“TypeError: 'int' object is not iterable” on gresycale image

Question

I have an image treatment program, where one of it's functions makes a contrast from the image the user chooses. But in the case of a greyscale image, I get the following error:

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Program Files\EduPython\App\lib\tkinter\__init__.py", line 1456, in __call__
    return self.func(*args)
  File "C:\Users\megzari.nassim\Desktop\Projet Complet\Test 2.py", line 194, in use_contrast
    result = change_contrast(S2.get())
  File "C:\Users\megzari.nassim\Desktop\Projet Complet\Test 2.py", line 188, in change_contrast
    new_color = tuple(int(factor * (c-128) + 128) for c in color)
TypeError: 'int' object is not iterable

I tried reconverting the color variable into RGB, and it still doesn't work.

Here the bit of code from this error:

def change_contrast(level):

    img = Image.open(a)
    img.load()

    factor = (259 * (level+255)) / (255 * (259-level))
    for x in range(img.size[0]):
        for y in range(img.size[1]):
            color = img.getpixel((x, y))
            new_color = tuple(int(factor * (c-128) + 128) for c in color)
            img.putpixel((x, y), new_color)

    return img

In case you need the full code, here it is:

from tkinter import*
import tkinter as Tkinter
from tkinter import filedialog, DISABLED, messagebox as tkMessageBox
import os
import ntpath
from PIL import Image, ImageTk, ImageFilter
import PIL
from collections import Counter
from random import randint
import random
import PIL.ImageOps


def EchelleDeGris():
    Ima2=Image.new("RGB",(z[0],z[1]))
    px=Ima1.load()
    px1=Ima2.load()
    for x in range(z[0]):
        for y in range(z[1]):
            p=px[x,y]
            if type(p)==int:
                p=(p,p,p)
            o=int((p[0]+p[1]+p[2])/3)
            px1[x,y]=(o,o,o)
    Ima2.save(""+dir_path+"\\Requirements\\ImageMod.png")
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\ImageMod.png")
    main.image = im2
    I2 = Tkinter.Label(main, image=im2)
    I2.grid(row=0, column=4, columnspan =4)

def SupprimerImage():
    I2 = Tkinter.Label(main, image=imt)
    I2.grid(row=0, column=4, columnspan =4)

def Luminosite():
    Ima2=Image.new("RGB",(z[0],z[1]))
    px=Ima1.load()
    px1=Ima2.load()
    for x in range(z[0]):
        for y in range(z[1]):
            p=px[x,y]
            if type(p)==int:
                p=(p,p,p)
            px1[x,y]=(p[0]+S1.get(),p[1]+S1.get(),p[2]+S1.get())
    Ima2.save(""+dir_path+"\\Requirements\\ImageMod.png")
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\ImageMod.png")
    main.image = im2
    I2 = Tkinter.Label(main, image=im2)
    I2.grid(row=0, column=4, columnspan =4)

def AnnulerModifications():
    I2 = Tkinter.Label(main, image=im1)
    I2.grid(row=0, column=4, columnspan =4)

def get_pixel(pixels, x, y):
    try:
        return pixels[x, y]
    except IndexError:
        return None


def get_neighbors(pixels, x, y):
    neighbors = list()
    neighbors.append(get_pixel(pixels, x, y - 1))
    neighbors.append(get_pixel(pixels, x, y + 1))
    neighbors.append(get_pixel(pixels, x - 1, y))
    neighbors.append(get_pixel(pixels, x + 1, y))
    neighbors.append(get_pixel(pixels, x - 1, y - 1))
    neighbors.append(get_pixel(pixels, x - 1, y + 1))
    neighbors.append(get_pixel(pixels, x + 1, y - 1))
    neighbors.append(get_pixel(pixels, x + 1, y + 1))
    return neighbors


def filter_art(pixels, size):
    indexes = dict()
    for x in range(size[0]):
        for y in range(size[1]):
            color = get_pixel(pixels, x, y)
            neighbors = get_neighbors(pixels, x, y)
            new_color = Counter(neighbors).most_common()[0][0]
            if new_color is not None:
                indexes[x, y] = new_color
    for x, y in indexes:
        pixels[x, y] = indexes[x, y]


def pop_art(path_orig, path_mod, coef):

    s=[]
    for i in range(9):

        r=(randint(0,255), randint(0,255), randint(0,255))
        g=(randint(0,255), randint(0,255), randint(0,255))
        b=(randint(0,255), randint(0,255), randint(0,255))

