I should have said that you need to copy all bands 'individually'. On Mon, Nov 28, 2011 at 11:35 AM, Graeme Merrall <[email protected]>wrote:
> I've discovered that he bands are determined by the args to > driver.Create() that is if I create a 4 band image then the bands are > correct, however if I'm going to copy the image chunk around using > ReadAsArray and WriteArray, doesn't it mean I need to retreive each band in > turn? > Or have I missed something and there's an easier way to extract a portion > of an image and write it out? > > Cheers, > Graeme > > > On Mon, Nov 28, 2011 at 3:40 PM, Chaitanya kumar CH < > [email protected]> wrote: > >> 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 <[email protected]>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 >>> [email protected] >>> http://lists.osgeo.org/mailman/listinfo/gdal-dev >>> >> >> >> >> -- >> Best regards, >> Chaitanya kumar CH. >> >> +91-9494447584 >> 17.2416N 80.1426E >> > > -- Best regards, Chaitanya kumar CH. +91-9494447584 17.2416N 80.1426E
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