Nevermind fixed it.  I was mixing up i and j and forgot to increment ptr2.  Fixed below<br><br>        for(int i = 0; i &lt; 720; i++)<br>        {<br>            for(int j = 0; j &lt; 720; j++)<br>            {<br>                if(j &lt;600 &amp;&amp; j &gt; 119 &amp;&amp; i &lt; 680 &amp;&amp; i &gt; 39)<br>
                {<br>                    *ptr = *ptr2;<br>                    *ptr++;<br>                    *ptr2++;<br>                    *ptr = *ptr2;<br>                    *ptr++;<br>                    *ptr2++;<br>
                    *ptr = *ptr2;<br>                    *ptr++;<br>                    *ptr2++;<br>    <br>    <br>                }<br>                else<br>                {    <br>                    *ptr++;<br>                    *ptr++;<br>
                    *ptr++;<br>    <br><br>                }<br><br>                <br><br>            }<br><br>        }<br><br><div class="gmail_quote">On Mon, Apr 26, 2010 at 2:27 PM, John Durkin <span dir="ltr">&lt;<a href="mailto:jrd5084@psu.edu">jrd5084@psu.edu</a>&gt;</span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi vtk community, <br><br>I can&#39;t seem to remember how the data is represented in vtkImageData.  I have a 720x720x1 3 component RGB image being represented by vtkImageData.  I am using imageData-&gt;GetScalarPointer() to access the data.  I have another image 480x640x1 3 component RGB that I want to place in the middle of the new image.  Here is the code I have but its not lining up correctly.  Any ideas?<br>

<br><br>thanks,<br><br>John<br><br><br>    ptr = (unsigned char*)imageData-&gt;GetScalarPointer();<br>        unsigned char *ptr2 = (unsigned char*)origData-&gt;GetScalarPointer();<br><br>    <br>        for(int i = 0; i &lt; 720; i++)<br>

        {<br>            for(int j = 0; j &lt; 720; j++)<br>            {<br>                if(i &lt;600 &amp;&amp; i &gt; 119 &amp;&amp; j &lt;680 &amp;&amp; j &gt; 39)<br>                {<br>                    *ptr = *ptr2;<br>

                    *ptr++;<br>                    *ptr = *ptr2;<br>                    *ptr++;<br>                    *ptr = *ptr2;<br>                    *ptr++;<br>    <br>    <br>                }<br>                else<br>

                {    <br>                    *ptr++;<br>                    *ptr++;<br>                    *ptr++;<br>    <br><br>                }<br><br>                <br><br>            }<br>}<br>
</blockquote></div><br>