Changes between Initial Version and Version 1 of Ticket #3059


Ignore:
Timestamp:
Jul 12, 2009, 9:59:58 AM (15 years ago)
Author:
warmerdam
Comment:

Joaquim,

GDAL always reports bounds in terms of a pixel-as-area model. It seems to me that GDAL is properly adjusting the origin by half a pixel as is required to convert from the pixel-as-point model of the grid to the model in GDAL.

So far I don't see any problem.

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  • Ticket #3059

    • Property Keywords GSBG added
    • Property Status new → assigned
    • Property Component default → GDAL_Raster

  • Ticket #3059 – Description

    initial v1  
    11The info on grid size provided by gdalinfo on Surfer grids is wrong by half a grid cell.
    22Example, generate one of such grids with GMT
    3 
     3{{{
    44grdmath -R0/10/1/14 -I1 = lixo.grd=sf
    55
    … …  
    1616lixo.grd: z_min: 0 z_max: 0 name: z
    1717lixo.grd: scale_factor: 1 add_offset: 0
    18 
     18}}}
    1919Now run gdalinfo
    20 
     20{{{
    2121C:\>gdalinfo lixo.grd
    2222Driver: GSBG/Golden Software Binary Grid (.grd)
    … …  
    3535  Min=0.000 Max=0.000
    3636  NoData Value=1.701410009187828e+038
    37 
     37}}}
    3838The problem is that SURFER grids do not even have the concept of Pixel-is-area or pixel-registration, so the grid limits must always be given using the Pixel-is-point or grid node registration model.
    3939