        image_orig = Image.open(path_orig)
        size = image_orig.size
        image_mod = Image.new("RGB",(size[0],size[1]))
        pixels_orig = image_orig.load()
        pixels_mod = image_mod.load()
        for x in range(size[0]):
            for y in range(size[1]):
                p = pixels_orig[x, y]
                if isinstance(p, int):
                    rgb = (p,p,p)
                elif isinstance(p, tuple) and len(p) in (3, 4):
                    rgb = p[:3]
                else:
                    raise TypeError('Unknown pallete')
                average_color = sum(rgb) / 3
                if average_color <= 85:
                    pixels_mod[x, y] = r
                elif 85 < average_color <= 170:
                    pixels_mod[x, y] = g
                elif average_color > 170:
                    pixels_mod[x, y] = b
        for _ in range(coef):
            filter_art(pixels_mod, size)
        image_mod.save(''+dir_path+'\\PopArt\\Modified Images\\result'+str(i)+'.png')
        Img=[None]*9
    for i in range(9):
        Img[i]=Image.open(""+dir_path+"\\PopArt\\Modified Images\\result"+str(i)+".png")
        basewidth = int(Img[i].size[1]/3)
        wpercent = (basewidth / float(Img[i].size[0]))
        hsize = int((float(Img[i].size[1]) * float(wpercent )))
        Img[i] = Img[i].resize((basewidth , hsize ), PIL.Image.ANTIALIAS)
        Img[i].save(''+dir_path+'\\PopArt\\Resized Images\\resized_image'+str(i)+'.png')


    Img1=[None]*9
    pixels1=[None]*9
    Imaz=Image.new("RGB",(basewidth*3,hsize*3))
    pixels=Imaz.load()
    for i in range(9):
        Img1[i]=Image.open(''+dir_path+'\\PopArt\\Resized Images\\resized_image'+str(i)+'.png')
        pixels1[i]=Img1[i].load()


    for x in range(0,basewidth):
        for y in range(0,hsize):
            pixels[x,y]=pixels1[0][x,y]
        for y in range(hsize,hsize*2):
            pixels[x,y]=pixels1[1][x,y-hsize]
        for y in range(hsize*2,hsize*3):
            pixels[x,y]=pixels1[2][x,y-hsize*2]

    for x in range(basewidth,basewidth*2):
        for y in range(0,hsize):
            pixels[x,y]=pixels1[3][x-basewidth,y]
        for y in range(hsize,hsize*2):
            pixels[x,y]=pixels1[4][x-basewidth,y-hsize]
        for y in range(hsize*2,hsize*3):
            pixels[x,y]=pixels1[5][x-basewidth,y-hsize*2]

    for x in range(basewidth*2,basewidth*3):
        for y in range(0,hsize):
            pixels[x,y]=pixels1[6][x-basewidth*2,y]
        for y in range(hsize,hsize*2):
            pixels[x,y]=pixels1[7][x-basewidth*2,y-hsize]
        for y in range(hsize*2,hsize*3):
            pixels[x,y]=pixels1[8][x-basewidth*2,y-hsize*2]
    Imaz = Imaz.resize((size[0] , size[1] ), PIL.Image.ANTIALIAS)
    Imaz.save(""+dir_path+"\\PopArt\\Result Image\\result.png")


def usepop():
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\traitement.png")
    main.image = im2
    I2 = Tkinter.Label(main, image=im2)
    I2.grid(row=0, column=4, columnspan =4)
    I2.update_idletasks()
    pop_art(a, None, coef=4)
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\PopArt\\Result Image\\result.png")
    main.image = im2
    I2 = Tkinter.Label(main, image=im2)
    I2.grid(row=0, column=4, columnspan =4)

def change_contrast(level):

    img = Image.open(a)
    img.load()

    factor = (259 * (level+255)) / (255 * (259-level))
    for x in range(img.size[0]):
        for y in range(img.size[1]):
            color = img.getpixel((x, y))
            new_color = tuple(int(factor * (c-128) + 128) for c in color)
            img.putpixel((x, y), new_color)

    return img

def use_contrast():
    result = change_contrast(S2.get())
    result.save(""+dir_path+"\\Requirements\\ImageMod.png")
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\ImageMod.png")
    main.image = im2
    I2 = Tkinter.Label(main, image=im2)
    I2.grid(row=0, column=4, columnspan =4)

def recherche_contours():
    Ima2=Image.new("RGB",(z[0],z[1]))
    px=Ima1.load()
    px1=Ima2.load()
    for x in range(z[0]):
        for y in range(z[1]):
            p=px[x,y]
            if type(p)==int:
                p=(p,p,p)
            o=int((p[0]+p[1]+p[2])/3)
            px1[x,y]=(o,o,o)
    Ima2 = Ima2.filter(ImageFilter.FIND_EDGES)
    image = Ima2
    if image.mode == 'RGBA':
        r,g,b,a = image.split()
        rgb_image = Image.merge('RGB', (r,g,b))

        inverted_image = PIL.ImageOps.invert(rgb_image)

        r2,g2,b2 = inverted_image.split()

        final_transparent_image = Image.merge('RGBA', (r2,g2,b2,a))

        final_transparent_image.save(""+dir_path+"\\Requirements\\ImageMod.png")

    else:
        inverted_image = PIL.ImageOps.invert(image)
        inverted_image.save(""+dir_path+"\\Requirements\\ImageMod.png")
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\ImageMod.png")
    main.image = im2
    I2 = Tkinter.Label(main, image=im2)
    I2.grid(row=0, column=4, columnspan =4)

main=Tk()

main.withdraw()
a = filedialog.askopenfilename()
main.deiconify()

dir_path = os.path.dirname(os.path.realpath("Test2.py"))

main.configure(background="#a1dbcd")
main.title("Photoshop Version.Megzari")

