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Contributor
Posts: 68
Registered: ‎03-13-2016
Accepted Solution

Layer Stacking with ERDAS 2015

Dear Community Members,

 

I am cutting my teeth in RS and image processing so this gives me difficulties in carrying out some basic operations.  Given that i am working towards generating a thesis , i have to be careful about each step i take in the image analysis process.

 

Here is my challenge :

 

I just noticed something while layer stacking of the original bands .  The default deacription on the 'Layer' in input layer field stands at 1. But if you drop down you will see 'All'
 
I didnt take care to change it from '1' to  'All' before or doing adsing of individual bands.
 
But what i noticed was that on selecting the first band , B2 and clicking add, ERDAS reordered it as (1).
 
I expected  that on adding B3, ERDAS will apply the same logic  to identify it as (2).tiff as it did with the first band. 
 
Rather the second band i added , B3 was highlighted as (1) .tiff again and so with subsequent bands
 
Does it mean erdas is lumping all of the bands  into one layer?
 
Im worried because during multiapectral band composting,  i want to be able to carry out my false colour combination flawlessly.
 
Was i wrong in allowing the default of '1' to remain in the layer field while adding the bands or should i have changed it to 'All' ?
 
Please kindly share your expert advice pls.
 
Highlighted
Contributor
Posts: 26
Registered: ‎06-01-2016

Re: Layer Stacking with ERDAS 2015

Hello, 

 

The layer number refers to the band number within the image you are adding at the time. Therefore if you are adding a single layer image you can only have layer number (1). If you are adding a layer from a multispectral image, then you can choose which band to add, or you can add all bands. 

 

For example, I have a 4 band multispectral sentinel image in the layer stack attached, I can ask it to only add in one band such as band number 3 into my layer stack. Then this will display as 'image(3).tiff'. Selecting all, in this case, would add in band (1)(2)(3)(4) from my one image. 

 

If you only have one band in an image you can only add band number (1). Therefore, using the default 1 is absolutely fine. 

 

If you are stacking Landsat7/8 Imagery it is easiest to use the import function in IMAGINE which stacks the data for you.  Manage Data Tab> Import Data > Landsat-7 or Landsat 8 from USGS

 

Hope that clarifies things a little for you!

Contributor
Posts: 68
Registered: ‎03-13-2016

Re: Layer Stacking with ERDAS 2015

Dear

 

I am really grateful for your quick reply.

 

Let me use pictorial representations to explain what im struggling to understand and overcome.

 

As you can see

  1. on opening the software, the default in the Layer field is at " All"
  2. selecting and adding the first band is shown as ( b2).tiff 1
  3. Now one would expect that on adding band b3, ERDAS should see and represent it as (b3 ).tiff2 but NO, it still remains as ( b3).tiff 1
  4. This is where I am very confused and afraid that i might be progressing in error and you know what that means when writing a research!!
  5. 5. I am also worried that if tehse bands are nt stacked correctly and in order, my attempt at false colour composting under multispectral will be in futility. 

Maybe a quick video tutorial might help. I would truct the  video from ERDAS community than I would trust any other on You tube

 

I count on your remote technical support. Its crucial

 

 

Contributor
Posts: 68
Registered: ‎03-13-2016

Re: Layer Stacking with ERDAS 2015

Oh Apologies , I forgot to add the 1st image .

 

here I have added it now.

 

So its a bit easier to follow my question

 

Thanks  and many more

Contributor
Posts: 68
Registered: ‎03-13-2016

Re: Layer Stacking with ERDAS 2015

Dear Emily,

 

I just tried stacking the bands again and now doing it differently.  I have just realized the following :

 

  1. that my 2015 university licensed ERDAS interface doesnt giive me the same flexibility to chose which layer to add the selected band as yours ( which you attached in teh image)
  2. That after adding the first band, which ERDAS sees as  ( b2).tiff 1, I manually changed the layer to "All" ( as there are no more flexible options) and ERDAS doesnt record the subsequent band additions as ( b3).tiff 1, BUT rather as _b3.tiff  or _b4.tiff
  3. No more adding ( 1) after each selected band.
  4. Please what should i do in thsi regard given that my ERDAS doesnt give me the flexibility to chose which layer i want the band to be placed?

Thank you so much

Contributor
Posts: 26
Registered: ‎06-01-2016

Re: Layer Stacking with ERDAS 2015

Hello Kansy,

 

I have found a video which may help you understand. 

 

https://www.youtube.com/watch?v=71Euy5WvC2s

 

 

You can check your image afterwards by using the inquire cursor, to check the pixel values remain the same. Home Tab, left hand side, Inquire. 

 

Regards,

Emily

Demonstration of stacking bands 1 through 7 of Landsat 8 OLI. Path-Row 27-39
Contributor
Posts: 68
Registered: ‎03-13-2016

Re: Layer Stacking with ERDAS 2015

Dear Ms Emily,

 

Thank you so much for your video.

I have just watched it now and her ERDAS interface is exactly what i have . As you can see, all the individual bands she has added has been represented by ERDAS as ( b3).tiff 1; ( b4).tiff1 and so on EVEN when she changed the layer field to "All" after the addition of teh first band 1

 

Unlike the your ERDAS environmet picture you sent to me where the layers are listed as 1, 2, 3, 4 which allows ERDAS to place each band selection /addition into the highlighted layer in the drop down, 'mine and the one in video " DOESNT have this drop down of differnet layers

 

so the big question now is , is it ok to proceed with the band addition irrespective of whether ERDAS keeps the layer default number at 1 or All?

Or shoudl I be conscious of highling "All " before clicking to add a new band?  I am just worried over this step because a mistake here can cause me  some trouble in the assigning of bands to colour channels in the band composition of the  multispectral environment

 

Please I request your kind indulgence in this simple but crucial step for me

 

Thanks

Contributor
Posts: 26
Registered: ‎06-01-2016

Re: Layer Stacking with ERDAS 2015

Hello Kansy, 

 

There is no number option because your image only has one band/layer. So using either option will work, All or 1. As either way there is only one band to layer stack. 

 

I've always used 1. 

 

Regards,

Emily 

Contributor
Posts: 68
Registered: ‎03-13-2016

Re: Layer Stacking with ERDAS 2015

Dear Ms Emily,

Thank you once again.  So in essence , you are saying that whether my layer field was left at "1" or "All' during my layer stacking process is inconsequential and that this will not alter ERDAS's logical arrangement of the bands in the approapraite layer and so by extention , it wil not affect my band composting in a false colour mode under Multispectral  environment.

 

 

If that is true, that means that all the previous layer stacking process I did where the layer feild was left at "1" is correct !

 

 

 

 

 

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