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0 Replies and 1234 Views
Histogram generation 1234 0
Started by Deleted User
Hi everyone,
I have a script that will run through a bunch of images and generate stats and histograms values for each image. I'm looking to speed this process up since it is quite slow. I'm really only interested in 2 histogram values: 0 and the highest histogram value (differs depending if 8-bit or 16-bit image). Is there anyway that I could get ENVI/IDL to only give me these values to speed things up Thanks in advance
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1234 |
20 Mar 2014 09:19 AM |
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1 Replies and 1540 Views
Mosaicking 1540 1
Started by Deleted User
I have two KOMPSAT3 scenes that were acquired in different dates (january and february respectively). Everytime I try to mosaic in the Georreferenced based method the equalization is poor, and it seems that the stretch changes I make, editing the entry doesn´t affect the final product. What is the best method to mosaic with images acquired in different dates
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1 |
1540 |
18 Mar 2014 12:24 PM |
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1 Replies and 1166 Views
AVHRR calibrate 1166 1
Started by Deleted User
&91Simple question but can't find the answer in the documentation anywhere!&93
Does anyone know if the AVHRR calibration tool takes into account sensor degradation over time I assume not but I want to be sure.
Many thanks.
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1 |
1166 |
18 Mar 2014 09:50 AM |
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1 Replies and 2283 Views
Create own filter function file 2283 1
Started by Deleted User
How I create my own filter function file for unknown multispectral sensor (4 channels: blue, green, red, NIR) for atmospheric correction FLAASH in ENVI
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1 |
2283 |
17 Mar 2014 01:11 AM |
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1 Replies and 1069 Views
two band seperate 1069 1
Started by Deleted User
I have NDVI and Surface Temperature map I want to find hot and cold pixel. I must find the pixels.but how for example, in hot pixel NDVI nearly 0 and Surface Temp Max both of them are in same pixel. or cold pixel ndvi max and surface temp. is min how can i do it
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1 |
1069 |
04 Mar 2014 02:14 PM |
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1 Replies and 1374 Views
RPCOrthorectification Task not found 1374 1
Started by Deleted User
ENVITASK: No task matches name: RPCOrthorectification
Execution halted at: $MAIN$ 10 D:\schl7523\idl_pros\orthorect_2.pro
ENVI>
Is this because we are still at ENVI 5.0.3 and have not upgraded fully to 5.1
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1 |
1374 |
04 Mar 2014 07:05 AM |
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2 Replies and 1766 Views
Compute statistics - what does DN stand for? 1766 2
Started by Deleted User
I tried to use the "Compute statistics" tool histograms in order to get an idea how many pixels of which value are there in my map. However, the column "DN" in the Statistics results output clearly does not correspond to the values in the Cursor Location/Value box. E.g., in the statistics results output there is a DN -9999 with 26720 points, which does not exist as a value in my map. Likewise, DN -3 with 12 points does not exist, and the same for all DNs occurring in the stat...
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2 |
1766 |
03 Mar 2014 05:59 PM |
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2 Replies and 1478 Views
pixel location 1478 2
Started by Deleted User
I want to find max pixel value or second or third one with compute statistic in a map. I find max or min pixel value, but I can't find the pixel in a map. How can I find it. Can anyone help me
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2 |
1478 |
03 Mar 2014 10:57 AM |
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1 Replies and 1473 Views
Liniar regresion using ENVI 1473 1
Started by Deleted User
Hi!
I have a problem with a nDSM file. He have negative values in some pixels, even it is not normal. Now i need to use liniar regresion for pixel
There is another method to resolve this
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1 |
1473 |
01 Mar 2014 07:42 AM |
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0 Replies and 1436 Views
resource leak problem: plenty of memory, big slowdown in code 1436 0
Started by Deleted User
I have an ENVIIDL program that performs hierarchical classification by iteratively clustering images. The problem is that although the program is very fast for the first few hundred iterations, it gradually decreases in speed until each iteration takes (say) 100 times longer to execute. There are definitely memory leaks in the code that I need to (painstakingly) address. However, I wonder if the slowdown is caused by memory leaks or by some other resource leak because when the code runs sl...
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1436 |
28 Feb 2014 09:30 AM |
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2 Replies and 1256 Views
FILEPATH?? 1256 2
Started by Deleted User
Colleagues,
I am doing exactly what I did not want to do today, fighting with ENVI and IDL. I am trying to create a batch file to do orthrectification. My installation path is on Drive C and my data and code are on Drive D, but the FILEPATH examples that are on the website assume that our data is hanging off of some subdirectory of our installation path. I would guess this is not the case in the majority of situations. In any case, the first line of my code, the online program suggests a call to...
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2 |
1256 |
27 Feb 2014 12:03 PM |
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1 Replies and 1411 Views
batch automation code or method??? 1411 1
Started by Deleted User
Colleagues, I don't want to fight with IDL, I just want to automate some simple routines. How can I run, say 60, back to back orthocrectifications in some sort of batch mode without using IDL If IDL is the only mechanism to do this, where are there simple easy to follow examples on how to do this (for me, the standard IDL sites are not really user-friendly) This used to be possible in much older versions of the software. Where is the batch capability now Thanks much.
