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

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How to modify extent (layer) for Fuzzy Membership analysis?

When applying the Fuzzy Membership, how do I modify the extent (layer) to which it is applied? I don't mean showing the extent, but changing the values (mid point & spread) to a different layer? ...
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30 views

How can I remove dipoles from rasterlayer in QGIS 2.2?

I work with geomagnetic survey data. When convertet into a rasterlayer, every object with a high magnetic potential (for exampel an iron-nail on the surface) is shown as very sharp anomalie called ...
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133 views

I had an error in Gdalwarp and i don't know the reason

I was trying to warp a raster using a mask and shift it before clipping but when i exectute the command bellow in Qgis/PyQt using QProcess: gdalwarp -s_srs "+proj=merc +a=6378137 +b=6356752 ...
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56 views

problem saving GRID to .img keeping original names (export by attributes)

I am really new in Python programming. I try to make a loop for Extract by Attributes tool in ArcGIS 10.1. I have a huge dataset of raster (760pc) and I want to extract a specific value. This part of ...
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24 views

How do I randomly alter a raster with som correlation

I need to randomly alter an existing raster. The original raster is essentially a topography map that measures its values around a normal distribution ranging between 0.5 and 1.5 The new raster ...
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117 views

Convert raster_stats list output to array / csv file

I usually program in R, but recently I have started to use python for most of my spatial programming. My python skills are still limited, and please excuse the simplicity of the question. I am ...
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93 views

Turn vector layer in raster layer based on cost

Hy, I am trying to rasterize some vector layers into raster layers and I know this is possible with QGIS by using the rasterize function in the raster menu but I don't know how to do the following ...
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40 views

I want to reproject data from 0-360 to -180 - 180 [duplicate]

I've been downloading data from NOAA in a CRS that goes from 0-360. The rest of my data is in -180 to 180. What's the easiest way to reproject or shift the data in QGIS? It took 30 seconds in ArcMap, ...
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43 views

Find Distance within each Raster contiguous cell block

I was asked to find for each Individual Contiguous Forest Block the distances INSIDE of each where it would be the farthest (aka the most isolated) from each forest cell block's respective edges. I ...
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297 views

Create Tiles for a raster(georeferenced) to use in leaflet

I have raster, with each pixel containing some data. What i want is to split a large image with each pixel's color is determined by its value, to show on leaflet layer.How to go about this ? raster ...
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65 views

Zonal statistics won't work after re-projecting vector layer

I have qgis 2.0. I want to analyze raster information within a buffer of 30 miles around a vector layer of cities across the world. However, both the raster and the vector are in WGS84. I have no ...
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82 views

Dates are off when opening netcdf file in R

I have a netcdf file with the time dimension that goes from 12/2007 until 12/2010 with monthly time steps. I can see the correct dates in both arcgis and panoply. Panoply tells me this file is a ...
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211 views

Cannot read postgis RASTER into ArcGIS using the interoperability extension, either directly by Query Layer

This post accessing postgis raster data using Query layer in ArcGIS was created in Jul-12. Since then, I have not found any other related-post published. Using QGIS with DBManager ON, my postGIS ...
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1answer
25 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 ...
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53 views

Publish rasters stored in PostGreSQL with GeoServer [duplicate]

we are trying to publish some raster images stored in our Postgres database. First, they were generated from satellite images (spectral indexes). Then we uploaded them with raster2psql as tables. So ...
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85 views

Update a NetCDF file using GDAL

I have to edit a NetCDF file using GDAL in C++ code. When I try to update a subset I have this error message: ERROR 6: The NETCDF driver does not support update access to existing datasets. How can ...
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1answer
174 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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167 views

recording pixel value with Python script in ArcGIS 10.x

A scripting newbie question... I'd like to write a Python script for ArcGIS 10.x that would record the pixel value for all pixels in a raster. Furthermore, I'd like to only record a given value once ...
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1answer
274 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 ...
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154 views

Choose what zoomlevel to read from for mbtiles file in GDAL

GDAL is supposed to read MBTiles files and to do so, it selects the highest zoomlevel available. However, is there a way to choose another zoomlevel? i.e. override the default and go for a lower one? ...
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99 views

How to split a raster into multiple rasters using QGIS?

I would like to know how to split a raster into multiple rasters in a single operation using QGIS. Although I can clip the raster image, it would be better to split it using a single operation. I am ...
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368 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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37 views

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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76 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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34 views

Warping Rasters in QGIS

There seems to be a bug warping rasters in the new QGIS version 2.0 When you have to option of target and Source SRS, the Coordinate reference system does not get automatically writen into the box ...
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269 views

How to convert Raster to points in MapInfo?

I wanted to convert Raster data to point data in MapInfo.Does there any tool to convert? can anyone help me?
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79 views

Interpolation Technique

We have following solar metro logy parameter through satellite data with resolution of 100 Km^2 (10Kmx10Km) Insolation on horizontal surface Diffuse radiation on horizontal surface ...
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1answer
86 views

QGIS proximity raster with extent beyond original coverage?

