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

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How to get polyline features from a raster file using ArcGIS 10.1?

I have a watershed accumulation file look like this: There are several white lines by visual, and I tried the raster to polyline tool and got this: Are there better ways to extract polyline ...
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576 views

Why does Topo to raster tool stall in ArcMap 10.1?

I'm having the following problem - An 8 mile by 4 mile set of 2 foot contours. Whenever I start the topo to raster tool, I get a constant loop of the tool running. And running, and running, and ...
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162 views

How to force deletion of corrupt ArcSDE Raster?

ArcSDE 9.3 / ArcGIS Server 10.0 / ArcCatalog Advanced 10.0 After an unsuccessful attempt at creating a mosiac, ArcCatalog refuses to allow deletion of the corrupt Raster file. The Mosiac creation ...
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603 views

gdal python set projection of a raster - does not work

Gdal 1.9.2, ECW driver: ECW/ERDAS Compressed Wavelets (SDK 3.x) I am having problems with the script that supposed to set projection of the ECW to EPSG:27700, i.e. the British_National_Grid. Please ...
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469 views

OpenLayers 2.13 : How to display a local tiled raster?

I am trying to display (on OpenLayers 2.13) a local tiled raster I made with gdal2tiles.py. Unfortunately it's all blank or pink. Here is my layer definition: var tiles = new ...
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243 views

Why doesn't the mosaic to new raster tool or the mosaic tool work when I try to use them?

I am trying to mosaic 4 raster datasets of elevation together using the 'Mosaic to new raster' tool in ArcGIS 10.1. I have even tried using the 'mosaic' tool and it still doesn't work. The errors that ...
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Is it possible to preview a raster catalogs raster field in a Windows form?

What I want to achieve: The attribute table for an ArcGIS Raster Catalog contains a raster field. When a raster field cell is clicked with the mouse, a preview window displaying the raster associated ...
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391 views

Is there a way to find out which pixel values are around the current pixel?

I would like to write a cycle which takes a current pixel, look at the surrounding pixels, choose the pixel with max/min value and skip to that pixel...and so on. Is there in arcpy such a function ...
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412 views

Where is this raster offset being introduced in the QGIS processing toolbox?

I'm using the (awesome!) processing toolbox in QGIS 2.0 to reclassify some NoData values in a raster from -9999 to 0, but at some point in the process there's an offset of about 0.2 degrees being ...
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201 views

Rasterlite db with multi table

When working with Spatialite DBs, I can store multiple tables in single DB. But now I want to store multiple raster tables on a single Rasterlite DB. I tried QGIS for conversion but it converts only ...
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How I can merge three rasters with sum cell

I am working by ArcGIS 10 and I have three raster all of raster have value cell and I want output raster have the sum of pixels values
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498 views

how to plot gps coordinates on my own raster map?

I have lat log values available in degree format, i donot know how to access raster maps using c#, and how to plot accurately. which libraries should i use and what are the controls avialable ,i am ...
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118 views

Making spatial clusters by direct manipulation of raster pixel values using R

I think this is an overambitious million dollar question, but I'm always optimistic when I pose a question even though I feel like I left no stone unturned! I've processed a raster layer with pixel ...
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68 views

Calculating loss of value from a wind turbine on surrounding properties depending on distance

I have to evaluate where installing a turbine would be most efficient, depending on wind speed and price of properties surrounding each cell in a raster. The cost on value of properties is computed ...
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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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combine raster with another raster mask file - gdal

I have 2 rasters in GeoTiff format. One has all of the land and water and the other is a mask file that shows either 0 for water or 1 for land. I basically want my output to just have the land values ...
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571 views

How to Calculate Custom Zonal Statistics?

I have a vector polygon shapefile outlining counties for which I have a raster of nighttime-luminosity data. I've been able to compute Zonal Statistics in ArcGIS 10.0 using Zonal Statistics as Table ...
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TIF file creation from shapefile in GRASS?

Does anyone have any idea how to get around this problem? I've been looking for a solution to no avail. I'm trying to convert a shp file to a grid, and the tif is hanging up. Output raster layer: ...
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R - How to sampleRandom() from large raster without NA values

I have a number of vary large rasters which need to be randomly sampled with the return value being a matrix of x, y, and value. The raster package sampleRandom(raster,n, na.rm=TRUE, xy=TRUE) will do ...
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278 views

How to find matching pixel values in seperate rasters

I am looking to scan two separate rasters, capture the pixel information, then draw a polygon of the matching pixels. any thoughts? I am at a loss. Edit: I have two aerials, both are in ...
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783 views

How to extracting raster data to multiple polygons?

I have a reclassified raster dataset (10 classes) and I want to find out the area of each class contained within multiple (hundreds-to-thousands) polygons. I have all the polygons in the same ...
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763 views

How to translate (reposition) a .tif raster layer?

