Support for Geosoft Binary Grids

[tcgeophysics]

Hi,

I have seen that Geosoft Grid Exchange format (.gxf) is supported but what about the Geosoft Binary Grids (.grd)?

This format is very common in mining exploration and geosciences, and I wonder if there was a specific reason why it was not supported by GDAL.

Any comments are welcome.

Thank you

[warmerdam]

I do not recall having the specification or significant demand for this format. If someone wants to implement it and contribute that would be nice.

[tcgeophysics]

Hi, Not being an expert in the GDAL source code, knowing that the Geosoft API provides reading and writing capabilities for GXF and GRD formats, would it be complicated to or could it be considered to modify the GXF "parser" to get GRD support? Is there any record of who contributed to the GXF support?

Thanks

[warmerdam]

Thomas,

I wrote the GXF driver.

I would not suggest starting from the GXF driver as the issues it addresses will be somewhat different than a format is that using an external library - though the GXF driver may offer guidance on some issues (ie. coordinate systems).

The driver implementation tutorial at:

​http://www.gdal.org/gdal_drivertut.html

should be of some help.

[tcgeophysics]

By any chance is the external library used by the GXF driver named GEOGX or part of the GXDeveloper toolkit from geosoft? If not, what is the library used?

[warmerdam]

The GXF driver does not use any external library to access the GXF file. It was written based on the spec and sample files.

[tcgeophysics]

Frank,

Is there any driver you could refer me to that is using an external library? The library I wish to use most likely only works on Windows... Is there anything special programming-wise that I should know before looking into using this library to create a GDAL driver?

Thanks

[warmerdam]

There are lots of drivers using external libraries. The "FITS" driver in gdal/frmts/fits is a relatively simple example of depending on an external library.

In general the problems are usually around build time configuration. If it is windows only then we would likely just make it's use somewhat manual and of course optional.

[tcgeophysics]

Thanks!

I agree it's use would have to be optional if it is a Windows only driver. I am still digging to find out more about the format. Maybe official information about their binary format is available which would then make the use of their Windows library obsolete.

[mkass]

I ran across this with the same question. In case others have the same issue, here's some more information. Geosoft does not release the specs on their binary *.grd and *.gi files. In order to access those, you need to use the GX API which they provide. I BELIEVE there is a python interface.

[Even Rouault]

This ticket has been automatically closed because Trac is no longer used for GDAL bug tracking, since the project has migrated to GitHub. If you believe this ticket is still valid, you may file it to ​https://github.com/OSGeo/gdal/issues if it is not already reported there.