All Questions
423 questions
14
votes
9
answers
60k
views
How to export/save a layer composition to GeoTiff?
I want to export/save a QGIS composition of raster/vector layers to a GEOTIFF or ECW raster with high resolution (20 000 * 20 000 Pixel).
- 141
13
votes
3
answers
18k
views
Installing ECW for QGIS in Ubuntu 12.04?
I have followed various online help guides on how to make ecw for QGIS 1.8 work in Ubuntu 12.04. I had it all working in Ubuntu 10.04 but since migration to 12.04 no such luck.
Is there a guide that ...
- 139
13
votes
2
answers
9k
views
GeoServer: Best way to publish 2500 TIFF or 71 ECW files?
I have ortophotos of an area that I need to serve as a background map for my vectors. I got it as 2500 files (71,5MB each) in raw TIFF format with corresponding TFW word file - 180GB of data. ...
- 1,715
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
7k
views
What format and settings to use for aerials photos in QGIS?
Following question which was more about handling Aerials with ArcGIS:
Most Effective Format to Manage Aerial Photography for Viewing Only
It seems there are 2 major options for storing / resampling /...
- 9,794
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
3
answers
6k
views
Displaying raster Background Value as hollow for more than one set of RGB values using ArcMap?
I have two overlapping .ecw layers of the same area, though one is clipped in the middle, with a white edge.
When I set the background value to 255,255,255, and define it as hollow, it only hollows ...
- 8,718
9
votes
3
answers
12k
views
Best way to clip a large raster ECW file ?
I am trying to clip a large ECW (details below) but the raster file is too big to be processed entirely.
Some details of the ECW below
Driver: ECW/ERDAS Compressed Wavelets (SDK 5.0)
file size: ...
- 335
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
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
7
votes
5
answers
11k
views
Installing QGIS with ECW support on Mac?
I bought a imac recently and I tried to install qgis: without success! It is not possible to read the raster files. I installed GDAL ECW plugin, but it is necessary to copy and paste another file ...
- 79
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
4
answers
4k
views
Quantum GIS and ECW images?
How might I enable Quantum GIS to read ECW imagery?
At the moment I'm mostly concerned about this on Ubuntu 10.4 amd64, but I also use WinXP & Win7.
- 28.3k
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
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
2
answers
3k
views
Installing QGIS with ECW support on ubuntu 20.04
I know there are similar questions here, but I've tried every answer and every tutorial I could find, and I still can't open ECW with QGIS (and I kind of broke my qgis install? When I try to install ...
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
1
answer
2k
views
Geoserver 2.6 with ECW support
Did read "Geoserver 2.1.1 with ECW support"
but when I look at the link - http://docs.geoserver.org/stable/en/user/data/raster/gdal.html, it refers MSVC installation and other vague Window binary ...
- 61
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
5k
views
What are the benefits of RGBI Geotiffs vs ECW format?
I just received a batch of imagery for my project area in 2 formats: Geotiff (RGBI) and ECW. The imagery looks very similar and covers the same footprint, but the file size difference is massive: ...
- 1,165
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
2
answers
23k
views
Opening ECW files in QGIS?
QGIS 2.14.1 opened .ECW files simply via the open raster menu, without any problems. In 2.14.3, the entire ERDAS Compressed Wavelets option has disappeared from the file type drop down, and QGIS ...
- 231
5
votes
5
answers
9k
views
Unable to install ECW support on lubuntu 14.04
I try unsuccessfully to install the ECW support (mainly to use ECW file in QGIS 2.2).
We attempt to follow and adapt the howto provided by makina-corpus.
My first supprise was the repository ...
- 53
5
votes
3
answers
1k
views
Using gdal_merge to create a grayscale mosaic
My gdal fu is weak and I need help! ;)
I'm creating a mosaic in geotiff from hundreds of ecw. I created a list of all my rasters and used this command:
gdal_merge -o c:\temp\output_image.tif -q -v --...
- 1,524
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
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
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
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
2
answers
7k
views
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
2k
views
Importing ECW into PostGIS database with raster2pgsql (windows)
I'm working on windows 7 64 bits, postgis 2.01. I have to import ECW files into my PostGIS database. Unfortunately, my PostGIS seems to has been compiled without gdal ecw support.When i do a ...
- 111
5
votes
3
answers
2k
views
Mosaicing many large ECW files for display in ArcGIS Server apps
I have about 200 ECW files of recently acquired 1-foot resolution aerial photos. Its about 15GB worth, covering over 250 sq. miles. Unfortunately, you need a license from ER Mapper that runs about $...
- 12.7k
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
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
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
4
votes
3
answers
7k
views
Converting orthophotomap to .ecw file? [closed]
I am looking for a method for convert orthophotomap (.adf files) to ERDAS .ecw file.
Have you got any ideas ?
Or maybe you have got any other idea how i can reduce a size of orthophotomap .adf ...
- 3,694
4
votes
2
answers
1k
views
What Information Does the Blue Band Provide?
I am playing around with ERDAS and was implementing image difference on two rasters separated by interval of time. I was using a blue band raster and I created a default threshold for percentage ...
- 4,415