human/demo/nodejs/node-webcam.js

90 lines
3.5 KiB
JavaScript

/**
* Human demo for NodeJS
* Unsupported sample of using external utility fswebcam to capture screenshot from attached webcam in regular intervals and process it using Human
*
* Note that node-webcam is not part of Human dependencies and should be installed manually
* Working version of fswebcam must be present on the system
*/
const util = require('util');
const process = require('process');
const log = require('@vladmandic/pilogger');
// eslint-disable-next-line node/no-missing-require
const nodeWebCam = require('node-webcam');
// for NodeJS, `tfjs-node` or `tfjs-node-gpu` should be loaded before using Human
// eslint-disable-next-line no-unused-vars, @typescript-eslint/no-unused-vars
const tf = require('@tensorflow/tfjs-node'); // or const tf = require('@tensorflow/tfjs-node-gpu');
// load specific version of Human library that matches TensorFlow mode
const Human = require('../../dist/human.node.js').default; // or const Human = require('../dist/human.node-gpu.js').default;
// options for node-webcam
const optionsCamera = {
callbackReturn: 'buffer', // this means whatever `fswebcam` writes to disk, no additional processing so it's fastest
saveShots: false, // don't save processed frame to disk, note that temp file is still created by fswebcam thus recommendation for tmpfs
};
const camera = nodeWebCam.create(optionsCamera);
// options for human
const optionsHuman = {
backend: 'tensorflow',
modelBasePath: 'file://models/',
};
const human = new Human(optionsHuman);
const results = [];
const list = util.promisify(camera.list);
const capture = util.promisify(camera.capture);
async function init() {
try {
const found = await list();
log.data('Camera data:', found);
} catch {
log.error('Could not access camera');
process.exit(1);
}
}
const buffer2tensor = human.tf.tidy((buffer) => {
if (!buffer) return null;
const decode = human.tf.node.decodeImage(buffer, 3);
let expand;
if (decode.shape[2] === 4) { // input is in rgba format, need to convert to rgb
const channels = human.tf.split(decode, 4, 2); // tf.split(tensor, 4, 2); // split rgba to channels
const rgb = human.tf.stack([channels[0], channels[1], channels[2]], 2); // stack channels back to rgb and ignore alpha
expand = human.tf.reshape(rgb, [1, decode.shape[0], decode.shape[1], 3]); // move extra dim from the end of tensor and use it as batch number instead
} else {
expand = human.tf.expandDims(decode, 0); // inpur ia rgb so use as-is
}
const cast = human.tf.cast(expand, 'float32');
return cast;
});
async function detect() {
// trigger next frame every 5 sec
// triggered here before actual capture and detection since we assume it will complete in less than 5sec
// so it's as close as possible to real 5sec and not 5sec + detection time
// if there is a chance of race scenario where detection takes longer than loop trigger, then trigger should be at the end of the function instead
setTimeout(() => detect(), 5000);
const buffer = await capture(); // gets the (default) jpeg data from from webcam
const tensor = buffer2tensor(buffer); // create tensor from image buffer
if (tensor) {
const res = await human.detect(tensor); // run detection
// do whatever here with the res
// or just append it to results array that will contain all processed results over time
results.push(res);
}
// alternatively to triggering every 5sec sec, simply trigger next frame as fast as possible
// setImmediate(() => process());
}
async function main() {
await init();
detect();
}
log.header();
main();