[Gdal-dev] Creating a color geotiff

[Brian Marchand]

Ed,

 

I was using a windows viewer by Kodak. With this viewer I was able to
view other color geotiff files successfully. The image appeared to
repeat itself (in black and white) with stripes of black interleaved.

 

When I use the "create" function does the type need to match the type
that I use for the RasterIO function for a band? In this case both are
set to GDT_Byte. 

 

For instance I create the data set with;

 

GDALDataset* poDstDS = poDriver->Create(destFile, sourceGrid.GetCols(),
sourceGrid.GetRows(), 3, GDT_Byte, NULL);

 

And write bands with

 

poBandR->RasterIO( GF_Write, 0, row, nXSize, 1, scanline, nXSize, 1,
GDT_Byte, 0, 0 );

 

where scanline is a char buffer of size nXSize. Or should I be using
something like GDT_Int32 for the data set type?

 

Brian

 

 

-----Original Message-----
From: Ed McNierney [mailto:ed at topozone.com] 
Sent: Wednesday, January 14, 2004 3:21 PM
To: gdal-dev at remotesensing.org
Subject: RE: [Gdal-dev] Creating a color geotiff

 

Brian -

 

How did you conclude it was "garbage"?  There are quite a few programs
(such as the Windows "Image and Fax Viewer") that don't read them
correctly, or that fail to read certain data organization/formats.

 

    - Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
ed at topozone.com
(978) 251-4242 

 

  _____  

From: Brian Marchand [mailto:bmarchand at ara.com] 
Sent: Wednesday, January 14, 2004 3:10 PM
To: gdal-dev at remotesensing.org
Subject: [Gdal-dev] Creating a color geotiff

Hello,

 

I'm trying to create geotiff files for the first time and I was
successful in creating a black and white geotiff. So I moved on to
creating a color one. I have a grid of RGB values so I created a data
set with 3 bands of type GDT_Byte.  I used RasterIO to write out a row
at a time. The result was garbage. 

 

Is there a specific order to writing out bands? I first tried writing a
row of red band, then a row of the green band, then the row of the blue
band. This didn't work so I dried writing all of rows for one band
before writing the next. Am I way off on this? How should I be doing
this?

 

Thanks in advance,

 

Brian Marchand

 

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