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

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38 views

clipping raster changes raster values?

I am working with BIOCLIM temperature/precipitation layers and I have noticed that when I clip the global raster down to a specific region, something happens and the raster value at a specific point ...
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103 views

Align vector and raster layers with D3

I have a geocoded raster image that I want to use as the background to a vector map with D3.js. The screenshot shows the layers in QGIS (grey is raster). Here's the markup for the map: <div ...
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26 views

Combine Raster and Feature Class selection

I've been working on a quite complex analysis with ArcGIS 10.2. But now I'm stuck at a problem... I have a raster file and a polygon feature. The Raster file stores information about Zmax, Zmin and ...
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47 views

Calculate cover loss between years using r.mapcalc

I am working on forest cover raster data for 2 years and am interested in areas with >5% loss in forest cover. I am pretty new in GRASS GIS, so any suggestions for how to create a difference map of ...
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31 views

Help Summing Raster cells to equal circles with a specific sum

So I have this application user density data that I've collected. Each gps point has a user density associated with it (for example: 150 users within a 1 km radius, which calculates to users/[pi*R-sq] ...
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55 views

How to run Focal Stats on specific values in python

I'm a beginning programmer and am new to the site but it has helped me quite a bit so thank you! I'm trying to recreate a raster calculator operation using python scripts but am having a hard time ...
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126 views

Different obs. when I extract raster values from polygons in R

I have two raster layers with the same projection, extent and resolution: r1: class : RasterLayer dimensions : 33434, 89431, 2990036054 (nrow, ncol, ncell) resolution : 0.001447053, ...
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102 views

Large Rasters in ArcGIS & MapInfo

My geoscientists like to work with MapInfo and ArcGIS. I require a common 1 band raster format that can hold obscene amounts of data without damaging the data (compression). I have tried .tif and ...
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28 views

Raster Copy: Output bit size does not match specified value

Using ArcGIS (Map/Catalog) 10.0. I have a raster file (kdens) developed from point data using the kernel density tool. It is 32-bit float file format. I need this file converted to a polygon ...
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53 views

ArcGIS 10 restricted WEIGHTED Flow Accumulation

I have a question very similar to one asked by wxfox4god on 12th June 2013 ("Arcmap 10 restrict Flow Accumulation") that was answered by whuber. (I have had to post it as a new question as I do not ...
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43 views

How to create raster from table containing cell values in PostGIS?

I am having a table with integer values. These values are in between 0 and 2. I want to create a raster out of that table with integers as cell values. Or else how to create polygons out of that table ...
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59 views

How to re-grid a raster using area-overlap weighted averaging?

I have two rasters r and r2 with different resolutions. I want to re-sample (re-grid) r2 to be the same as r using area-overlap weighted averaging:If an r grid cell is covered by more than 1 ...
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71 views

Python Script to iterate numerous, single-band rasters for arcpy.CompositeBands

I have a large collection of single-band geotiffs (NIR, Green, and Red) that I would like to composite using a Python script. The goal is to iterate through multiple folders in a main directory, ...
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180 views

ImportError: No module named gdal qgis2.8.1

i am using QGIS 2.8.1 (32 bit) in windows 7). I imported two DEMs and trying to merge (QGIS>Raster>Miscellaneous>Merge)them. Unfortunately it gives me import error as below. Traceback (most recent ...
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66 views

Adjusting heights within a DEM raster for visualisation

Problem I have a bathymetry DEM which I want to display in 3D (ArcScene or Fledermaus). The data set is one single raster but looks like it is a mosaic of several smaller datasets. The problem is ...
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177 views

Calculate Euclidean distance to raster WITHIN multiple polygons

I am using ArcGIS 10.1 on a Windows x64 system. I am working in a study area where I have 360 000 locations of about 50 territorial animals. I have a shapefile containing 125 sometimes overlapping ...
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121 views

Arcpy script for summing pixel values in loop can't handle large number of rasters

I want to sum the pixel values of large numbers of rasters of different extents (ArcMap v10.2). 16GB RAM. I have the following code (with help from this site) which solves the different extent ...
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86 views

ArcMap - Export raster symbology to a raster function template programmatically

I would like to programmatically export symbology for a raster dataset as a raster function template xml file, as can be done by clicking the export button in the symbology tab of the layer properties ...
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267 views

Working with AIG Raster format in ArcGIS for Desktop?