Ima1=Image.open(a)
z=Ima1.size
nux=Image.new("RGB",(z[0],z[1]))
nuxy=nux.load()
for x in range(z[0]):
    for y in range(z[1]):
        nuxy[x,y]=(255,255,255)
nux.save(""+dir_path+"\\Requirements\\Blank.png")


if z>(400,400):
    main.withdraw()
    tkMessageBox.showinfo( "Resolution Error", "The image is too big, please select a smaller one.")
    sys.exit()


elif z<(400,400):
    im1 = ImageTk.PhotoImage(file=a)
    I1 = Tkinter.Label(main, image=im1)
    I1.grid(row=0, column=1, columnspan =3)
    imt = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\Blank.png")
    T1 = Tkinter.Label(main, image=imt)
    T1.grid(row=0, column=4, columnspan =4)
    B1 = Tkinter.Button(main, text ="Echelle de gris", command = EchelleDeGris, fg="#a1dbcd", bg="#383a39", state=NORMAL)
    B1.grid(padx=20, pady=20, row=1, column=0)
    B3 = Tkinter.Button(main, text ="Appliquer Luminosité", command = Luminosite, fg="#a1dbcd", bg="#383a39")
    B3.grid(padx=20, pady=20, row=1, column=1)
    S1 = Scale(main, from_=0, to=254, orient=HORIZONTAL, fg="#a1dbcd", bg="#383a39", length = 200)
    S1.grid(row=2, column=1)
    B2 = Tkinter.Button(main, text ="Supprimer Image", command = SupprimerImage, fg="#a1dbcd", bg="#383a39")
    B2.grid(padx=20, pady=20, row=1, column=7)
    B3 = Tkinter.Button(main, text ="Annuler Modifications", command = AnnulerModifications, fg="#a1dbcd", bg="#383a39")
    B3.grid(padx=20, pady=20, row=1, column=6)
    B4 = Tkinter.Button(main, text ="Pop Art", command = usepop, fg="#a1dbcd", bg="#383a39")
    B4.grid(padx=20, pady=20, row=1, column=3)
    S2 = Scale(main, from_=-258, to=258, orient=HORIZONTAL, fg="#a1dbcd", bg="#383a39", length = 200)
    S2.grid(row=2, column=4)
    B4 = Tkinter.Button(main, text ="Appliquer Contraste", command = use_contrast, fg="#a1dbcd", bg="#383a39")
    B4.grid(padx=20, pady=20, row=1, column=4)
    B5 = Tkinter.Button(main, text ="Trouver Contours", command = recherche_contours, fg="#a1dbcd", bg="#383a39")
    B5.grid(padx=20, pady=20, row=1, column=5)

    s=S1.get()
    s2=S2.get()





main.mainloop()

EDIT: I tried using:

if type(color)==int:
    color=(color,color,color)

and it required me an integer on the new_color

Answer 1

From the documentation:

.getpixel(xy)

Returns the pixel value or values at the given coordinates. For single-band images, returns a single number; a sequence of pixel values is returned for multi-band images. For example, if the top left pixel of an image im of mode "L" has value 128, then im.getpixel((0,0)) returns 128.

So, it can return either a single value or a tuple. If it's a single value, you'll get the not iterable error. That means you have to check what you get from the call.

Answer 2

Since no one could answer this simple question, I found out myself after a bunch of tests and maneuvers. In fact, all I had to do was check the type() of color. If it is an int, I make color a tuple. You can do this by either assigning: color=(color,color,color) or making it a list this way: color=[color,color,color] or color=[color]*3 then making it tuple: color=tuple(color). Since new_color will be now a tuple, its still 3 identical values, but img.putpixel((x, y), new_color) requires an integer, so you just extract the first value of new_color by writing new_color=new_color[0]. If type() of color is not an int, you just run the other piece of code without any modification. Here is the working code of the one up above:

def change_contrast(level):

    img = Image.open(a)
    img.load()

    factor = (259 * (level+255)) / (255 * (259-level))
    for x in range(img.size[0]):
        for y in range(img.size[1]):
            color = img.getpixel((x, y))
            if type(color) == int:
                color=(color,color,color)
                new_color = tuple(int(factor * (c-128) + 128) for c in color)
                new_color = new_color[0]
                img.putpixel((x, y), new_color)
            elif type(color) != int:
                new_color = tuple(int(factor * (c-128) + 128) for c in color)
                img.putpixel((x, y), new_color)
    return img