utils/ops.py

from PIL import Image, ImageEnhance, ImageOps
import random
import torch
import numpy as np
class Cutout(object):
    def __init__(self, n_holes, length):
        self.n_holes = n_holes
        self.length = length

    def __call__(self, img):
        h = img.size(1)
        w = img.size(2)

        mask = np.ones((h, w), np.float32)

        for n in range(self.n_holes):
            y = np.random.randint(h)
            x = np.random.randint(w)

            y1 = np.clip(y - self.length // 2, 0, h)
            y2 = np.clip(y + self.length // 2, 0, h)
            x1 = np.clip(x - self.length // 2, 0, w)
            x2 = np.clip(x + self.length // 2, 0, w)

            mask[y1: y2, x1: x2] = 0.

        mask = torch.from_numpy(mask)
        mask = mask.expand_as(img)
        img = img * mask

        return img
    
class ShearX(object):
    def __init__(self, fillcolor=(128, 128, 128)):
        self.fillcolor = fillcolor

    def __call__(self, x, magnitude):
        return x.transform(
            x.size, Image.AFFINE, (1, magnitude * random.choice([-1, 1]), 0, 0, 1, 0),
            Image.BICUBIC, fillcolor=self.fillcolor)


class ShearY(object):
    def __init__(self, fillcolor=(128, 128, 128)):
        self.fillcolor = fillcolor

    def __call__(self, x, magnitude):
        return x.transform(
            x.size, Image.AFFINE, (1, 0, 0, magnitude * random.choice([-1, 1]), 1, 0),
            Image.BICUBIC, fillcolor=self.fillcolor)


class TranslateX(object):
    def __init__(self, fillcolor=(128, 128, 128)):
        self.fillcolor = fillcolor

    def __call__(self, x, magnitude):
        return x.transform(
            x.size, Image.AFFINE, (1, 0, magnitude * x.size[0] * random.choice([-1, 1]), 0, 1, 0),
            fillcolor=self.fillcolor)


class TranslateY(object):
    def __init__(self, fillcolor=(128, 128, 128)):
        self.fillcolor = fillcolor

    def __call__(self, x, magnitude):
        return x.transform(
            x.size, Image.AFFINE, (1, 0, 0, 0, 1, magnitude * x.size[1] * random.choice([-1, 1])),
            fillcolor=self.fillcolor)


class Rotate(object):
    def __call__(self, x, magnitude):
        rot = x.convert("RGBA").rotate(magnitude * random.choice([-1, 1]))
        return Image.composite(rot, Image.new("RGBA", rot.size, (128,) * 4), rot).convert(x.mode)


class Color(object):
    def __call__(self, x, magnitude):
        return ImageEnhance.Color(x).enhance(1 + magnitude * random.choice([-1, 1]))


class Posterize(object):
    def __call__(self, x, magnitude):
        return ImageOps.posterize(x, magnitude)


class Solarize(object):
    def __call__(self, x, magnitude):
        return ImageOps.solarize(x, magnitude)


class Contrast(object):
    def __call__(self, x, magnitude):
        return ImageEnhance.Contrast(x).enhance(1 + magnitude * random.choice([-1, 1]))


class Sharpness(object):
    def __call__(self, x, magnitude):
        return ImageEnhance.Sharpness(x).enhance(1 + magnitude * random.choice([-1, 1]))


class Brightness(object):
    def __call__(self, x, magnitude):
        return ImageEnhance.Brightness(x).enhance(1 + magnitude * random.choice([-1, 1]))


class AutoContrast(object):
    def __call__(self, x, magnitude):
        return ImageOps.autocontrast(x)


class Equalize(object):
    def __call__(self, x, magnitude):
        return ImageOps.equalize(x)


class Invert(object):
    def __call__(self, x, magnitude):
        return ImageOps.invert(x)