All Questions
545 questions
30
votes
5
answers
8k
views
OpenSource Remote Sensing Tools for Classifying Roofs
with envi image processing and classification tools, you can get roofs from images with some spectral value and then you can convert it some vector data for your app.
in python with OpenCV which have ...
- 22.6k
11
votes
1
answer
2k
views
What's the binary format of ENVI (Classic) ROIs?
I'm a Pythonist in an office full of ENVI/IDL users. I've created some tools to help bridge the gap, but one big stumbling block is ENVI Classic .roi files, which my colleagues use a lot.
I can ...
- 314
11
votes
0
answers
2k
views
Why is GDAL ECW compression much poorer than ECW compression from ERDAS [closed]
We use ECW compressor shipped with ERDAS Imagine to export Orthoimagery for our different departments. Because we are facing problems with the Imagine license server, we had to choose GDAL (built with ...
- 1,643
11
votes
0
answers
1k
views
What is the convergence threshold for ArcGIS Iso Cluster?
The ArcGIS tool Iso Cluster Unsupervised Classification does not seem to have any documentation on the convergence threshold used in the tool. To compare, Erdas Imagine has all of the necessary ...
- 51.8k
10
votes
5
answers
12k
views
How to workaround large mosaic process which is failing?
I need to mosaic about 550Gb of tif imagery together and the software I have tried keeps failing. The area has been split into zones so that the smallest has approx 200 tiles.
I have used the latest ...
- 8,298
10
votes
3
answers
6k
views
Remove clumps of pixels in R
I would like to remove isolated pixels (or clumps of pixels <9) from my raster image.
library(raster)
# create some raster data
r <- raster(ncols=12, nrows=12)
set.seed(0)
r[] <- round(runif(...
- 3,386
10
votes
1
answer
2k
views
How to Remove Dark Bands Where Scenes Overlap in Mosaic Landsat TM5 Image?
I have an image mosaic of 5 Landsat TM5 scenes. Where the scenes overlap there is a dark band, only on the left and right sides, but the top and bottom are seamless. What is the best way to correct ...
- 101
9
votes
1
answer
9k
views
Reprojected MODIS NDVI has range from -32768 to 32767, expected -1 to 1
I'm new to StackExchange and to remote sensing. I am working with MOD13Q1 250m 16-day MVCs. My goal is to use NDVI time-series to classify cropping pattern and crop type, then link this data to ...
- 769
9
votes
2
answers
17k
views
How to repair topology of a shapefile?
I performed an object-based image analysis using ENVI EX, and each of the classified features were exported as a shapefile. I transferred those shapefiles into ArcMap 10, and tried to intersect them ...
- 981
9
votes
2
answers
4k
views
Landsat8 DN to TOA Reflectance (minus values)
I'm learning how to perform atmospheric correction manually, hence not using the automated methods available in ENVI
metadata (band 1) for my Landsat 8 scene is as follows;
RADIANCE_MULT_BAND_1 = 1....
- 93
9
votes
1
answer
523
views
Confidence in pan-sharpened classification?
I pan-sharpened one Landsat Image on ERDAS using the resolution merge resource, with brovey transform and nearest neighbor techniques. But I was told that in terms of land-use classification, it would ...
- 91
8
votes
1
answer
2k
views
Rotate ENVI hyperspectral imagery with GDAL
I am developing an application with the GDAL library to combine georeferenced raster hyperspectral imagery in ENVI format from NASA's Airborne Visual/Infrared Imaging Spectrometer (AVIRIS) with other ...
8
votes
3
answers
18k
views
Load a raster file directly in Leaflet
Is it possible to load a raster file (e.g. GeoTIFF or Erdas img) directly into a Leaflet map? If so, can you guide me to the correct documentation or method to do this?
I am trying to do this with the ...
- 529
8
votes
1
answer
448
views
Opening MOD17A3 in ENVI so it is properly georeferenced?
I am using ENVI 5.1 on Windows 8. I am trying to open a MOD17A3 (MODIS Net Primary Productivity standard product - L4) .hdf file which I downloaded from the USGS website. I am still a beginner at ENVI,...
- 89
8
votes
1
answer
331
views
Phenological event extraction in IDL
I’m doing phenological study using a threshold method in IDL. I have a twelve-band image in 2005 (format is in .tiff not ENVI format). Twelve-band means that monthly images (Jan to Dec) have been ...
- 81
7
votes
5
answers
3k
views
Georeferencing aerial photos when only centroid is known using ArcGIS for Desktop or ERDAS Imagine?
I have heaps of aerial photos that need to be georeferenced.
I have access to ArcMap and ERDAS.
All I am given is an excel sheet with the centroid coordinates of each image.
