| Re: is-it possible to extract multiple profiles on multiple images from shape files [message #67626] |
Thu, 20 August 2009 11:20 |
yoann06
Messages: 6
Registered: August 2009
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Junior Member |
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On Aug 20, 7:53 pm, David Fanning <n...@dfanning.com> wrote:
> yoann06 writes:
>> I saw your methode but I wasn't sure : I thought that the
>> interpolation induced
>> that some values are not true but are interpolated values..
>> I am wrong are not? because if your method really extract each values
>> of each pixel along the profil I am going to try to use this.
>
> The interpolation is to find the pixels that lay
> underneath the profile line. It is those pixels
> that supply the values. So your image values are
> NOT being interpolated.
>
> Cheers,
>
> David
> --
> David Fanning, Ph.D.
> Coyote's Guide to IDL Programming (www.dfanning.com)
> Sepore ma de ni thui. ("Perhaps thou speakest truth.")
OK, it's perfect...please excuse my first "bad feeling" regarding the
notion of interpolation..
thanks a lot, I will let you know how I will deal with all this.
Have a nice day
cheers
Yoann
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| Re: is-it possible to extract multiple profiles on multiple images from shape files [message #67627 is a reply to message #67626] |
Thu, 20 August 2009 10:53  |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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yoann06 writes:
> I saw your methode but I wasn't sure : I thought that the
> interpolation induced
> that some values are not true but are interpolated values..
> I am wrong are not? because if your method really extract each values
> of each pixel along the profil I am going to try to use this.
The interpolation is to find the pixels that lay
underneath the profile line. It is those pixels
that supply the values. So your image values are
NOT being interpolated.
Cheers,
David
--
David Fanning, Ph.D.
Coyote's Guide to IDL Programming (www.dfanning.com)
Sepore ma de ni thui. ("Perhaps thou speakest truth.")
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| Re: is-it possible to extract multiple profiles on multiple images from shape files [message #67628 is a reply to message #67627] |
Thu, 20 August 2009 10:47 |
yoann06
Messages: 6
Registered: August 2009
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Junior Member |
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On Aug 20, 6:32 pm, "Jean H." <jghas...@DELTHIS.ucalgary.ANDTHIS.ca>
wrote:
> yoann06 wrote:
>> dear members,
>
>> I am a new member of this group, I come from france, and I am a new
>> user of IDL too.
>
>> firstly, I would like to say hello to everyone, and thanks those who
>> are going to help me.
>> I have a problem with a program I try to make without any solution for
>> me.
>> I have 5 profiles in ".shape" format (that I can convert to .evf
>> without any problem), and I have 16 images. what I want to do is to
>> extract all the values along each profile in each images. I tried with
>> the "PROFILE" function in IDL but I can't use the profil that I
>> allready have in my possesion.
>> my question is does anyone allready make this kind of task and if yes
>> could you give to me some advises to reach my goal.
>
>> thanks a lot
>> best regards
>> yoann
>
> Hi,
>
> If you want to do it by hand, follow this (from the help file):
>
> Creating a Transect from Polyline Vectors
> You can use polyline vectors from the Available Vectors List with the
> Spatial Profile tool. Polygon and point vectors are not accepted. To
> create a transect from vectors opened in ENVI, do the following.
>
> In the Spatial Profile Tool, select Options → Create Transect from
> Vector. The Import Vector Layers dialog appears. This dialog contains
> the following items:
> Select one or more vector layers to select them for import.
> Click OK. ENVI converts the polylines individually into a transect. The
> transects produce spatial profiles listed in the Extracted Profiles
> section of the Spatial Profile Tool. The resulting spatial profiles
> display individually in new plot windows.
>
> Jean- Hide quoted text -
>
> - Show quoted text -
thanks jean
but in fact my goal is to program it, in order to avoid a lot of
manuals
and repetitives tasks, where it's possible to make a lot of error due
to a moment of less attention.
and it's to improve my very very very basic knowledge in IDL.
cheers
Yoann
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| Re: is-it possible to extract multiple profiles on multiple images from shape files [message #67629 is a reply to message #67628] |
Thu, 20 August 2009 10:41 |
yoann06
Messages: 6
Registered: August 2009
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Junior Member |
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On Aug 20, 6:08 pm, David Fanning <n...@dfanning.com> wrote:
> yoann06 writes:
>> I am a new member of this group, I come from france, and I am a new
>> user of IDL too.
>
>> firstly, I would like to say hello to everyone, and thanks those who
>> are going to help me.
>> I have a problem with a program I try to make without any solution for
>> me.
>> I have 5 profiles in ".shape" format (that I can convert to .evf
>> without any problem), and I have 16 images. what I want to do is to
>> extract all the values along each profile in each images. I tried with
>> the "PROFILE" function in IDL but I can't use the profil that I
>> allready have in my possesion.
>> my question is does anyone allready make this kind of task and if yes
>> could you give to me some advises to reach my goal.
>
> I'm not sure about ENVI, but here is how I would
> extract such a profile from an image in IDL:
>
> http://www.dfanning.com/ip_tips/image_profile.html
>
> Note that the method will apply to curved or jointed
> lines as well as straight-line profiles.
>
> Cheers,
>
> David
>
> --
> David Fanning, Ph.D.
> Coyote's Guide to IDL Programming (www.dfanning.com)
> Sepore ma de ni thui. ("Perhaps thou speakest truth.")
dear david,
I saw your methode but I wasn't sure : I thought that the
interpolation induced
that some values are not true but are interpolated values..
I am wrong are not? because if your method really extract each values
of each pixel along the profil I am going to try to use this.
Yoann
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