All Questions
874 questions
20
votes
1
answer
36k
views
Panchromatic Image association with high spatial resolution
How and Why is a Panchromatic Satellite Image associated with high spatial resolution? I googled and found that it is a single band image, but then why is it called pan-chromatic(All Colors). Does it ...
- 595
16
votes
5
answers
33k
views
Finding ways to get free radar (SAR) satellite imagery data sets [closed]
I am looking for finding ways to obtain free (non-commercial use) sources of synthetic aperture radar (SAR) satellite imagery. Does anyone know of sources?
- 403
12
votes
2
answers
1k
views
Adding site photos to a print composer atlas in QGIS
This is the first time in over three decades of existence that I cannot find an answer and I actually have to ask one for myself, so please accept my apologies for any formatting issues or lack of ...
- 121
11
votes
3
answers
4k
views
Rendering images in OpenLayers?
My organization has a web application for displaying global and regional climate data and we're considering improvements to it. Our leading idea is to create an OpenLayers-based application to ...
- 119
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
4
answers
2k
views
Comparing areas in scanned historical land use maps using QGIS?
I am a relative beginner to using GIS, and am running QGIS 2.0.1 in Linux. I have two historical maps which I want to analyze, that show land use patterns in the same area at two different moments in ...
- 225
10
votes
3
answers
22k
views
Is it possible to query/download satellite images with Python?
I was wondering if there exists a Python library/API for downloading satellite images. Ideally, I would want to enter the latitude and longitude of a bounding box and get a high resolution image ...
- 1,545
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
2
answers
18k
views
image segmentation of RGB image by K means clustering in python
I want to segment RGB images for land cover using k means clustering in such a fashion that the different regions of the image are marked by different colors and if possible boundaries are created ...
- 567
9
votes
1
answer
1k
views
Creating vector (with lines/polygons) from raster based on paper map in QGIS
For a task I have several maps created with GIS that look like the following:
I am mainly interested in the colored zones that aren't roads (red) or rivers (blue) and would like to turn these into ...
- 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
8
answers
15k
views
Automatically download and merge webmap tiles into one big image?
Is there an easy way to download a bunch of web map tiles (in /z/x/y.png format) and stitch them together into a single large image? I could probably script this using ImageMagick, but would prefer ...
- 5,720
8
votes
1
answer
10k
views
How to Combine Two Image Overlaying Into One Image in Google Earth Engine?
I have two images of different sizes. I can make them overlay each other using Map.addLayer() for each. But I want to combine them into one image as shown in illustration below. How to achieve this?
- 341
8
votes
2
answers
8k
views
Leaflet.geojson webpage performance out of hand, how to convert to .png?
I exported some countries as a single .geojson file. The file includes every country's vertices and coordinates, as that's what a .geojson is ─ a vector file.
Thing is, there are about 20 countries ...
- 815
8
votes
2
answers
2k
views
Retrieving heights of buildings using remotely sensed data (except lidar)
How can I get the height values of buildings from a certain sector a city without going into the field to collect data? Is there anyway to do via satellite imagery, SRTM, ASTER GDEM or any DEM for ...
- 773
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
2
answers
2k
views
Georeferencing Photos With No Spatial Reference?
I have about 100-200 field ground shot photos I would like to overlay in ArcGIS 10 that have no spatial information which I need to somehow develop using a photogrammetric formula. The camera was ...
- 280
7
votes
4
answers
3k
views
Is there a way to filter the colors out of an image?
I am using ArcGIS 10.2 to show a facility's size and position in a project area. I was not given any shape files or survey files of the area. I only have a deed (.pdf) with a B&W sketch of what ...
- 528
7
votes
3
answers
3k
views
Seeking software for opening .img files?
I have some cpc precipitation data stored in IMG format.
Could anyone suggest a software beside ERDAS imagine or Arcgis which can be freely downloaded?
