# coding: utf-8
from time import time, sleep
from typing import Tuple, Any
from .camera import Camera
from .._global import OptionalModule
import numpy as np
from threading import Thread, RLock
try:
import cv2
except (ModuleNotFoundError, ImportError):
cv2 = OptionalModule("opencv-python")
try:
from picamera import PiCamera
from picamera.array import PiRGBArray
except (ModuleNotFoundError, ImportError):
PiCamera = OptionalModule("picamera")
picamera_iso = [0, 100, 200, 320, 400, 500, 640, 800]
[docs]class Picamera(Camera):
"""Class for reading images from a PiCamera.
The Picamera Camera block is meant for reading images from a Picamera.
It uses the :mod:`picamera` module for capturing images, and :mod:`cv2` for
converting bgr images to black and white.
Warning:
Only works on Raspberry Pi !
"""
[docs] def __init__(self) -> None:
"""Instantiates the available settings."""
Camera.__init__(self)
self._cam = PiCamera()
self.name = "picamera"
# Settings definition
self.add_setting("Width", self._get_width, self._set_width, (1, 3280),
default=1280)
self.add_setting("Height", self._get_height, self._set_height, (1, 2464),
default=720)
self.add_setting("Iso (0 for auto)", self._get_iso, self._set_iso,
(0, 800), default=0)
self.add_setting("Brightness", self._get_brightness, self._set_brightness,
(0, 100), default=50)
self.add_setting("Contrast", self._get_contrast, self._set_contrast,
(-100, 100), default=0)
self.add_setting("Saturation", self._get_saturation, self._set_saturation,
(-100, 100), default=0)
self.add_setting("Shutter speed (0 for auto)", self._get_shutter_speed,
self._set_shutter_speed, (0, 30), default=0)
self.add_setting("Black_and_white", self._get_black_white,
self._set_black_white, False, default=True)
self.add_setting("Crop: X offset", self._get_crop_x_offset,
self._set_crop_x_offset, (0.0, 1.0), default=0.0)
self.add_setting("Crop: Y offset", self._get_crop_y_offset,
self._set_crop_y_offset, (0.0, 1.0), default=0.0)
self.add_setting("Crop: width", self._get_crop_width, self._set_crop_width,
(0.0, 1.0), default=1.0)
self.add_setting("Crop: height", self._get_crop_height,
self._set_crop_height, (0.0, 1.0), default=1.0)
self._frame_grabber = Thread(target=self._grab_frame)
self._lock = RLock()
self._frame = None
self._stop = False
self._started = False
[docs] def open(self, **kwargs: Any) -> None:
"""Sets the settings to their default values and starts the thread."""
for k in kwargs:
assert k in self.available_settings, \
str(self) + "Unexpected kwarg: " + str(k)
self.set_all(**kwargs)
# Starting the video stream
self._capture = PiRGBArray(self._cam, (self._get_width(),
self._get_height()))
self._stream = self._cam.capture_continuous(self._capture, format='bgr',
use_video_port=True)
self._frame_grabber.start()
sleep(1)
self._started = True
def _stop_stream(self) -> None:
"""Stops the video stream before changing the image size."""
if not self._started:
return
self._stop = True
self._frame_grabber.join()
self._capture.close()
def _restart_stream(self) -> None:
"""Restarts the video stream after a change in the image size."""
if not self._started:
return
self._stop = False
self._frame_grabber = Thread(target=self._grab_frame)
self._capture = PiRGBArray(self._cam, (self._get_width(),
self._get_height()))
self._stream = self._cam.capture_continuous(self._capture, format='bgr',
use_video_port=True)
self._frame_grabber.start()
sleep(1)
[docs] def get_image(self) -> Tuple[float, np.ndarray]:
"""Simply returns the last image in the buffer.
The captured image is in bgr format, and converted into black and white if
needed.
Returns:
The timeframe and the image.
"""
t = time()
with self._lock:
output = self._frame
if self.Black_and_white:
output = cv2.cvtColor(output, cv2.COLOR_BGR2GRAY)
return t, output
def _grab_frame(self) -> None:
"""Thread for grabbing the last image in the video stream and putting it in
the buffer"""
for frame in self._stream:
with self._lock:
self._frame = frame.array
self._capture.truncate(0)
if self._stop:
break
[docs] def close(self) -> None:
"""Joins the thread and closes the stream and the :class:`picamera.PiCamera`
object."""
self._stop = True
self._frame_grabber.join()
self._capture.close()
self._cam.close()
def _get_width(self) -> int:
return self._cam.resolution[0]
def _get_height(self) -> int:
return self._cam.resolution[1]
def _get_iso(self) -> int:
return self._cam.iso
def _get_brightness(self) -> int:
return self._cam.brightness
def _get_contrast(self) -> int:
return self._cam.contrast
def _get_saturation(self) -> int:
return self._cam.saturation
def _get_shutter_speed(self) -> float:
return self._cam.shutter_speed
def _get_black_white(self) -> bool:
return self._cam.color_effects == (128, 128)
def _get_crop_x_offset(self) -> float:
return self._cam.zoom[0]
def _get_crop_y_offset(self) -> float:
return self._cam.zoom[1]
def _get_crop_width(self) -> float:
return self._cam.zoom[2]
def _get_crop_height(self) -> float:
return self._cam.zoom[3]
def _set_width(self, width: float) -> None:
# The Picamera only accepts width that are multiples of 32
self._stop_stream()
self._cam.resolution = (32 * (width // 32), self._get_height())
self._restart_stream()
def _set_height(self, height: float) -> None:
# The Picamera only accepts heights that are multiples of 32
self._stop_stream()
self._cam.resolution = (self._get_width(), 32 * (height // 32))
self._restart_stream()
def _set_iso(self, iso: float) -> None:
# The Picamera only accepts a limited range of iso values
self._cam.iso = min(picamera_iso, key=lambda x: abs(x - iso))
def _set_brightness(self, brightness: float) -> None:
self._cam.brightness = brightness
def _set_contrast(self, contrast: float) -> None:
self._cam.contrast = contrast
def _set_saturation(self, saturation: float) -> None:
self._cam.saturation = saturation
def _set_shutter_speed(self, shutter_speed: float) -> None:
self._cam.shutter_speed = shutter_speed
def _set_black_white(self, boolean: bool) -> None:
if boolean:
self._cam.color_effects = (128, 128)
else:
self._cam.color_effects = None
def _set_crop_x_offset(self, x_offset: float) -> None:
self._cam.zoom = (x_offset, self._get_crop_y_offset(),
self._get_crop_width(), self._get_crop_height())
def _set_crop_y_offset(self, y_offset: float) -> None:
self._cam.zoom = (self._get_crop_x_offset(), y_offset,
self._get_crop_width(), self._get_crop_height())
def _set_crop_width(self, width: float) -> None:
self._cam.zoom = (self._get_crop_x_offset(), self._get_crop_y_offset(),
width, self._get_crop_height())
def _set_crop_height(self, height: float) -> None:
self._cam.zoom = (self._get_crop_x_offset(), self._get_crop_y_offset(),
self._get_crop_width(), height)