camera.py

"""camera.py
A class to constantly take photos, for quik access
"""
import threading

from picamera import PiCamera
from picamera.array import PiRGBArray
import cv2
from time import sleep

from settings import RESOLUTIONX, RESOLUTIONY


class ConstantCamera(threading.Thread):
    def __init__(self, *args, **kwargs):
        super().__init__(daemon=True)
        self.camera = PiCamera(*args, **kwargs)
        self.camera.resolution = (RESOLUTIONX, RESOLUTIONY)
        self.camera.rotation = 0
        # Set ISO to the desired value
        self.camera.iso = 200
        # Wait for the automatic gain control to settle
        sleep(2)
        # Now fix the values
        self.camera.shutter_speed = self.camera.exposure_speed
        self.camera.exposure_mode = 'off'
        g = self.camera.awb_gains
        self.camera.awb_mode = 'off'
        self.camera.awb_gains = g
        self._camarray = PiRGBArray(self.camera, size=(RESOLUTIONX, RESOLUTIONY))
        self._image = None
        self.preview = False
        self._imgot = False
        self._lock = threading.Lock()
        self._close_event = threading.Event()
        self._ready_event = threading.Event()

    def run(self):
        # capture frames from the camera
        for frame in self.camera.capture_continuous(self._camarray, format="bgr", use_video_port=True):
            # grab the raw NumPy array representing the image, then initialize the timestamp
            # and occupied/unoccupied text
            with self._lock:
                # capture_continuous yields buffer array
                self._image = frame.array

            if not self._ready_event.is_set():
                self._ready_event.set()

            if self.preview:
                cv2.imshow("PREVIEW", self._image)
                cv2.waitKey(1)
            
            # clear the stream in preparation for the next frame
            self._camarray.truncate(0)
            if self._close_event.is_set():
                print("AAAAH")
                break
        self.camera.close()

    def get_image(self):
        # Avoid catching it halfway thru
        with self._lock:
            returnval = self._image
        # Return appropriate array...
        return returnval


    def is_ready(self):
        return self._ready_event.is_set()
    
    def wait_for_ready(self):
        self._ready_event.wait()

    def start_preview(self):
        with self._lock:
            self.preview = True
    def stop_preview(self):
        with self._lock:
            self.preview = False

    def halt_capture(self):
        self._close_event.set()
        self.join()