QGis 2.0.1. I tried as well to convert to UINT16 no sucess
2013/12/19 Rémi Cura <[email protected]> > Is there a special trick to display the raster in QGIS? > I do > db manage/right click on the raster table/add to canvas > Seems like there is nothing in it afterward. > > Thanks again, > > Rémi-C > > > 2013/12/19 Rémi Cura <[email protected]> > >> Buffering make it works. >> >> Cheers, >> Rémi-C >> >> >> 2013/12/19 Rémi Cura <[email protected]> >> >>> Hey, thanks for the answer, and nice catch ! >>> I'll try to simply buffer points, >>> then try th eother method to count >>> >>> About performance : >>> this is not about plpgsql or C. >>> I did quit the same processing when importing files of 3 millions points >>> to split into small 1*1*1 m cubes. >>> There were a lot of cubes (around 2k for 3 millions points), a lot of >>> points (3 millions) with a lot of attributes (around 20 flaot/double per >>> point), and it was around 60 sec/ file (for the data processing. Data >>> reading from disk was little longer). >>> >>> >>> For a 50x50 pixels and a few thousand points I would expect around 200ms. >>> >>> >>> I suspect it all boils down to current pixel access mechanism. >>> *Can you please confirm if there is or isn't a method to set/get several >>> pixels at a time?* >>> >>> Thanks anyway, >>> I wouldn't have found =) >>> >>> Cheers, >>> Rémi-C >>> >>> >>> 2013/12/19 Pierre Racine <[email protected]> >>> >>>> "MEAN_OF_VALUES_AT_PIXEL_CENTROID", which is the default >>>> ST_ExtractToRaster() method, search for geometries intersecting with the >>>> centroid of the pixel (a point). That's the method you use both calls to >>>> ExtractToRaster(). As it's almost impossible that a point intersects a >>>> point, this is certainly not the right method to get the value of points >>>> inside the pixel. A proper method would be "MEAN_VALUE_OF_POINTS" or >>>> "MEAN_VALUE_OF_GEOMETRIES" or "FIRST_GEOMETRY_VALUE" which are not >>>> implemented... >>>> >>>> I suggest you try 'COUNT_OF_POINTS' for now which will set each pixel >>>> value to the number of point intersecting with it. If you get it to work >>>> and you're satisfied with the performance I could help adding a method for >>>> your specific need. >>>> >>>> Can't do anything about the performance. All this is pure pl/pgsql and >>>> it's as fast as it can. 5 seconds to compute 2500 pixels value using SQL is >>>> not that bad though if you're not on the web... Otherwise you should have a >>>> specific C function doing exactly what you want. Expect time and $$$. >>>> >>>> Pierre >>>> >>>> >>> >> >
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