down-image-form-canvas.js

// other type like gif, bmp,... maybe not working because browser not
// it may fallback to png
function saveImage(canvas, exportType) {
    window.open(canvas.toDataURL(`image/${exportType}`));
    var gh = canvas.toDataURL(exportType);

    var a  = document.createElement('a');
    a.href = gh;
    a.download = `image.${exportType}`;

    a.click()
}