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

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333 views

How to store Large Raster Images of Equipotential Surface Generation Using Monte Carlo Simulation?

I have a large (1GB+) raster that I am using as the base for the generation of an equipotential surface. This is to assess the accuracy of DEMs derived from another source. In situ observation is ...
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364 views

How to convert a raster (array) to a NetworkX graph and do a * search?

I want to use a slope-raster for a a_star path analysis in NetworkX. I am using Python for this project. My test raster looks like this First I read in the raster with GDAL input_raster = ...
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22 views

IRasterLayer background transparency in C++ with ArcObjects 10.x .NET

I have a georeferenced IRasterLayer which is displaying data with no alpha channel. I am trying to specify a color which should be treated as transparent. In ArcMap it is possible to set a specific ...
4
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136 views

Vector to raster, then map algebra

I have a table of polygons representing travel time isochrones on particular days. For each origin point, there are five isochrone geometries (stored in separate rows). For each origin point, I want ...
4
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93 views

Postgis database query optimisation

I have a set of rasters in DTED format which I load into postgis database using raster2pgsql command line tool. Each of rasters is simply stored in a row and described by rid and a value of raster ...
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120 views

Add attribute table to a raster in postGIS

I would like to add attributes to a raster stored in a postgis database. I use the following command to insert the raster in the database: raster2pgsql -s 4236 -I -C -M ...
3
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64 views

How to compute NDSI in ArcGIS for Desktop?

How do I compute a Normalized Difference Snow Index (NDSI) in ArcGIS's Raster Calculator? I have a Landsat 8 scene (hdf4 format) that contains derived surface reflectance band-by-band. Each band is a ...
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35 views

Why does @data@values slot for RasterLayer only contain logical(0) and not the actual values?

Trying to get to the bottom of why, when I read in a raster of NDVI, the @data@values slot does not contain the actual values until I set them manually. For example: NDVI <- ...
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110 views

How to calculate areas in raster files

I got three files. The first is a shape file for country boundaries and the second and third are two raster files with the global land covers for 2005 and 2009. I'm thus encharged to calculate the ...
3
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57 views

Subset two rasters with different extent and origin (and resolution) only where there are data in both in R

in R, I have two rasters with different extents and origins (and possibly even resolution). How to efficiently take the subset of each of them only where there are data in both of them? Here is a ...
3
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88 views

Merge Raster Layer Specific Order in Graphic Modeler

I'm using the Graphic Modeler/Processing Modeler to automate a process. The last step in this process is Merging three different Raster Layers. I'm using the "Merge Raster Layers" from Saga 2.0.8. ...
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51 views

Subtracted 2 DTM layers to find the height of trees but all we have is the pixel values, can I convert this to height?

For a piece of coursework we have an aster layer that captures the tops of trees and a panorama layer that sees ground height (both are raster) so we have subtracted one from the other to get tree ...
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40 views

How to set m parameter of clusterR function in R?

I want to manage a clustered computation on raster and thus use the "clusterR" function in R (package 'raster'). However, there's a tuning m parameter to set, but the only explanation about this ...
3
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32 views

Need to run a Groundwater Analysis Based on Points to a Raster

The title sounds daunting, but this task really isn't. I have well samples over a decade in certain locations through an area. These samples contain a value of that element at that point in time. I ...
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44 views

Distortion in projected raster

I am having a frustrating problem with something that I think should be very simple. I have a number of DEMs from the National Elevation Dataset (NED), that come standard in the NAD83 coordinate ...
3
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138 views

How to calculate 90% confidence interval in a raster stack

I have a stack of grid files (23) in ASC format from a MODIS sensor and I need to calculate a 90% confidence interval, mean, min, etc, for each one in R, how can I do that? specially the interval. ...
3
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61 views

ArcPy: Initialize zero valued grid Raster and iteratively increment

I'm jumping right into ArcPy to help out a friend who needs to automate some ArcGIS work. The problem at hand can be reduced to the following pseudocode: accumulationRaster = SomeZeroedRaster for ...
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69 views

Raster loaded in ArcMap 10.2.1 not showing decimal places for value

I have an IMG format raster that I am loading into ArcMap 10.2.1. The pixel type and depth, as reported by the Source tab in Layer Properties is 32-bit floating point. The values, as reported in the ...
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45 views

Looking for a QGIS solution to make aerial imagery ArcSDE compatiable

Would like to avoid having to use 3d Analyst and use free raster tools in QGIS or elsewhere to make aerial rasters ArcSDE compatible. This 18 page work flow is what I am trying to use. Any suggestions ...
3
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100 views

How to create cost surface for least cost water transport analysis?

I am working on a project to derive least cost pathways between sites by dug out canoe travel. Has anyone worked on a similar project or found a function like the Tobler hiking function that can be ...
3
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260 views

Does QGIS support .sld style files for raster layers?

I'm currently looking at the documentation for geoserver, and I'm trying to load a raster and .sld file in QGIS to see if I can edit .sld files for raster layers. The .sld and raster are located here: ...
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146 views

How to compute surface of raster or any point using ARCGIS?

