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1 Replies and 1413 Views
Lat/Lon coordinates of each country of a worldmap 1413 1
Started by Deleted User
Hi, guys,
I have a txt file with concentration data at each
Lat-Lon on 1 deg resolution for world map.
i know i can create a Geo Lat/Lon world map at 1 deg X 1 deg resolution but then
how can i compare these 2 file to calculate the total concentration
of each region like asia or countries like china, usa etc..
or if i could assign all the Lat/Lon according to countries or
regions.
could someone give me suggestions on how to proceed.
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1 |
1413 |
25 Apr 2008 11:00 AM |
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1 Replies and 1874 Views
RMSE 1874 1
Started by Deleted User
What units is the RMSE reported in when doing image-to-image registration in ENVI
Pixels or meters
Thanks!
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1 |
1874 |
24 Apr 2008 03:48 PM |
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1 Replies and 1338 Views
ENVI forest health tool 1338 1
Started by Deleted User
I am looking for some technical information about the ENVI forest health tool .how does it calculate different health classes
Thanks
Anu
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1 |
1338 |
22 Apr 2008 01:16 PM |
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1 Replies and 1351 Views
script to export image as individual bands? 1351 1
Started by Deleted User
Hello,
I need to export multiple bands from an envi image as individual .bil or .asc files to use in a predictive modeling program (Maxent). Can ENVI export a multi-band file to multiple single band files, or has anyone written a script written that can do this
-John
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1 |
1351 |
22 Apr 2008 12:00 PM |
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1 Replies and 1383 Views
GAINOFF_DOIT 1383 1
Started by Deleted User
when I use GAINOFF_DOIT routine as follow:
ENVI_DOIT, 'GAINOFF_DOIT',dims=dims,fid=openfid,gain=reflectance_scales,
offset=reflectance_offsets,out_name='I:\EXAMPLE\Image\out_ref',pos=0,r_fid=reffid
reflectance_scales and reflectance_offsets are float arrays. The datatype of inputfile is Unsighted Int. why the datatype of the result image is Unsighted Int If I hope the datatype is float, What should I do
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1 |
1383 |
21 Apr 2008 07:41 AM |
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1 Replies and 1220 Views
The coordinate is not accurate! 1220 1
Started by Deleted User
Hello , I want to do georeference to MODIS data, but a headache bother me.
First ,open the data, there are two ways to open MODIS 1B data(HDF) in ENVI software:
1. File -> open image file
2. File -> open external -> EOS -> MODIS
I both have a try to do .
Second step , I choose the menu of 'map' ,then click on ' georeference MODIS'. I have choosen the 'Geographic Lat/Lon' projection with bow-tie correction,then it did procession.
but the coordinate of t...
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1 |
1220 |
19 Apr 2008 11:58 PM |
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1 Replies and 996 Views
Update views (ENVI) 996 1
Started by Deleted User
How can i, update the views (IMAGE ,SCROLL and ZOOM ) in my program after alter the data into file of an image (without close the views)
rodrigo.
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1 |
996 |
16 Apr 2008 04:33 PM |
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0 Replies and 1244 Views
ArcGIS shape file and Envi 1244 0
Started by Deleted User
I have put random points on an image (.img format) and made a shape file. I want to extract pixel values of those random points. How is it possible please explain step by step. thanks
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0 |
1244 |
16 Apr 2008 12:05 PM |
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1 Replies and 1136 Views
ArcGIS shape file and Envi 1136 1
Started by Deleted User
I have put random points on an image (.img format) and made a shape file. I want to extract pixel values at those random points. How is it possible please explain step by step. thanks
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1 |
1136 |
16 Apr 2008 12:05 PM |
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0 Replies and 1252 Views
ROIs in multiple images 1252 0
Started by Deleted User
I want to create regions of interest in multiple images for subsequent classification (in all images at once using the same mean and covariance matrices) and exportation to ArcGIS. So far, I have always merged the geocoded images by creating a mosaic, but due to the size of the images this is no longer possible. I've tried all the hints I've found on the web and in the tutorials, but I can't seem to make it work.
Thanks in advance,
Wilfried Maps
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0 |
1252 |
10 Apr 2008 11:53 AM |
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0 Replies and 1271 Views
How to get stats from difference map 1271 0
Started by Deleted User
Hello. I ran the Compute Difference Map on a couple TM images to do a basic land cover change analysis (after atmospheric correction). I did this for the vis green, red and NIR bands. Is there a way to get any statistics behind the resulting change maps
Similarly, how can I combine this image differencing method with the post-classification change analysis method to get a really intuitive analysis and possibly compare and contrast the two approaches for my dataset and study region
Man...
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0 |
1271 |
09 Apr 2008 08:47 PM |
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1 Replies and 1292 Views
Problem with ENVI_SETUP_HEAD with INHERIT option 1292 1
Started by Deleted User
I have two images (TIFF)...
