安卓手机上的 OPENCV+KIVY+BUILDOZER答案

【问题标题】：OPENCV+KIVY+BUILDOZER ON ANDROID PHONE安卓手机上的 OPENCV+KIVY+BUILDOZER
【发布时间】：2021-02-05 08:46:35
【问题描述】：

我正在尝试使用 opencv、kivy 和 buildzer 在我的 android 手机上构建应用程序。我可以成功调试应用程序并构建到 android 手机。但是当我打开应用程序时，相机无法正常工作。但是在使用 buildozer for android 构建此代码后，当我打开应用程序时，它会显示一个黑屏，屏幕左角有一个小方块。任何人都可以帮助我吗？我相信相机没有被访问。

如果您有任何建议或其他方法，请告诉我。

谢谢！

这是我正在使用的代码：

# 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()

【问题讨论】：

标签： python android opencv kivy buildozer

【解决方案1】：

我也一直在努力解决这个问题。我发现您需要添加几行才能从 android 设备请求权限。这些应该包含在构建中。目前我无法访问自拍摄像头，所以我认为您需要从self.capture = cv2.VideoCapture(1) 中删除 1。

参考：https://github.com/kivy/buildozer/issues/1004

# 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
from android.permissions import request_permissions # Added import


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):
        # Give the app permissions to communicate
        request_permissions([Permission.CAMERA,
                             Permission.READ_EXTERNAL_STORAGE, 
                             Permission.WRITE_EXTERNAL_STORAGE,])
        self.capture = cv2.VideoCapture() # Removed the 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()

【讨论】：