Imagery refers to raster based datasets acquired from sensors on satellites or aircraft.

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5
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2answers
385 views

Extract certain area of contours/satellite images

I have 2 satellite images (jpeg2000 format) and 2 xyz-files from the same area. I am trying to extract certain region from the area including contour lines and the satellite image in order to import ...
3
votes
2answers
107 views

How many stereo satellite imagery required to prepare DEM of an area?

I want to know how to find the nos. of scene of stereo CARTISAT-1 data required to prepare DEM of an area(say 84000 sq km)? any suggestion/solution/calculation?
3
votes
1answer
28 views

How to know the required scene required to cover an area?

I want to know how to find the nos. of scene of LISS 4 data required to cover an area(say 84000 sq km)? any suggestion/solution/calculation?
12
votes
2answers
1k views

How to equalise colour, brightness and contrast across several scanned paper maps

I am a vectors guy mostly, but for a current project I need to work with a bunch of old scanned paper maps (ww2 bomb damage maps for London, if your interested!) We scanned and georeferenced the ...
2
votes
0answers
533 views

Automated testing for GIS apps

There are several commercial and opensource tools for regression automation. While many of them could be employed to test GIS apps, they fall short, at times, dealing with the unique characteristics ...
2
votes
2answers
335 views

How to identify image footprints of an aerial photograph

I need a tool that will take aerial images with Lat, Long, and Alt in their EXIF data and produce foot prints of the images. We need to verify that the images cover the photographed area with proper ...
1
vote
1answer
349 views

Is there a way of viewing a photo has a point tag from Photo2shape in QGIS?

Is there a way to view images (photos) that have location point from Photo2shape by clicking on the point in QGIS?
7
votes
4answers
900 views

Where can I download free satellite imagery of Cambodia for offline use?

I am an entry level GIS user - I have had one semester of GIS in college. I have successfully downloaded raster satellite imagery from Seamless (tiff files) for my class project. Now I am trying to ...
14
votes
3answers
632 views

Alternative vegetation indices

I have been using NDVIs with limited success to identify trees in the central Great Plains region of the USA. The problem I have been encountering is that reflectance from farm fields/pastures have ...
7
votes
4answers
903 views

Visualization of satellite image - directly in python

Is there any way (a package or what not), to visualize a geotiff image directly in Python? I don't want to use ENVI or ArcGIS or anything else. Thank you in advance.
2
votes
1answer
855 views

Convert 3-band raster imagery to distinct vector zones in ArcGIS

So much like the title says I would like to convert a 3-band infrared image TIF file of vegetation into distinct vector feature zones using ArcGIS. I'm guessing the only way to do this is with ...
5
votes
2answers
985 views

Creating a multispectral image from scratch

I want to make a multispectral image from cero to do some tests on it. Something really simple like 5 completely uniform bands with salt and pepper noise on them or a square of different values at the ...
6
votes
2answers
265 views

Wavelet vs Discrete compression for imagery

What is the main reasons to choose wavelet (jp2, sid, ecw) instead of discrete (JPEG) compression methods for raster data? Lets limit this question to aerial imagery and lossy compression. Why ...
2
votes
3answers
289 views

Finding Satellite Imagery For Use Without Internet Connection

So, I am not a GIS expert. I just write software and I've done some work with ArcMap, ArcGIS Server, and FalconView. What I need is world wide satellite imagery I can use on a local machine. Street ...
4
votes
2answers
369 views

Purpose of building footprints

What are the uses (public and private industry) of building footprints? I'm trying to figure out how polygon building footprints can be used. i.e. are they used for determining tax liabilities, ...
2
votes
3answers
578 views

Looking for high resolution (1m or better) aerials for Turkey

Would prefer free but under a couple hundred dollars is also doable. It would be nice to have actual tif, sid, etc. files but a WMS would also work... using ArcGIS 10 Would also consider any of the ...
2
votes
0answers
81 views

Are there any naming conventions for aerial imagery?

