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Frequent Contributor
Posts: 95
Registered: ‎01-04-2017
Accepted Solution

How to display 3 different bands from three different files in RGB display

Hi,

 

How can I display 3 different bands from three different files in the RGB display. For Example:

 

Band1 - File1 -  Blue Color Gun of Display

Band2 - File2 -  Green Color Gun of Display

Band3 - File3 -  Red Color Gun of Display

 

Thanks and Best Regards,

 

RSGIS

Super Contributor
Posts: 339
Registered: ‎11-16-2015

Re: How to display 3 different bands from three different files in RGB display

Hi. You can either use the Stack Layers operator in Spatial Modeler or with the Select Layer to Add dialogue (File > Open Raster) select the three files, go to the Multiple tab and select Virtual Stack. Cheers, Johnnie

Technical Evangelist
Posts: 1,079
Registered: ‎10-01-2015

Re: How to display 3 different bands from three different files in RGB display

Another option is 

 

Multispectral tab > Bands group > Properties button , which brings up the Set Layer Combinations dialog. 

 

Cheers

 

Ian Anderson
Chief Product Owner, Desktop Remote Sensing
Hexagon Geospatial
Frequent Contributor
Posts: 95
Registered: ‎01-04-2017

Re: How to display 3 different bands from three different files in RGB display

Hi,

Thanks JohnnieJ, but this procedure stacks all the bands in each file and there is no choice to select specific band from each file. I want to visualize various band combination from different files on-fly without having to produce any output file, as in this case. vsk file.

 

Thanks and Best regards,

 

RSGIS

Frequent Contributor
Posts: 95
Registered: ‎01-04-2017

Re: How to display 3 different bands from three different files in RGB display

Hi,

 

Thanks ian.anderson, this is what I wanted.

 

But:

 

1. Initially there is no multispectral tap option available, unless first a multispectral file is displayed, then only we can choose to add bands fom other files.

 

Also, if I want to display three panchromatic files through each color gun, it is not possible, unless I choose first pan file as “True color” in Raster options.

 

Is there any solution to the above two problems?

 

If there is no solution, I would suggest the following addiions in future releases:

 

  1. Multispectral tab under main Raster Menu, may be under Classification group, same as hyperspectral  and other tab, with open raster option.
  2. The Three/Multi layer dialogue appearing when right clicked in the viewer, shall be modified with the option of selecting the “files” under each Red, Green and Blue colors, under “layers to colors” section

Thanks and Regards,

RSGIS

Super Contributor
Posts: 339
Registered: ‎11-16-2015

Re: How to display 3 different bands from three different files in RGB display

[ Edited ]

Glad you got the solution but just for info; the vsk is just a text file - you're not really producing a new file. Also, once you have the stack of all your files you can then select whatever band from whatever file you require.

 

If you want to open a single band image as multispectral, just go to the Raster Options tab and change Greyscale to True Color. Oh, just re-reading, I see you've already done this. Is this a problem for you?

 

This is a fairly niche case (although one that I do reasonably often, but always in Spatial Modeler).

 

Cheers, Johnnie

Technical Evangelist
Posts: 1,079
Registered: ‎10-01-2015

Re: How to display 3 different bands from three different files in RGB display

Hi @rsgis ,

 

It looks like you've answered your own question. When you select an image file to display as Raster, ERDAS IMAGINE will choose a default display mode for you in the file chooser. For example if you select a single band athematic image it will default to the Greyscale display mode. However there's nothing preventing you from changing that default in the File Chooser - change to TrueColor and you can open the Pan band to red, green and blue and then substitute in other files for the guns you wish to use. 

 

Or, as Johnnie points out, using the Virtual Stack approach does much the same thing (and the only file created is a small header which basically says "these are the filenames which form the stack).

 

Cheers

 

Ian Anderson
Chief Product Owner, Desktop Remote Sensing
Hexagon Geospatial