Opencv crash in android app

Python
, ,
1

OpenCV camera is working in python but crashes in the Android app when i build it with kivy buildozer.

here is the code and error

08-26 20:10:44.564  8048  8426 I python  : [CRITICAL] [Application ] No window is created. Terminating application run.
08-26 20:10:44.605  8048  8426 I python  : [WARNING] [Base        ] Unknown <android> provider
08-26 20:10:44.606  8048  8426 I python  : [INFO   ] [Base        ] Start application main loop
08-26 20:10:44.609  8048  8426 I python  : [ERROR  ] [Base        ] No event listeners have been created
08-26 20:10:44.610  8048  8426 I python  : [ERROR  ] [Base        ] Application will leave
08-26 20:10:44.611  8048  8426 I python  : Python for android ended.

import time

from kivy.app import App
from kivy.lang import Builder

from kivy.utils import platform
import cv2
from pyzbar import pyzbar

if platform == “android”:
from android.permissions import request_permissions, Permission

request_permissions([Permission.CAMERA, Permission.WRITE_EXTERNAL_STORAGE, Permission.READ_EXTERNAL_STORAGE])

time.sleep(2)

class CameraClick:

def read_barcodes(self, frame):
    barcodes = pyzbar.decode(frame)
    for barcode in barcodes:
        print(barcodes)
        x, y, w, h = barcode.rect
        # 1
        barcode_info = barcode.data.decode('utf-8')
        cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 255, 0), 2)

        # 2
        font = cv2.FONT_HERSHEY_DUPLEX
        cv2.putText(frame, "BC=" + barcode_info, (x + 6, y - 6), font, 2.0, (255, 255, 255),
                    1)  # print barcode on camera image
   
        with open("barcode_result.txt", mode='a') as file:  # open file for appent
           
            file.write("Recognized Barcode:" + barcode_info + "\n")

    return frame

class TestCamera(App):
if platform == “android”:
Builder.load_file(‘android_layout.kv’)
else:
Builder.load_file(‘layout.kv’)

def build(self):
    camera = cv2.VideoCapture(0)
    ret, frame = camera.read()
    # 2
    while ret:
        ret, frame = camera.read()
        print("camera read")
        camera_click = CameraClick()
        frame = camera_click.read_barcodes(frame)
        cv2.imshow('Barcode/QR code reader', frame)
        if cv2.waitKey(1) & 0xFF == 27:  # esc key pressed exit
            camera.release()
            cv2.destroyAllWindows()
            break

if name == “main”:
TestCamera().run()

type or paste code here
2

I don’t know what kivy bulldozer is, but the error does not mention camera, but a window - perhaps the window for imshow.

Anyway, you need to to debug the code and find the exact thing that makes it crash.