human/src/face/embedding.ts

113 lines
4.3 KiB
TypeScript

/**
* EfficientPose model implementation
*
* Based on: [**BecauseofAI MobileFace**](https://github.com/becauseofAI/MobileFace)
*
* Obsolete and replaced by `faceres` that performs age/gender/descriptor analysis
*/
import { log, join } from '../util/util';
import * as tf from '../../dist/tfjs.esm.js';
import type { Tensor, GraphModel } from '../tfjs/types';
import { env } from '../util/env';
let model: GraphModel | null;
export async function load(config) {
const modelUrl = join(config.modelBasePath, config.face.embedding.modelPath);
if (env.initial) model = null;
if (!model) {
model = await tf.loadGraphModel(modelUrl) as unknown as GraphModel;
if (!model) log('load model failed:', config.face.embedding.modelPath);
else if (config.debug) log('load model:', modelUrl);
} else if (config.debug) log('cached model:', modelUrl);
return model;
}
export function enhance(input): Tensor {
const image = tf.tidy(() => {
// input received from detector is already normalized to 0..1
// input is also assumed to be straightened
// const data = tf.image.resizeBilinear(input, [model.inputs[0].shape[2], model.inputs[0].shape[1]], false); // just resize to fit the embedding model
// do a tight crop of image and resize it to fit the model
const box = [[0.05, 0.15, 0.85, 0.85]]; // empyrical values for top, left, bottom, right
const tensor = input.image || input.tensor;
if (!(tensor instanceof tf.Tensor)) return null;
if (!model || !model.inputs || !model.inputs[0].shape) return null;
const crop = (tensor.shape.length === 3)
? tf.image.cropAndResize(tf.expandDims(tensor, 0), box, [0], [model.inputs[0].shape[2], model.inputs[0].shape[1]]) // add batch dimension if missing
: tf.image.cropAndResize(tensor, box, [0], [model.inputs[0].shape[2], model.inputs[0].shape[1]]);
// convert to black&white to avoid colorization impact
const rgb = [0.2989, 0.5870, 0.1140]; // factors for red/green/blue colors when converting to grayscale: https://www.mathworks.com/help/matlab/ref/rgb2gray.html
const [red, green, blue] = tf.split(crop, 3, 3);
const redNorm = tf.mul(red, rgb[0]);
const greenNorm = tf.mul(green, rgb[1]);
const blueNorm = tf.mul(blue, rgb[2]);
const grayscale = tf.addN([redNorm, greenNorm, blueNorm]);
const merge = tf.stack([grayscale, grayscale, grayscale], 3).squeeze(4);
/*
// optional increase image contrast
// or do it per-channel so mean is done on each channel
// or do it based on histogram
const mean = merge.mean();
const factor = 5;
const contrast = merge.sub(mean).mul(factor).add(mean);
*/
// normalize brightness from 0..1
const darken = tf.sub(merge, merge.min());
const lighten = tf.div(darken, darken.max());
return lighten;
});
return image;
}
export async function predict(input, config): Promise<number[]> {
if (!model) return [];
return new Promise(async (resolve) => {
// let data: Array<[]> = [];
let data: Array<number> = [];
if (config.face.embedding.enabled) {
const image = enhance(input);
const dataT = model?.execute(image) as Tensor;
/*
const dataT = tf.tidy(() => {
/*
// if needed convert from NHWC to NCHW
const nchw = image.transpose([3, 0, 1, 2]);
const res = model.execute(image);
// optionally do it twice with flipped image and average results
const res1 = model.execute(image);
const flipped = tf.image.flipLeftRight(image);
const res2 = model.execute(flipped);
const merge = tf.stack([res1, res2], 2).squeeze();
const res = reshape.logSumExp(1);
// optional normalize outputs with l2 normalization
const scaled = tf.tidy(() => {
const l2 = res.norm('euclidean');
const scale = res.div(l2);
return scale;
});
// optional reduce feature vector complexity
const reshape = tf.reshape(res, [128, 2]); // split 256 vectors into 128 x 2
const reduce = reshape.logSumExp(1); // reduce 2nd dimension by calculating logSumExp on it
return reduce;
});
*/
const output = await dataT.data();
data = Array.from(output); // convert typed array to simple array
tf.dispose(dataT);
tf.dispose(image);
}
resolve(data);
});
}