Possible to set virtual directory over top of physical directory?

Mod_Rewrite aliasing

[badbadmonkey]

Is it possible to configure a 'virtual directory' over top of a physical directory of the same path?

For example, if I have a source file at physical path:
/path/picture.jpg

I want to use Mod_Rewrite to point URL
example.com/path/picture.jpg?w=100&h=50
to an image processing script at say /include/image-resizer.php

E.g.:

RewriteCond %{QUERY_STRING} .
RewriteRule ^(.+)\.(jpe?g|png|gif|bmp|pdf)$ /include/image-resizer.php?src=/$1.$2 [NC,QSA,L]

This works if I inject a virtual path in there but not in the above form where it conflicts with the existing physical directory.

Is this possible or will I have to invent a virtual directory to base the paths on?

[badbadmonkey]

Edit: just realized the above is working, but I have an .htaccess file in the physical /path/ which is blocking access because I don't actually want to permit accessing of the source image.

Is there a way to allow the above to work while disallowing physical access to /path/picture.jpg?

[badbadmonkey]

Edit 2: had to resort to doing this in the root htaccess.

RewriteCond %{QUERY_STRING} .
RewriteRule ^(.+)\.(jpe?g|png|gif|bmp|pdf)$ /include/phpthumb/phpThumb.php?src=/$1.$2 [NC,QSA,L]
RewriteCond %{QUERY_STRING} ^$
RewriteRule ^path/to/protect/(.+)\.(jpe?g|png|gif|bmp|pdf)$ - [F,L]

For some reason I couldn't put the blocking instructions, the 2nd Cond block, in an htaccess in the relevant dir as a generic copy-and-dump file along the lines of

RewriteCond %{QUERY_STRING} ^$
RewriteRule ^(.+)\.(jpe?g|png|gif|bmp|pdf)$ - [F,L]