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p.MsoNormal,p.MsoNoSpacing{margin:0}</style></head><body><div style="font-family:Arial;">PPS: Looks like some experimentation is probably better than weeks of worrying :-). It looks like the input no data values are actually not included in the computation. But I'd still like to know how they are handled, if that's possible.<br></div><div style="font-family:Arial;"><br></div><div style="font-family:Arial;">Laurentiu<br></div><div style="font-family:Arial;"><br></div><div>On Mon, Jan 16, 2023, at 14:05, Laurențiu Nicola via gdal-dev wrote:<br></div><blockquote type="cite" id="qt" style=""><div style="font-family:Arial;">PS:<br></div><div style="font-family:Arial;"><br></div><div>On Mon, Jan 16, 2023, at 13:58, Laurențiu Nicola wrote:<br></div><blockquote type="cite" id="qt-qt" style=""><div style="font-family:Arial;"><br></div><ul><li style="font-family:Arial;">the <span class="qt-qt-font" style="font-family:menlo, consolas, monospace, sans-serif;"><span class="font" style="font-family:menlo, consolas, monospace, sans-serif;"><span class="qt-font" style="font-family:menlo, consolas, monospace, sans-serif;"><span class="font" style="font-family:menlo, consolas, monospace, sans-serif;"><code style="border-top-color:rgb(204, 204, 204);border-top-style:solid;border-top-width:1px;border-right-color:rgb(204, 204, 204);border-right-style:solid;border-right-width:1px;border-bottom-color:rgb(204, 204, 204);border-bottom-style:solid;border-bottom-width:1px;border-left-color:rgb(204, 204, 204);border-left-style:solid;border-left-width:1px;border-image-outset:0;border-image-repeat:stretch;border-image-slice:100%;border-image-source:none;border-image-width:1;border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;background-color:rgb(246, 246, 246);background-position-x:0%;background-position-y:0%;background-repeat:repeat;background-attachment:scroll;background-image:none;background-size:auto;background-origin:padding-box;background-clip:border-box;font-family:menlo, consolas, monospace;font-size:90%;padding-top:1px;padding-right:3px;padding-bottom:1px;padding-left:3px;">-srcnodata</code></span></span></span></span> docs and <span class="qt-qt-font" style="font-family:menlo, consolas, monospace, sans-serif;"><span class="font" style="font-family:menlo, consolas, monospace, sans-serif;"><span class="qt-font" style="font-family:menlo, consolas, monospace, sans-serif;"><span class="font" style="font-family:menlo, consolas, monospace, sans-serif;"><code style="border-top-color:rgb(204, 204, 204);border-top-style:solid;border-top-width:1px;border-right-color:rgb(204, 204, 204);border-right-style:solid;border-right-width:1px;border-bottom-color:rgb(204, 204, 204);border-bottom-style:solid;border-bottom-width:1px;border-left-color:rgb(204, 204, 204);border-left-style:solid;border-left-width:1px;border-image-outset:0;border-image-repeat:stretch;border-image-slice:100%;border-image-source:none;border-image-width:1;border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;background-color:rgb(246, 246, 246);background-position-x:0%;background-position-y:0%;background-repeat:repeat;background-attachment:scroll;background-image:none;background-size:auto;background-origin:padding-box;background-clip:border-box;font-family:menlo, consolas, monospace;font-size:90%;padding-top:1px;padding-right:3px;padding-bottom:1px;padding-left:3px;">gdalwarpkernel.cpp</code></span></span></span></span> suggest that masked pixels are not included in the computation (unlike those of no data?)<br></li></ul></blockquote><div style="font-family:Arial;">The remark in the brackets is wrong, of course, since the docs are specifically about <code style="border-top-color:rgb(204, 204, 204);border-top-style:solid;border-top-width:1px;border-right-color:rgb(204, 204, 204);border-right-style:solid;border-right-width:1px;border-bottom-color:rgb(204, 204, 204);border-bottom-style:solid;border-bottom-width:1px;border-left-color:rgb(204, 204, 204);border-left-style:solid;border-left-width:1px;border-image-outset:0;border-image-repeat:stretch;border-image-slice:100%;border-image-source:none;border-image-width:1;border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;background-color:rgb(246, 246, 246);background-position-x:0%;background-position-y:0%;background-repeat:repeat;background-attachment:scroll;background-image:none;background-size:auto;background-origin:padding-box;background-clip:border-box;font-family:menlo, consolas, monospace;font-size:90%;padding-top:1px;padding-right:3px;padding-bottom:1px;padding-left:3px;">-srcnodata</code> . But I'm still unsure how these are handled in the code. I probably missed something, but I saw <a href="https://github.com/OSGeo/gdal/blob/master/alg/gdalwarpkernel.cpp#L1225">the checks</a> for a mask, but not no data.<br></div><div>_______________________________________________<br></div><div>gdal-dev mailing list<br></div><div><a href="mailto:gdal-dev@lists.osgeo.org">gdal-dev@lists.osgeo.org</a><br></div><div><a href="https://lists.osgeo.org/mailman/listinfo/gdal-dev">https://lists.osgeo.org/mailman/listinfo/gdal-dev</a><br></div><div><br></div></blockquote><div style="font-family:Arial;"><br></div></body></html>