mod.ts

import * as OpenCV from 'https://unpkg.com/opencv-wasm@4.3.0-10/types/opencv.ts';
import {cv as _cv} from 'https://unpkg.com/opencv-wasm@4.3.0-10/opencv-deno.js';

export const cv: typeof OpenCV = _cv;

/**
 * Translate error number from OpenCV into a meaningful message
 * @param cvObject OpenCV object
 * @param err OpenCV error number 
 */
export function cvTranslateError (cv: typeof OpenCV, err: any): string | Error | undefined {
    // Code modified from OpenCV TryIt playground
    // https://docs.opencv.org/3.4/d0/d84/tutorial_js_usage.html

    let errorStatement: string | Error | undefined = undefined;

    if (typeof err === 'undefined') {
        errorStatement = '';
    } else if (typeof err === 'number') {
        if (!isNaN(err)) {
            if (typeof cv !== 'undefined') {
                errorStatement = 'Exception: ' + cv.exceptionFromPtr(err).msg;
            }
        }
    } else if (typeof err === 'string') {
        let ptr = Number(err.split(' ')[0]);
        if (!isNaN(ptr)) {
            if (typeof cv !== 'undefined') {
                errorStatement = 'Exception: ' + cv.exceptionFromPtr(ptr).msg;
            }
        }
    } else if (err instanceof Error) {
        errorStatement = err;
    }

    return errorStatement;
}