Lampix Apps API
Comment on page

End result

# The images will be processed using OpenCV and Numpy
import cv2
import numpy
# The decode_qrcode function will be used for decoding the found QR Code
from pyzbar.pyzbar import decode as decode_qrcode
# Used for sending the logs to the ':8888/logs' endpoint
import logging
# For identifying the source of the logs
logger = logging.getLogger("lampix.QRCodeDetector")
from watcher import Watcher
# Will be used to specify the used trigger for this Watcher
from watcher import TriggerType
class QRCodeDetector(Watcher):
# Calling the base class constructor
def __init__(self, id, contour):
# self.contour is the property which holds the corners of the registered area
Watcher.__init__(self, id, contour)
def get_vision_trigger(self):
return TriggerType.TRIGGER_RGB
def on_movement(self, depth_frame, grey_frame, color_frame, movement_mask):
# Code that will be executed when an object is placed on the projection surface,
# exactly where the watcher was registered'The QRCodeDetector Watcher was triggered')
x, y, width, height = cv2.boundingRect(self.contour.astype(
# Cropping the color_frame and getting the ROI (Region of Interest) containing the object that triggered the Watcher
qr_code_roi = color_frame[y:y + height, x:x + width]
# Decoding the QR Code and retrieving the data
qr_code = decode_qrcode(qr_code_roi)[0]
qr_code_data =
if len(qr_code_data):
# The self.report_to_js() method requires a formatted object
reported_object = self.create_formatted_object(metadata=qr_code_data)
self.report_to_js(reported_object, method='located')
reported_object = self.create_formatted_object(message="QR Code not detected")
self.report_to_js(reported_object, method='located')
def on_delete(self):
Code that will be executed on Watcher's removal
e.g. closing connections