問題描述

我正在使用帶有網絡攝像頭的 Kivy.我按照@Arnav 的 this example 使用 opencv 來形成和將相機顯示為小部件.我已經擴展"了python中的布局，添加了兩個按鈕作為測試，為更復雜的布局做準備.

I am using Kivy with a webcam. I have followed this example by @Arnav of using opencv to form and display the camera as a widget. I have "extended" the layout within python it to add two buttons as a test, in preparation for a more complicated layout.

class CamApp(App):
    def build(self):
        self.capture = cv2.VideoCapture(0)
        self.my_camera = KivyCamera(capture=self.capture, fps=30,resolution=(1920,1080))
        root = BoxLayout(orientation = 'vertical')
        root.add_widget(self.my_camera,1)
        box2 = BoxLayout(orientation = 'vertical')
        btn1 = Button(text='Hello world 1')
        btn2 = Button(text='Hello world 2')
        box2.add_widget(btn1)
        box2.add_widget(btn2)
        root.add_widget(box2, 0)
        return root
        #return Builder.load_string(kv)

雖然這可行，但我更愿意將 UI 組件從 python 中移出并放入 kv 語言 文件中.問題是知道如何在 kv 文件中描述"self.my_camera?

While this works I would prefer to move the UI components out of python and into a kv language file. The problem is knowing how to "describe" the self.my_camera in the kv file?

我不確定是否將 KivyCamera 類作為 kv 文件中的 widget 繼承，即

I am not sure whether to inherit the KivyCamera class as a widget within the kv file i.e.

kv = '''
<Cam1@KivyCamera>:
    texture: self.my_camera
    resolution: (1920, 1080)
    pos: self.pos
    size: self.size

或者是否使用canvas小部件

<MyWidget>:
    canvas:
        Rectangle:
            source: self.my_camera
            pos: self.pos
            size: self.size

我嘗試過其他被黑"的實現，但在所有情況下，問題都是通過 self.my_camera 鏈接到 kv 文件.

I have tried other "hacked" implementations, but in all cases the problem is linking through the self.my_camera into the kv file.

有什么建議嗎?

推薦答案

也許這個例子可以幫到你.

Perhaps this example may help you.

# Import 'kivy.core.text' must be called in entry point script
# before import of cv2 to initialize Kivy's text provider.
# This fixes crash on app exit.

import kivy.core.text
import cv2
from kivy.app import App
from kivy.base import EventLoop
from kivy.uix.image import Image
from kivy.clock import Clock
from kivy.graphics.texture import Texture
from kivy.uix.boxlayout import BoxLayout
from kivy.core.window import Window


class KivyCamera(Image):

    def __init__(self, **kwargs):
        super(KivyCamera, self).__init__(**kwargs)
        self.capture = None

    def start(self, capture, fps=30):
        self.capture = capture
        Clock.schedule_interval(self.update, 1.0 / fps)

    def stop(self):
        Clock.unschedule_interval(self.update)
        self.capture = None

    def update(self, dt):
        return_value, frame = self.capture.read()
        if return_value:
            texture = self.texture
            w, h = frame.shape[1], frame.shape[0]
            if not texture or texture.width != w or texture.height != h:
                self.texture = texture = Texture.create(size=(w, h))
                texture.flip_vertical()
            texture.blit_buffer(frame.tobytes(), colorfmt='bgr')
            self.canvas.ask_update()


capture = None


class QrtestHome(BoxLayout):

    def init_qrtest(self):
        pass

    def dostart(self, *largs):
        global capture
        capture = cv2.VideoCapture(0)
        self.ids.qrcam.start(capture)

    def doexit(self):
        global capture
        if capture != None:
            capture.release()
            capture = None
        EventLoop.close()


class qrtestApp(App):

    def build(self):
        Window.clearcolor = (.4,.4,.4,1)
        Window.size = (400, 300)
        homeWin = QrtestHome()
        homeWin.init_qrtest()
        return homeWin

    def on_stop(self):
        global capture
        if capture:
            capture.release()
            capture = None

qrtestApp().run()

還有kv文件:

<QrtestHome>:

    BoxLayout:
        orientation: "vertical"

        Label:
            height: 20
            size_hint_y: None
            text: 'Testing the camera'

        KivyCamera:
            id: qrcam

        BoxLayout:
            orientation: "horizontal"
            height: 20
            size_hint_y: None

            Button:
                id: butt_start
                size_hint: 0.5,1
                text: "start"
                on_press: root.dostart()

            Button:
                id: butt_exit
                text: "quit"
                size_hint: 0.5,1
                on_press: root.doexit()

這篇關于Kivy 相機作為 KV 語言小部件的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！