X
Search this forum:
Search
You are not authorized to create a new topic
Page 16 of 137 << < 1415161718 > >>
Topics
 Replies
 Views
 Last Post
10 Replies and 2749 Views ENVI Crashes on Linux  2749  10 Started by  Deleted User Hello, I am running ENVI and IDL on Ubuntu 16.04 LTS. At first it was working fine, but now it keeps crashing all the time. This is the error I get: A fatal error has been detected by the Java Runtime Environment: SIGSEGV (0xb) at pc=0x00007f98ea5e7d8b, pid=3863, tid=140296014931712 JRE version: 7.0_25-b15 Java VM: Java HotSpot(TM) 64-Bit Server VM (23.25-b01 mixed mode linux-amd64 compressed oops) Problematic frame: C &91i965_dri.so0x20ad8b&93 _init0x1bf86b...
10 2749
by  Deleted UserJump to last post
29 Apr 2017 10:01 AM
1 Replies and 2474 Views Intrepretation of MNF eigenvector matrix  2474  1 Started by  Deleted User Hi all, I performed minimum noise fraction transformation on a hyperspectral image with 129 bands. This produces 129 new bands, as it should. Okay, then I get the eigenvalues that I can use to interpret which bands contain information and which bands contain noise. Now I need to understand which bands constituted most to each new MNF band. To my understanding we need to look at the eigenvector matrix to see the 'loading' from each original band. But, which way should we look at the matrix...
1 2474
by  MariMJump to last post
26 Apr 2017 02:12 PM
0 Replies and 3449 Views Convert radiance to reflectance  3449  0 Started by  Deleted User I'm working on a project using hyperspectral data collected in a greenhouse. The data is in radiance (mW/m^2*2str*nm) and I'm trying to convert this to reflectance. We did take images of the calibration board before collecting the data. This white and dark calibration board is in the first image but none of the subsequent images. What would be the simplest way to convert the data to reflectance (I don't have the license for FLAASH.)
0 3449
25 Apr 2017 10:37 AM
1 Replies and 2173 Views Generate Point CLoud Error  2173  1 Started by  Deleted User I've been testing Generate Point Cloud from stereo images on WorldView-1/2, GeoEye and QuickBird data in ENVI 5.4. But in most the cases ENVI returns message "Generating point clouds requires at least two rasters in the supportes formats", while all the images contain RPC, overlap more than 50 and listed in supported data types. Exporting data to ENVI format with a generic RPC sensor model doesn't help. What can be the cause of the error Are there any limitations for this tool not l...
1 2173
by  Deleted UserJump to last post
17 Apr 2017 01:12 PM
3 Replies and 1748 Views Computing Vegetation Indices from Difference Landsat Sensors  1748  3 Started by  Deleted User I am working to estimate Above Ground Biomass (AGB) using ground sample data and then intending to work out its potential relationship between different vegetation indices like NDVI, RVI, DVI, SAVI, MSAVI etc. This relationship will be ascertained using regression equation. Resultantly, I will be able to predict AGB of earlier date after choosing suitable index to proceed with. I am using images from two different sensors, Landsat 8 OLI (January 2017) and ETM (January 2007) to derive above note...
3 1748
by  Deleted UserJump to last post
15 Apr 2017 07:23 AM
4 Replies and 2500 Views rotate raster does not behave as expected  2500  4 Started by  Deleted User Hi, I am trying to rotate a large orthophoto with row crops to see the effect that will have on susceptibility to moire when I resize. I applied rotations of 17 and 23 degrees in the rotate/flip raster tool. In both instances I can see small changes in the image at small scales (fine patterns in the edges of the rows changed) but the overall row angle remained exactly the same. I expected the whole image to rotate by the amount I entered, and so I expected to see the row angle noticeably chan...
4 2500
11 Apr 2017 12:17 PM
1 Replies and 2758 Views image translation while apllying a second mask  2758  1 Started by  Deleted User Hello, First of all, sorry if the question is stupid, but I am still a beginner in remote sensig, I work with ENVI 5.1 on Landsat 8 images. I want to apply cloud masks on a same image ( a NDVI created from landsat 8 bands ). I created the cloud masks from the QA band of Landsat 8, the first cloud mask is a classic one, made for masking the clouds of the image, the second one correspond to the opposite of the cloud mask of another image, the purpose here is to retrieve the pixels that are without...
1 2758
11 Apr 2017 02:21 AM
0 Replies and 2628 Views Fmask Cloud Cover Overestimation  2628  0 Started by  Deleted User I've been testing Calculate Cloud Mask Using Fmask tool in ENVI 5.4 on Sentinel-2 and Landsat-8 data and results have been unsutisfactory. Algorithm tends to overestimate cloud cover and classify bright soils, snow, artificial structures and sometimes even vegetation as clouds. Futhermore, shadows stay undetected, while original algorithm detects cloud shadows as well. Additionally, different configuration parameters doesn't have any affect on results. Have somebody expirienced the same proble...
