[gdal-dev] Clipping an image via Python API problems

[Chaitanya kumar CH]

Graeme,

You do need to copy all bands. Also, make sure you set the correct number
of bands while creating the destination dataset.

Color interpretation is useful when you have multiple bands. If you want to
show your image in red, set it to GCI_PaletteIndex and set a colortable.

On Mon, Nov 28, 2011 at 6:40 AM, Graeme Merrall <graeme at inetix.com.au>wrote:

> The smallest almost working code chunk I have right now is below.  This is
> taaking a 40k by 40k and pulling out the top left quarter.  The original
> has 4 bands - RGBA
>
> from osgeo import gdal
> import numpy
> img = gdal.Open("original.tif")
> geotransform = img.GetGeoTransform()
> band1 = img.GetRasterBand(1)
>
> driver = gdal.GetDriverByName("GTiff)
> # coordinates will be calculated but hardcoded for now
> dst = driver.Create('sliver.tif', 20000, 20000, 1, gdal.GDT_Byte)
> dst.SetProjection(img.GetProjection())
> scanline1 = band1.ReadAsArray(0, 0,  20000, 20000)
> dst.GetRasterBand(1).WriteArray(scanline1)
>
> Should I be looping through each band and reading/writing to the image?
> I'm assuming yes
>
> Also. band 1 of the original image is red but in the new image the band
> color is grey. I've tried a few variations with
> GDALRasterBand.SetColorInterpretation() with no luck.  What have I missed?
>
> Cheers,
>
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>



-- 
Best regards,
Chaitanya kumar CH.

+91-9494447584
17.2416N 80.1426E
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/gdal-dev/attachments/20111128/8dbe1d4a/attachment.html