camera.py

import time
from uuid import uuid4

import picamera2
import rawpy
from PIL import Image


def convert_dng_to_jpg(input_dng_file, output_jpg_file):
    with rawpy.imread(input_dng_file) as raw:
        rgb = raw.postprocess(
            use_camera_wb=True,
            output_color=rawpy.ColorSpace.sRGB,
        )
    image = Image.fromarray(rgb)
    image.save(output_jpg_file, format="JPEG", quality=100)


SETTINGS = set(["exposure", "iso"])


class Camera:
    def __init__(self, logger) -> None:
        self.logger = logger
        self.camera = picamera2.Picamera2()
        self.config = self.camera.create_still_configuration(main={}, raw={})
        self.settings = {
            "exposure": 1000000,
            "iso": 100,
        }
        self.refresh_controls()
        self.init = False

    def initialise_camera(self):
        self.camera.start()
        self.init = True

    def release(self):
        self.camera.stop()

    def refresh_controls(self):
        with self.camera.controls as ctrl:
            ctrl.AnalogueGain = int(self.settings["iso"]) / 100
        self.camera.shutter_speed = int(self.settings["exposure"]) * 1000

    def step_preview(self):
        impath = "static/preview/" + str(uuid4()) + ".png"

        self.camera.start()
        self.refresh_controls()
        self.camera.capture_file(impath)
        self.camera.stop()

        return "../" + impath

    def capture(self):
        t = str(time.time())
        impath = "static/captured-raw/" + t + ".dng"
        impath_jpg = "static/captured/" + t + ".jpg"
        if self.init:
            self.release()

        self.initialise_camera()
        self.refresh_controls()
        self.camera.capture_file(impath, "raw")
        self.release()

        self.logger.info(
            f"[internals/_camera] Converting DNG to JPG for preview: {impath} -> {impath_jpg}"
        )
        convert_dng_to_jpg(impath, impath_jpg)

        return "../" + impath_jpg

    def setting(self, key, value):
        if key not in SETTINGS:
            self.logger.error(f"[internals/_camera] No such setting: {key}")
            return "[!!]"
        if key == "exposure":
            try:
                value = float(value)
                if value <= 0:
                    self.logger.error(
                        f"[internals/_camera] Expected value > 0 for {key}, got {value}"
                    )
                    return "[!!]"
                self.settings[key] = value
            except Exception:
                self.logger.error(
                    f"[internals/_camera] Cannot convert to float for {key}: {value}"
                )
                return "[!!]"
        if key == "iso":
            try:
                value = int(value)
                if value <= 0:
                    self.logger.error(
                        f"[internals/_camera] Expected natural number for {key}, got {value}"
                    )
                    return "[!!]"
                self.settings[key] = value
            except Exception:
                self.logger.error(
                    f"[internals/_camera] Cannot convert to natural number: {value}"
                )
                return "[!!]"

        self.refresh_controls()

        self.logger.info(f"[internals/_camera] Setting {key} is now {value}!")
        return "[OK]"