Hi I used to be able to get image url from macro with:

var imgMain = Model.MacroParameters["image"];
    int imgWidth = Convert.ToInt32(Model.MacroParameters["imageWidth"]);
    var mediaItemOne = Umbraco.TypedMedia(imgMain);
    <img src='@mediaItemOne.Url.GetCropUrl(width:imageWidth)' alt=''/ >

What is the new way in Umbraco 8 as I get the following error now and I cannot find any documentation on how to do it:

UmbracoHelper' does not contain a definition for 'TypedMedia' and no accessible extension method 'TypedMedia' accepting a first argument of type 'UmbracoHelper' could be found (are you missing a using directive or an assembly reference?)

OK, if anyone comes across this post, this is how it works for me.

@inherits Umbraco.Web.Macros.PartialViewMacroPage
@using Umbraco.Web;
@using Umbraco.Web.Composing
@{
    var img = Model.MacroParameters["image"].ToString();
    int imageWidth = Convert.ToInt32(Model.MacroParameters["imageWidth"]);
    var udi = Udi.Parse(img);
    var imgUrl = Current.UmbracoHelper.ContentQuery.Media(udi).Url;
    <img src='@imgUrl.GetCropUrl(width:imageWidth)' alt='' />
}