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I would like to obtain the information of a raster layer at some points. Apparently the Point sampling tool does the job. I have used this tool, and all the raster values extracted at specific points are NULL... Both vector and raster layer are in the same CRS. I use QGIS 2.0.i in Windows 8.1. Any clue ?

By the way, does anybody knows how the raster value is computed by this tool = Is it interpolated ? or is it the closest raster value to the point coordinate ? )

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What dataset type is your raster (e.g. tif, jpg, MrSID, jp2)? – artwork21 May 1 '14 at 16:51

Use the Coordinate Reference System (CRS) of the raster image.

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We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.

Welcome to GIS SE! Normally "about a paragraph" is considered minimum length for an answer (or question) here so I recommend that you edit your question to explain briefly how your answer addresses the asker's question. – PolyGeo Jul 23 '14 at 8:24

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