I figured it out, sorry for asking so fast before I even try it myself.<br><br>Basically, I convert to and from raw, and just copy the bits and pieces in the right place.&nbsp; Here&#39;s part of my code, where &quot;image&quot; is the final one, and &quot;char_image&quot; is one of the smaller (I loop through all of them).
<br><br>&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; <span style="color: rgb(51, 51, 255);">Raw.sets (GlPix.to_raw image) ~pos:(3*(i*image_w + j + c*char_w))</span><br style="color: rgb(51, 51, 255);"><span style="color: rgb(51, 51, 255);">&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (Raw.gets
 (GlPix.to_raw char_image) ~pos:(3*(i * char_w + j)) ~len:3)</span><br style="color: rgb(51, 51, 255);"><br>Best,<br><br>Orlin<br><br><div><span class="gmail_quote">On 10/22/07, <b class="gmail_sendername">Orlin Grigorov</b>
 &lt;<a href="mailto:ogrigorov@gmail.com">ogrigorov@gmail.com</a>&gt; wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi.&nbsp; It&#39;s me again and my peculiar needs ;)
<br><br>At hand is the following problem.&nbsp; Let&#39;s assume that we have the following:<br><br><span style="color: rgb(51, 51, 255);">let image1 = GlPix.create `ubyte ~format:`rgb ~width:100 ~height:100 in
</span><br style="color: rgb(51, 51, 255);"><span style="color: rgb(51, 51, 255);">.</span><br style="color: rgb(51, 51, 255);"><span style="color: rgb(51, 51, 255);">(* some code *)</span><br style="color: rgb(51, 51, 255);">

<span style="color: rgb(51, 51, 255);">.</span><br style="color: rgb(51, 51, 255);"><span style="color: rgb(51, 51, 255);">let image2 = GlPix.create `ubyte ~format:`rgb ~width:100 ~height:100 in</span><br style="color: rgb(51, 51, 255);">

<span style="color: rgb(51, 51, 255);">.</span><br style="color: rgb(51, 51, 255);"><span style="color: rgb(51, 51, 255);">(* some code *)</span><br style="color: rgb(51, 51, 255);"><span style="color: rgb(51, 51, 255);">

.</span><br style="color: rgb(51, 51, 255);"><span style="color: rgb(51, 51, 255);">let image3 = GlPix.create `ubyte ~format:`rgb ~width:200 ~height:100 in</span><br style="color: rgb(51, 51, 255);"><span style="color: rgb(51, 51, 255);">

(* ?????????? *)</span><br style="color: rgb(51, 51, 255);"><br>The question marks are to be filled with code, which will join image1 and image2 together (will glue them one next to the other), and the result will be stored in image3 (notice how the width is the sum of the other two widths).
<br><br>Please help!<br>
</blockquote></div><br>