Issue referencing images in JQuery code

Issue referencing images in JQuery code

Probably a silly question but I'm having quite a bit of trouble trying to
figure out how to reference an image from my folder in JQuery code.
I want to turn images to greyscale, that revert to colour on mouse
rollover. However, my image referencing isn't working. I've tried the
usual ('folderofimages/myimage') but that isn't working. I've tried the
suggested way ('.myimage folderofimages') and that's not working either.
This is the website that supplied the code,
http://webdesignerwall.com/tutorials/html5-grayscale-image-hover/comment-page-4#comments
Any help is greatly appreciated!
Here is my code,
// On window load. This waits until images have loaded which is essential
$(window).load(function(){
// Fade in imagimages/homeannual.jpeges so there isn't a color "pop"
document load and then on window load
$("images.homeannual").fadeIn(500);
// clone image
$('images.homeannual').each(function(){
var el = $(this);
el.css({"position":"absolute"}).wrap("<div class='img_wrapper'
style='display:
inline-block'>").clone().addClass('img_grayscale').css({"position":"absolute","z-index":"998","opacity":"0"}).insertBefore(el).queue(function(){
var el = $(this);
el.parent().css({"width":this.width,"height":this.height});
el.dequeue();
});
this.src = grayscale(this.src);
});
// Fade image
$('images.homeannual').mouseover(function(){
$(this).parent().find('img:first').stop().animate({opacity:1}, 1000);
})
$('.img_grayscale').mouseout(function(){
$(this).stop().animate({opacity:0}, 1000);
});
});
// Grayscale w canvas method
function grayscale(src){
var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');
var imgObj = new Image();
imgObj.src = src;
canvas.width = imgObj.width;
canvas.height = imgObj.height;
ctx.drawImage(imgObj, 0, 0);
var imgPixels = ctx.getImageData(0, 0, canvas.width, canvas.height);
for(var y = 0; y < imgPixels.height; y++){
for(var x = 0; x < imgPixels.width; x++){
var i = (y * 4) * imgPixels.width + x * 4;
var avg = (imgPixels.data[i] + imgPixels.data[i + 1] +
imgPixels.data[i + 2]) / 3;
imgPixels.data[i] = avg;
imgPixels.data[i + 1] = avg;
imgPixels.data[i + 2] = avg;
}
}
ctx.putImageData(imgPixels, 0, 0, 0, 0, imgPixels.width,
imgPixels.height);
return canvas.toDataURL();
}