img_trans.py

import numpy as np
import random
from skimage import draw
from skimage import morphology as mp
from skimage import exposure as ep
from keras.preprocessing import image


def light(img):
    # adjust_gamma(x, gamma)
    # gamma > 1 --- darker
    # gamma < 1 --- brighter
    return ep.adjust_gamma(img, random.uniform(0.8, 1.05))


def shift(img):
    # random_shift(x, wrg, hrg, row_axis=1, col_axis=2, channel_axis=0, fill_mode='nearest', cval=0.0)
    img = img.reshape(1, 28, 28)
    wrg = 0.2
    hrg = 0.2
    return image.random_shift(img, wrg, hrg).reshape(28, 28)


def rotate(img):
    # random_rotation(x, rg, row_axis=1, col_axis=2, channel_axis=0, fill_mode='nearest', cval=0.0)
    img = img.reshape(1, 28, 28)
    rg = 30
    return image.random_rotation(img, rg).reshape(28, 28)


def flip(img):
    # flip_axis(x, axis)
    # horizontal
    return image.flip_axis(img, 1)


def zoom(img):
    # random_zoom(x, zoom_range, row_axis=1, col_axis=2, channel_axis=0, fill_mode='nearest', cval=0.0)
    img = img.reshape(1, 28, 28)
    zoom_range = (0.6, 1.3)
    return image.random_zoom(img, zoom_range).reshape(28, 28)


def dilation(img):
    # return greyscale morphological dilation of an image
    return mp.dilation(img, mp.square(2, dtype=np.uint64))


def erosion(img):
    # return greyscale morphological erosion of an image
    return mp.erosion(img, mp.square(2, dtype=np.uint64))


def draw_line(img):
    # draw a straight line across the digit
    r0 = random.randint(0, 28)
    c0 = random.randint(0, 4)
    r1 = random.randint(0, 28)
    c1 = random.randint(24, 28)
    rr, cc = draw.line(r0, c0, r1, c1)
    img[rr, cc] = 255
    return img


def s_p_noise(img):
    # salt and pepper noise
    rows, cols = img.shape
    for i in range(50):
        x = np.random.randint(0, rows)
        y = np.random.randint(0, cols)
        img[x, y] = 255
    return img