how can i extract the vacant land boundary ?

[ahmed taman]

Dears,

i have satellite image for urban region in this region there are different land use such as residential, transportation and vacant land  i want to extract the Land boundary that is now vacant by any RS software 

[bejokaryo]

Dear Ahmed,

 

based on my understanding, if i'm not mistaken you can follow this step:

firstly, you can perform classification if you haven't classify your data.
in ENVI you can use classification from Toolbox > Classification > Supervised Classification.
for urban area possibly you can also choose example based classification (in ecognition software known as object based classification).
From the Toolbox, select Feature Extraction > Example Based > Feature Extraction Workflow.

secondly you can select vacant land based on your classification
for me it is easier using ENVI CLASSIC

load your classified data
Select Basic tools> region of interest>roi tools

from roi tools, select vacant land class using options>band threshold to roi.
fill the value with the classified data (for example vacant land has value of 5, then fill min and max with 5)

then export roi to shapefile.

finally you have vacant land boundary in shapefile

 

hopefully this can help

[ahmed omar abd el aziz]

Dear Ahmed 

there is no method to extract Vacant land by normal classification because the classification based on pixel value which reflect the surface type . the vacant land has no pacified surface or soils i mean may be initially roads or airport or any empty land .

so the only way to extract vacant land based on visualization method .

greetings