still_capture.py

#!/usr/bin/env python3

'''
Author:   Maximilian Sittinger (https://github.com/maxsitt)
Website:  https://maxsitt.github.io/insect-detect-docs/
License:  GNU GPLv3 (https://choosealicense.com/licenses/gpl-3.0/)

This Python script does the following:
- save encoded still frames in highest possible resolution (e.g. 4032x3040 px)
  to .jpg at specified time interval
- optional argument:
  "-min [min]" (default = 2) set recording time in minutes
               -> e.g. "-min 5" for 5 min recording time

based on open source scripts available at https://github.com/luxonis
'''

import argparse
import time
from datetime import datetime
from pathlib import Path

import depthai as dai

# Define optional arguments
parser = argparse.ArgumentParser()
parser.add_argument("-min", "--min_rec_time", type=int, choices=range(1, 721), default=2,
    help="set record time in minutes")
args = parser.parse_args()

# Set capture frequency in seconds
# 'CAPTURE_FREQ = 1' saves ~57 still frames per minute to .jpg (RPi Zero 2)
CAPTURE_FREQ = 1

# Create depthai pipeline
pipeline = dai.Pipeline()

# Create and configure camera node
cam_rgb = pipeline.create(dai.node.ColorCamera)
#cam_rgb.setImageOrientation(dai.CameraImageOrientation.ROTATE_180_DEG)
cam_rgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_12_MP) # OAK-1 (IMX378)
#cam_rgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_13_MP) # OAK-1 Lite (IMX214)
#cam_rgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_5312X6000) # OAK-1 MAX (IMX582)
cam_rgb.setNumFramesPool(2,2,2,2,2)
cam_rgb.setFps(25) # frames per second available for focus/exposure

# Create and configure video encoder node and define input + output
still_enc = pipeline.create(dai.node.VideoEncoder)
still_enc.setDefaultProfilePreset(1, dai.VideoEncoderProperties.Profile.MJPEG)
still_enc.setNumFramesPool(1)
cam_rgb.still.link(still_enc.input)

xout_still = pipeline.create(dai.node.XLinkOut)
xout_still.setStreamName("still")
still_enc.bitstream.link(xout_still.input)

# Create script node (to send capture still command)
script = pipeline.create(dai.node.Script)
script.setProcessor(dai.ProcessorType.LEON_CSS)

# Set script that will be run on-device (Luxonis OAK)
script.setScript('''
ctrl = CameraControl()
ctrl.setCaptureStill(True)

while True:
    node.io["capture_still"].send(ctrl)
''')

# Send script output to camera (capture still command)
script.outputs["capture_still"].link(cam_rgb.inputControl)

# Connect to OAK device and start pipeline in USB2 mode
with dai.Device(pipeline, maxUsbSpeed=dai.UsbSpeed.HIGH) as device:

    # Create output queue to get the encoded still frames from the output defined above
    q_still = device.getOutputQueue(name="still", maxSize=1, blocking=False)

    # Create folder to save the still frames
    rec_start = datetime.now().strftime("%Y%m%d_%H-%M")
    save_path = f"insect-detect/stills/{rec_start[:8]}/{rec_start}"
    Path(f"{save_path}").mkdir(parents=True, exist_ok=True)

    # Create start_time variable to set recording time
    start_time = time.monotonic()

    # Get recording time in min from optional argument (default: 2)
    rec_time = args.min_rec_time * 60
    print(f"Recording time: {args.min_rec_time} min")

    # Record until recording time is finished
    while time.monotonic() < start_time + rec_time:

        # Get encoded still frames and save to .jpg at specified time interval
        timestamp = datetime.now().strftime("%Y%m%d_%H-%M-%S.%f")
        enc_still = q_still.get().getData()
        with open(f"{save_path}/{timestamp}.jpg", "wb") as still_jpg:
            still_jpg.write(enc_still)

        time.sleep(CAPTURE_FREQ)

# Print number and path of saved still frames to console
frames_still = len(list(Path(f"{save_path}").glob("*.jpg")))
print(f"Saved {frames_still} still frames to {save_path}.")