|
|
|
|
|
|
3 Replies and 1189 Views
Default pixel size when applying GLT 1189 3
Started by Deleted User
When operating ENVI from the menu (interactively), when you want to georeference from GLT, after selecting the GLT and the image, one of the items already filled in is a box with a default pixel size.
When writing a program, is there a way obtain this default value That is, is the some ENVI or ENVI_doit call that returns this BEFORE applying a GLT I know it is returned when using envy_doit to apply the GLT, but that is only after the GLT is applied.
Thanks.
|
|
|
|
3 |
1189 |
27 Feb 2013 10:02 AM |
|
1 Replies and 1428 Views
Masking, Jenks in ENVI? 1428 1
Started by Deleted User
Hello, I'm new to ENVI and have a question about classifications:
I need to run some stats on various classifications of vegetation data. I can easily do this with the ENVI supervised and unsupervised classifications but am having trouble with Jenks/natural breaks.
I've tried using a decision tree with ArcGIS-generated natural break values, but because the ENVI-generated masked image cannot have "nodata" mask value and needs a defined value, the Arc Jenks distribution is being s...
|
|
|
|
1 |
1428 |
25 Feb 2013 10:19 AM |
|
1 Replies and 1562 Views
No-Data Pixel After Mosaicking 1562 1
Started by Deleted User
Hi~
I try to mosaic a set of hyperspectral images. However, after mosaicking, a lot of black pixels(no-data) appeared on overlapping area and edge area. My input data is 16 bits(1~2^16) and there are no such black pixels before mosaicking. It should not happen. My Options: Data Value to Ignore = 0, Feathering Distance = 10~50, No Color Balancing. I must use Feathering because there are some bad data (low value) in edge on every image, or is there any way to mosaic images using the max value ...
|
|
|
|
1 |
1562 |
23 Feb 2013 01:34 AM |
|
2 Replies and 1840 Views
Unable to acquire device context message and Preference setting 1840 2
Started by Deleted User
I use CentOS 6.3 and ENVI 5.0 sp2 Runtime.
I have no problem using ENVI classic. But when I launch New ENVI, I got the messages like this.
On Shell :
IDLGRSRCDEST::DRAW: Failure to acquire window rendering context
On dialog message box :
Internal Error: Unable to acquire device context
And I cannot use New ENVI. Could someone help me to solve this problem I just guess it might be a Graphic Card related problem. So, I decided to turn off the Graphic Acceleration option in the preference. B...
|
|
|
|
2 |
1840 |
21 Feb 2013 09:59 PM |
|
3 Replies and 3051 Views
spectral separability 3051 3
Started by Deleted User
I could see the values transformed Divergence and Jefferies- Matusita Distance ranges from 0 to 2. but it is actualy not in literatures. For eg Tranformed divergence value ranges from 0 to 2000 and Jefferies- Matusita Distance ranges around thousand.
Is it right way to multiply the envi values by thousand to get the original values
|
|
|
|
3 |
3051 |
19 Feb 2013 06:06 AM |
|
1 Replies and 1409 Views
landsat Gap Fill 1409 1
Started by Deleted User
Hi
Please am trying to perform landsat gap fill using 2 band gap fill ( but global and local). but I have black output result. please i need your help
Is it ok to use &91Gap_Mask&93 provided by USGS together with the landsat image.
|
|
|
|
1 |
1409 |
14 Feb 2013 12:33 AM |
|
4 Replies and 1292 Views
rule based feature extraction not working 1292 4
Started by Deleted User
Hi, I am trying to use the rule based feature extraction in ENVI5, but an error saying " internal error: OBJ_NEW" keeps happening. It seems like the function cannot compute attribute values since the attribute histogram does not work and I cannot set rules based on attribute values. Does anyone have the same problem Really appreciate any ideas or clues about how to fix this problem. Thanks again!
|
|
|
|
4 |
1292 |
11 Feb 2013 10:18 AM |
|
1 Replies and 1316 Views
orthorectification 1316 1
Started by Deleted User
I have set of L1T hyperion image.The filename is EO1H1440512002081110PY. Should we orthorectify L1T Hyperion images Where do I get the DEM from
|
|
|
|
1 |
1316 |
08 Feb 2013 12:50 AM |
|
1 Replies and 1380 Views
cube or stacked 1380 1
Started by Deleted User
Hello!! I have a set of radiometrically corrected Hyperion images. I want to perform atmospheric correction on these images. My question is should we perform layer stacking and then perform atmospheric correction or build an image cube and perform correction on the cube
|
|
|
|
1 |
1380 |
07 Feb 2013 08:45 AM |
|
1 Replies and 1731 Views
Bsq format 1731 1
Started by Deleted User
Hello,
May i know how to obtain .bsq format using envi. Because i want to used envi file in atcor. However when i save my image in envi it shows .img format. How i want to convert it to .bsq format. I really hope that someone can help me regarding on this. Thanks
|
|
|
|
1 |
1731 |
05 Feb 2013 12:24 AM |
|
1 Replies and 1218 Views
layer stacking HANDLE NO OVERLAP ERROR 1218 1
Started by Deleted User
Hi all,
I'm writing an automatic code where I have to use the "envi_layer_stacking_doit" routine. It could happen that the 2 files to be layered are not overlapping and this will generate an error by mean of a ENVI warning popup and then the program stops processing data
Since I have to process a long time series data is there a way to handle this error in order to avoid stopping the running of the program
Thanks in advance
|
|
|
|
1 |
1218 |
04 Feb 2013 12:11 AM |
|
1 Replies and 1261 Views
Reprojecting/resampling classification images 1261 1
Started by Deleted User
ENVIers:
When resizing or reprojecting classification rasters, many times I would prefer to take the most common class falling within the output pixel, not the nearest neighbor. Is there any trick to doing this with ENVI Bilinear and cubic convolution are not appropriate with categorical data, which is why I ask. The only way I could think of would involve making a single image for each class filled with 0s (where the class is not) and 1s (where the class is), do the resample where the outp...
