4_overlay_magic_circle.py

import cv2
import mediapipe as mp

cap = cv2.VideoCapture(0)

mpHands = mp.solutions.hands
hands = mpHands.Hands()
mpDraw = mp.solutions.drawing_utils

orange = (0, 140, 255)

coorx = [0] * 21
coory = [0] * 21

wrist = thumb_tip = index_mcp = index_tip = midle_mcp = midle_tip = ring_tip = pinky_tip = (0,0)

shield = cv2.imread('magic_circle.png',-1)

def moveData():
    global wrist
    global thumb_tip
    global index_mcp
    global index_tip
    global midle_mcp
    global midle_tip
    global ring_tip
    global pinky_tip
    wrist = coorx[0],coory[0]
    thumb_tip = coorx[4],coory[4]
    index_mcp = coorx[5],coory[5]
    index_tip = coorx[8],coory[8]
    midle_mcp = coorx[9],coory[9]
    midle_tip = coorx[12],coory[12]
    ring_tip = coorx[16],coory[16]
    pinky_tip = coorx[20],coory[20]

def shiningLine(back_img, coor1, coor2, color, size):
    #draw dot
    cv2.circle(img, coor1, size+1, color, cv2.FILLED)
    cv2.circle(img, coor2, size+1, color, cv2.FILLED)
    #draw color line
    cv2.line(back_img, coor1, coor2, color, size)       
    #draw white line
    cv2.line(back_img, coor1, coor2, (255, 255, 255), round(size/2))

def drawLine():
    #draw line
    shiningLine(img, thumb_tip, index_tip, orange, 2)
    shiningLine(img, thumb_tip, midle_tip, orange, 2)
    shiningLine(img, thumb_tip, ring_tip, orange, 2)
    shiningLine(img, thumb_tip, pinky_tip, orange, 2)

def drawPentagram():
    #draw pentagram
    shiningLine(img, index_tip, midle_tip, orange, 2)
    shiningLine(img, index_tip, ring_tip, orange, 2)
    shiningLine(img, index_tip, pinky_tip, orange, 2)
    shiningLine(img, midle_tip, ring_tip, orange, 2)
    shiningLine(img,  midle_tip, pinky_tip, orange, 2)
    shiningLine(img, ring_tip, pinky_tip, orange, 2)

def calculateDistance(coor1,coor2):
    x1,y1,x2,y2 = coor1[0],coor1[1],coor2[0],coor2[1]
    dist = ((x2 - x1)**2 + (y2 - y1)**2)**(1.0/2)
    return dist

def overlay_transparent(background_img, img_to_overlay_t, x, y, overlay_size=None):
	bg_img = background_img.copy()
	
	if overlay_size is not None:
		img_to_overlay_t = cv2.resize(img_to_overlay_t.copy(), overlay_size)

	# Extract the alpha mask of the RGBA image, convert to RGB 
	b,g,r,a = cv2.split(img_to_overlay_t)
	overlay_color = cv2.merge((b,g,r))
	
	# Apply some simple filtering to remove edge noise
	mask = cv2.medianBlur(a,5)

	h, w, _ = overlay_color.shape
	roi = bg_img[y:y+h, x:x+w]

	# Black-out the area behind the logo in our original ROI
	img1_bg = cv2.bitwise_and(roi.copy(),roi.copy(),mask = cv2.bitwise_not(mask))
	
	# Mask out the logo from the logo image.
	img2_fg = cv2.bitwise_and(overlay_color,overlay_color,mask = mask)

	# Update the original image with our new ROI
	bg_img[y:y+h, x:x+w] = cv2.add(img1_bg, img2_fg)

	return bg_img

while True:
    success, img = cap.read()
    img = cv2.flip(img,1)
    imgRGB = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
    results = hands.process(imgRGB)

    if results.multi_hand_landmarks:
        for handLms in results.multi_hand_landmarks:
            for id, lm in enumerate(handLms.landmark):
                h, w, c = img.shape
                # coorx, coory = int(lm.x * w), int(lm.y * h)
                # cv2.circle(img, (coorx,coory), 6, (0,255,0), cv2.FILLED)
                coorx[id], coory[id] = int(lm.x * w), int(lm.y * h)
     
            moveData()
            drawLine()

            palm = calculateDistance(wrist, index_mcp)
            distance = calculateDistance(index_tip, pinky_tip)
            ratio = distance/palm

            if(ratio > 1):
                drawPentagram()

                if(ratio > 1.5):
                    #find the center of the hand A.K.A the center of the shield
                    centerx = midle_mcp[0]
                    centery = midle_mcp[1]

                    #determine the diameter of the shield 
                    shield_size = 3.0
                    diameter = round(palm*shield_size)

                    #calculate top left corner
                    x1 = round(centerx - (diameter/2))
                    y1 = round(centery - (diameter/2))
                        
                    h, w, c = img.shape

                    #keep the shield inside the frame
                    if x1<0:
                        x1 = 0
                    elif x1>w:
                        x1 = w

                    if y1<0:
                        y1 = 0
                    elif y1>h:
                        y1 = h
    
                    if x1+diameter > w:
                        diameter = w-x1

                    if y1+diameter > h:
                        diameter = h-y1

                    shield_size = diameter,diameter

                    #if diameter is exist, add shield
                    if(diameter != 0):          
                        img = overlay_transparent(img, shield, x1, y1, shield_size)
     
            # mpDraw.draw_landmarks(img, handLms, mpHands.HAND_CONNECTIONS)
    
    cv2.imshow("Image", img)
    cv2.waitKey(1)