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Clipping raster using vector layer?

idham khalil

May 01, 2012 17:07

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Hi guys,

Anybody how to do it in Idrisi?

Thanks in advance

Cheers

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7 comments

• 0
  
  Clark Labs Tech Support Team May 02, 2012 16:13

  To clip a raster using a vector layer, you will first need to convert the vector layer to raster, assigning a value of 0 to all cells outside of your area of interest (AOI) and a value of 1 to all cells inside your AOI, this is called a mask.  Then you will use the OVERLAY module to multiply your raster image and your mask image.  All values multiplied by 1 (inside your AOI) will remain the same, while all values multiplied by 0 (outside your AOI) will become background values.  

  Here is a step by step walk through:

  1. Convert the vector layer to raster using the RASTERVECTOR module.
         a. You will be prompted to bring up the INITIAL module to create a blank raster.  Select to copy the spatial parameters from the raster you wish to clip.
     2.  You should now have an image with values of 1 for all areas within your AOI and values of 0 for all areas outside your AOI.
     3.  Next, use the OVERLAY module to multiply the two images together.  This will clip, or mask, your raster.
     4.  If your AOI is much smaller than your full original raster image, you can use the WINDOW module to extract a smaller subset of the clipped raster.  Alternatively, you can simply zoom into the area you wish to see, and then in the Composer window click the save button and select to "Save current view of highlighted raster layer as a new IDRISI image".  
     
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  idham khalil May 16, 2012 18:07

  Thank you very much!

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  maculata lukuxus November 18, 2013 09:35

  Thank you for your answer Clark Labs. I have a classified raster that I want to cut with a vector but I can't . When I am your approach, I have a raster with the values ​​0 and 1 and my classified raster with values 'Unclassified, ​​1, 3, 7, 10, and several "NODATA". I can't multiply my classified raster with binary raster. Thank you for helping me.

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  Richard Osaliya June 19, 2014 13:18

  But when it comes to multiplying the two, it brings an error that the rows and columns of the two images do not match.

   

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  Alyssa November 15, 2017 07:55

  Hi, I`ve doing the Vector to Raster conversion but there`s always an error saying, "RGB24 is not compatible with this module". What does this mean?

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  kishore naidu May 08, 2019 17:27

  hi can anybody show how to clip an AOI in TERRSET using ARC shapefile?

  Edited by kishore naidu May 08, 2019 17:27
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  sumanta mondal April 04, 2020 04:36

  hii, kishore to clip AOI in terrset using ARC shapefile ,is difficult, because in order to clip first of all u have to change the format to arc shapefile to idrisi..then  display with  metadata utility to see minimum and maximum x and y value of both arc shape file and your AOI image .the arc shapefile minimum and maximun value should contain in your AOI image..otherwise it will not be possible