|
|
|
|
1 |
1261 |
31 Jan 2013 02:55 PM |
|
3 Replies and 1482 Views
Tasseled Cap tool 1482 3
Started by Deleted User
Hi, supports
Does the Tasseled Cap tool works correct on the CASI data. There is only LandSAT sensor type available.
I want calculate Soil Brightness Index on the potato crop. I had read one paper where SBI were calculated using ENVI Tasseled Cap tool on CASI data. So, now i am wondering it is true or not. Maybe you could suggest witch bands should i use in some kind of equation.
Thanks for the answer.
|
|
|
|
3 |
1482 |
30 Jan 2013 04:04 AM |
|
2 Replies and 1358 Views
basic question on automating ENVI functions 1358 2
Started by Deleted User
Hi,
I would like to automate some ENVI tasks for a few hundred images. Specifically, I have HDF files from each of which I want to extract certain layers, and then to save these into standard ENVI files. I am familiar with ENVI from the GUI, but I don't think I want to do this for hundreds of HDF files. My question is: do I use ENVI IDL to automate this task, or is there some other way to do it If I have to use IDL, can someone please direct me to some relevant tutorials/documents to get me st...
|
|
|
|
2 |
1358 |
30 Jan 2013 12:45 AM |
|
5 Replies and 1881 Views
GRVI in Band Math 1881 5
Started by Deleted User
Hi everyone
I would like to know the correct expression of GRVI in band math. I tried to write the many expression, but the result was not realistic. I think the problem in writing is Prioritization of algebraic operations. How can i write the correct expression. I will be glad to help me.
Thank you
Hadi
|
|
|
|
5 |
1881 |
24 Jan 2013 09:58 PM |
|
1 Replies and 1567 Views
getting traing areas from few imagerys 1567 1
Started by Deleted User
Dear Forum
is it possible with Envi to set training areas from few different imagerys and with this traing areas perform the supervised classiffication on the third image
Lets say I get TTA for forest from imagery A, TTA for wetlands from imagery B and I want to classified imagery C with this definition
Thanks in advance
|
|
|
|
1 |
1567 |
23 Jan 2013 01:01 PM |
|
2 Replies and 1376 Views
MODIS conversion toolkit -swt_name of MOD11_L2 1376 2
Started by Deleted User
Hi all!
I'm using the MCTK in batch mode to analyze a series of MODIS level2 files. Followed the example in user's guide, I sucessfully ran MOD05 files using 'convert_modis_data', but I don't no how to specify the key word 'swt_name' when I convert the MOD11_L2 files. I tried 'MOD11_L2' and 'MOD11', and it didn't work.
Any suggestions Thank you!
|
|
|
|
2 |
1376 |
23 Jan 2013 05:25 AM |
|
4 Replies and 1343 Views
Correcting MERIS on FLAASH [Problem] 1343 4
Started by Deleted User
Hello,
I'm having problems trying to correct MERIS data via FLAASH. The image is a MER_RR__1P (calibrated TOA radiance).
I'm using ENVI 4.8 and FLAASH doesn't have MERIS on Sensor Type's list. The thing is, even if I use the UNKNOWN MSI sensor option FLAASH will require a Filter Function (.sli) file and there's no MERIS on the avaible list.
So, after georeferencing the image and converting the interleave, I've tried using MODIS on Sensor Type and alsoUNKNOWN MSI modis.sli (witch must be p...
|
|
|
|
4 |
1343 |
22 Jan 2013 07:10 AM |
|
1 Replies and 1181 Views
nan data for emissitivity 1181 1
Started by Deleted User
i tried to do land surface temperature using landsat 4 TM image. using ndvi to estimate emissitivity, i found that the value data for water become nan. what should i do
i used this algorithm at band math to retrieve emissitivity,
1.0094 ( 0.0047*alog (b1))
|
|
|
|
1 |
1181 |
21 Jan 2013 06:59 PM |
|
5 Replies and 1439 Views
Negative NDVI over algal blooms 1439 5
Started by Deleted User
Hi everyone,
I'm relatively new to envi, so I know, perhaps, the barest minimum of how to make it work,
I'm looking at MODIS L1b 500m data of the Baltic sea and Barents sea in order to attempt to crudely quantify algal blooms.
I have an issue with NDVI (and every other vegetation index there is) where green algal blooms report back negative values much greater than the surrounding water and and clouds that escaped masking (e.g. water= -0.3, thick algae = -0.6). I understand that algal blooms...
|
|
|
|
5 |
1439 |
20 Jan 2013 03:32 AM |