#!/usr/bin/python3

### Convertir un ficher .PNG en .PPM 256

import numpy as np
import matplotlib.pyplot as plt

import sys


# Importer une image
def chargeImage(nom_de_fichier):
    img_f=plt.imread(nom_de_fichier)
    img_uint8 = (255*img_f).astype(dtype=np.uint8)
    return img_uint8

def exporterImage(img, filename):
    with open(filename, "w") as f:
        (n,p,r) = img.shape
        f.write("P3\n")
        f.write("{} {}\n".format(p,n))
        f.write("255\n")
        for i in range(n):
            for j in range(p):
                f.write("{} {} {}\n".format(img[i,j,0], img[i,j,1], img[i,j,2]))

# script
try :
    filename = sys.argv[1]
    filename2 = sys.argv[2]
    assert filename[-4:] == ".png"
    assert filename2[-4:] == ".ppm"
    img = chargeImage(filename)
    exporterImage(img, filename2)
except:
    print("Usage : ./convertColor filename.png filename.ppm")
    raise