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

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343 views

How to extract breaklines from a given DEM?

Breaklines are very useful for describing a terrain - for example to build an exact TIN. My question is, how to extract these breaklines from a given DEM? I calculated the curvature (vertical) - ...
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3answers
114 views

Apply rotation before FeatureToRaster_conversion

I am converting polygon shapefiles to rasters. With arcpy I am using the function FeatureToRaster_conversion. gp.FeatureToRaster_conversion(InFeatures, InField, OutRaster, InCellSize) This function ...
9
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2answers
384 views

What is the correct way to convert a USGS Orthoimage from WorldImage format to tiled GeoTiff for GeoServer?

USGS provides different resolution orthoimage quadrangles in the WorldImage format (*.tif with an accompanying *.tfw world file). Some of these quadrangles can be used by GeoServer (2.1.0 - 2.1.2) by ...
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2answers
62 views

ArcGIS - Extract by Attibutes in Model Builder

I have a model which at one point uses the Extract by Attributes tool to produce a new raster with just the areas containing the maximum values of the first. I would think that the SQL expression ...
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2answers
88 views

Copy Jp2000 from Mosiac Dataset turns white

I am trying to copy a raster to jp2000 from another File Geodatabase that I created as a Mosaic Dataset. It came out as a whiteout in the middle. I don't know what it cause this. See screenshot : ...
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2answers
50 views

How to import R-generated .gri/.grd raster files in grass?

I received data in .grd + .gri format, where the first one is a small text file and the second one (having the same name) is a binary file. I am unable to open them in grass/qgis. Any hint ? Missing ...
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2answers
240 views

GDAL/proj4 equirectangular projection coordinate system units assumed by OGRSpatialReference and GDALDataset::GetGeoTransform()?

How do I configure my OGRSpatialReference object to specify an equirectangular projection system http://en.wikipedia.org/wiki/Equirectangular_projection where the affine geo-transform matrix (provided ...
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2answers
94 views

TIFF/Raster to Point shapefile question

Apologies in advance if this question is incredibly basic, but I've been googling around and I just don't know where to start. I've downloaded some nighttime luminosity data from NASA, and the data ...
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2answers
59 views

Rasters added to mosaic dataset only display at large acale

I have a set of 357 rasters in .jp2 that I've added to a mosaic dataset. All but 7 of them display properly, but the 7 only display at larger scales, around 1:6500 and under. I've tried adding them ...
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2answers
270 views

Clip_management to raster extent outputs larger raster than raster extent

Using Python and ArcMap 10.0 SP5, I'm trying to reproject and clip a large input raster to exactly the same grid as a smaller target raster (same extent, pixel sizes and projection). The problem is ...
0
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2answers
26 views

Reading a raster map cells values in C#?

Suppose I have a raster map file (TIFF, TGA, JNG... etc) loaded with geo-info manifested by the cells values. I need to read the values of the raster map cells "programatically" in a C# program. P.S: ...
0
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2answers
36 views

How to display a raster using Javascript API

It's all a proof of concept for myself and my learning but I have definitely hit a brick wall here! Here's what I've done and can get to work. I have written a Python script that: Sets its ...
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2answers
38 views

Arcpy GetRasterProperties returns odd results

I have this simple piece of python code to test whether a raster has integer values or not: res = arcpy.GetRasterProperties_management(ws, 'VALUETYPE') res = res.getOutput(0) ...
0
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2answers
78 views

How can I see average of raster value over certain area, marked by mouse?

I have a raster in Quantum GIS and I am just exploring it. How can I see average of raster value over certain area, marked by mouse? In other words: How can I select particular area in QGIS? How can ...
0
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1answer
38 views

Merging Raster: ImportError: No module named _gdal_array

When I try to merge rasters I got following error message: _gdal_array = swig_import_helper() File "C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\osgeo\gdal_array.py", line 18, in ...
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1answer
33 views

Building attribute table from raster in ArcMap 10.1

I have a NetCDF file containing the latitude, longitude and porosity for the entire US. I am trying to add another value (wilting point) which depends on the porosity. I wanted to extract the netcdf ...
0
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1answer
14 views

How do you distribute values evenly within zones when converting polygon to raster?

