape = out_shape self.resize_back = resize_back def __call__(self, im): if self.activate_matlab: out = imresize_np(im, scale=self.scale) if self.resize_back: out = imresize_np(out, scale=1/self.scale) else: out = cv2.resize( im, dsize=self.out_shape, fx=self.scale, fy=self.scale, interpolation=cv2.INTER_CUBIC, ) if self.resize_back: out = cv2.resize( out, dsize=self.out_shape, fx=1/self.scale, fy=1/self.scale, interpolation=cv2.INTER_CUBIC, ) return out class SmallestMaxSize: def __init__(self, max_size=256, interpolation=None, pass_smallmaxresize=False): from albumentations import SmallestMaxSize self.resizer = SmallestMaxSize( max_size=max_size, interpolation=cv2.INTER_CUBIC if interpolation is None else interpolation ) self.pass_smallmaxresize = pass_smallmaxresize def __call__(self, im): if self.pass_smallmaxresize: out = im else: out = self.resizer(image=im)['image'] return out # ----------------------augmentation---------------------------- class SpatialAug: def __init__(self, pass_aug, only_hflip=False, only_vflip=False, only_hvflip=False): self.only_hflip = only_hflip self.only_vflip = only_vflip self.only_hvflip = only_hvflip self.pass_aug = pass_aug def __call__(self, im, flag=None): if self.pass_aug: return im if flag is None: if self.only_hflip: flag = random.choice([0, 5]) elif self.only_vflip: flag = random.choice([0, 1]) elif self.only_hvflip: flag = random.choice([0, 1, 5]) else: flag = random.randint(0, 7) if isinstance(im, list) or isinstance(im, tuple): out = [] for current_im in im: out.append(data_aug_np(current_im, flag)) else: out = data_aug_np(im, flag) return out if __name__ == '__main__': im = np.random.randn(64, 64, 3).astype(np.float32) grad1 = imgrad(im)['grad'] grad2 = imgrad_fft(im)['grad'] error = np.abs(grad1 -grad2).max() mean_error = np.abs(grad1 -grad2).mean() print('The largest error is {:.2e}'.format(error)) print('The mean error is {:.2e}'.format(mean_error))