Deleting White from Bitmap

[Windspar]

using pillow for python 3.

import tkinter as tk
from PIL import ImageTk, Image

def filter_image(image, color):
    alpha_mask = Image.new('1', image.size)
    for y in range(image.size[1]):
        for x in range(image.size[0]):
            if image.getpixel((x, y)) == color:
                alpha_mask.putpixel((x,y), 0)
            else:
                alpha_mask.putpixel((x,y), 1)

    image.putalpha(alpha_mask)

class App:
    def __init__(self):
        self.root = tk.Tk()
        filename = "../Images/test.bmp"
        p_image = Image.open(filename)
        # grab topleft corner or input rgb color
        filter_image(p_image, p_image.getpixel((0,0)))
        self.image = ImageTk.PhotoImage(p_image)
        self.label = tk.Label(self.root, image = self.image)
        self.label.pack()

app = App()
app.root.mainloop()

---

Remember bitmaps do not hold transparent. You have to tell program what not to draw.