human/src/object/centernet.ts

95 lines
3.4 KiB
TypeScript

/**
* CenterNet object detection model implementation
*
* Based on: [**NanoDet**](https://github.com/RangiLyu/nanodet)
*/
import { log, now } from '../util/util';
import * as tf from '../../dist/tfjs.esm.js';
import { loadModel } from '../tfjs/load';
import { labels } from './labels';
import type { ObjectResult, ObjectType, Box } from '../result';
import type { GraphModel, Tensor } from '../tfjs/types';
import type { Config } from '../config';
import { env } from '../util/env';
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 loadModel(config.object.modelPath);
const inputs = Object.values(model.modelSignature['inputs']);
inputSize = Array.isArray(inputs) ? parseInt(inputs[0].tensorShape.dim[2].size) : 0;
} else if (config.debug) log('cached model:', model['modelUrl']);
return model;
}
async function process(res: Tensor | null, outputShape: [number, number], config: Config) {
if (!res) return [];
const t: Record<string, Tensor> = {};
const results: Array<ObjectResult> = [];
const detections = await res.array() as number[][][];
t.squeeze = tf.squeeze(res);
const arr = tf.split(t.squeeze, 6, 1) as Tensor[]; // x1, y1, x2, y2, score, class
t.stack = tf.stack([arr[1], arr[0], arr[3], arr[2]], 1); // reorder dims as tf.nms expects y, x
t.boxes = tf.squeeze(t.stack);
t.scores = tf.squeeze(arr[4]);
t.classes = tf.squeeze(arr[5]);
tf.dispose([res, ...arr]);
t.nms = tf.image.nonMaxSuppression(t.boxes, t.scores, config.object.maxDetected, config.object.iouThreshold, (config.object.minConfidence || 0));
const nms = await t.nms.data();
let i = 0;
for (const id of Array.from(nms)) {
const score = Math.trunc(100 * detections[0][id][4]) / 100;
const classVal = detections[0][id][5];
const label = labels[classVal].label as ObjectType;
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 });
}
Object.keys(t).forEach((tensor) => tf.dispose(t[tensor]));
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;
return new Promise(async (resolve) => {
const outputSize = [input.shape[2] || 0, input.shape[1] || 0] as [number, number];
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);
});
}