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1 Replies and 1221 Views
A Strip in The Center of MNF Image 1221 1
Started by Deleted User
Hi all,
There is an obvious strip in some of my MNF eigenimages. It looks odd. So I double-checked my original AVIRIS image and did find some bands which have strip in the center. However, after I removed those "bad" bands from original image and redid MNF transform, there still is a stip in the center of image. I don't know why. Does it mean there are still some noisy bands in my data If so, how can I find those bands
Thanks very much,
Lin
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1 |
1221 |
25 Jun 2009 09:28 PM |
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1 Replies and 1264 Views
Assign Wavelength 1264 1
Started by Deleted User
Hi,
Is it possible to assign a wavelength range to a band, rather than just one value I've been trying to assign a wavelength by editing the header, but it will only allow a single value. I'd like to account for the range that each band encompasses so as to do spectral classification.
E.g. ASTER bands:
Band 1 = 0.52 - 0.60 (um)&160;
Thanks ... Randall
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1 |
1264 |
25 Jun 2009 11:13 AM |
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3 Replies and 1620 Views
K Nearest Neighbor 1620 3
Started by Deleted User
Hello,
I need to use the KNN classification algorithm on ENVI in order to classify forests from a SPOT5 image, but I can't find it. Does anyone know where I can find it and how to use it
Thanks
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3 |
1620 |
23 Jun 2009 02:09 AM |
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1 Replies and 1133 Views
saving an image without background 1133 1
Started by Deleted User
This time, I am trying save subset of an image which is &160;to select&160;part of the image that shows&160;only my study area using ROI in the scroll.&160;Eventually, I saved it, however it appears that there is a background image (with black) also saved which I donot need it. I just only need to save part of my study area without any background. How can I fix that&160; I tried to build and apply mask many times but it didnot work.&160; Basically, I am interested to save&160; composite ...
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1 |
1133 |
17 Jun 2009 07:21 AM |
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1 Replies and 1246 Views
Cloud Shadow Suppression 1246 1
Started by Deleted User
Hi
Does anyone have any tips on cloud shadow suppression&160; I read in a paper by Choi and Milton (1999) that their method&160;had been coded&160;as a User Function for ENVI but i cannot find it on the&160;website.&160;
I thought this might be related to the age of the function and so i wanted to ask on here if anyone knew of any other methods that are fairly simple to use for Landsat 7 ETM data
thanks
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1 |
1246 |
15 Jun 2009 04:43 AM |
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0 Replies and 1023 Views
Calculating ROI Separability 1023 0
Started by Deleted User
I'm trying to calculate the separability of 22 sets of roi points that were input from ASCII. When I select all of these I get an error saying 'TRIQL: too many iterations in tqli. The result may be invalid' and if I try to select only a few I get an error saying 'Singular value encountered in calculation for ROI' for each region. and the results show zero for divergence.
&160;
Has anyone come across these errors or know why they're occuring
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0 |
1023 |
11 Jun 2009 03:06 PM |
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1 Replies and 1249 Views
Problem with Mosiak- using georeference 1249 1
Started by Deleted User
Dear&160;ENVI users&160;,
&160;&160;
This time, I am challenged by mosiaking two&160; landsat (same bands) images (using georeferencing).&160; When I tried to masiak them, a wide gap of irregular shape&160;(in the intersection of the two scenes, with black background colour)&160;appears when&160;attempted to&160;overlap to each other. why is that
&160;
Do you think there is something wrong with the datum/projection&160;Ofcourse, there was an error associated with UTM projectio...
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1 |
1249 |
08 Jun 2009 07:08 AM |
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0 Replies and 1448 Views
Saving NITF metadata question 1448 0
Started by Deleted User
When exporting NITF metadata to a text file in ENVI 4.5, it seems that the file length and header length fields within the NITF 2.1 file header are not exported. Is there a reason for this
Thanks in advance,
Eric
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0 |
1448 |
03 Jun 2009 12:58 PM |
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1 Replies and 1099 Views
ROI Summary by Polygon 1099 1
Started by Deleted User
This is the first step in a two-step process that I want to complete.
In this step, I want to be able to summarize the ROI data not by pixel, but by polygon.
I have many ROIs for a collection of images. All of the entities in each ROI are polygons, exclusively. I know that ENVI still 'knows' about the polygons, because the ENVI ROI tool still shows how many polygons in each of my ROI regions.
If you are familiar with ASCII file output of ROI data, you have each row representing a pixe...
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1 |
1099 |
02 Jun 2009 09:37 PM |
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3 Replies and 1080 Views
ENVI batch mode problem 1080 3
Started by Deleted User
&160;
Hi all,
Because the large amount of image data, I have to use the batch model of ENVI.
My aim is to registrate the images in the batch model. Coordinate info of each image is in the .pts file using the same file name as the images. The projection is set up using the parameters, and the image dat files contain only the grey values.
The IDL programme can be compiled successfully, so does the Running Process, but the out file titled with "test" contains nothing. The batch...
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3 |
1080 |
01 Jun 2009 06:53 PM |
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8 Replies and 1307 Views
re-applying masked areas 1307 8
Started by Deleted User
Hello,
I am still a new user to ENVI and I am working on a supervised classification, using a hierarchical masking approach.&160; in other words, i have masked out easy to classify classes, then reclassified the remaining areas.&160; The problem I am encountering is that now that I have performed the classifications, I would like to "add back" the areas that were already masked out.&160; I understand I could do this through mosaic, by specifying background values that would allow t...
