# -*- coding: utf-8 -*-
# @Time    : 2022-7-26 0026 11:41
# @Author  : Qing
# @Email   : derighoid@gmail.com
# @File    : GammaCorrection.py
# @Software: PyCharm
'''
gamma矫正公式：
f(x)=xγ
即输出是输入的幂函数，指数为γ．
'''
import matplotlib.pyplot as plt
import numpy as np
from PIL import Image

root = "E:\\桌面\\Python_Picture_Analysis\\data\\"


def gammaCorrect(filePath,val):
    im = Image.open(filePath)
    img = np.array(im)

    img1 = np.power(img / float(np.max(img)), 1 / 1.5)
    img2 = np.power(img / float(np.max(img)), val)

    plt.subplot(131)
    plt.imshow(img)
    plt.title("origin")
    plt.subplot(132)
    plt.imshow(img1)
    plt.title("gammar=1/1.5")
    plt.subplot(133)
    plt.imshow(img2)
    plt.title("user-defined")
    plt.show()
    Image.fromarray(np.uint8(img2)).save(root + 'picture10' + '.jpg')
    return img2