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I have an equidistant point grid (0.5m) and created a raster from it in QGIS and ArcMap, with different results:

QGIS:

  • Raster -> Conversion -> Rasterize
  • Result: raster, with points in the top left corner of each "pixel"

ArcMap:

  • Toolbox: Point To Raster
  • Result: raster, with points centered

Which is the better approach? Can I emulate ArcMap's behavior with QGIS?

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    I don't think there is a 'better' here, it depends on your data. If you have an equidistant raster does it meet the requirement for XYZ raster data? If you want to make the raster centred then shift it by half a cell north/west see ssrebelious.wordpress.com/2012/09/02/… – Michael Stimson May 26 '15 at 23:06
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    Interesting question, and I can't find any documentation or settings for why it would be putting the points at the upper left rather than centroid. As Michael says, I'm not sure there is a better or worse, but I'd definitely be wondering why my raster cells weren't centered on the points. Easily fixable, but maybe the QGIS routine just doesn't do the shift for the points. Makes me wonder what happens going the other way (raster to points). – Chris W May 27 '15 at 1:56
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    It feels like the difference comes from pixel-is-area vs. pixel-is-point. Some reading to start with trac.osgeo.org/gdal/wiki/rfc33_gtiff_pixelispoint. Can you share small samples of ArcMap and QGIS outputs? – user30184 May 27 '15 at 4:56
  • @user30184 I think that link and a summary of the issue would make a good answer. – Chris W May 27 '15 at 20:39
  • Sorry, I don't agree because I can't know what really happens without studying the samples and perhaps not even then. Being just half-a-pixel shift this pixel-is-point vs. pixel-is-area interpretation is amazingly fuzzy. – user30184 May 27 '15 at 20:47

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