0 2628
10 Apr 2017 08:58 AM
3 Replies and 2582 Views ML classification performing process: how pass the statistics from a roi  2582  3 Started by  Deleted User Hi all, i am trying to perform a ML classification using ENVI API ENVIMaximumLikelihoodClassificationTask. I had seen the example https://www.harrisgeospatial.com/docs/ENVIMaximumLikelihoodClassificationTask.html where it is used a vector to calcolate the needed statistics. How implemenmt the same ML workflow using a set of ROI in xml or envi classic .roi format
3 2582
06 Apr 2017 07:00 AM
1 Replies and 2796 Views How create a lookup array for the ENVI_DO_IT Net Neural Classification  2796  1 Started by  Deleted User Hi all, i need to perform a Net Neural Classification using EVI:NEURAL_NET_DOIT api function. My input raster is a 7 bands ENVI file (.dat extension) and my training ROI file has 5 class (vegetation, water, sand, groung, build). Full code follows: COMPILE_OPT IDL2 envi ;, /restore_base_save_files ENVI_BATCH_INIT output_nn = classfication_output output_nnrule = rulke_classification_output ; variabili globali inputsms = myraster ; aggiungere apertura file raster con est...
1 2796
06 Apr 2017 05:19 AM
5 Replies and 3953 Views How modify the pixels value inside a ROI  3953  5 Started by  Deleted User Hi all, i need to execute a change detection with the certainty of obtaining a result in term of change from vegetation class to built class. I use the SVM classifier. In order to obtain at least a result i would artificially change the pixels values inside a ROI. Thank you for any Suggestion
5 3953
04 Apr 2017 03:02 AM
0 Replies and 3052 Views Advanced use of idlpy bridge: open-close license management  3052  0 Started by  Deleted User Hi all, i have a python script that calls and executes some python function making idl processes following the IDL.run('instruction') syntax. More in detail, i have a set of function making "radiometric correction", "pansharpening" "layer stacking", and so on. I make the import of idlpy module ad the begin of my file. The problem is that license remains busy throughout the execution duration. I try also to make the import only from the function. There is a way to im...
0 3052
03 Apr 2017 03:16 AM
10 Replies and 3006 Views Resizing raster cuts and shifts image  3006  10 Started by  Deleted User Hi, Has anyone seen this I'm resampling a moderate raster (118 MB, 8-bit grayscale) 8 --> 1 with cubic convolution. When its done, the image has been sliced vertically and re-shuffled. I can't show the data, but schematically it looks like this: before after abcdefghijk defghijkabc abcdefghijk defghijkabc abcdefghijk defghijkabc abcdefghijk defghijkabc ...
10 3006
by  MariMJump to last post
30 Mar 2017 10:38 AM
0 Replies and 2837 Views Removal the shadow effect in hyperion images  2837  0 Started by  Deleted User How to remove shadow effect in Hyperion imagein hilly region area
0 2837
28 Mar 2017 11:11 PM
1 Replies and 3017 Views Reprojecting and Resizing Rasters  3017  1 Started by  Deleted User I have two raster files, A and B (see Table below). I am looking to reproject B to the same projection as A, and also resize (aggregate) pixels in B to the same size as A (0.5 x 0.5 degrees) so they can be stacked. I have been trying to reproject raster B to the same gcs as A using the "Reproject Raster Tool" and selecting the coordinate system to reproject to using the "import from existing data set icon". This works fine, but I've noticed that when B is projected into degr...
1 3017
26 Mar 2017 10:46 AM
1 Replies and 2923 Views ENVI no longer working with OSX Sierra  2923  1 Started by  Deleted User Hi all, I've been running ENVI Classic 53 on OSX 10.11.3 El Capitan using X Quartz 2.7.9 without issue; however, after updating to Sierra this afternoon, I can no longer get ENVI to open. That's an issue. Any suggestions Thanks.
1 2923
25 Mar 2017 07:17 PM
1 Replies and 2764 Views georeference a flipped image  2764  1 Started by  Deleted User Hello, I have an image that is flipped E-W. I have the lat/lon of the upper left pixel and the pixel sizes in degrees. When I try Edit header/Spatial Reference, I get the same flipped image with incorrect lat/lons in the image. If I Rotate/Flip the image first, using Transpose and Rotate 270 deg. I get the image right side up, but then when I tried telling ENVI which pixel was which lat/lon, it came out wrong again. I'd rather do only one operation on the image as I have many more with the same...
1 2764
21 Mar 2017 06:02 PM
8 Replies and 3638 Views Error opening Sentinel 2  3638  8 Started by  Deleted User Hi all, i am trying to import Sentinel 2 dataset. I downloaded the file S2A_MSIL1C_20170313T093031_N0204_R136_T33SXR_20170313T093510.zip. How can i open this file into ENVI 5.4 Thank you for any succestion.
8 3638
17 Mar 2017 05:11 AM
1 Replies and 3440 Views WV3 Radiometric Calibration  3440  1 Started by  Deleted User I am working on a WV2 and a WV3 image, with ENVI 5.2. The WV2 one can be convert into either radiance or reflectance by using the Radiometric Calibration Tool. However, for the WV3 image, it can only be converted into Radiance, but NOT reflectance. After looking at the metadata, I have found that the irradiance data is missing for the WV3 image, so I believe that is why ENVI cannot convert it into reflectance Is there any solutions for the situation or what steps should I take to get it to refl...
1 3440
15 Mar 2017 10:35 PM
2 Replies and 2838 Views majority/mode from bands  2838  2 Started by  Deleted User Is there any tool, or band math function, that can compute the majority or mode from bands of the image I mean that I want to know for each pixel, the value that is most frequent through all the bands of the image. For example: Image with 3 bands, for pixel(i,j) values are: b1=2, b2=3, b3=3 the result should be: majority=3 Actually I need this to combine different classification results and for each pixel select the most frequent class.
2 2838
15 Mar 2017 04:52 AM
You are not authorized to create a new topic
Page 16 of 137 << < 1415161718 > >>