Hi John,

Adding an 'altText' field to the image media type is the usual way.  You can also add a fallback to the media node name in your code, e.g. an extension method like image.AltText().   NB This would use the same alt text for all crops - I'm not sure how you would go about having different values for different crops, if thats what you are after.  But it would be a lot more difficult, probably you would need to a customised mage cropper property editor.

public static string AltText(this IPublishedContent content)

        {

            return content.GetPropertyValue<string>("altText").HasValue() ? content.GetPropertyValue<string>("altText") : content.Name;

        }

NB HasValue() above is also a simple extension method:

public static bool HasValue(this object input)

        {

            return input != null && !string.IsNullOrWhiteSpace(input.ToString());

        }