X
Search this forum:
Search
You are not authorized to create a new topic
Page 65 of 137 << < 6364656667 > >>
Topics
 Replies
 Views
 Last Post
3 Replies and 863 Views Maximum Pixel Value 323 after Mosaicking 2 files?  863  3 Started by  Deleted User Hi, I just realized, that after i ve done the mosaicking process with two files (which each has a maximum pixel value of 255), i get Maximum Values on the mosaicked picture of 323.256042. What does this mean and how is it possbile (i mosaicked a slc-on and slc-off file together, landsat 7 - through color mapping i can see that the values over 255 are in the gap filled sectors) kind regards k.chien
3 863
11 Mar 2012 11:02 AM
1 Replies and 944 Views Quality accuracy, ENVI Zoom  944  1 Started by  Deleted User Hi. I am working on a classification based on QuickBird images, and I'm using the feature extraction-guide by ITTvis. However, I can not find an obvious way to make a quality control of my classification (confusion matrix). Can any of you give me some hints/ideas Thank you in advance
1 944
10 Mar 2012 11:18 AM
3 Replies and 952 Views 3D view in ENVI  952  3 Started by  Deleted User I have a DEM, ASTER, and geological map (GIS layer) of an area. I would like to create a 3D view from this. I can create that possibly by combining them. Is this possible in ENVI Regards Yask
3 952
09 Mar 2012 02:33 PM
2 Replies and 900 Views compare/classify different gap fill methods for landsat  900  2 Started by  Deleted User hi there, being a new user to landsat, there are a few questions i have, and will be lucky about any suggestions and answers. what i need to know, is how can i compare/classify 4 different hdr files of the same regions (single bands only), which each has been already gap filled wtih a different method (mosaicking, add on local vs global, replace bad value). for every method the same slc-on and slc-off files were used. I want now to classify them and compare which resulting ...
2 900
09 Mar 2012 11:56 AM
1 Replies and 961 Views DN to radiance for FLAASH input  961  1 Started by  Deleted User Hi, I am working with L5 TM and P6 LISS III. I intend to aplly FLAASH in the images. So, the input image in FLAASH is radiance. For Landsat 5 TM I can do this directly on ENVI menu (calibration utilities) filling the solar elevation and date parameters. But for P6 LIS III there aren't any directly option (I guess). So, I can calculate the radiance from DN using the equation: Lmin &91(Lmin Lmax)*Qcal/Qcalmax&93 This equation will return a radiance image. But, in the e...
1 961
09 Mar 2012 07:01 AM
0 Replies and 1068 Views envi_stats_doit error - ROIS  1068  0 Started by  Deleted User Dear all, I am using ENVI IDL 4.8 and the ROI tool to calculate statistics from a raster (*tif, 500m pixel spacing) Having overlaid the ROI to the image I use "stats" from ROI tool; however I get the following error: envi stats doit: An error has occurred during processing Error: "Out of range subscript encountered: ADDR. "The result may be invalid" Any ideas Regards Dimitris
0 1068
07 Mar 2012 08:55 AM
3 Replies and 1003 Views Using FLAASH on a Geoeye-1 image  1003  3 Started by  Deleted User Hello, I'm trying to make a radiometric correction of a Geoeye-1 image using ENVI 4.8 and FLAASH. Due to the lack of an automatic method to transform Digital Values to Radiance, I want to do it by myself applying the formula: Lλ = Gainλ *DNλ Offsetλ where λ is Specific spectral band of image: Near-IR, Red, Green, Blue or Panchromatic.; Lλ is Spectral radiance for band λ at the sensor’s aperture (mW/cm2/μm/str); Gain...
3 1003
07 Mar 2012 04:15 AM
1 Replies and 928 Views PCA again  928  1 Started by  Deleted User band1 band2 band3 band1 0.3 -0.6 0.2 band2 -0.4 0.5 0.1 band3 .... .... .... is it means below format band1 band2 band3 PC1 0.3 -0.6 0.2 PC2 -0.4 0.5 0.1 PC3 .... .... .... thank you very much!
1 928
03 Mar 2012 09:04 PM
1 Replies and 963 Views PCA  963  1 Started by  Deleted User Hi, My data (multispectral) has some background which I have assigned Nan. I am doing PCA for the whole region, and some subsets. The scatter plot' nature (using same PCA bands), and color composite images (using PCA bands) are different for these different regions. Is it true If I want to check whether my PCA is coming ok or not, how can I cross-checked Regards Guneshwar
1 963
02 Mar 2012 02:05 PM
0 Replies and 1042 Views Creating time series analysis tools for ENVI  1042  0 Started by  Deleted User Greetings, As some of you know I have created a number of command-line based PRO files which I use in my processing of time series Terra-MODIS derived NDVI and NDWI imagery. Due to the number of requests that I have received from others for these files, I am thinking it time to begin developing a set of tools that can be shared amongst ENVI users and applicable for a number of different data sets (8-bit Terra and Aqua data, daily, 8, 16, and other max data, eMODIS data, etc..). ...
