Histogram_equalization

image.py

#!/usr/bin/env python3
# -*- encoding: utf-8 -*-
# vim: set et sw=4 ts=4 sts=4 ff=unix fenc=utf8:
import os
import sys
from PIL import Image
import numpy as np
def read(imgPath):
    img = Image.open(imgPath)
    img = img.convert("L")
    pix = img.load()
    value = img.histogram()
    cumulative = np.cumsum(value)
    min=0
    for index in range(0,img.size[1]):
        if(cumulative[index]>0):
            min=cumulative[index]
            break
    pixdata={}
    for index in range(0,256):
        data=convert(cumulative,index,min,img.size[0],img.size[1])
        pixdata[index]=data
    for y in range(0,img.size[1]):
        for x in range(0,img.size[0]):
            temp=pix[x,y]
            pix[x,y]=pixdata[temp]
    img.save(os.path.dirname(os.path.abspath(imgPath))+os.sep+"new_"+os.path.basename(os.path.abspath(imgPath)))
    print("new_"+os.path.basename(os.path.abspath(imgPath)) +" file is generated!")
def convert(cumulative,index,min,M,N,L=256):
    result=round((cumulative[index]-min)/((M*N)-min)*(L-1))
    return int(result)
def main(argv):
    args = argv[1]
    read(args)

if __name__ == "__main__":
    main(sys.argv)