liveAprilTags.py

# import the necessary packages
import apriltag
import cv2




vid = cv2.VideoCapture(0)

while(True):

	ret, frame = vid.read()
	gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
	options = apriltag.DetectorOptions(families="tag36h11")
	detector = apriltag.Detector(options)
	results = detector.detect(gray)
	# loop over the AprilTag detection results
	for r in results:
		# extract the bounding box (x, y)-coordinates for the AprilTag
		# and convert each of the (x, y)-coordinate pairs to integers
		(ptA, ptB, ptC, ptD) = r.corners
		ptB = (int(ptB[0]), int(ptB[1]))
		ptC = (int(ptC[0]), int(ptC[1]))
		ptD = (int(ptD[0]), int(ptD[1]))
		ptA = (int(ptA[0]), int(ptA[1]))

		# draw the bounding box of the AprilTag detection
		cv2.line(frame, ptA, ptB, (0, 255, 0), 2)
		cv2.line(frame, ptB, ptC, (0, 255, 0), 2)
		cv2.line(frame, ptC, ptD, (0, 255, 0), 2)
		cv2.line(frame, ptD, ptA, (0, 255, 0), 2)

		# draw the center (x, y)-coordinates of the AprilTag
		(cX, cY) = (int(r.center[0]), int(r.center[1]))
		cv2.circle(frame, (cX, cY), 5, (0, 0, 255), -1)

		# draw the tag family on the image
		tagFamily = r.tag_family.decode("utf-8")
		cv2.putText(frame, tagFamily, (ptA[0], ptA[1] - 15),
			cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0), 2)


	# show the output image after AprilTag detection
	cv2.imshow("Image", frame)
	if cv2.waitKey(1) & 0xFF == ord('q'):
		break

# After the loop release the cap object
vid.release()
# Destroy all the windows
cv2.destroyAllWindows()