Do GIS projects involving high resolution NAIP quarter quad imagery typically use the USGSID code and qq (e.g. 3910232ne) or the GNIS code and qq (e.g. 39102e1ne) to organize data? I can't seem to ...
2
votes
3answers
544 views

Combine aerial imagery pictures to create a layer

We are looking for software or a web service that we can put in pictures we took using our weather balloon to create a single image, that we can use as a layer for our GIS project. Preferably free, or ...
4
votes
2answers
6k views

Where can i download a good World image in GeoTIFF?

I can either be from MERIS (ESA) or from MODIS (Nasa). I already reached these sites: http://www.unearthedoutdoors.net/global_data/true_marble/download ...
2
votes
2answers
137 views

What exactly is 'anti-aliased image generation'?

I tried to google it, but didn't quite get it. Any help and/or examples? Thank you!
1
vote
1answer
365 views

GDAL Brightness RGB Contrast Gamma Saturation

I've not had much experience with modifying imagery, I've recently been playing with GDAL for some batch processing of geo-referenced images, I've been supplied with some imagery in ECW format that is ...
3
votes
1answer
334 views

Viewing panoramic imagery in ArcGIS

Is there an ArcGIS extension or utility that will view 360 degree panoramic images? I've found utilities that are part of larger software packages for managing mobile scanning data, but all I'm after ...
3
votes
2answers
362 views

Third party base layer other than Google map

Can we use third party base map (images tiles) for displaying vector data?, like we use google map as base layer for displaying vector data in OpenLayers application.
1
vote
1answer
93 views

Is there an image service from GOES available for ArcGIS?

I have an arcmap project using an arcims service from NOAA ENC (http://ocs-spatial.ncd.noaa.gov) but maybe the service is unavailable right now and I can't access to imagery... Is there an image ...
7
votes
3answers
2k views

Poor image quality of raster pyramid files in ArcGIS (no anti-aliasing)

There are several GeoTIFF files (size ~7000x7000 px) which I try to open in ArcGIS Desktop 10.0. I have already created raster pyramids for them (.ovr files) using geoprocessing tool but their quality ...
2
votes
2answers
338 views

Convert Georeferenced imagery to vector data using python

Are there any opensource tools I could use to take a projected georeferenced image such as a jpg with world file, that is UTM projection such as NAD83 and convert it into distinct vector polygons ...
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vote
2answers
2k views

How to convert GeoTIFF to grayscale and add gaussian blur?

I have a giant GeoTIFF I'd like to convert to grayscale and add a gaussian blur to. As far as I know, GDAL can strip two of the three color bands and call it grayscale, which might work, but is there ...
2
votes
1answer
198 views

Trouble viewing MrSID in ArcView 3.3

I have been using 3.3 for some time and now I have Arcmap10 on the same computer. My problem is that I cannot pull up the Mr Sid files. 3.3 can't find them ,the id has the right info but no image of ...
5
votes
1answer
409 views

Is there any plugin for QGIS to calibrate contrast and brightness of a raster layer?

I frequently need to deal with the contrast and brightness of raster layers in QGIS and I miss the tools in ArcGIS for this task. Should there be a plugin already developed for QGIS? If there is, ...
2
votes
2answers
784 views

Where can I find non-rectified stereo satellite imagery?

I'm looking for free (as in beer and as in commercial-use-friendly freedom) sources of stereo satellite imagery. I assume that such imagery should not be rectified since that would remove the benefits ...
4
votes
1answer
645 views

How to identify image location?

I have a satellite image of only one part of some city with a lot of vegetation. I need to find out where is that image taken. I'm interested is there any way to find out where it is taken on Google ...
2
votes
0answers
958 views

Clipping MrSID files

Does anyone have experience subsetting/clipping a large NAIP imagery file in MrSID format? Some of the NAIP files we have are by county and they have really large file sizes. The files are from the ...
5
votes
2answers
355 views

Which is the best way to create a polygon with the extents of a raster file in QGIS?