Each photo covers ...
- 133
7
votes
2
answers
3k
views
Creating shapefile of satellite image footprints?
I'm looking for a tool or a workflow to compute satellite image footprints, for a large number of images across directories, and produce a shapefile. Ideal work flow would be:
fire up tool
point to a ...
- 1,543
7
votes
3
answers
4k
views
Calculating area of vegetation in raster file?
How do I calculate area of several vegetation types in a raster (.img file type) image. They are color coded. Am using QGIS (1.8.0) and ERDAS 9.2.
- 79
7
votes
1
answer
557
views
What are pros and cons of forcing square pixels on reprojection?
I am using Erdas Imagine 2014 to reproject 4-band raster data from GRS 1980 NAD83 Lambert Conformal Conic (ft) to UTM GRS 1980 NAD83 North UTM Zone 11 (m). Unlike ArcGIS, Erdas provides the option to ...
- 51.8k
7
votes
1
answer
1k
views
How to produce a vegetation stress map utilizing the spectral blue shift of the red edge?
I am interested in mapping vegetation stress utilizing the blue shift to the red edge phenomenon in remote sensing. The figure below shows the expected change in reflectance of green leaves under ...
- 51.8k
6
votes
4
answers
5k
views
Seeking alternative to ERDAS Imagine? [closed]
I am having trouble with the ArcGIS 10.1 and ERDAS Imagine 9.2 license conflict.
From what I found out it isn't that rare, but I do not understand why there such a conflict in the first place.
...
6
votes
4
answers
494
views
Transform raster donuts to circles
Let's assume I have a raster image consisting of 0's and several donut-shaped rings of 1's. This raster could for example be the result of classifying a satellite image with ponds and lakes in it into ...
- 1,077
6
votes
1
answer
1k
views
How to remove clouds in High resolution Imagery(.5 mGeoeye)
I have imagery with high resolution .5m, large parts covered with clouds, so it's obscure many urban areas.
How can I remove the clouds?
- 1,123
6
votes
1
answer
1k
views
Floor height creation from Aerial Lidar/Imagery only
I was wondering if it is possible to generate the floor heights of buildings from aerial lidar? We don't have terrestrial lidar or stereo imagery. I don't need the ground DEM level or the roof (DSM) ...
- 8,298
6
votes
5
answers
10k
views
Fixing Landsat 7 SLC-off in ENVI
I have a couple of Landsat 7 images and they all have striping as a result of the SLC failure. Does anyone have any suggestions as to how to destripe the image using ENVI? I plan to use these images ...
- 165
6
votes
2
answers
529
views
How to remove vehicles from an aerial photograph
I have an aerial photograph of an area. The image includes visible traffic signs and vehicles. How can I remove the vehicles from the image? Is it possible to do so in software like Erdas or Envi ...
- 767
6
votes
1
answer
2k
views
How to convert an Erdas training set to .csv?
I am working with Erdas Imagine's Signature Editor to perform maximum likelihood classification. I need to use the same training set created in Erdas for other classification using R. Is there a way ...
- 51.8k
6
votes
1
answer
2k
views
Methods of cloud shadow detection for Landsat data?
Detecting clouds doesn't seem to be much of a problem, rather the challenge is in selecting cloud-shadow classes that don't also include coastal areas, agriculture, etc. For a project I'm working on, ...
- 151
5
votes
1
answer
5k
views
Open Source Alternatives to ERDAS IMAGINE ATCOR?
I have been using ERDAS IMAGINE's ATCOR extension for ATmospheric CORrection of ASTER imagery.
What opensource options exist for atmospheric correction of ASTER Level 1B products?
I'm primarily ...
- 51.8k
5
votes
3
answers
1k
views
Will Toshiba Satellite 70-A-11h meet GIS student notebook requirements?
I'm just about to start a college to study GIS and I need new notebook computer.
I would like a one that will last me for awhile and that can run the ArcGIS and ERDAS Imagine programmes that are ...
- 59
5
votes
3
answers
900
views
ENVI EX reviews?
Does anyone have a review of ENVI EX? I am wondering how well the Feature Extraction and Image Classification workflows function.
- 339
5
votes
2
answers
3k
views
Erdas python scripting help
I want to write scripts for Erdas in Python.
I downloaded some Python examples here but I could not make much.
Where can I get the full Help material for Erdas python scripting?
- 1,419
5
votes
2
answers
12k
views
Replacing Raster Values in Ras1 with Ras2
I have two rasters Ras1 and Ras2.
I want to change the Ras1.
In Ras1, there are few areas, lines, points I am interested having nodata cells and wrong data cells.(limited to interested areas only ...
- 812
5
votes
4
answers
11k
views
Determining which "color" each image band represents?
