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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>April,<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>There are at least two possibilities.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>First, the mask could be a whole other image in the TIFF file. This image would have a NewSubfileType tag value with the second bit turned on. You could disable this bit (then the mask image would either be ignored or treated as another image in the dataset) or you could remove the whole mask image by relinking the IFD chain without including the mask IFD.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>The other possibility is that the mask is an additional sample included with the 4 band image (so the image has actually 5 samples). In this case the ExtraSamples tag would likely have a value of 2 for “Unassociated alpha data” for the sample representing the mask. If you changed this value to 0, the mask would possibly be treated as another band and you might then be able to avoid displaying it.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>See the <a href="http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf">TIFF spec</a> for more info. You may also want to investigate the source of the images (why is that mask being put in there in the first place?).<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Max<o:p></o:p></span></p><p class=MsoNormal><span style='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"'> geotiff-bounces@lists.maptools.org [mailto:geotiff-bounces@lists.maptools.org] <b>On Behalf Of </b>April Davis<br><b>Sent:</b> Thursday, April 07, 2011 2:20 PM<br><b>To:</b> geotiff@lists.maptools.org<br><b>Subject:</b> [Geotiff] GeoTIFFs in ArcGIS 10<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>All,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>We have recently upgraded to Esri ArcGIS 10, and have started pulling in 4 band (red,green,blue,IR) GeoTIFFs. We began to see areas of “no data”. When looking at the image in other software platforms, we do not see the areas of “no data”. All the pixels have a value. We sent an image to Esri technical support and they replied by stating “The tiff has a mask tag that ArcGIS didn’t use in the past. At ArcGIS 10.0 we read and apply this tag. In this case, the tag specifies band 4 to be a nodata mask – any place where band 4 has the value 0 will show as nodata. This is a setting on the tiff file and not in ArcGIS. ArcGIS just started to honor this tag.”<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Does anyone know what tag Esri may be referring to? If I could figure out what the tag is or what exactly it specified, then I could remove the tag or change it. But I am at a loss as to what to look for.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Any help would be appreciated.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>April H. Davis, GISP<o:p></o:p></p><p class=MsoNormal>GIS Analyst III<o:p></o:p></p><p class=MsoNormal><i><span style='color:#1F497D'>Southwest Florida Water Management District<o:p></o:p></span></i></p><p class=MsoNormal><i><span style='color:#1F497D'>Mapping and GIS Section<o:p></o:p></span></i></p><p class=MsoNormal><i><span style='color:#1F497D'>2379 Broad Street<o:p></o:p></span></i></p><p class=MsoNormal><i><span style='color:#1F497D'>Brooksville, FL 34604<o:p></o:p></span></i></p><p class=MsoNormal><i><span style='color:#1F497D'>(v): 352-796-7211 x 4216<o:p></o:p></span></i></p><p class=MsoNormal><i><span style='color:#1F497D'>(f): 352-540-6018<o:p></o:p></span></i></p><p class=MsoNormal><i><span style='color:#1F497D'><a href="http://www.watermatters.org">www.watermatters.org</a><o:p></o:p></span></i></p><p class=MsoNormal><o:p> </o:p></p><pre>IMPORTANT NOTICE: All E-mail sent to or from this address are public record and archived. The Southwest Florida Water Management District does not allow use of District equipment and E-mail facilities for non-District business purposes.<o:p></o:p></pre><pre><o:p> </o:p></pre></div></body></html>