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1 Replies and 1398 Views
knowledge base classification. 1398 1
Started by Deleted User
Hi all,
I want to make a rule set (like the ones in Knowledge Classifier in Erdas Imagine). I explored "Decision Tree" but it was not flexible as compared to Erdas. Is there other way to do this.
As an example this is what I want to do. Say if the valuse of an index is from 0.2 to 0.5 classify as forest. Within that if band 1 is > .8, classify as x.
Guidance much appreciated.
Regards,
Deo
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1 |
1398 |
09 Mar 2009 04:52 AM |
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2 Replies and 937 Views
Overlaying vectors on image 937 2
Started by Deleted User
Hi experts, I am unable to overlay my shape file on Geotif image, however these both have same projection type ie lcc, and&160;I&160;&160;can overlay these two in envi zoom. Both have similar projection environment but False- easting, northing, Standard_Parrallel, central meridian, and latitude of origin is not same. If this is the cause how to change these parameters in envi 4.4.
Thanks
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2 |
937 |
06 Mar 2009 12:42 AM |
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0 Replies and 1156 Views
Costruzione e verifica della bontatà di un DEM 1156 0
Started by Deleted User
Ciao a tutti!
Mi chiamo Giulia e sono una studentessa universitaria della facolt&224; di Ing. Civile presso Ferrara.
Sto svolgendo la tesi della laurea specialistica in campo del telerilevamento e vorrei alcuni suggerimenti per poter svolgere al meglio il mio lavoro.
Ho costruito il DEM partendo da 2 immagini Ikonos avendo a disposizione i GCP da un rilievo GPS ora vorrei entrare a conoscenza della bont&224; del mio lavoro ma non riesco a capire come fare.
In pratica mi servirebbe capire i...
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1156 |
03 Mar 2009 07:14 AM |
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2 Replies and 1666 Views
problem in ENVI_OPEN_FILE 1666 2
Started by Deleted User
Hello,
I encounter a problem in IDL programing.
I use ENVI_OPEN_FILE, inputfilename, r_fid = t_fid
and I "help&160;t_fid"&160;
T_FID LONG = Array&913&93
and I "print&160;t_fid"
32 12 2
if (t_fid eq -1) then begin
IDL tell me expression mus be a scalar or 1 element arra in this context:
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below is from the HELP&160;ENVI_OPEN_FILE&160;
fname = '/data/img_001'&160;
envi_open_file, fname, r_fid=fid&160;
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if (fid eq -1) then return&160;...
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2 |
1666 |
01 Mar 2009 05:47 AM |
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3 Replies and 1333 Views
user defined datum results in different ways between envi 4.3 and 4.5 1333 3
Started by Deleted User
I try&160;to define my own datum for my works&160;with Envi.&160;But V4.3 and V4.5 give me different results.
I add my own datum into ellipse.txt and datum.txt .
Envi 4.3 failed in writing and reading&160;the user defined&160;datum into&160;the&160;Geotiff header, but&160; Envi&160;4.5 succeed.&160;
Why Who knows
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3 |
1333 |
27 Feb 2009 07:39 AM |
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1 Replies and 1317 Views
orthorectification aerial photographs 1317 1
Started by Deleted User
Dear list,
We have aerial photographs of the '30s and want to orthorectify them in ENVI. We have no camera information available.&160; Are we doing the right thing if we use the build RPC function and subsequently use the orthorectify using RPC function Or is there a possibility to orthorectify them without knowing the focal length of the imagery etc
At present we tried the first method, but got an error message saying that the interior and exterior information are not accurate enough for o...
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1 |
1317 |
27 Feb 2009 06:06 AM |
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1 Replies and 1270 Views
ENVI reader for ArcGIS 1270 1
Started by Deleted User
Hi--I downloaded this before on a different machine--but I seem to be unable to download the ENVI reader for ArcGIS&160; Am I missing something
Thanks--
--s
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1 |
1270 |
26 Feb 2009 02:08 PM |
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1 Replies and 1362 Views
MrSID support on new ENVI version and Help problems 1362 1
Started by Deleted User
Dear ENVI's users
I've updated my 4.5 version to the 4.6 and today to the 4.6.1 and I've found two main problems:
1- MrSID it is not supported, I receive an error message each time that I try to open a MrSID image. The same image can be opened without problems using the previous version 4.5, 4.4.... Someone has observed the same problem
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2- The Help from the Help menu in the main toolbar don't want to be opened (no problem instead with the 4.5 version). I'm using Microsoft XP SP3 OS.
...
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1 |
1362 |
24 Feb 2009 07:14 AM |
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3 Replies and 1793 Views
Negative Reflectance Value after FLAASH 1793 3
Started by Deleted User
Guys,
Need some help.
I'm dealing with Quickbird images. Converting from DN to radiance seems to run smoothly in ENVI. But after FLAASH, majority of pixels are in negative values. Just couldnt understand the logic because there were no negative value in radiance image. Aren't reflectance is the ratio of incoming and outgoing radiance There should be no negative values.
Am I right Anybody can help
Thanks in advance.
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3 |
1793 |
23 Feb 2009 03:44 AM |
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1 Replies and 1491 Views
Best way to export for ArcView 9.2 1491 1
Started by Deleted User
Hi. I have a classified image (4 classes) that I want to export for use in ArcView 9.2, however none of my trials so far seem to work out. First of all ArcView doesn't seem to recognize some of the formats I'm exporting (even after installing the ENVI Reader for ArcGIS). Second of all, when I run a Tabulate Areas tool on a raster that does show/load, such as a geotiff or .bil file, I'm presented with a GRIDCODE value which I can't reconcile to a specific class in the original raster.
