This plugin will add a watermark to an image on the fly.

Usage:
<txp:sab_wm_image src="source_image.jpg" wmsrc="watermark.gif" xpos="right" ypos="bottom" tmpdir="img/zir/" pad="5" />

Reference:

• src= – REQUIRED – The path to the source image. This can be a URL! Valid file types are GIFs, PNGs and JPEGs.
• wmsrc= – REQUIRED – The path to the image used for the watermarking. Because of the common use of transparency in a watermark image, valid types are GIFs and PNGs.
• xpos={left|center|right} – The horizontal position of the watermark. Defaults to center.
• ypos={top|center|bottom} – The horizontal position of the watermark. Defaults to center.
• tmpdir= – The temporary directory to store the image while it’s being displayed in the browser. This directory MUST be writable by your webserver (chmod 777)! If you have problems getting the to display and you don’t knwo what this means, ask! Defaults to “img/zir/”.
• pad= – The number of pixels to pad the side of the watermark. For example, specifying pad=”10”, xpos=”left” and ypos=”top”, the watermark will end up starting from 10 pixels away from the top-left edge. Defaults to 5.