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I need to merge the RGB bands of three TIFF images. I'm trying to use a PIL library (Python Imaging Library), but this execution error happens:

Traceback (most recent call last): File "merge.py", line 7, in Imagem = Image.merge("RGB", (red, green, blue)) File "/usr/lib/python2.7/dist-packages/PIL/Image.py", line 2367, in merge raise ValueError("mode mismatch") ValueError: mode mismatch

The output must to be a new TIFF image with three bands. This is my code:

import Image

red = Image.open("red.TIF")
blue = Image.open("blue.TIF")
green = Image.open("green.TIF")

out = Image.merge("RGB", (red, green, blue))
out.save("img-out.TIF")

Can anyone help me?

  • Are these GeoTiffs or just regular tif images? If the latter you might be better off asking this question on StackOverflow as it has no clear GIS relation. – Kersten Feb 12 '16 at 13:32
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    Are you sure that the input images are single band images? Test with red.getbands() etc to see if the result has length 1. – Detlev Feb 12 '16 at 13:33
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    have you tried github.com/mapbox/rasterio instead? – bugmenot123 Feb 12 '16 at 14:00
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    Does it need to be in Python, or do GDAL tools work? gdal_merge.py -separate -o RGB.tif -co PHOTOMETRIC=RGB red.tif green.tif blue.tif – Alec Bennett Apr 9 '17 at 5:04
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You need to convert each channel into a luminosity channel. So instead of this:

red = Image.open("red.TIF")

you need to do this:

red = Image.open("red.TIF").convert('L')

rinse and repeat for G and B and you're done!

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