安卓手机上的OPENCV+KIVY+BUILDOZER

Question

我正试图使用opencv、kivy和buildzer在我的android手机上构建一个应用程序。我可以成功地调试应用程序并构建到android手机。但当我打开应用程序时，相机不工作了。但在用buildozer for android构建了这段代码后，当我打开应用程序时，它会显示一个黑色屏幕，屏幕左角有一个小正方形。有人能帮我吗？我相信摄像头没有被访问。

如果你有什么建议或其他方法，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()

Answer 1

我也一直在处理这个问题。我发现你需要添加几行来请求安卓设备的许可。这些应该包含在构建中。目前我无法访问自拍相机，所以我认为你需要从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()