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8 |
1307 |
29 May 2009 02:04 PM |
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1 Replies and 1819 Views
Random sample using ground truth ROIS 1819 1
Started by Deleted User
I&160;want to generate&160;a random sample from one big ROI to&160;other smaller ROIS (points).&160;&160;I want to use&160;the resulting&160;&160;ROIS to train&160;and assess&160;the classification of a landsat image after.
When I&160;carry out the&160;Random sample using ground truth ROIS, the&160;problem is that what I want to get is one ROI per point&160;and no&160;one global ROI.&160;Otherwise&160;it&180;s only possible to&160;obtain an unique ROI&160;with&160;all the p...
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1 |
1819 |
29 May 2009 12:29 PM |
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1 Replies and 1441 Views
FLAASH AUTOCHAN error 1441 1
Started by Deleted User
FLAASH is causing some problems for me as well. This problem did not appear until yesterday afternoon, as I was able to correct an image that morning.&160; The error reads:
ACC error: autochan:
IDL error:
ACC_AUTOCHAN: No water absorption channels selected
&160;
ACC_AUTOCHAN
ACC_AVRD
ACC_HYPER2
ACC_ACC
ENVI_ACC_EVENT
ENVI_FLAASH_PROCESS_MANAGER
&MAIN$
Since I have seen it suggested before, I would be willing to send my journal and template files if it would help.&160; I have it se...
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1 |
1441 |
27 May 2009 08:47 AM |
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1 Replies and 1265 Views
ACC_CHANNEL_DEFN_READ: Error in reading channel divination file 1265 1
Started by Deleted User
Normal
0
false
false
false
MicrosoftInternetExplorer4
Hi
I think I have same problem as vrgalianougr.es but can’t figure it out
Problem: The FLAASH program exited with the following errors:
ACC error: avrd:
IDL error:
ACC_CHANNEL_DEFN_READ: Error in reading channel divination file U:\......\*.ers
ACC_AVRD
ACC_HYPER2
ACC_ACC
ENVI_ACC_EVENT
ENVI_FLAASH_PROCESS_MANAGER
IDLRTMAIN
$MAIN$
Is th...
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1 |
1265 |
27 May 2009 12:30 AM |
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0 Replies and 1131 Views
Images Normalization-Decision Tree 1131 0
Started by Deleted User
Hello all,
since my last entry, I find some interesting applications and functions in ENVI. But now I faced some problems.
The fact is, that I have some Landsat images (Landsat 5 TM and Landsat 7 ETM) with different values for the same landcover. For my classification (change detection) one of my ways is the decision tree, but I do not want to change the thresholds for classification in every image - which makes the classification in my perspective useless.
Now I'm looking for a function whi...
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0 |
1131 |
26 May 2009 10:24 AM |
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2 Replies and 1101 Views
programatical histogram equalization 1101 2
Started by Deleted User
Hello all,
I wonder if anybody has faced already such a task as programatical histogram equalization in IDL/ENVI of long integer data (HIST_EQUAL treats only byte data). It seems to me right now that I need to write a program myself but may be I missed some batch processing routine or other IDL function for this
Cheers
Michael
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2 |
1101 |
20 May 2009 08:35 AM |
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0 Replies and 1305 Views
MERIS Georeferencing error 1305 0
Started by Deleted User
Hello,
I have the 4.5 Envi version, and I am trying to georeference a MERIS image with the specific georeferencing comand from ENVI (Map> Georeference ENVISAT> Georeference MERIS) and it doesn&180;t seem to be accurate, since geografical points that are supposed to be on land are on the sea. Can anyone help me
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0 |
1305 |
19 May 2009 09:35 AM |
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8 Replies and 1768 Views
reconcile rois 1768 8
Started by Deleted User
hi everybody,
&160;
i've got a problem with the reconciling of ROIs. I digitized some areas in an image with the dimensions 8056/9042 and saved the rois in a roi-file. later, i resized the image by 0.5, which means, the image dimension changed to 4027/4521. because i want to compare the values of the rois, i now want to restore the rois to the resized image. in ENVI help, i found the tool reconciling rois via map. ENVI asks me to selecat the source file where the rois were drawn (the large im...
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8 |
1768 |
18 May 2009 07:05 AM |
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1 Replies and 1316 Views
restore same ROI's on multiple geo-referenced images 1316 1
Started by Deleted User
Hi,
I have created ROI's using one georeferenced image, which was pre-processed in BEAM VISAT for Noise reuction and atmospheric correction, then warped using image to image registration in ENVI.
I have 4 other files that went through the same process using specicific GCP's, so have slight&160;different spatial extents,&160;and I'm trying to resote the ROI's onto all of them and save separte ASCII files&160;to compare the spectral info. ENVI says the ROI's have been restored, but none appea...
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1 |
1316 |
15 May 2009 09:14 PM |
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0 Replies and 1358 Views
Haze Reduction 1358 0
Started by Deleted User
I am new to ENVI and I would like to use it to reduce/remove haze in an IKONOS image. I was hoping to use the haze optimized transform, but am unsure of how to perform this in ENVI. Any advice would be greatly appreciated.
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0 |
1358 |
14 May 2009 12:19 PM |