0 1042
27 Feb 2012 02:02 PM
1 Replies and 1040 Views Enhanced Vegetaion Index  1040  1 Started by  Deleted User Hi I'm new to using ENVI and I would like to produce a vegetation index. I have SPOT imagery but am time poor so I dont want to carry out a supervised classification. I have produced an NDVI but I would like to make an EVI to compare it to. Can anyone tell me how to go about it Many Thanks
1 1040
22 Feb 2012 05:09 PM
0 Replies and 837 Views Extracting single band  837  0 Started by  Deleted User Hi guys, i found some similar topic, which was solved by a programming code. But what i need to know is way more simple (and honestly i have done it before) but somehow its not working out right now. So i have a landsat HDR file with two bands (they show separate in the "available band list" when i unfold the .hdr file) But for some landsat gap fill methods, i need them to stand alone, how can i extract a single band into a new file big thanks in advance f...
0 837
22 Feb 2012 04:28 PM
2 Replies and 1276 Views Extracting single band  1276  2 Started by  Deleted User Hi guys, i found some similar topic, which was solved by a programming code. But what i need to know is way more simple (and honestly i have done it before) but somehow its not working out right now. So i have a landsat HDR file with two bands (they show separate in the "available band list" when i unfold the .hdr file) But for some landsat gap fill methods, i need them to stand alone, how can i extract a single band into a new file big thanks in advance f...
2 1276
22 Feb 2012 04:28 PM
1 Replies and 1037 Views E3DE lidar software  1037  1 Started by  Deleted User anyone who can sent me the E3DE software setup file.thanks a lot.my e-mail: mykamenergmail.com
1 1037
18 Feb 2012 12:18 AM
5 Replies and 1916 Views Setting data ignore to ******** values  1916  5 Started by  Deleted User I have some imported MODIS images which have ***** as the pixel values (not entirely sure what this is -- NaN Inf) I'd like to set this as the data ignore value in the header to get it to display properly, rather than having to generate a mask. Any ideas
5 1916
16 Feb 2012 12:41 PM
2 Replies and 1239 Views Creating a virtual stacked image  1239  2 Started by  Deleted User Greetings, As some of you know, I work with time-series data and have even written a couple of tools for this purpose with my somewhat limited IDL skills. One issue I have with my processing is that I spend a lot of time stacking data, as I need to sometimes update the image stacks once a month or every two weeks. This approach uses up a lot of time and twice the storage space as necessary. I have noticed that ENVI can stack imagery without actually having to write to the disk, as evid...
2 1239
13 Feb 2012 08:41 PM
4 Replies and 1157 Views QuickBird 16 Bit  1157  4 Started by  Deleted User Hello, I'm trying to do some processing on 16 bit QuickBird Imagery and I'm getting incorrect values. So, QuickBird's sensor reads the images as 11 bit (DN range 0-2048) and either stores them as 8 bit (DN range 0-256) or 16 bit (DN range 0-65536). I've been reading that I might need to tell ENVI the true values of the imagery( i.e. 0-2048). Should I do this in ENVI and if I do what is the process Thanks
4 1157
13 Feb 2012 09:00 AM
0 Replies and 2174 Views Neural Network Classification  2174  0 Started by  Deleted User Hi all, I am postgraduate student which done research on cloud classification. I have some problem regarding on classification technique in ENVI. I want to use neural network classifier provided in ENVI 4.7. However, there appear some error after the processing. Can anyone help me
0 2174
13 Feb 2012 01:10 AM
4 Replies and 1180 Views Neural Network Classification  1180  4 Started by  Deleted User Hi all, I am postgraduate student which done research on cloud classification. I have some problem regarding on classification technique in ENVI. I want to use neural network classifier provided in ENVI 4.7. However, there appear some error after the processing. Can anyone help me
4 1180
13 Feb 2012 01:07 AM
0 Replies and 1183 Views problem adding derivative plot function  1183  0 Started by  Deleted User Hi, I want to add the capability of derivative plot function to the program. So, I followed the instruction at http://www.exelisvis.com/portals/0/tutorials/envi/Plot_Functions.pdf step by step successfully and added "pf_1st_derivative", and "pf_2nd_derivative" functions, but I get an error whenever using these functions. the error says they are undefined function. I get the same error even when I run them inside IDL, so I guess the problem is because of the code itsel...
0 1183
12 Feb 2012 09:54 AM
You are not authorized to create a new topic
Page 65 of 137 << < 6364656667 > >>