I have a satellite image that has a few bands in it. But I don't know what colors they are supposed to represent, nor do I know where to look for this information--the file's metadata say nothing ...
- 83
5
votes
2
answers
534
views
Matching Landsat 8 with previous Landsat images
I am working with Landsat 8 in ENVI. My image's dimensions are 8921 x 13131. I need to apply a forest mask to this image with dimensions of 8805 x 12321. I try to resize an image, but it doesn't work. ...
- 129
5
votes
4
answers
3k
views
Vector Machine Classification in ArcGIS
Is it possible to perform a vector machine classification of raster image using the ArcGIS software package. This supervised classification method is available in the ENVI software but not for ArcGIS.
...
- 61
5
votes
1
answer
3k
views
Writing band names into header (ENVI file type) using GDAL?
I am writing numpy arrays out as ENVI images using gdal in python. Until today, I always accessed the header the hard way by reading in all lines, changing some information and writing it out again. ...
- 211
5
votes
2
answers
457
views
Knowing the pixel size for a raster before it was resampled
Is there a method to know the exact pixel size (the original size) of a raster “aerial photo”?
I have purchased an Arial photo with 10 cm pixel size resolution, and I received a sample of it, but ...
- 1,044
5
votes
1
answer
337
views
Classifying different surfaces having almost similar Reflectance responses
I am using ENVI 5.3 to classify a Region of Interest clipped from Landsat 8 OLI. I have already performed calibration of my DNs by transforming it into Radiance and derived Reflectance image using ...
- 1,218
5
votes
1
answer
844
views
Stereo Analyst & ArcGIS 10.1 - volume calculation
I use to perform analysis and imagery exploitation with the software above.
I have created a Stereo Analyst report with some 3d polygon by a stereoscopic block.
How do I calculate the volume of some ...
- 93
5
votes
1
answer
1k
views
Setting "REAL" work/scratch workspace in ESRI/ERDAS etc
I thought the issue was only in ARCGIS but it seems that ERDAS does the same thing. I have my C with 1.7TB and my D with 10TB and my scratch set to d:\scratch but still ERDAS (and ESRI) fills my ...
- 8,298
5
votes
1
answer
751
views
Identifying pixels with sun glint in a satellite image (for atmospheric correction)
Wondering if anyone knows a way (perhaps objective) to identify pixels that are infected with sun glint in an image. I'm using Hedley's 2005 approach in a python to deglint my image but this approach ...
- 507
5
votes
1
answer
652
views
Using original Landsat multispectral image or pan-sharpened image in land cover classification?
I am currently creating land cover maps of a number of national parks across Asia from Landsat 8 imagery and also later from SPOT imagery. I plan to use supervised classifications in ERDAS IMAGINE and ...
- 861
5
votes
2
answers
1k
views
Applying pixel reliability mask to time series MOD13Q1
I am working with a 23-band GEOTiff in which each band is a 16-day MVC MODIS NDVI image. The MODIS .hdfs include a "pixel reliability" image with the following values:
[-1]: Fill/No Data-Not ...
- 769
5
votes
1
answer
251
views
Options for manually identifying road defects from Terrestrial Lidar
I am trying to create a process to identify road defects manually from Lidar. We have Erdas 2013, ArcGIS10.1 and Global Mappper 14.2 as options for paid software.
So far Merrick Mars displays the ...
- 8,298
5
votes
2
answers
420
views
ENVI to map composition
I'd like to print out 6 images in a single page. How can I do this using map composition tools in ENVI (6 images are year-to-year dynamic images with the same size and the same geo-referencing)?
- 579
4
votes
2
answers
7k
views
Converting *.tif file into headerless (flat) binary file?
I am using NDVI files (value range -1 to +1) created from Landsat CDR images to produce a timeseries in TIMESAT software.
My .tif file has following characteristics.
File type TIFF,Data Type ...
- 61
4
votes
3
answers
8k
views
How to create animation from raster data?
I have some NDVI and precipitation/temperature images at the monthly time step from Jan, 2005 to Dec, 2008.
I need to create animation image to show the temporal change.
How can I do this?
Is it ...
- 579
4
votes
2
answers
4k
views
Calculating Net Primary Production (NPP)?
When I calculate Net primary production (NPP) for a local scale, what kind of software should I use?
I always use ENVI, ERDAS IMAGINE, ArcGIS for Desktop and IDRISI.
Is it possible to use these ...
- 579
4
votes
3
answers
3k
views
Matching colours in already mosaiced single image? [closed]
I have an already mosaiced image for a large area. I need to match colours in this single image. I do not have each image separately. I just have this large single image downloaded from GLS. How can I ...
- 91