I need a raster coverage of distances from points outside the geographic region of interest, and am having trouble doing this with QGIS. Questions like this one (Calculating distance to points in ...
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1answer
100 views

How to display NoData of a raster in QGIS

How can I show raster pixels with NoData value in QGIS? In ArcMap there is a button to choose the color for the NoData value. Is there something like this in QGIS?
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28 views

calculating mean and standard deviation for raster values using whole pixels within a polygon [duplicate]

i have a raster image and a corresponding shape file. i would like to calculate the statistics of the values within polygons which have a common attribute but only using pixels which are fully ...
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164 views

Problem with merging 15 DEM files in ArcGIS

I have 15 DEM files downloaded from USGS website. The pixel depth of each file is 32 bit floating, generic with format FLT. I'm then using data Management Tools > Raster dataset > Mosaics to new ...
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427 views

Tabulate area - Spatial Analyse

I am trying to calculate the amount (sqm) of land cover types (forest, water ect.) in 1045 buffer zones, all the same size (500m in diameter).. The buffer zones are polygons and the land cover is a ...
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275 views

Trying to build pyramids for large raster

I finally was able to make a slope with a rather large 5m DEM. But now I it usually wont finish drawing. When ArcMap asks to 'build pyramids' it always freezes sometimes instantly after accepting ...
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1answer
202 views

How to import and patch multiple ASTER files in QGIS?

I'm a new user and just began with GRASS, where I learned to import 30x30 resolution ASTER files and then patch them (the six I'm working with) into one map. On QGIS, it doesn't appear that there's a ...
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164 views

QGIS 2.0 cannot open TIFF

I've just installed QGIS 2.0 on my Windows 7 computer. I'm trying to open a raster and the system reports this message: Cannot open TIFF file due to missing codec. How can I solve it? Thanks in ...
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168 views

How to create a raster dataset from a known decimal extent?

I have an input raster pInputRaster. I want to create a new raster dataset called pOutputRasterDS that is the same width, height and cellsize as my input raster dataset (I'm not worried about ...
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40 views

How to select raster layers for averaging based on values in another layer?

I wonder if anyone have some ideas about how to solve this geoprocessing situation: 1: I have a raster layer called mixlyr_apr (representing depth values) 2: I have a series of raster layers called: ...
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1answer
56 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 ...
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84 views

Vector/Raster Intersection - Speedup and replacement for ST_Centroid

I have some raster data which is the altitude above sea level and also some vector data which represents building outlines. What I want to do is grab some buildings outlines and fetch all the raster ...
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105 views

QGIS merge rasters error

I've been trying to merge some raster tiles at work and I've been getting an error message saying I don't have the correct permissions. This works fine on my home pc. Any obvious reasons for this? ...
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1answer
94 views

Multiple Rasters into PostGIS

This may have been asked before, but A) what software/libraries etc do I need to B) load multiple rasters into PostGIS? I have Python 2.7.5, QGIS 1.9 (latest Weekly Build), PostGIS (whatever the ...
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186 views

Assign spatial reference for 1000 different ECW raster datasets using 1000 different *.prj files through python programming or .net

I am having 2000 ECW raster datasets without spatial reference and also I have 2000 *.prj files in another folder. I know only the way as right click on raster datasets-->properties-->Spatial ...
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61 views

How to deal with the situation when two rasters stacked together in arcgis?

I am doing a project about petroleum geology. There are several formations needed to add attributes (e.g. name, thickness and age). I have the raster data of thickness, so I created a raster catalog ...
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106 views

Copy Raster Tool and 1bit to 8bit

I have a bunch of 1 bit rasters (700+) of scanned maps that I need to convert to 8-bit rasters. It's the only way Geosoft will recognize the spatial coordinates of the TIF as they don't deal in 1bit ...
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20 views

Scale factor (constant not linear stretch) GDAL [duplicate]

I need to re-scale a geotiff with gdal. I'm aware that gdal_translate has a -scale function, but i need to actually apply a constant (eg value(x,y) * 100) instead of scale the pixels to within a ...
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79 views

QGIS: “No data” raster value for missing rows conflicts with data?

I’m having a problem with specifying “no data” in a raster dataset in QGIS 1.8.0-Lisboa. QGIS does fine in interpreting pixels I don’t have rows for as “no data” if I set Layer Properties -> ...
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92 views

Why does a shapfile shift after transformation?

I have a shapefile created in the raster package (ER_14.3_2000_poly). > #read in a raster file > ER_14.3_2000<-raster('E:/Ecoregions Models/Outputs/ER_14.3/ER_14.3_ConsensusMap3.asc') > ...
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46 views

How to reclassify raster data on a scale of 0-1? [duplicate]

I have various raster layers generated after using euclidean distance tool. How can I reclassify them on a scale of 0-1 instead of 1-10, etc?
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389 views

How to fill in the parameters for kernel density estimation?

I am desperately trying to calculate animals home range with kernel. Unfortunately, the result is obviously incorrect and I cannot identify my mistake (I would like to post a screenshot but its not ...
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70 views

ArcGIS API for Silverlight: Retrieve all Data From a Raster layer?

Is it possible to use ArcGIS api for silverlight to get the data in each cell of a raster layer and store them in an array?