Showing only raster attribute table using GDAL?

I have a binary ArcGRID raster (AIG/Arc/Info Binary Grid) with an attribute table. I would like to get only this attribute table but gdalinfo outputs also projection information and bounds and then wanted GDALRasterAttributeTable XML part:

$ gdalinfo us_120fbfm13 -nogcp -nomd -noct filename
Driver: AIG/Arc/Info Binary Grid
...
Coordinate System is:
PROJCS["unnamed",
...
Center      ( 1540680.000, 1553400.000) ( 78d42'42.88"W, 35d46' 8.50"N)
Band 1 Block=256x4 Type=Byte, ColorInterp=Undefined

  Min=1.000 Max=99.000 
  NoData Value=255

...

How to show only raster attribut table using GDAL command line tools gdalinfo or perhaps gdal_translate?

Additional question which might be separate but might be also answered together with this is whether there is a possibility to get the attribute table in format such as CSV and not XML.

I'm on Linux, so I can actually do something like:

gdalinfo us_120fbfm13 -nogcp -nomd -noct -nofl | grep "<.*>"

but I would rather use some more general and possibly cross-platform solution.

Answer

Unless you use os/shell specific operations i.e. grep etc... there's no way that I know of to do this from the command line with gdalinfo.

A python alternative is to use the GetDefaultRAT() method and output to XML (which is what gdalinfo does):

import sys
from osgeo import gdal
import xml.etree.ElementTree as et #I much prefer the lxml library
                                   #but it's 3rd party and must be installed

def toxml(rat):

    #partial port of Serialize() from svn.osgeo.org/gdal/trunk/gdal/gcore/gdal_rat.cpp

    rattree=et.Element('GDALRasterAttributeTable')

    coltypes=[]

    #Define each column.
    icolcount=rat.GetColumnCount()
    for icol in range(icolcount):
        field=et.SubElement(rattree,'FieldDefn', {'index':str(icol)})

        fname=et.SubElement(field,'Name')
        ftype=et.SubElement(field,'Type')
        fusage=et.SubElement(field,'Usage')

        itype=rat.GetTypeOfCol(icol)

        fname.text=rat.GetNameOfCol(icol)
        ftype.text=str(rat.GetTypeOfCol(icol))
        fusage.text=str(rat.GetUsageOfCol(icol))


        if itype==gdal.GFT_Integer:
            coltypes.append(['%s', rat.GetValueAsInt])
        elif itype==gdal.GFT_Real:
            coltypes.append(['%.16g', rat.GetValueAsDouble])
        else:
            coltypes.append(['%s', rat.GetValueAsString])

    #Write out each row.
    irowcount = rat.GetRowCount()
    for irow in range(irowcount):

        row=et.SubElement(rattree,'Row', {'index':str(irow)})
        for icol in range(icolcount):
            rowcol=et.SubElement(row,'F')
            itype=rat.GetTypeOfCol(icol)
            if itype==gdal.GFT_Integer:
                rowcol.text='%s'%rat.GetValueAsInt(irow,icol)
            elif itype==gdal.GFT_Real:
                rowcol.text='%.16g'%rat.GetValueAsDouble(irow,icol)
            else:
                rowcol.text='%s'%rat.GetValueAsString(irow,icol)


    return et.tostring(rattree)

if __name__ == '__main__':
    ds=gdal.Open(sys.argv[1])
    rat=ds.GetRasterBand(1).GetDefaultRAT()
    sxml=serialize(rat)

    print sxml


    #Or if you want to pretty print
    import xml.dom.minidom as md
    print md.parseString(sxml).toprettyxml()

and here's a function to write out a CSV file.

import csv
import sys

from osgeo import gdal


def tocsv(rat,filepath):
    with open(filepath, 'wb') as csvfile:
        csvwriter = csv.writer(csvfile)

        #Write out column headers
        icolcount=rat.GetColumnCount()
        cols=[]
        for icol in range(icolcount):
            cols.append(rat.GetNameOfCol(icol))
        csvwriter.writerow(cols)


        #Write out each row.
        irowcount = rat.GetRowCount()
        for irow in range(irowcount):
            cols=[]
            for icol in range(icolcount):
                itype=rat.GetTypeOfCol(icol)
                if itype==gdal.GFT_Integer:
                    value='%s'%rat.GetValueAsInt(irow,icol)
                elif itype==gdal.GFT_Real:

                    value='%.16g'%rat.GetValueAsDouble(irow,icol)
                else:
                    value='%s'%rat.GetValueAsString(irow,icol)
                cols.append(value)
            csvwriter.writerow(cols)