nccamera

Electron integration for node-gphoto2.

Usage

Initialization

const NCCamera = require('@nouvellecuisine/nccamera');

const nccamera = new NCCamera({
  autostart: true,
  callback: image => {
    // Do something with image
  },
});

The constructor takes a dictionary of options as parameter with the following keys:

• autostart: Boolean. Live Preview will be started automatically as soon as the camera is ready.
• callback: Function. Called for each frame of the Live Preview that should be displayed by the client.

Trigger Auto-Focus

nccamera.autofocus();

The camera will try to focus the current view.

autofocus takes no parameters. It returns a promise that resolves if the command was sent successfully. However, there is no way to know if the camera has finished focusing or has managed to do it.

Capture Image

nccamera.capture(autofocus).then(
  image => {
    // Do something with image
  },
  () => console.error('Capture failed')
);

The camera will take a picture.

capture takes one parameter:

• autofocus: Boolean. Tells the camera to trigger auto-focus before taking the picture. If true, the operation will be retried until focus is obtained or up to 5 times.

This returns a promise which resolves with the image data. It fails if no focus could be obtained.

Capture Video

nccamera.startVideo();

nccamera.stopVideo('/tmp/foo.mov').then(() => {
  // Process video file
});

The camera will take a video. path is the path on the host where video file will be written.

Please note the following limitations:

• The video will not fit in the camera's RAM so a memory card should be inserted in the camera.
• The provided path should not exist, otherwise it will not be overwritten.
• A temporary file will be created in the same directory as the given path.

Example of using image data

Writing to a PixiJS texture

// Create blob URL from data
const arraybuffer = Uint8Array.from(image).buffer;
const blob = new Blob([arraybuffer], { type: 'image/jpeg' });
const blobUrl = URL.createObjectURL(blob);

// Load it as an image, then draw as texture when the image is ready
const img = new Image();
img.addEventListener('load', () => {
  URL.revokeObjectURL(blobUrl);
  const texture = new PIXI.Texture(new PIXI.BaseTexture(img));
  const oldTexture = videoSprite.texture;
  videoSprite.texture = texture;
  oldTexture.destroy(true);
});
img.src = blobUrl;

Writing to an image

const encoded = Buffer.from(image).toString('base64');
document.getElementById('capture').src = 'data:image/jpeg;base64,' + encoded;

Debug tools

The module includes a GUI debug tool that allows changing some configuration settings on the camera. Press the c key on your keyboard to open it.