I downloaded a specific layer which has the format "AIG" as you can see in the screenshot. It has no projection so I applied "Define Projection" on it. I searched for the projection and found the ...
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80 views

Geoserver : create a rasterized polygon / dynamic fill for polygons with features from database

I decided to post here because I couldn't find any answer to my problems on the internet. So I am using geoserver 2.7-SNAPSHOT, everything is working fine but I need to implement a new function or ...
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49 views

Storing a coverage in a JDBC database

There is another question about raster data for GeoServer. Conditions: - PostGIS 2.0.3 and PostgreSQl 9.2. - I followed: ...
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25 views

What are the problems of loading overlapping (or the same) tifs into postgis?

I am still early on the Postgis learning curve. I have an existing table in Postgres - it looks like this: create table "public"."mytable" ( "rid" serial primary key, "rast" raster, "filename" ...
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50 views

Looking for a tool like (IDW) for raster

I am looking for a tool that gives the same outputs like the IDW, but for rasters instead of points. I have a Corine land cover raster layer in ArcMap 10.2 with different friction values, displaying ...
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82 views

How to calculate the slope with isolines/raster?

I'm trying to calculate the slope (in %) in ArcGis 9.3, but don't remember how it works. I already did it some time ago, but this time it doesn't work... I used a shapefile with Isolines (see ...
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100 views

Hyperspectral Data in ArcGIS Desktop

The public organization I work for has some archived hyperspectral data (.raw - radiance, non georectified). Has anyone processed hyperspectral data for consumption within ArcMap? If so, what sort of ...
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169 views

Retrieve list of all features and values from raster layer (Geoserver and Openlayers)

I'm trying to retrieve a list of all values from a raster layer (GeoTIFF) in geoserver (2.5.x). I tried to modify the code from http://trac.osgeo.org/openlayers/wiki/GetFeatureInfo but I can't seem ...
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70 views

geoserver and openlayers select rectangle pixel values

I'm running a geoserver (2.5.x) with 1 raster file (GeoTIFF) as a layer. From my application I can access a single pixel value when clicked (through WMS), but what I'm really interested in is to get a ...
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74 views

ArcMap - Adding Multiple raster datasets to mosaic dataset (for temporal change)

I have a number of raster datasets containing lake water temperature data. I am looking to make these time enabled as to be able to scroll through them. I have converted them to .TIFF format and have ...
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65 views

What are my options to handle Raster Clipper ERROR 6: ADRG driver doesn't support 4 bands?

I have a tif file which contains 4 bands (RGB + alpha). The clipper does not work and gave me the message below; ERROR 6: ADRG driver doesn't support 4 bands. Must be 3 (rgb) bands. Any patch file ...
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82 views

QGIS 2.4 Clip function in Raster layer Style Single band pseudocolour not working?

I've been using QGIS for a while and recently upgraded to 2.4, but now find that displaying raster layers is difficult. In particular, the clip function (tick box bottom left of "Style">"Singleband ...
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91 views

Changing grid orientation of a raster

I'm trying to load some XYZ data into a program called OpendTect. However, the orientation of the existing data is different from the grid orientation of the XYZ file. this makes it imposible to load ...
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69 views

How to Use GetGeomtype Gdal Python

I am just wondering what I am doing wrong when trying to use the GetGeomType. I need to focus on separating layers from a pix file. Two categories are the bitmaps(which are vectors) and then the ...
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234 views

Why do comparisons in QGIS 2.4.0 Raster Calculator return -3.40282e+38 aka no_data?

