Is possible create map html area in percentage?

Question

I need to create something like this:

http://www.mrporter.com/journal/journal_issue71/2#2

where every product in my big image is associated with a tooltip wh

Answer 1

I know this is an old question but maybe someone needs this at some point as I did. I modified @David Thomas' answer a bit to be have this little piece of JS be able to handle future recalculations:

function findSizes(el, src) {
    if (!el || !src) {
        return false;
    }
    else {
        var wGCS = window.getComputedStyle,
        pI = parseInt,
        dimensions = {};
        dimensions.actualWidth = pI(wGCS(el, null).width.replace('px', ''), 10);
        var newImg = document.createElement('img');
        newImg.src = src;
        newImg.style.position = 'absolute';
        newImg.style.left = '-10000px';
        document.body.appendChild(newImg);
        dimensions.originalWidth = newImg.width;
        document.body.removeChild(newImg);
        return dimensions;
    }
}

function remap(imgElem) {
    if (!imgElem) {
        return false;
    }
    else {
        var mapName = imgElem
        .getAttribute('usemap')
        .substring(1),
        map = document.getElementsByName(mapName)[0],
        areas = map.getElementsByTagName('area'),
        imgSrc = imgElem.src,
        sizes = findSizes(imgElem, imgSrc),
        currentWidth = sizes.actualWidth,
        originalWidth = sizes.originalWidth,
        multiplier = currentWidth / originalWidth,
        newCoords;

        for (var i = 0, len = areas.length; i < len; i++) {
            // Save original coordinates for future use
            var originalCoords = areas[i].getAttribute('data-original-coords');
            if (originalCoords == undefined) {
                originalCoords = areas[i].getAttribute('coords');
                areas[i].setAttribute('data-original-coords', originalCoords);
            }

            newCoords = originalCoords.replace(/(\d+)/g,function(a){
                return Math.round(a * multiplier);
            });
            areas[i].setAttribute('coords',newCoords);
        }
    }
}

function remapImage() {
    var imgElement = document.getElementsByTagName('img')[0];
    remap(imgElement);
}

// Add a window resize event listener
var addEvent = function(object, type, callback) {
    if (object == null || typeof(object) == 'undefined') return;
    if (object.addEventListener) {
        object.addEventListener(type, callback, false);
    } else if (object.attachEvent) {
        object.attachEvent("on" + type, callback);
    } else {
        object["on"+type] = callback;
    }
};

addEvent(window, "resize", remapImage);