Peter
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1 |
1411 |
27 Feb 2014 08:15 AM |
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1 Replies and 1128 Views
Applying time series mask to time series data 1128 1
Started by Deleted User
Hello,
I am working with MOD13Q1 data in ENVI 5.1. I currently have a .tiff datacube with 23 bands (time points). I want to mask this 23-band image with a 23-band pixel reliability raster. I want values of Band 1 of the pixel reliability raster (DN>2) to mask Band 1 of the NDVI raster; same for Band 2 (time point 2) of the pixel reliability raster masking Band 2 of the NDVI raster; etc... until all 23 NDVI images have received the appropriate quality mask. I have not been able to use the &q...
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1 |
1128 |
25 Feb 2014 03:42 PM |
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4 Replies and 1757 Views
Build Raster Pyramid 1757 4
Started by Deleted User
When I load my jp2 image to ENVI 5.0, the build raster pyramid takes it time to run. Is there a way around for me to build it like in ENVI 5.0 Classic or IDL
Re-post : I wanted to let you know that I am using 5.0 with no upgrade SP. I am working under US Government and doesn't look like we will upgrade to SP or 5.1 due to constraint our budget.
Is there any other way around to correct it
Thank you.
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4 |
1757 |
24 Feb 2014 02:11 PM |
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1 Replies and 1288 Views
/invisible option does not work 1288 1
Started by Deleted User
Hi,
I am trying to use the /invisble option of the envi_open_file function in ENVI 5.0, but it does not work -> the image is visible in the available band list. When I use the option in th ENVI_Doit function it is ok, but with envi_open_file it does not work:
This is ok:
ENVI_Doit,'Morph_Doit', FID = fid, DIMS = dims, POS = Lindgen(nb), METHOD = 1, GRAY = 1, KERNEL = Fltarr(win1,win1) 1, VALUE = Fltarr(win1,win1) 1, OUT_NAME = temp, R_FID = fid0,/INVISIBLE , /NO_REALIZE
This is not ok:
en...
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1 |
1288 |
20 Feb 2014 04:19 AM |
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0 Replies and 1352 Views
Identifying Training Areas - Wildfire Scars 1352 0
Started by Deleted User
In order to do a supervised classification of wildfire scars I need some training samples. I have to identify them visually (only a few). The aim is to omit pixels from the satellite image until I am left with possible training area candidates. I am considering using NDVI to omit vegetation from the image. I am new to ENVI, so very little experience - if anyone could lend some advice on how to go about this it would be greatly appreciated!
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0 |
1352 |
18 Feb 2014 03:57 PM |
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4 Replies and 2263 Views
Atmospheric correction of RapidEye imagery using FLAASH 2263 4
Started by Deleted User
I am using FLAASH to apply atmospheric correction to RapidEye imagery. However, the output contains pixels with negative values for reflectance. The percentage of these pixels in different RapidEye bands are: B1=89, B2=30, B3=21, B4=4 and B5=0.5. As you can see, a large number of pixels are incorrect except for the fifth band. Any ideas why this happens and how to fix this issue. Has this something to do with RapidEye images I can provide a more detailed of the steps I took if need be.
Tha...
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4 |
2263 |
17 Feb 2014 07:03 PM |
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3 Replies and 6404 Views
converting DN Values of Landsat 8 to surface reflectance 6404 3
Started by Deleted User
Hello
I am trying to convert the DN values of Landat 8 OLI to surface reflectance, I did the atmospheric correction with flaash module using ENVI 5.1, and also the new filter function landsat8_oli.sli from the \envi51\resource\filterfuncs directory. would you please tell me, how can I calculate the surface reflectance values between 0 and 1 the result of atmospheric correction is just digital numbers, the maximum value in my study area is approximately 5000 so when I try to use the usg...
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3 |
6404 |
17 Feb 2014 11:04 AM |
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2 Replies and 1578 Views
class_doit on classic roi points 1578 2
Started by Deleted User
I want to quickly classify a selection of points within an image using k-means. The problem is that 'class_doit' returns an image consisting of a single point when supplied with an roi consisting of multiple points when the following code is used:
; Create roi
ENVI_DELETE_ROIS, /all
xpts = lindgen(100)
ypts = lindgen(100)
envi_define_roi, roi_id, /point, xpts=xpts, ypts=ypts
; Open File
target = 'D:\Spot\SPOT 5\site\pan_site'
envi_open_file, target, r_fid = fid
envi_file_...
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2 |
1578 |
15 Feb 2014 10:31 AM |
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1 Replies and 1191 Views
How to delete raster/images ? 1191 1
Started by Deleted User
So what is the best method when you decided to delete a images/rasters Unlike ArcCatalog you can delete it and it removes everything in it. I dont see ENVI does that I may be wrong but I am new to this software.
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1 |
1191 |
14 Feb 2014 09:54 AM |