@vladmandic/face-api/src/utils/index.ts

FaceAPI: AI-powered Face Detection & Rotation Tracking, Face Description & Recognition, Age & Gender & Emotion Prediction for Browser and NodeJS using TensorFlow/JS

import * as tf from '../../dist/tfjs.esm';

import { Point } from '../classes/index';
import { Dimensions, IDimensions } from '../classes/Dimensions';

export function isTensor(tensor: any, dim: number) {
  return tensor instanceof tf.Tensor && tensor.shape.length === dim;
}

export function isTensor1D(tensor: any): tensor is tf.Tensor1D {
  return isTensor(tensor, 1);
}

export function isTensor2D(tensor: any): tensor is tf.Tensor2D {
  return isTensor(tensor, 2);
}

export function isTensor3D(tensor: any): tensor is tf.Tensor3D {
  return isTensor(tensor, 3);
}

export function isTensor4D(tensor: any): tensor is tf.Tensor4D {
  return isTensor(tensor, 4);
}

export function isFloat(num: number) {
  return num % 1 !== 0;
}

export function isEven(num: number) {
  return num % 2 === 0;
}

export function round(num: number, prec = 2) {
  const f = 10 ** prec;
  return Math.floor(num * f) / f;
}

export function isDimensions(obj: any): boolean {
  return obj && obj.width && obj.height;
}

export function computeReshapedDimensions({ width, height }: IDimensions, inputSize: number) {
  const scale = inputSize / Math.max(height, width);
  return new Dimensions(Math.round(width * scale), Math.round(height * scale));
}

export function getCenterPoint(pts: Point[]): Point {
  return pts.reduce((sum, pt) => sum.add(pt), new Point(0, 0))
    .div(new Point(pts.length, pts.length));
}

export function range(num: number, start: number, step: number): number[] {
  return Array(num).fill(0).map((_, i) => start + (i * step));
}

export function isValidNumber(num: any) {
  return !!num && (num !== Infinity) && (num !== -Infinity) && !Number.isNaN(num) || num === 0;
}

export function isValidProbablitiy(num: any) {
  return isValidNumber(num) && num >= 0 && num <= 1.0;
}