Inforest Research Forum
February 22, 2018, 04:36:13 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
   Home   Help Search Calendar Login Register  
Pages: [1]
  Send this topic  |  Print  
Author Topic: SPEAR TOOLS - Change Detection Substractive  (Read 7550 times)
Regular Members
Posts: 5

View Profile Email
« on: April 11, 2009, 09:35:42 AM »

When using change detection (substractive)  in spear tools in ENVI version 4.5, if the bands of the image did not include information about the wavelength  the wizard prompt to define the B, G, R, NIR bands  of the images and continued with the process thereafter. In version 4.6.1 if you use images without band wavelength definition, the wizard won't prompt to define bands and won't continue with methods such as NDVI difference.

Has anyone seen this before? Is it supposed to be like this?
Full Member
Posts: 132

View Profile Email
« Reply #1 on: April 22, 2009, 11:10:20 AM »


The following answer was generated from ITTVIS staff. It clarifies the situation.

In ENVI 4.6 all of the different SPEAR Change Detection wizards were folded together into one master tool.  The band picking wasn't necessary for most of the options in that new wizard, so he replaced it with the warning message.  That way people who don't need to pick bands aren't forced to.

The idea, I think, is that you can always add the wavelengths for the image into the header, and then you can use the wizard the way you want to without having to pick the bands.  To add wavelengths to image bands in ENVI, you right click on the image in the Available Bands List, and choose Edit Header.  In the resulting Header Info dialog, choose Edit Attributes -> Wavelengths.  In the resulting dialog, you can enter the wavelengths for your bands.
Pages: [1]
  Send this topic  |  Print  
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!