           }

            keypoints.length = numKeypoints;

            return keypoints;
        }
    }

    function main()
    {
        const options = {
            'blur': 1,
            'harrisK': 0.04,
            'harrisThr': 0.01,
            'nmsRadius': 2,
            'toggle source': () => toggleSource(),
            'toggle stacking': () => document.querySelector( '.container' ).classList.toggle( "stacked" ),
            'toggle webgl': () => canvas2d.parentElement.classList.toggle( "hide" ),