1) original_image
2) final_image
And I want that the final_image inherits the original_image map info.
But when I use the ENVI_SETUP_HEAD routine with the INHERIT option my final_image is shifted 8 pixels to the right in correspondence to the original_image.
The code I am using is more or less the following...
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Get the size of the original image
ENVI_OPEN_FILE, original_image_path, r_fid = original...
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1 |
1292 |
09 Apr 2008 08:12 AM |
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1 Replies and 1468 Views
Avoid authomatic ASTER calibration 1468 1
Started by Deleted User
Dear all
I'm searching for a solution to avoid the automatic ASTER calibration (see at http://www.ittvis.com/services/techtip.aspttid=4114&pv=yes) to conserve the original 8bit unsigned pixel values.
Some suggestions
Thanks a lot
Enrico
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1 |
1468 |
09 Apr 2008 07:39 AM |
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1 Replies and 1272 Views
Display DEM in meters 1272 1
Started by Deleted User
Hello,
i've generated a DEM from the bands 3N and 3B of an ASTER image using the tool DEM Extraction Wizard. I defined myself some GCPs (X Y Z coordinates) all around the studied area.
My problem is that the generated DEM is displayed in gray values and i need it in meters. Is there any way to convert it or maybe did i miss a step during processing
I wish you can help me,
Charles
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1 |
1272 |
04 Apr 2008 09:33 AM |
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0 Replies and 1402 Views
How to merge EVF and DBF files? Or merge IDL structure variables into one? 1402 0
Started by Deleted User
I have 4 sub-images each one with one EVF and one DBF file.
The 4 images are slightly overlapped in some areas.
I can merge the EVF into one but I'm having some dificulty in creating a unique DBF file.
The ENVI help is no help at all...
How do I do this It seems that ENVI only writes DBF files and doesn't read them...
For each sub-image I also have structures variables with the DBF attributes.
How do I join this structures from the several sub-images into only one final image
The ...
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1402 |
03 Apr 2008 06:02 AM |
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1 Replies and 1135 Views
Landsat and Envi FLAASH 1135 1
Started by Deleted User
Dear all
I want to correct a Landsat image using FLAASH. But Im not sure about what I have to do with de viewing geometry parameters.
In Flaash the zenith angle and the azimuth angle can be modified, I think that Landsat use a nadir viewing geometry, so the zenith angle is 180, is it correct. Besides I have to set the zenith angle but I dont know if the angle is the sun azimuth or the sensor azimuth. In the image header appear the sun azimuth, is that the angle I have to use.
Would ...
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1 |
1135 |
02 Apr 2008 06:25 AM |
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0 Replies and 2089 Views
Need for help in Support Vector Machine (SVM) Classification 2089 0
Started by Deleted User
I'm working on classifications of very high spatial resolution Quickbird (agricultural plot) and I would like to use SVM classification with the software ENVI. I encounter some difficulties and I would like to know if somebody could help me.
In the literature (C-W. HSU, C-C. CHANG and C-J. LIN, A practical Guide to Support Vector Classification, 2008), the RBF kernel is first considered. A simple scaling on the data must have been previously conducted. How can we do this scaling in concrete ter...
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0 |
2089 |
01 Apr 2008 03:26 AM |
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1 Replies and 1766 Views
Covariance matrix 1766 1
Started by Deleted User
Hello forum,
Generally a covariance is statistical measure of the tendency of variables to move or vary together. So I would like to ask about the meaning of values in covariance matrix that I produced for certain ROI over multispectral image.
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1 |
1766 |
01 Apr 2008 03:02 AM |
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1 Replies and 1592 Views
ENVI_get_roi_data 1592 1
Started by Deleted User
Dear all, I want obtain the image data within a region(saved as evf file ,only 1 polygon) ,such as pixel values,so I writed the program like this:
;open a file and get info
label_file = envi_pickfile(title='Please select a Label file')
envi_open_file,label_file, r_fid=label_fid
envi_file_query, label_fid, ns=ns, nl=nl
;open evf fine
evf_fname = 'a1.evf'
evf_id = envi_evf_open(evf_fname)
envi_evf_info, evf_id, num_recs=num_recs
for i=0L, num_recs-1 do begin
r...
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1 |
1592 |
30 Mar 2008 01:32 PM |
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0 Replies and 1465 Views
Raster to vector- batch processing 1465 0
Started by Deleted User
Hello, everyone
I am a junior user of ENVI programming, I try to transter a raster image to a vector file.
The Raster to Vector function in ENVI only can transfer specified DN value to a vector file. I want use batch processing to transfer the whole image to a vector file in which different DN values are in different layers.
But I can not find a suitale ENVI routine to realize the tranformation in ENVI programming, how can I realize this
Many thanks!
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0 |
1465 |
27 Mar 2008 08:01 AM |