not sure how useful but I added a function to load a standard image instead of a background image with size and positions.
addImage(imageBase64Code, "810", "366", "5", "5")..
function addImage(imgBase64Code, imgWidth, imgHeight, imgLeft, imgTop)
return
"<img style='display:block;position:fixed;left:"..imgLeft.."px;top:"..imgTop.."px;width:"..imgWidth.."px;height:"..imgHeight.."px;'"..
"id='base64image'"..
"src='data:image/png;base64,"..imgBase64Code.."'/></style>"
end