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

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1answer
169 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
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1answer
335 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
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2answers
657 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
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1answer
446 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
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0answers
835 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
263 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
369 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, ...
5
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1answer
326 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
270 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
3answers
2k 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
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5answers
795 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
225 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 ...
6
votes
4answers
5k 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 ...
12
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4answers
455 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
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3answers
168 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
4k 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
403 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
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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
882 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 ...
4
votes
3answers
465 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
101 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 ...
3
votes
1answer
441 views

WMS Image Services Do Not Display

We recently upgraded to Image Server 10.0.1 and in the process our WMS Image Services quit displaying. The connection to them works in ArcCatalog, but it never displays. If I preview the service it ...
7
votes
2answers
2k views

Does an open source alternative to ESRI's Image Server exist?

I noticed the default way to store imagery is by using a database in the open source world. I like ESRI's Image Server software because it removes the need for a database and makes backing up a lot ...
4
votes
2answers
152 views

Purple anomaly on imagery

Can someone please tell me what this purple anomaly is on the imagery that we just received. The only thing I have done processing wise is to build the pyramids when they first came into ArcMap. Other ...
10
votes
6answers
946 views

What is this “brown spot” in Google maps?

I was in Google maps today and noticed near Baltimore, US where the river is, there's a huge brown spot. Is this due to all of the waste? If so, will this keep going all the way into the ocean?
5
votes
3answers
1k 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 ...
8
votes
4answers
960 views

How can I work with 3+ Gigabyte TIFF Files?

While I don't work in GIS myself I'm trying to support one of our users here who looks after all our mapping and GIS data. We've received a 3.2GB Tiff image containing satellite imagery of our site ...
2
votes
3answers
172 views

Medium resolution imagery for the US?

For my web map application http://ian01.geog.psu.edu/geoserver/www/pa/pa3.html I have three levels of background imagery as the user zooms in. At small scales I'm using NASA Blue Marble and a large ...
3
votes
6answers
289 views

Source for high-res subscription imagery service

I'm developing a diagramming tool using aerial imagery as a reference layer. This tool should allow the user to zoom in quite close to a roadway or intersection. Unfortunately none of the public map ...
4
votes
2answers
162 views

Unrestricted codec for creating raster files with interior pyramids files

I'm looking for a tool that will allow me to mosaic a collection of images into a file format with performance similar to MrSID or ECW, but without the licensing restrictions that those formats come ...
21
votes
7answers
2k views

Work flow for georeferencing imagery using open source tools?

Does anyone have a recommendation for a work flow for georeferencing high resolution aerial photography using open source tools? Comparison of user friendliness and robustness between Quantum GIS ...