human/src/object/centernet.ts

103 lines
3.7 KiB
TypeScript

/**
* CenterNet object detection model implementation
*
* Based on: [**NanoDet**](https://github.com/RangiLyu/nanodet)
*/
import { log, join, now } from '../util/util';
import * as tf from '../../dist/tfjs.esm.js';
import { labels } from './labels';
import type { ObjectResult, Box } from '../result';
import type { GraphModel, Tensor } from '../tfjs/types';
import type { Config } from '../config';
import { env } from '../util/env';
import { fakeOps } from '../tfjs/backend';
let model: GraphModel | null;
let inputSize = 0;
let last: ObjectResult[] = [];
let lastTime = 0;
let skipped = Number.MAX_SAFE_INTEGER;
export async function load(config: Config): Promise<GraphModel> {
if (env.initial) model = null;
if (!model) {
fakeOps(['floormod'], config);
model = await tf.loadGraphModel(join(config.modelBasePath, config.object.modelPath || '')) as unknown as GraphModel;
const inputs = Object.values(model.modelSignature['inputs']);
inputSize = Array.isArray(inputs) ? parseInt(inputs[0].tensorShape.dim[2].size) : 0;
if (!model || !model['modelUrl']) log('load model failed:', config.object.modelPath);
else if (config.debug) log('load model:', model['modelUrl']);
} else if (config.debug) log('cached model:', model['modelUrl']);
return model;
}
async function process(res: Tensor | null, outputShape, config: Config) {
if (!res) return [];
const results: Array<ObjectResult> = [];
const detections = await res.array();
const squeezeT = tf.squeeze(res);
tf.dispose(res);
const arr = tf.split(squeezeT, 6, 1); // x1, y1, x2, y2, score, class
tf.dispose(squeezeT);
const stackT = tf.stack([arr[1], arr[0], arr[3], arr[2]], 1); // reorder dims as tf.nms expects y, x
const boxesT = tf.squeeze(stackT);
tf.dispose(stackT);
const scoresT = tf.squeeze(arr[4]);
const classesT = tf.squeeze(arr[5]);
arr.forEach((t) => tf.dispose(t));
const nmsT = await tf.image.nonMaxSuppressionAsync(boxesT, scoresT, config.object.maxDetected, config.object.iouThreshold, config.object.minConfidence);
tf.dispose(boxesT);
tf.dispose(scoresT);
tf.dispose(classesT);
const nms = await nmsT.data();
tf.dispose(nmsT);
let i = 0;
for (const id of nms) {
const score = Math.trunc(100 * detections[0][id][4]) / 100;
const classVal = detections[0][id][5];
const label = labels[classVal].label;
const [x, y] = [
detections[0][id][0] / inputSize,
detections[0][id][1] / inputSize,
];
const boxRaw: Box = [
x,
y,
detections[0][id][2] / inputSize - x,
detections[0][id][3] / inputSize - y,
];
const box: Box = [
Math.trunc(boxRaw[0] * outputShape[0]),
Math.trunc(boxRaw[1] * outputShape[1]),
Math.trunc(boxRaw[2] * outputShape[0]),
Math.trunc(boxRaw[3] * outputShape[1]),
];
results.push({ id: i++, score, class: classVal, label, box, boxRaw });
}
return results;
}
export async function predict(input: Tensor, config: Config): Promise<ObjectResult[]> {
const skipTime = (config.object.skipTime || 0) > (now() - lastTime);
const skipFrame = skipped < (config.object.skipFrames || 0);
if (config.skipAllowed && skipTime && skipFrame && (last.length > 0)) {
skipped++;
return last;
}
skipped = 0;
if (!env.kernels.includes('mod') || !env.kernels.includes('sparsetodense')) return last;
return new Promise(async (resolve) => {
const outputSize = [input.shape[2], input.shape[1]];
const resize = tf.image.resizeBilinear(input, [inputSize, inputSize]);
const objectT = config.object.enabled ? model?.execute(resize, ['tower_0/detections']) as Tensor : null;
lastTime = now();
tf.dispose(resize);
const obj = await process(objectT, outputSize, config);
last = obj;
resolve(obj);
});
}