import numpy as np
import cv2


def imcv2_recolor(im, a=.1):
    t = [np.random.uniform()]
    t += [np.random.uniform()]
    t += [np.random.uniform()]
    t = np.array(t) * 2. - 1.

    # random amplify each channel
    im = im * (1 + t * a)
    mx = 255. * (1 + a)
    up = np.random.uniform() * 2 - 1
    # 	im = np.power(im/mx, 1. + up * .5)
    im = cv2.pow(im / mx, 1. + up * .5)
    return np.array(im * 255., np.uint8)


def imcv2_affine_trans(im):
    # Scale and translate
    h, w, c = im.shape
    scale = np.random.uniform() / 10. + 1.
    max_offx = (scale - 1.) * w
    max_offy = (scale - 1.) * h
    offx = int(np.random.uniform() * max_offx)
    offy = int(np.random.uniform() * max_offy)

    im = cv2.resize(im, (0, 0), fx=scale, fy=scale)
    im = im[offy: (offy + h), offx: (offx + w)]
    flip = np.random.binomial(1, .5)
    if flip: im = cv2.flip(im, 1)
    return im, [w, h, c], [scale, [offx, offy], flip]