I'm starting to use QGIS for my thesis (environmental physics) and have to admit I'm pretty ignorant about it - I've always used Mathematica or Matlab. My problem is: I have a raster layer, in .tif ...
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PostGIS Raster: raster2pgsql was not found in /usr/lib/postgresql/9.3/bin

I have installed sucessfully Postgresql-9.3-postgis on Ubuntu 12.04, following this instructions: http://trac.osgeo.org/postgis/wiki/UsersWikiPostGIS21UbuntuPGSQL93Apt Having done that, I have ...
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627 views

Equivalence of EPSG:3857 for MapInfo 9.5

I have a raster projected on EPSG:3857 with QGIS. I have image registration in Mapinfo but there is no projection for EPSG:3857. Do you know the projection that I need to use?
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974 views

Creating Random Points in ArcGIS 10.1

I would like to create random points across my study area (which is a DEM raster) using the Feature Class> Create Random Points. However, I need to select/copy/move/delete these points and re-arrange ...
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223 views

How to reduce Polygon to Raster (Conversion) bit depth?

I have a polygon featureclass that I am trying to convert to raster format at a low bit depth (i.e. <8 bit unsigned). The FC contains 50,000 polygons which have five values: 1,3,5,7,9. I have set ...
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149 views

Strange black pixel on edge when generating with gdaldem -hillshade

I'm getting a strange result when I'm generating an hillshade with the gdaldem hillshade command. Here is my command (see the compute_edges parameter): ...
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How to clip an Openlayers OSM Background to a Vector Boundary?

I'm new to QGIS. In my project i have two layers: one is my vector (city boundaries) and the other is the OSM (obtained with the plugin). How can I cut the OSM along the edges of the vector? I want to ...
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145 views

Which File to load from National Hydrography Dataset?

Start-over beginner here. I'm using QGIS 2.0 on MacBook with OS X 10.8.5. I downloaded a National Hydrography Database file. Unzipped, it is titled NHD11032_NM.gdb. I try to add the layer as a vector ...
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Two r.mapcalc calculations return a much bigger raster cell size than the input raster

I tried the following calculations with a GeoTiff sample, having a cell size of 25m: Calculating the togographic exposure (TOPEX) and estimating the mean topographic curvature Both, the resulting ...
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130 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 ...
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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. ...
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174 views

Whats the best way to create bathymetric contour lines?

I have a raster dataset with both Topographic and Bathymetric stored in it. What is the best way to create exact contours of the lake-bed? This becomes tricky when I want to make the contour for depth ...
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740 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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376 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 ...
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396 views

How to identify valleys on DEM in ArcGIS 10.1 [closed]

First, What is the best and easiest way to identify valleys in a DEM raster? Second, how do you create a least-cost pathway for each valley in a region based on low angle slope and proximity to ...
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133 views

How to get Name of IRaster object using ArcObjects?

I have an IRaster object as output from a function. I need to be able to get the name of that raster. Is there a way that I can do that? I know that I can't mask an IRaster as an IRasterDataset. If I ...
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Retrieving raster/coverage width and height in pixels from GeoServer

Is it possible to retrieve the original width and height in pixels for a coverage in GeoServer using either the Python API or REST? I could not find anything in the documentation regarding how to ...
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Creating spatially projected polygon grid with ArcMap

i need to create a grid with 1x1 square kilometres cells in ArcMap. The operation located in Data Management Tools -> Feature Class -> Create Net is almost what i need but in the parameters, i can't ...
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181 views

GeoServer raster tiles are individually contrast-balanced: how to turn this off?

I'm running GeoServer locally as a servlet (in JBoss), and I'm serving a GeoTIFF file through the WMS protocol. In a webpage running an OpenLayers map, I have the GeoTIFF-WMS layer overlaid above an ...
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234 views

R - Efficient way to segment rasters into sub-regions and sample… without using extract()

My question is: Is there a more efficient way to sample from a sub-region (defined by a shapefile read into a spatial object) of multiple rasters without having to use extract() for each region on ...
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2k views

extend the size (area) of raster

My problem is that I would like to multiply two rasters using raster calculation tool. Both rasters have values 0 and 1, but the covered area of first raster is bigger (100 x 100 miles) then the area ...
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working with hydrography raster the cost array ignores the end of water

We have our maps laid out using hydrography maps from NOAA. We had to run the graphics through several steps to create the water feature raster. I have a process that pulls in that raster, sets a ...
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How to automate creation of toe of slope from DEM?

I was looking for an automated process to "identify" the toe of a slope from a DEM and ran across this ESRI thread and technique: I am at Step 7 but have no idea how this is accomplished. I get it is ...
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How to calculate the sum of all cells in a raster layer upstream of a specific point?

I have a rainfall map which covers large area. However, I'm interested in the total value of rainfall over a specific subcatchment. If I don't have the shapefile which defines the boundary of this ...
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How do I fill gaps in a raster to zero value cells?

I am trying to add some forest elevations to a DEM using ArcView. I have converted a polygon feature class of a forest into a raster with the same resolution as my DEM. Then I reclassed the forest ...
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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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423 views

If I convert a TIN to a raster in ArcGIS will results from the two versions of the surface be comparable?

I have converted a TIN to a raster. I found that the top of a bund wall shifts laterally in position between the TIN and the raster into which it has been converted using the TIN to raster tool in ...
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787 views

Use of Raster Calculator in ModelBuilder

I have the following equation: 3000*(1-exp((-0.000664)*input raster)) I want to make a tool to use this equation on raster images. I want to do this with the Raster Calculator with the help of ...
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Can I export an imagery directly to a geo-referenced raster form File|Export Map in Arcmap?

While using File|Export to export an imagery to raster, is there a way to have it geo-referenced in a way that if I load the exported raster into the map, the image sits exactly in its place without ...