handwritten-mathematics-recogniser/digit/dnn/handwritten-digit-recogniser-dnn.js

Easy and abstracted way to recognise handwritten mathematics in a browser or in a web view.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const handwritten_digit_transformer_1 = require("../common/handwritten-digit-transformer");
const model_1 = require("./model");
class HandwrittenDigitRecogniserDNN {
    static recognise(canvas) {
        const image = handwritten_digit_transformer_1.HandwrittenDigitTransformer.transform(canvas);
        const recognitions = this.feedForward(image);
        return recognitions.indexOf(Math.max(...recognitions));
    }
    static recogniseWithMetadata(canvas) {
        const image = handwritten_digit_transformer_1.HandwrittenDigitTransformer.transform(canvas);
        const recognitions = this.formatRecognitions(this.feedForward(image));
        return recognitions;
    }
    static formatRecognitions(recognitions) {
        return recognitions
            .map((probability) => Math.round(probability * 100) / 100)
            .map((probability, recognition) => ({ probability, recognition }));
    }
    static feedForward(image) {
        const activation2 = [];
        for (let i = 0; i < model_1.w12.length; i++) {
            activation2[i] = model_1.b2[i];
            for (let j = 0; j < model_1.w12[i].length; j++) {
                activation2[i] += image[j] * model_1.w12[i][j];
            }
            activation2[i] = 1 / (1 + Math.exp(-activation2[i]));
        }
        const activation3 = [];
        for (let i = 0; i < model_1.w23.length; i++) {
            activation3[i] = model_1.b3[i];
            for (let j = 0; j < model_1.w23[i].length; j++) {
                activation3[i] += activation2[j] * model_1.w23[i][j];
            }
        }
        const maxProbability = Math.max(...activation3);
        const normalisedProbabilities = activation3.map((probability) => Math.exp(probability - maxProbability));
        const totalProbability = normalisedProbabilities.reduce((partialProbability, probability) => partialProbability + probability);
        const recognitions = normalisedProbabilities.map((probability) => probability / totalProbability);
        return recognitions;
    }
}
HandwrittenDigitRecogniserDNN.treshold = 1.5;
exports.HandwrittenDigitRecogniserDNN = HandwrittenDigitRecogniserDNN;

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