ENVI EX Tutorial

ENVI EX Tutorial: ImageDifference ChangeDetectionI m a g e D i f f e r e n c e C h a n g e D e t e c t i o n W o r k f l o w 2F i l e s U s e d i n t h i s T u t o r i a l 4S e l e c t i n g F i l e s f o r I m a g e D i f f e r e n c e C h a n g e D e t e c t i o n 4I m a g e D i f f e r e n c e C h a n g e D e t e c t i o n 4C h a n g e T h r e s h o l d i n g 6C l e a n i n g U p I m a g e D i f f e r e n c e C h a n g e D e t e c t i o n R e s u l t s 8E x p o r t i n g I m a g e D i f f e r e n c e C h a n g e D e t e c t i o n R e s u l t s 91E N V I E X T u t o r i a l : I m a g e D i f f e r e n ce C h a n g e D e t e ct i o nImage Difference Change Detection WorkflowIn this tutorial, you will use the Image Difference Change Detection workflow to compare two imagesof an area over Indonesia that was impacted by the December 26, 2004 tsunami. The first image is abefore image, taken in April, 2004. The second image was taken in January, 2005.The first image shown below is from t s u n a m i _ b e f o r e . d a t, the second image shows t s u n a m i _a f t e r . d a t in a Portal. You can see in the Portal that there are substantial differences between thetwo images when you adjust the Transparency sliders on the toolbar. Specifially, many vegetation areaswere washed out by the tsunami.2E N V I E X T u t o r i a l : I m a g e D i f f e r e n ce C h a n g e D e t e ct i o nReferences Image Difference Change Detection:Normalized Difference ...