I have a tiff image file and want to get a polygon with the extent of the tiff. Is there a direct way of doing this? Right now i have to convert the image to vector (with gdal_polygonize) and then ...
3
votes
1answer
419 views

How can I georeference a second image without losing georeferencing for first image in ArcGIS 10?

What happens: 1) Take a map with an image that was georeferenced earlier, which works fine. 2) Add a second image to the TOC and fire up the georeferencing toolbar. 3) Select the new, ...
7
votes
1answer
391 views

50cm imagery - aerial or satellite?

The area of interest is 1450 km2. My options are: 50cm newly collected aerial natural color imagery for $28,300 OR 50cm recent archival satellite imagery (includes near IR band) for $20,600 The ...
0
votes
1answer
299 views

Incorrect spatial extent for imported hdf image on ArcGIS

I imported an hdf image onto ArcGIS but I cannot make correct projection of it. Also, it does not have correct spatial extent (please see the enclosed figure, the small one is projected under WGS84). ...
3
votes
4answers
3k views

How to redefine the nodata value into zero in QGIS?

I have an image which i cliped with an AOI polygon. The contour area was set to pixel value = 0 and I have a nodata value of -32768. I want to redefine the nodata value into zero. I used to do this ...
5
votes
5answers
990 views

georeferencing aerial photos with only known centroid

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 an ...
1
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0answers
238 views

Assign Custom Band Combination To Image Catalogs In ArcGIS

I have an image catalog composed of 4 band rasters. I would like to use the same image catalog, and set custom renderers for a true color and false color combination and save each of those catalogs ...
7
votes
4answers
7k views

Spatial resolution of Google Earth Imagery

What is the spatial resolution of imagery used in Google Earth? At various places on the web, I have been reading it varies from place to place - 60 cm, 2.5 m, 15 m and so on. I was wondering if there ...
13
votes
4answers
499 views

When should I be calling a 'rectangular grid of pixels' a raster or an image?

Reading through GIS literature, it sometimes feels that authors use the two terms with a specific meaning in mind. I always treat the terms interchangeably. Am I wrong? Read the first line in the ...
7
votes
3answers
1k views

Use of Pictometry images in GIS

I am wondering if anyone has worked with Pictometry in GIS and their .pmi files. I recently acquired imagery from them for my area and have discovered that I cannot add the pmi files to the webmap, I ...
6
votes
3answers
175 views

Best practices for identifying training sites

Prior to image classification, collection of training sites and obtaining a signature file is the most critical step. Field visits with a reliable GPS Unit is usually the first step followed by ...
5
votes
5answers
5k views

How Do You Remove No Data From A Raster (.sid)?

I have an Image.sid that has a white border which is No Data. I've tried using Clip Raster Tool with no success. I've also changed the symbology value for No Data to be transparent. I'd like to ...
0
votes
1answer
407 views

Is there a way to save images with none stretching in ArcGIS

I have some satellite images, when I imported these in ArcGIS and went to properties and then symbology tab, I saw stretch type was set to standard deviation. I want to save these images with no ...
1
vote
0answers
234 views

Recomputing footprints on old satellite imagery [duplicate]

I am trying to create an image service out of some 1976 satellite imagery. But first I need to get all of the no data cells out of my mosaic dataset. I have tried to recompute the footprints on my ...
3
votes
1answer
1k views

How to add images containing attributes in QGIS?

I am new to QGIS. I know how to add vector and raster files into QGIS. I have some satellite images taken at different times of the same location. In addition, there are some annotation data ...
5
votes
3answers
548 views

Image viewer or browser for large images

I have some big images. I'm looking for an easy way to browse and view them. Currently I'm using Preview.app on OS X, but it wasn't designed for these types of images. My images are, for example: ...
6
votes
1answer
1k views

What causes these shiny artifacts in Google Maps imagery?

Do you know what causes artifacts like this one: Source: ...
5
votes
1answer
104 views

Non-Research Transportation Raster applications

My experience with rasters is pretty basic. 99.95% of what I do involves vector and transportation modelling. In research, there are numerous transportation applications using rasters and imagery ...