Filling colour logically while drawing rectangle Tkinter

Question

While using PIL draw rectangles on an image in the canvas. I wish to change the fill rectangle depending on the pixel color of my image in the canvas.

I have referred one of the cross posts (link pasted below) to create rectangles with mouse events in Tkinter.

create_rectangle fills the rectangle with a color specified with mouse events (example: the rectangle is filled with black in this example). Is there a way to logically change the fill color depending on the existing pixel color of the background image? I mean, while drawing a rectangle, I need only the white colored pixels of the background image to be turning red and the rest with a different color.

Drawing rectangle using mouse events in Tkinter

[1]: https://i.sstatic.net/W41kX.jpg

def rec_on_button_press(self,event):
    self.start_x = event.x
    self.start_y = event.y
    self.rect=self.image_canvas.create_rectangle(self.x, self.y, 1, 1,fill=self.python_red)
def rec_on_move(self, event):
    curX, curY = (event.x, event.y)
    imagenp= np.array(image)
    if imagenp[curY,curX]==255:
        self.python_red="#EE204D"
    else:
        self.python_red=None
    self.image_canvas.coords(self.rect, self.start_x, self.start_y, curX, curY)

def rec_on_button_release(self, event):
    pass

Answer 1

Principle: Crop the image you select,create it and show it.

The code need to be modified,the example of full code(the example is convert 255(white) to 0(black)):

import tkinter as tk # this is in python 3.4. For python 2.x import Tkinter
from PIL import Image, ImageTk
import numpy as np
import ctypes
ctypes.windll.shcore.SetProcessDpiAwareness(2) # for windows 10

class ExampleApp(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.x = self.y = 0
        self.canvas = tk.Canvas(self, width=512, height=512, cursor="cross")
        self.canvas.pack(side="top", fill="both", expand=True)
        self.canvas.bind("<ButtonPress-1>", self.on_button_press)
        self.canvas.bind("<B1-Motion>", self.on_move_press)
        self.canvas.bind("<ButtonRelease-1>", self.on_button_release)

        self.rect = None

        self.start_x = None
        self.start_y = None
        self.python_red = None

        self.im = Image.open(r'ImagePath').convert("L")
        self.move_imageID = None
        self.move_image = None
        self.tk_im = ImageTk.PhotoImage(self.im)
        self.canvas.create_image(0,0,anchor="nw",image=self.tk_im)



    def on_button_press(self, event):
        # save mouse drag start position
        self.start_x = event.x
        self.start_y = event.y
        self.rect = self.canvas.create_rectangle(self.x, self.y,  0, 0, outline="black")

    def on_move_press(self, event):
        self.canvas.delete(self.move_imageID)
        crop_image = self.im.crop((self.start_x,self.start_y,event.x,event.y))
        imageArray = np.array(crop_image)
        if imageArray.shape:
            for i in range(imageArray.shape[0]):
                for j in range(imageArray.shape[1]): # convert  the white pixel to black
                    if imageArray[i,j] == 255:
                        imageArray[i,j] = 0
            self.move_image = Image.fromarray(imageArray)
            self.move_image = ImageTk.PhotoImage(self.move_image)
            self.move_imageID = self.canvas.create_image(self.start_x,self.start_y,anchor="nw",image=self.move_image)
            self.canvas.coords(self.rect,self.start_x,self.start_y,event.x,event.y)
            self.canvas.lift(self.rect)

    def on_button_release(self, event):
        pass


if __name__ == "__main__":
    app = ExampleApp()
    app.mainloop()

Now:

Select area: