I don't get the point of this :confused:
BBCode (things like [B], ...) won't work in PHP. They are PHP based and will work with the vB Code Parser only.
You may not use the HTML equivalents (<b>, ...) in your code, you just can't put any special markup in the img src attribute (and all the other attributes).
The extension of your image is missing, so you need to add .gif, .jpg, .png, ... I added .gif to the example.
Try this:
echo '<img src="/community/arcade/image/'.$gname1.'.gif" alt="gname" />';
(the alt attribute is necessary for W3C compliance and a selfclosing tag (/ at the end) because of XHTML)