import random import cv2 import numpy as np from data.util import read_img from PIL import Image from io import BytesIO # Performs image corruption on a list of images from a configurable set of corruption # options. class ImageCorruptor: def __init__(self, opt): self.blur_scale = opt['corruption_blur_scale'] if 'corruption_blur_scale' in opt.keys() else 1 self.fixed_corruptions = opt['fixed_corruptions'] if 'fixed_corruptions' in opt.keys() else [] self.num_corrupts = opt['num_corrupts_per_image'] if 'num_corrupts_per_image' in opt.keys() else 0 if self.num_corrupts == 0: return self.random_corruptions = opt['random_corruptions'] if 'random_corruptions' in opt.keys() else [] def corrupt_images(self, imgs): if self.num_corrupts == 0 and not self.fixed_corruptions: return imgs if self.num_corrupts == 0: augmentations = [] else: augmentations = random.choices(self.random_corruptions, k=self.num_corrupts) # Source of entropy, which should be used across all images. rand_int_f = random.randint(1, 999999) rand_int_a = random.randint(1, 999999) corrupted_imgs = [] applied_augs = augmentations + self.fixed_corruptions for img in imgs: for aug in augmentations: img = self.apply_corruption(img, aug, rand_int_a, applied_augs) for aug in self.fixed_corruptions: img = self.apply_corruption(img, aug, rand_int_f, applied_augs) corrupted_imgs.append(img) return corrupted_imgs def apply_corruption(self, img, aug, rand_int, applied_augmentations): if 'color_quantization' in aug: # Color quantization quant_div = 2 ** ((rand_int % 3) + 2) img = img * 255 img = (img // quant_div) * quant_div img = img / 255 elif 'gaussian_blur' in aug: # Gaussian Blur if aug == 'gaussian_blur_3': kernel = 3 elif aug == 'gaussian_blur_5': kernel = 5 else: kernel = 2 * self.blur_scale * (rand_int % 3) + 1 img = cv2.GaussianBlur(img, (kernel, kernel), 3) elif 'motion_blur' in aug: # Motion blur intensity = self.blur_scale * (rand_int % 3) + 1 angle = (rand_int // 3) % 360 k = np.zeros((intensity, intensity), dtype=np.float32) k[(intensity - 1) // 2, :] = np.ones(intensity, dtype=np.float32) k = cv2.warpAffine(k, cv2.getRotationMatrix2D((intensity / 2 - 0.5, intensity / 2 - 0.5), angle, 1.0), (intensity, intensity)) k = k * (1.0 / np.sum(k)) img = cv2.filter2D(img, -1, k) elif 'smooth_blur' in aug: # Smooth blur kernel = 2 * self.blur_scale * (rand_int % 3) + 1 img = cv2.blur(img, ksize=(kernel, kernel)) elif 'block_noise' in aug: # Large distortion blocks in part of an img, such as is used to mask out a face. pass elif 'lq_resampling' in aug: # Random mode interpolation HR->LR->HR scale = 2 if 'lq_resampling4x' == aug: scale = 4 interpolation_modes = [cv2.INTER_NEAREST, cv2.INTER_CUBIC, cv2.INTER_LINEAR, cv2.INTER_LANCZOS4] mode = rand_int % len(interpolation_modes) # Downsample first, then upsample using the random mode. img = cv2.resize(img, dsize=(img.shape[1]//scale, img.shape[0]//scale), interpolation=cv2.INTER_NEAREST) img = cv2.resize(img, dsize=(img.shape[1]*scale, img.shape[0]*scale), interpolation=mode) elif 'color_shift' in aug: # Color shift pass elif 'interlacing' in aug: # Interlacing distortion pass elif 'chromatic_aberration' in aug: # Chromatic aberration pass elif 'noise' in aug: # Random noise if 'noise-5' == aug: noise_intensity = 5 / 255.0 else: noise_intensity = (rand_int % 4 + 2) / 255.0 # Between 1-4 img += np.random.randn(*img.shape) * noise_intensity elif 'jpeg' in aug: if 'noise' not in applied_augmentations and 'noise-5' not in applied_augmentations: if aug == 'jpeg': lo=10 range=20 elif aug == 'jpeg-low': lo=15 range=10 elif aug == 'jpeg-medium': lo=23 range=25 elif aug == 'jpeg-broad': lo=15 range=60 elif aug == 'jpeg-normal': lo=47 range=35 else: raise NotImplementedError("specified jpeg corruption doesn't exist") # JPEG compression qf = (rand_int % range + lo) # Use PIL to perform a mock compression to a data buffer, then swap back to cv2. img = (img * 255).astype(np.uint8) img = Image.fromarray(img) buffer = BytesIO() img.save(buffer, "JPEG", quality=qf, optimize=True) buffer.seek(0) jpeg_img_bytes = np.asarray(bytearray(buffer.read()), dtype="uint8") img = read_img("buffer", jpeg_img_bytes, rgb=True) elif 'saturation' in aug: # Lightening / saturation saturation = float(rand_int % 10) * .03 img = np.clip(img + saturation, a_max=1, a_min=0) elif 'none' not in aug: raise NotImplementedError("Augmentation doesn't exist") return img