Virtual Paint.py

import cv2
import numpy as np

frameWidth = 640
frameHeight = 480
cap = cv2.VideoCapture(0) #webcam
cap.set(3,frameWidth) #width
cap.set(4,frameHeight) #height
cap.set(10,150) #control brightness

myColors = [#[0,140,0,97,255,255], #orange
            [39,56,121,80,220,249], #green
            [90,48,0,118,255,255]] #blue
            #[123,78,63,179,224,206]] #red
myColorValues = [#[51,153,255],  # BGR format
                 [0,255,0],
                 [255,0,0]]
                 #[0,0,255]]

myPoints = []  #[x, y, colorId]

def findColor(img,myColors,myColorValues):     # to find all different types of colors
    imgHSV = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
    count = 0
    newPoints=[]
    for color in myColors:
        lower = np.array(color[0:3])
        upper = np.array(color[3:6])
        mask = cv2.inRange(imgHSV, lower, upper)
        x,y = getContours(mask)
        cv2.circle(imgResult,(x,y),10,myColorValues[count],cv2.FILLED)
        if x!=0 and y!=0:
            newPoints.append([x,y,count])
        count +=1
        #cv2.imshow(str(color[0]),mask)
    return newPoints

def getContours(img):
    contours,hierarchy = cv2.findContours(img,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE)
    x,y,w,h = 0,0,0,0
    for cnt in contours:
        area = cv2.contourArea(cnt)
        if area>500:
            #cv2.drawContours(imgResult,cnt,-1,(255,0,0),3)
            peri = cv2.arcLength(cnt,True)
            approx = cv2.approxPolyDP(cnt,0.02*peri,True)
            x, y, w, h = cv2.boundingRect(approx)
    return x+w//2,y

def drawOnCanvas(myPoints,myColorValues):
    for point in myPoints:
        cv2.circle(imgResult, (point[0], point[1]), 10, myColorValues[point[2]], cv2.FILLED)


while True:
    success, img = cap.read()
    imgResult = img.copy()
    newPoints = findColor(img,myColors,myColorValues)
    if len(newPoints)!=0:
        for newP in newPoints:
            myPoints.append(newP)
    if len(myPoints)!=0:
        drawOnCanvas(myPoints,myColorValues)
    cv2.imshow("Result",imgResult)
    if cv2.waitKey(1) & 0xFF ==ord('q'):
        break