So what is...
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1 |
1491 |
22 Feb 2009 02:32 PM |
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1 Replies and 1153 Views
ENVI_GET_??? 1153 1
Started by Deleted User
hi all,
&160;
is it possible to read pixel values column by column...like ENVI_GET_SLICE. if i understand the command description correct, ENVI_GET_SLICE only reads data line by line and no columns is there a comparable command for this
thanks in advance,christine
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1 |
1153 |
19 Feb 2009 08:32 AM |
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1 Replies and 1112 Views
Change class value 1112 1
Started by Deleted User
Dear all,
I'd like to know how to change the class value of a classified image. I'd like to obtain a classified image or any raster. If my class "water" is 6 and "forest" 4 for exemple, i want to recode water as 4 and forest as 6. How to do
Thanks.
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1 |
1112 |
18 Feb 2009 05:53 AM |
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2 Replies and 1599 Views
Problem adding a user defined function to ENVI. 1599 2
Started by Deleted User
Hello.
I'm trying to add a function to ENVI that enables me to load a 3rd party file type.
Currently the script I have works fine, but only if I load ENVI with the "ENVI IDL 4.5" icon. If I try loading IDL without IDL then the menu item does not appear.
The script is saved as a .pro file, which I think may be the problem. However, if I try saving as a .sav file (using 'save, /ROUTINES, 'chipstoenvitiff4_define_buttons', 'chipstoenvitiff4', FILENAME = 'D:\Program Files\ITT\IDL70\Pr...
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2 |
1599 |
12 Feb 2009 06:42 AM |
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3 Replies and 1578 Views
ADS40 Imagery 1578 3
Started by Deleted User
Just wondering if anyone has been using ADS40 imagery in ENVI. I would like to try the DEM extraction module with this imagery to compare to some software we are already using but I can't even get an image to open correctly in ENVI. If anyone has any tips on using ENVI with ADS40 imagery I would be most appreciative!
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3 |
1578 |
11 Feb 2009 09:00 PM |
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1 Replies and 1266 Views
Orthorectification of QuickBird with GCP in ENVI 1266 1
Started by Deleted User
Hi everyone,
I am having some difficulty with orthorectifying a QB image with ground control points and I will try to summarize the available data sets and the problems I encountered.
I have an un-orthorectified QB image with the associated RCP file.&160; I also have the DEM of the same area. In order to have a more precise image, I wanted to run orthorectification with ground control points.
I selected GCP's and saved them as pts file and run the orth. with DEM. The result was an image with...
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1 |
1266 |
02 Feb 2009 02:50 PM |
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1 Replies and 2920 Views
Root Mean Square Error 2920 1
Started by Deleted User
Does anyone know if ENVI reports Root Mean Square Error (e.g. automatic image-to-image georegistration) in Pixels or Meters
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1 |
2920 |
02 Feb 2009 12:18 PM |
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2 Replies and 1296 Views
Batch error when opening MODIS hdf files 1296 2
Started by Deleted User
Dear Envi-ans, I wrote a batch process in ENVIIDL to import/mosaic MODIS snow cover images (2000-2008). My batch works perfectly when I run it for seperate years, but when applied to the whole stack of years, it hangs when opening the hdf files (i.e., it opens a dialog to enter the lines/columns etc. manuanlly) after processing X files. For example: it runs perfectly for the first two years, but hangs when processsing the images of the 3rd year. However, if I run the 3rd year seperately, it wor...
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2 |
1296 |
30 Jan 2009 01:14 PM |
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3 Replies and 1058 Views
Error message: Orthorectifying SPOT 1058 3
Started by Deleted User
Hello
&160;
I am trying to Orthorectify some SPOT images, with the Map/Orthorectification tool, using a DEM as well. But when I click OK to strat running it I get the following error message:
ENVI: Retrieve Data: An error has ocurred during processing
&160;
POINT_LUM: Variable is undefined: Unit. "the result may be invalid"
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An then the output image is completely shifted.
Can anyone help me with this please!
&160;
Thank you
&160;
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3 |
1058 |
21 Jan 2009 05:58 AM |
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1 Replies and 1581 Views
Using ROI's in the Spectral Angle Mapper 1581 1
Started by Deleted User
Hi--I'm a bit confused about the SAM classification algorithm, and how it extracts endmembers from ROI's.&160; I want to compare the results of a SAM classifier against a Max. Likelihood classification to identify archaeological sites.&160; I don't expect these sites to have any distinct endmembers, as they are difficult to distinguish from the surrounding landscape.&160; If I define an "archaeological site" ROI, how does it extract the endmembers&160; Is it best for me to select ...
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1 |
1581 |
20 Jan 2009 08:38 AM |
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1 Replies and 1324 Views
Question about MCTK 1324 1
Started by Deleted User
Hi all, I am using the MODIS conversion toolkit plugin to process some MODIS grid files. It works fine with the correct outputs but with with one issue. Each time the convert_modis_data function reads in a file and outputs it, it prints ""HDF_SD_ATTRFIND: Unable to find the HDF-SD attribute named scale_factor."" and "" HDF_SD_ATTRFIND: Unable to find the HDF-SD attribute named add_offset."" The MCTK user guide says "If scale and offset factors are pre...
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1 |
1324 |
17 Jan 2009 02:56 PM |