- 179
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
1k
views
LiDAR intensity image from multiple flight lines?
I'm working with multiple raw las tiles, and I've used Fusion to create an intensity image, but it shows the flight line overlap (see below). Any idea how can I smooth the image so that the overlap is ...
- 73
7
votes
1
answer
7k
views
Creating scatterplot with icons (svg or png) instead of points?
I'm just starting with R and I wanted to know if it's possible to create a scatterplot with custom icons (svg or png) instead of points.
I started to import a shapefile, and then I have a set of ...
- 763
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
1
answer
7k
views
How to export the map in very high resolution
I made a map in QGIS.
Now I want to export the resulting image (layers upon layers) for further processing in GDAL.
The print composer only lets me export an image up to a fixed size. If I try to ...
- 11.3k
7
votes
1
answer
3k
views
How to convert legend to graphics in QGIS?
In QGIS am trying to convert the legend element in the print composer into graphics, like the option in the ArcGIS "Convert To Graphics", see image below
Is there some way to do it with ...
- 4,082
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
2
answers
2k
views
Displaying images as part of multiattribute labels using QGIS
I would like to display images referenced in an attribute column as part of a multiattribute label, so that I can eventually print them with the map. I do not want to display geotagged images, since ...
- 71
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
948
views
Automate Exporting of Rasters Using Renderer in ArcGIS
It is possible to export rasters in ArcMap by right clicking the layer-> Data-> Export:
You can then click 'Use Renderer' check box to ensure the image you export uses the current symbology/rendering ...
- 156
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
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
6k
views
Creating a mask with transparent pixels in Python
I have a GeoTIFF image with pixel intensities ranging between certain values. Let's say between -2 and 2 (the image is normalized). I have a certain threshold which interests me, let's sat 1. I would ...
- 1,087
6
votes
2
answers
8k
views
Detecting overlapping blobs in image?
I have read the following two posts related to my question; however, my problem is slightly different and I'm having a hard time solving it.
Finding if two polygons Intersect in python?
Getting ...
- 163
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
1k
views
Displaying multiple images from same point in QGIS
After the dead of eVis plugin I have troubles working on my project in QGIS 3.16:
I have a shapefile with multiple row, each one with the same position: the content is data from archaeological sites ...
- 63
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
6
votes
3
answers
3k
views
How to generate image tiles from custom geo data for use with Leaflet
Migrating a webapp from Google Maps API V3 to OSM + Leaflet, which displays custom data that consists of lots of lines and points, on a background map.
When this custom data is drawn by Leaflet on ...
- 347
6
votes
1
answer
1k
views
I have a Web Application (ASP.NET) made in ArcGIS Server Manager. How to create a button for the user to export his vision for PDF / Image?
I am using ArcGIS Server Manager to create Web Applications (ASP.NET).
I would like the customer to access has an option to export your vision to PDF or Image, or both.
I would like to generate the ...
- 428
6
votes
1
answer
3k
views
Convert land-based camera image pixel x,y to ground lat/long or x,y,z
I have a number of cameras at various known locations (x,y,z) and directions that are above ground about 20 feet pointed at different ground locations about 100 feet away from each camera, and whose ...
- 61
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
223
views
View more than three pictures in the image viewer of QGIS
I'm adding photos inside point fields in a GeoPackage table in QGIS. The default image viewer cannot show more than three photos and the window is not scrollable.
Is there any settings so that I can ...
- 121
5
votes
4
answers
722
views
ArcGIS 10.3: Insert rotated image without background
How can I insert this image into an mxd so the white background doesn't show up? I've tried using photoshop to delete the background and save it as a format that supports transparent backgrounds (gif ...
- 542
5
votes
1
answer
786
views
Noisy lines in all scenes for Landsat 7?
I'm seeing patterned lines in all Landsat 7 images that clearly are image artifacts. There are lines that jet in from the edges (the center looks better) Does anyone know what it is and if there are ...
- 183
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