I'm trying to convert a (traffic analysis zone) TAZ polygon to raster so that the population values are evenly distributed within each zone. So far, when converting the TAZ polygon, the same ...
0
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1answer
43 views

Topo To Raster executing but not creating the raster

I am using Topo to Raster by File (ArcGIS version 10.1) via arcpy on a large stream and point dataset. Arcpy runs fine and executes without issuing any error message, however it does not create the ...
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1answer
70 views

QGIS 2.0 Howto copy raster data from a QgsRasterDataProvider to an OpenCV matrix

I'm hacking the half day arround a problem and that I' thought it was simple one. I'm using C++ (QtCreator) QGIS 2.0 und openCV2 on an 64 bit Workstation runnig Debian Wheezy. The Application I try to ...
0
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1answer
43 views

Raster to Surface

I have a raster and I have been asked to modify some pixel values in it. Is there an open source way to do this? I would guess that I have to create a 3d surface, then manipulate the surface, then ...
0
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1answer
138 views

Calculate area covered by a particular raster layer within polygons in QGIS

I am trying to extract information on vegetation cover within a set radius of point locations (my sites). I have succeeded in creating a new vector layer of circles with a 5 km radius around my sites. ...
0
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1answer
73 views

Hillshade tool in ArcMap returns terraced, pixelated image

I am applying Hillshade tool (ArcMap 10.1) to SRTM in Caucasus Mountains (border between Russia and Georgia). It gives me weird image with 'terraces' (see attachment). I reprojected SRTM from WGS-1984 ...
0
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1answer
46 views

Use of raster calculator in model builder

I have an equation as "3000*(1-exp((-0.000664)*input raster))". I want to make a tool to use this equation on raster images. That m gonna do in raster calculator with help of model builder. can you ...
0
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1answer
72 views

Viewshed calculation using SQL

Can i calculate viewshed in MS-SQL server? Viewshed analysis is Raster operation. I have elevation value vector observation as point vectors. Are there any methods to calculate Viewshed (using ...
0
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1answer
166 views

How to access each raster in a stack with a loop

I have a stack of rasters and I want to access each layer, combine each later with another file and finally export the resulting file as a csv file. Is there any way to do this with a loop? So far I ...
0
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1answer
74 views

Counting raster points within boundaries in another layer?

I know this question is similar to some out there, but I have tried all the 'solutions' and none of them are working for me. I am using the latest version of Qgis. I have a raster layer with ...
0
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1answer
48 views

USGS FLT Hdr file interpretation

I have a legacy program that attempts to read USGS 1/3 arcsec data. When I compare results to GDAL, I find that the lat/lon to pixel conversion is off by 1 line. The reason (I think) is because the ...
0
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1answer
147 views

Polygonize.py: AttributeError: 'NoneType' object has no attribute 'CreateDataSource'

Given a topographic raster tif of an european country where elevations are simplyfied to either 0, either 200. How to create a polygon ? Comment: With the following polygonize.py command: ...
0
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1answer
42 views

Precipitation or snow cover raster data for Scandinavia

I am looking for free precipitation or snow cover data in Scandinavia mountain during the winter 2011-2012. The WorldClim dataset is not enough acute. I would like 500 m scale at least. There is ...
0
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1answer
131 views

How to draw a custom map on top of base layer

I'm looking for the easiest way to draw a custom layer and export it as a tile cache. Basically what I would like to be able to do is load a base layer, and then draw objects and annotations on top ...
0
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1answer
348 views

ArcMap 10.1 - Tabulate Area tool “doubling up” for Overlapping Buffer Zones

This question is related to a previous question I asked: Raster Version of Spatial Join (one to many) I used the Tabulate Area tool to crosstabulate values between an overlapping "buffrast" raster ...
0
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1answer
41 views

Isolate And Save Raster Features From Existing Multivalue Raster Map

I have Cyprus Corine map with 44 different types of land use. I want to run a raster calculator query or any other way to isolate the areas with codes 10 to 22 and 26 to 34, all other values 1 to 44 ...