I tried to use comparisons as conditional statements in QGIS 2.4.0 raster calculator. My statement is: (a < 230) * 230 + (a >= 230) * a The expected result is raster a with all values lower ...
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88 views

List of vector to one raster in PostGIS

Hi PostGIS developers! I need to rasterize a part of OSM map by coordinates. I found rather good algorithm, but can’t finish it. I have problems in STEP 3. I described all algorithm here – may be ...
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141 views

Changing extent on a raster in QGIS

I rasterized a shape. The resulting raster (lets call it raster 1) has a different extent. I made a virtual raster with the original polygon and I tried to multiply the virtual raster with raster 1 ...
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292 views

Failing to merge rasters in QGIS

I am new to QGIS but have some familiarity with other GIS software (namely ArcGIS). I want to merge a number of LiDAR digital elevation model (DEM) tiles (specifically, 30 individual tiles) to ...
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46 views

How I can create a raster and have the same overlay as another raster in QGIS 2.4?

I have made a graphical model in QGIS 2.4. I have to create a raster equation to rasterize a polygon shapefile. I want to rasterize my shapefile and I want to ensure that this new raster will ...
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59 views

Why does my clipped raster seem to be slightly moved?

I'm having some problems with clipping rasters. I started clipping my raster using extents, but I saw that the clipped raster is different from the original raster. I created a virtual raster to use ...
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90 views

How to Interpolate very large datasets in QGIS?

I am working with a very large set of point data, (XYAttribute) which I wish to display as a raster. I've been using Interpolate, this is successful but very slow. I have other programmes that ...
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162 views

Using R to subtract the polygon area of one shp file from another

I'm looking to produce a map from two separate maps in R. My Maps files are as follows: ftp://ftp.cpc.ncep.noaa.gov/GIS/us_tempprcpfcst/610prcp_20140822.zip #Map1 ...
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53 views

Error in polygonising raster data with QGIS on Mac

I'm using QGis Chugiak on a Mac and I'm trying to converting a raster layer in a vector data by: Raster/Conversion/Polygonize. So, I select the layer needed from the drop-down menu, I give a name to ...
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274 views

Problem loading output layer QGIS

Every time I run operations with temporary file output from the graphical modeler, I get the following error message: Oooops! The following output layers could not be open CLIP: ...
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59 views

Align & Sum Grids in Python

I have two grids. One, call it A, is 4320x2160 cells and spans the whole globe. The other, call it B is 8640x3432 and spans the circumference of the globe, but is clipped toward mid-latitudes. Both ...
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134 views

Is it possible to change the default raster style of newly created rasters in QGIS?

If I do calculations on rasters with the raster calculator or other tools, the resulting rasters displayed in my canvas are always in the same default style (singleband gray, black to white...) so ...
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68 views

How to add a TIF raster layer programmatically?

This is my code whenever i try to load .tif image it shows layer is not valid,QgsRasterLayer always return invalid layer (I am using linux 12.04). QString myFileName = ...
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140 views

How to group a multiple rasters in MapServer?

I had a map files for each state (raster file) of India. Now I want group all mapfiles to show a single raster or single map file? How I can do in using qgis or any platform?.
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61 views

Problem with adding mosaic layer via arcpy

I have a mosaic layer that I want to add to my map in ArcMap. When I add this layer manually (i.e the "Add Data" button), a raster image, a boundary, and a footprint are added to my table of contents. ...
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71 views

Choosing the map scale (1:nnn) for the given raster dimension

Starting points: let define the raster image size, say: 1800x900 pixels I want draw my own raster image map - by drawing polygons e.g. like "draw line from pixel with coordinates x100y100 to pixel ...
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92 views

R{raster} getValues(): error accessing values of large raster

I am getting the following, while extracting all values with: rs<-getValues(rster) Error in getRasterData(con, offset = offs, region.dim = reg, band = object at data@band): long vectors not ...
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110 views

R: Can raster predict function pass to predict.rfsrc (a prediction function in a parallel verion of RandomForest)?

It seems that raster predict function can pass to predict.randomForest by setting the "type='response'". I am using a parallel version of randomForest package called the "randomForestSRC" and I am ...