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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-US">I have some images with wrong metadata. They are tagged as pixel-is-area images and listgeo shows the tag
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">GTRasterTypeGeoKey (Short,1): RasterPixelIsArea<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Actually geotiffs are measurements and they should use RasterPixelIsPoint and images should be shifted be half a pixel on a map.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I was thinking that I can make a clever fix with gdal_edit so I made a copy of “area.tif” as “point.tif” and then I edited it<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">gdal_edit -mo AREA_OR_POINT=Point point.tif<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">The key gets edited into RasterPixelIsPoint just as I wished. However, the georeferencing that is stored into tag 33922 gets edited by the same.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Before edit:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">ModelTiepointTag (2,3):<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> 0 0 0<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> 115 33 0<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> ModelPixelScaleTag (1,3):<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> 0.1 0.1 0<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">After edit:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Tagged_Information:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> ModelTiepointTag (2,3):<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> 0 0 0<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> 115.05 32.95 0<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> ModelPixelScaleTag (1,3):<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> 0.1 0.1 0<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Because the ModelTiepoint gets shifted by half a pixel it compensates the shift caused by image-is-area vs. image-is-point and the image footprint and pixels stay exactly where they used to be. I know I can use gdal_edit
again with -a_ullr ulx uly lrx lry for shifting the image but I wonder if there happens to be some trick for just changing raster type into pixel-is-point without touching the tiepoint. Option “swap PixelIsPoint/Area” in gdal_edit would be fine for me if the
current behavior with -mo AREA_OR_POINT=Point feels correct.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">-Jukka Rahkonen- <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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