I have the raster which contains 4 bands (RGBA), which ilustrates the pupulation (traffic) density. I want to convert it to the simple gridded ascii, however I'm getting in the trouble when I try the export it to the different formats. I suppose it comes from multi-band property of this map, therefore:
Is there any way I can convert from RGBA to single value representing the data I need ?
E.g. when I want to convert using RGB2PCT:
ERROR 1: TIFFOpen:traffic_przyciety2: Permission denied Traceback (most recent call last): File "C:\PROGRA~2\Quantum GIS Lisboa\bin\rgb2pct.py", line 136, in tif_ds.GetRasterBand(1).SetRasterColorTable( ct ) AttributeError: 'NoneType' object has no attribute 'GetRasterBand'
BTW: AttributeError: 'NoneType' error is dropped in other functions as well when I want to do something on this map
Info about the map:
Band 1 Block=903x1 Type=Byte, ColorInterp=Undefined Min=0.000 Max=255.000 Minimum=0.000, Maximum=255.000, Mean=254.667, StdDev=9.206 Band 2 Block=903x1 Type=Byte, ColorInterp=Undefined
Min=0.000 Max=124.000 Minimum=0.000, Maximum=124.000, Mean=119.886, StdDev=7.547 Band 3 Block=903x1 Type=Byte, ColorInterp=Undefined
Min=0.000 Max=0.000 Minimum=0.000, Maximum=0.000, Mean=0.000, StdDev=0.000 Band 4 Block=903x1 Type=Byte, ColorInterp=Undefined
Min=0.000 Max=255.000 Minimum=0.000, Maximum=255.000, Mean=217.937, StdDev=67.026'
Alternatively, do you know if there's any standard interpretation of the geodata maps ? E.g. if the resulting pixel value may be obtained by specific operation on the bands ?
Thanks for the answers