Raster is a data format consisting of regular grids of values, usually stored in an image-like format.

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592 views

How can I change the class of one pixel in a classified image?

I have a classified image (I did it in ERDAS) with six categories. There are some misclassified pixels (especially high-density urban category). Is there any way that I can choose one pixel and then ...
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3answers
7k views

How to calculate Raster Area per Polygon?

In ArcMap, I have a raster file that contains 6 classes of landcover and a shapefile that is the census data (OA boundaries and their population). I want the area of each class in each OA? For ...
8
votes
1answer
696 views

How to apply a Majority filter in GRASS GIS?

I was wondering if someone could help me write a majority filter for GRASS GIS. I have this map (see below) which I need to run a filter over to make the red areas a bit more dominant. I know I can ...
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5answers
3k views

Problems merging DEMs or other raster datasets? Clipping Raster dataset to vector line?

I have two DEMs that I am going create a hillshade from, and ultimately want one hillshade clipped to a county boundary. I am running into a couple problems, though. When I try to merge the two ...
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1answer
423 views

How to bring georeferenced raster data into MAPublisher?

What is the appropriate method to import a georeferenced raster image into MAPublisher? I have been able to import other forms of map data, and created map views and such for them, but I am now ...
8
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4answers
1k views

Looking for a fast, open-source raster cost-distance function to use in code

I've been scouring the internet for a fast, open-source cost-distance function that I can embed inside my code. The functionality should basically work like the ArcGIS implementation where I can ...
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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 ...
7
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7answers
818 views

seeking “Available Sky” implementations

I'm looking for implementations of an algorithm called "Available Sky". ArcGIS (Spatial Analyst or GRID) is preferred, but solutions in GDAL, SAGA GIS or others are perfectly acceptable. The ...
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2answers
429 views

Disaggregating aggregate GIS data using remote sensing

I haven't really done much with remote sensing imagery. I have census data for an area, and a TIFF raster image of the area. I'm sure this is possible, is there a simple way to disaggregate the ...
9
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7answers
5k views

How to get raster image as array in Python with ArcGIS

When starting to work with Python and ArcGIS 9.3, I assumed there would be a simple way to get a raster image into a Python array so that I can manipulate it before storing it back as another raster ...
7
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3answers
2k views

Make the nodata area of a resampled orthophoto overview white?

I have a set of orthophoto images which are each fully filled with data, but when placed together the coverage does not form a rectangle so there are nodata areas. In MapGuide, I need to be able to ...