irisDistance.py

import cv2 as cv 
import numpy as np
import mediapipe as mp 

mp_face_mesh = mp.solutions.face_mesh
LEFT_IRIS = [474,475, 476, 477]
RIGHT_IRIS = [469, 470, 471, 472]

input = cv.VideoCapture(0) #get video from 

with mp_face_mesh.FaceMesh(max_num_faces=1, refine_landmarks=True, min_detection_confidence=0.5, min_tracking_confidence=0.5) as face_mesh:
    while True:
        success, frame = input.read()
        if not success:
            print("No frame :(")
            break

        frame = cv.flip(frame, 1) #get the frame convert into nice colours
        rgb_frame = cv.cvtColor(frame, cv.COLOR_BGR2RGB)
        img_h, img_w = frame.shape[:2]

        results = face_mesh.process(rgb_frame) # google ai stuff

        if results.multi_face_landmarks:
            mesh_points=np.array([np.multiply([p.x, p.y], [img_w, img_h]).astype(int) for p in results.multi_face_landmarks[0].landmark]) #get the general landmarks
            cv.polylines(frame, [mesh_points[LEFT_IRIS]], True, (0,255,0), 1, cv.LINE_AA) #draw diamonds round iris points
            cv.polylines(frame, [mesh_points[RIGHT_IRIS]], True, (0,255,0), 1, cv.LINE_AA)
            (l_cx, l_cy), l_radius = cv.minEnclosingCircle(mesh_points[LEFT_IRIS]) #get a circle encompassing the eyes
            (r_cx, r_cy), r_radius = cv.minEnclosingCircle(mesh_points[RIGHT_IRIS])
            center_left = np.array([l_cx, l_cy], dtype=np.int32) # find the centre of the circle
            center_right = np.array([r_cx, r_cy], dtype=np.int32)
            cv.circle(frame, center_left, int(l_radius), (255,0,255), 1, cv.LINE_AA) # draw circle
            cv.circle(frame, center_right, int(r_radius), (255,0,255), 1, cv.LINE_AA)

            estFocal = 458.814 #needs to be updated for drone (https://pyimagesearch.com/2015/01/19/find-distance-camera-objectmarker-using-python-opencv/)
            estDistance = ((0.0177*estFocal)/(l_radius * 2) + (0.0177*estFocal)/(r_radius * 2))/2 #get average estimated distance of iris
            cv.putText(frame, str(estDistance) + "m", (10,450), cv.FONT_HERSHEY_SIMPLEX, 1, (255, 0, 0), 2, 1)

            
        cv.imshow('iris distance', frame)

        key = cv.waitKey(1)
        if key ==ord('q'):
            break

input.release()
cv.destroyAllWindows()