Hello,
I've previously extended Image using this method http://doc.silverstripe.org/recipes:customising_image but it seems to cause headaches - I think because it changes the class in the File table from 'Image' to 'Page_Image'. I end up with broken/missing images if images are used in different ways throughout the site - i.e. used as a standard 'Image' in page content and a 'Page_Image' elsewhere.
I would like to keep all the images using the standard 'Image' class but allow some custom resizing functions to be called on any image - so in the template something like '$Image.ZoomedImage' which returns my image with custom gd functions applied.
Is this possible perhaps using a DataObjectDecorator? I played around with it but I just can't work it out - if anyone can help me out I'd be really grateful!