Computer Science Mojo

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How to use GDAL Python to transform geotiff pixels to lat lon real-word coordinates

Category: GDAL     Tag: GDAL   Linux   Python  
By: David     On: Thu 06 August 2015      Pageviews: 182

GDAL gdaltransform is a easy way to transform a pixel of a tiff image to its corresponding lat/lon coordinate.



1. In terminal

Running the following in the terminal will give you the (lon, lat) coordinate of (12, 6) pixel (12th column and 6th row) of "myImage.tiff" :

gdaltransform myImage.tiff
12 6

this returns (lon, lat, z value) :

85.1234567890123 27.1234567890123 0

2. In Python Script

To achieve this through a python script and therefore transform an lot of pixels at once, you will have to first write the pixels to a file "pix.txt" and then run:

import os
os.system("gdaltransform " + imagePath + " <pix.txt "+ ">cor.txt")

This will produce "cor.txt" containing the (lon, lat, z value)

Example "pix.txt" and "cor.txt": pix.txt:

12 6
24 9


85.1234567890123 27.1234567890123 0
86.3234565432233 26.9876543345677 0