minimum Image width and height in Aurigma Image uploader

function Count() {
            var imageUploader = $au.uploader('Uploader1');
            var count = imageUploader.files().count();
            for (i = count; i > 0; i--) {
                var width = imageUploader.files().get(i - 1).width();
                var height = imageUploader.files().get(i - 1).height();
                var name = imageUploader.files().get(i - 1).name();
                if (width / height < 0.75 && height > 320 && height < 1024) {
                    alert("The image " + name + " is more than 768x1024 or less than 240x320");
                    imageUploader.files().remove(i - 1);
                }
                else if (height / width < 0.75 && width > 320 && width < 1024) {
                    alert("The image " + name + " is more than 1024x768 or less than 320x1024");
                    imageUploader.files().remove(i - 1);
                }
            }
        }
    </script>

    <form id="form1" runat="server">
    <div>
        <cc1:Uploader ID="Uploader1" runat="server" Height="400" Width="900" AutoSave="true"
            DestinationFolder="Uploaded">
            <ClientEvents>
                <cc1:ClientEvent EventName="UploadFileCountChange" HandlerName="Count" />
            </ClientEvents>
        </cc1:Uploader>
    </div>
    </form>