<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 12 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal;
font-family:"Arial","sans-serif";
color:windowtext;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:595.3pt 841.9pt;
margin:70.85pt 70.85pt 70.85pt 70.85pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">What version are you talking about? How do you know there is a shift? That is, what is your reference? Is it possible there’s a difference in the bounding box
model? For WMS the bbox represents the outside dimensions of the pixels in an image.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Steve<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Note: MapServer uses a pixel center bbox model but that difference (with WMS’s representation) is taken into account in the WMS code.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<div>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> mapserver-users-bounces@lists.osgeo.org [mailto:mapserver-users-bounces@lists.osgeo.org]
<b>On Behalf Of </b>Fritz van Deventer<br>
<b>Sent:</b> Monday, June 04, 2012 9:27 AM<br>
<b>To:</b> mapserver-users@lists.osgeo.org<br>
<b>Subject:</b> [mapserver-users] Shift of half a pixel<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="NL" style="font-size:10.0pt;font-family:"Arial","sans-serif"">Hi all,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="NL" style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:10.0pt;font-family:"Arial","sans-serif"">We are trying to get VHR satellite imagery to run as a WMS in different GIS clients. When we compare the original image (we tried different formats, tif, ecw,
virtual formats etc.) to the hosted image we see a shift in the pixels. Looks like a minor warp or transform.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:10.0pt;font-family:"Arial","sans-serif"">We are unable to find what is causing this error. We tried using different output drivers, and different output and input formats. It looks like serving with GDAL
as output format and Imagemode on FLOAT32 gives the best result, however in black and white.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:10.0pt;font-family:"Arial","sans-serif"">If this is a known issue, is anyone able to tell me the (in)accuracy of the shift? Or is it not supposed to happen altogether?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:10.0pt;font-family:"Arial","sans-serif"">Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="NL" style="font-size:10.0pt;font-family:"Arial","sans-serif"">Fritz van Deventer –
<a href="http://neo.nl">http://neo.nl</a> <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="NL" style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
</div>
</body>
</html>