Camera Parts API

Camera input parts for image capture from various hardware platforms

Camera parts capture image data from various camera hardware including Raspberry Pi cameras, webcams, CSI cameras, and mock cameras for testing.

Base Classes

BaseCamera

Base class for all camera implementations.

Methods:

run_threaded · () -> np.ndarray

Returns the most recently captured frame

Camera Implementations

PiCamera

Raspberry Pi camera using the Picamera2 library (Bullseye and later).

Constructor:

PiCamera(image_w=160, image_h=120, image_d=3, vflip=False, hflip=False)

image_w · int · default: "160"

Image width in pixels

image_h · int · default: "120"

Image height in pixels

image_d · int · default: "3"

Image depth/channels (3 for RGB, 1 for grayscale)

vflip · bool · default: "false"

Flip image vertically

hflip · bool · default: "false"

Flip image horizontally

Methods:

run · () -> np.ndarray

Captures and returns a new frame from the camera buffer

update · () -> None

Continuously captures frames in a threaded loop

shutdown · () -> None

Stops the camera and releases resources

Usage Example:

from donkeycar.parts.camera import PiCamera

# Create camera with custom resolution
cam = PiCamera(image_w=160, image_h=120, vflip=True)

# Get a frame
frame = cam.run()

# For threaded mode
import threading
thread = threading.Thread(target=cam.update)
thread.start()
frame = cam.run_threaded()

Webcam

USB webcam using pygame camera interface.

Constructor:

Webcam(image_w=160, image_h=120, image_d=3, framerate=20, camera_index=0)

image_w · int · default: "160"

Image width in pixels

image_h · int · default: "120"

Image height in pixels

image_d · int · default: "3"

Image depth/channels (3 for RGB, 1 for grayscale)

framerate · int · default: "20"

Target framerate in Hz

camera_index · int · default: "0"

Index of the camera device to use

Installation:

sudo apt-get install libsdl2-mixer-2.0-0 libsdl2-image-2.0-0 libsdl2-2.0-0
pip install pygame

Methods:

run · () -> np.ndarray

Captures and returns a new frame

update · () -> None

Continuously captures frames at the specified framerate

shutdown · () -> None

Stops the camera and releases resources

CSICamera

Jetson Nano CSI camera using GStreamer.

Constructor:

CSICamera(image_w=160, image_h=120, image_d=3, capture_width=3280, 
          capture_height=2464, framerate=60, gstreamer_flip=0)

image_w · int · default: "160"

Output image width in pixels

image_h · int · default: "120"

Output image height in pixels

image_d · int · default: "3"

Image depth/channels

capture_width · int · default: "3280"

Sensor capture width

capture_height · int · default: "2464"

Sensor capture height

framerate · int · default: "60"

Camera framerate

gstreamer_flip · int · default: "0"

Flip method: 0=none, 1=rotate CCW 90°, 2=flip vertical, 3=rotate CW 90°

Methods:

run · () -> np.ndarray

Captures and returns a new frame

update · () -> None

Continuously captures frames in a threaded loop

shutdown · () -> None

Stops the camera and releases resources

V4LCamera

Video4Linux camera using v4l2capture library.

Constructor:

V4LCamera(image_w=160, image_h=120, image_d=3, framerate=20,
          dev_fn="/dev/video0", fourcc='MJPG')

image_w · int · default: "160"

Image width in pixels

image_h · int · default: "120"

Image height in pixels

dev_fn · str · default: "/dev/video0"

Video device path

fourcc · str · default: "MJPG"

Video format FourCC code

Installation:

sudo apt-get install libv4l-dev
pip install python3-v4l2capture

Mock/Testing Cameras

MockCamera

Returns a static image for testing.

Constructor:

MockCamera(image_w=160, image_h=120, image_d=3, image=None)

image · np.ndarray · default: "None"

Optional image array to use. If None, creates a blank image.

ImageListCamera

Returns images from a directory in sequence.

Constructor:

ImageListCamera(path_mask='~/mycar/data/**/images/*.jpg')

path_mask · str

Glob pattern for image files

Methods:

run_threaded · () -> np.ndarray

Returns the next image in the sequence

Configuration

Cameras are typically configured in myconfig.py:

# Camera settings
CAMERA_TYPE = "PICAM"  # PICAM, WEBCAM, CVCAM, CSIC, etc.
IMAGE_W = 160
IMAGE_H = 120
IMAGE_DEPTH = 3
CAMERA_FRAMERATE = 20
CAMERA_VFLIP = False
CAMERA_HFLIP = False

Integration Example

From templates like complete.py:

if cfg.CAMERA_TYPE == "PICAM":
    from donkeycar.parts.camera import PiCamera
    cam = PiCamera(image_w=cfg.IMAGE_W, image_h=cfg.IMAGE_H,
                   image_d=cfg.IMAGE_DEPTH, vflip=cfg.CAMERA_VFLIP)
elif cfg.CAMERA_TYPE == "WEBCAM":
    from donkeycar.parts.camera import Webcam
    cam = Webcam(image_w=cfg.IMAGE_W, image_h=cfg.IMAGE_H,
                 image_d=cfg.IMAGE_DEPTH)

V.add(cam, outputs=['cam/image_array'], threaded=True)