kivy and opencv work together demo

kivy_cv.py

# coding:utf-8
from kivy.app import App
from kivy.uix.image import Image
from kivy.clock import Clock
from kivy.graphics.texture import Texture
import cv2


class KivyCamera(Image):
    def __init__(self, capture, fps, **kwargs):
        super(KivyCamera, self).__init__(**kwargs)
        self.capture = capture
        Clock.schedule_interval(self.update, 1.0 / fps)

    def update(self, dt):
        ret, frame = self.capture.read()
        if ret:
            # convert it to texture
            buf1 = cv2.flip(frame, 0)
            buf = buf1.tostring()
            image_texture = Texture.create(
                size=(frame.shape[1], frame.shape[0]), colorfmt='bgr')
            image_texture.blit_buffer(buf, colorfmt='bgr', bufferfmt='ubyte')
            # display image from the texture
            self.texture = image_texture


class CamApp(App):
    def build(self):
        self.capture = cv2.VideoCapture(1)
        self.my_camera = KivyCamera(capture=self.capture, fps=30)
        return self.my_camera

    def on_stop(self):
        #without this, app will not exit even if the window is closed
        self.capture.release()


if __name__ == '__main__':
    CamApp().run()

Has anyone succeeded in making an Android camera with Python using OpenCv?
Below is the code that succeeded in another way.

-- below --

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
import time

from android.permissions import request_permissions, Permission
request_permissions([Permission.CAMERA])

Builder.load_string('''
:
orientation: 'vertical'
Camera:
id: camera
resolution: (1280, 720)
play: False
ToggleButton:
text: 'Play'
on_press: camera.play = not camera.play
size_hint_y: None
height: '48dp'
Button:
text: 'Capture'
size_hint_y: None
height: '48dp'
on_press: root.capture()
''')

class CameraClick(BoxLayout):
def capture(self):
camera = self.ids['camera']
timestr = time.strftime("%Y%m%d_%H%M%S")
camera.export_to_png("IMG_{}.png".format(timestr))
print("Captured")

class TestCamera(App):
def build(self):
return CameraClick()

TestCamera().run()

I tried running it on a Raspberry Pi and it runs pretty slow. Do you have any optimizations for that?

Threads?

I don't know if anyone is still interested in this, but since it took me three days to get there, here is a "minimal" example of OpenCV VideoCapture displaying frame by frame on Android:

https://github.com/4ndr3aR/kivy-opencv-demo

I couldn't get this to work. The code ran ok but only for one frame after which the Kivy window closed.