Problem with "Image thresholding technique" (mask and extract)

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12-17-2014 11:52 PM
AhsanAbbas
New Contributor III

Hello Guys,

                 I have to extract water body from Landsat imagery, I used the NDWI to extract water area from imagery, but i want to use image thresholding technique to define my own mask and extract only water area in the image. What techniques are possible ? Is level slicing good enough or not ?

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2 Replies
larryzhang
Occasional Contributor III

First of all, you can refer to the 'traditional' practice that was done by Komeil et al in 2014, which demo some good experience with combined NDWI-PC (principal components) that can be done in ArcGIS..

      The article can be google-it, which is called  'Water Feature Extraction and Change Detection Using Multitemporal Landsat Imagery' http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCQQFjAB&url=http%3A%2F%2Fwww.mdp...

Secondly, we prefer to use 'object-oriented' feature extraction for high accuracy in operation. With this technique, ERDAS Objective is advisable to use...

Lastly, if you are using LANDSAT, better to use LANDSAT 8, which should be mainly using band 1, which can be used with two other bands for closer investigations of coastal waters and estimating the concentration of aerosols in the atmosphere, however, in most cases, models will use the radiance values of this band.

L8_band_combos_b.jpg

larryzhang
Occasional Contributor III

On the boundary extraction of water body from imagery, it is unfair not to mention object-based solution in ArcGIS 10.3. Pls refer to the discussion at Re: Object-Based Image Analysis 

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