I have a raster image whose values are a digital elevation model of terrain. I need to know the surface type (topographic characterization) of particular points along transects of this DEM. How to ...
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814 views

Move Scale Rotate raster in Qgis

I have some archaeological scanned raster that they have a north arrow and a scale bar. There is no grid, no coordinate system.I would like to put those files in a general map. I don't care about the ...
3
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129 views

Calculate surface elevation from DEM of pit and known volume with which it is being filled

I am using ArcGIS 10.1. I have a DEM of a pit. I have a known volume of material that I want to put in the pit. I want to know what the elevation of the flat surface of this material will be ...
3
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242 views

Image classification for a study site falling over two adjacent Landsat 8 scenes (qGIS or ArcGIS)

This question concerns work-flow rather than specific methodological problems. I will be using GRASS to classify Landsat 8 images to create a vegetation map for a study site that happens to fall over ...
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517 views

Extract values from raster based on weighted average area using polygon grid

EDIT: I am using Armap 10 sp 5 I have found similar questions but they were either unanswered or somewhat different to what I am asking. I have a raster with cell values 1-5 and a polygon shape file ...
3
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56 views

simple raster format to use in Web applications?

I'm building a Web application in which users create and edit very coarse raster data. They're assigning values to cells in a georeferenced grid. Right now I'm storing the values in a multidimensional ...
3
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153 views

Can extracting raster values work in polygons' CRS without raster resampling?

I am trying to extract raster values using polygon layer with different CRS. Raster is in WGS84 (EPSG:4326) and the polygons in UTM (EPSG:23031). 1. If I want to work in the projection of the ...
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495 views

Novel ways of filling in missing values in a raster

I am looking for robust ways to fill in missing values in some rasters. They all have a single layer. Missing values consist of single pixels to medium sized patches. Rasters are around 1000 x 1000 ...
3
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169 views

Why are my raster mean and standard deviation -1?

I have a set of about 25 rasters whose descriptive statistics I have been examining. The data in the rasters were calculated in Python and the rasters were created using Python-GDAL. In all but one ...
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667 views

Weighted Average of several raster “zones”

thanks for the visit! Suppose I have two rasters, A and B. I want to determine the value of a certain "zone" in raster A by taking the weighted average of several other zones from raster B, that ...
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312 views

How to create raster attribute table to a raster data using gdal python?

I classified a remote sensing data and saved it as a raster using Gdal python. I want to create a raster attribute table for this classified result.. my classified raster has five classes with ...
3
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66 views

arcpy adding time to Raster Mosiac Footprint

I am trying to create a raster mosiac for use in animating data over time. The current workflow is: Create .gdb (arcpy.CreateFileGDB_management) Create Raster Mosaic ...
3
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145 views

Is there a tool for automated quality assurance for vector data captured on raster data?

I wonder whether is any tool(or script) in ArcGIS or QGIS which allows to make an automated quality assurance for vector data captured on raster data? vector data on binary raster:
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161 views

How does Zonal statistics handle pixels that are on the border of the polygon?

I am using the plugin zonal statistics to calculate the sum of the raster cells within polygons. How does this plugin handle pixels that are on the border of the polygon, are those cell values ...
3
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110 views

Geoserver Raster layer cropped by polygon?

I've got a Geoserver raster layer which represents a satellite image. I use the Geoserver WMS to display the raster in OpenLayers. I want to display only parts of the raster - those within a certain ...
3
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305 views

Getting coordinates of pixels

I want to compute an area of certain object on a picture using Monte Carlo method. The picture shows some shape on white background. To do so I figured out that I'd get the coordinates of non-white ...
3
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224 views

Is there a way to create raster by interpolating point values using GeoTools 8.2?

im new in using GeoTools (8.2). I was able to create shp from asc file which contains my data. Now my question is is there a simple way to create (interpolate) a simple shapefile (only points) to ...
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1k views

How to serve OpenStreetMap Tiles locally using ArcGIS Server 10?

We want to serve OpenStreetMap Tiles locally using ArcGis Server 10 to use as base maps in our ESRI Silverlight and Flex GIS clients. We've downloaded our regions OSM file and created PNGs using ...
3
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185 views

Geoprocessing Service to return Multidimensional Raster from a NetCDF file

I have tried to make this work for weeks with no results. I am trying to create a model in ArcMap that uses the Multidimension Tool "Make NetCDF Raster Layer" and return a raster to which I can apply ...
3
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281 views

GFS SIG/SFC file format of siganl.gdas/sfcanl.gdas analyzing/decoding problem

I am creating a database from datafiles. I encountered many fails and errors, which I have already fixed (also with the help of this Q&A web). Now I am stucked a bit in decoding of 6 files because ...
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228 views

How to read pixel values from an image server layer with ArcObjects?

I'm having a problem with reading pixel values from the image server layer. The image server layer class implements IRasterLayer, so when I tried to read pixel values using IRaster2 obtained through ...
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40 views

Converting large rasters to NumPy

I have a geodatabase that contains a large number of raster datasets - there are two rasters for each country in the world, and they are very large, in some cases up to 3GB per raster dataset. I ...
2
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0answers
30 views

Using Terrain Profile plugin with an interpolated raster

I am very new to QGIS and the goal of this exercise is to view an elevation profile of a river from a set of discrete points taken from surveying records. Steps taken: A vector layer was created ...
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21 views

Raster memory usage in R

I am working with raster/brick data in R and running into memory issues. I am basically trying to use raster objects to perform some simple agent-based modeling, but the objects keep increasing in ...
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60 views

How to tell if map service is fully vector or raster?

sorry if this is a duplicate, but I was wondering how to tell if a map service (in web browser) is vector based or raster based? What I think to understood so far is that Google Maps for example is ...
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15 views

Efficiently calculate distance between raster patch edges

I have a binary raster which I've classified into patches using raster::clump. I now want to efficiently calculate the edge-to-edge, i.e. minimum, pairwise distance between patches. I am currently ...
2
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28 views

Spatial Analyst tools adding extra column of NoData

I've got a script tool in ArcGIS that runs Curvature and Aspect from Spatial Analyst, and the outputs of both contain an extra column. I've attempted to set the extent in the both the tool and the ...
2
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0answers
39 views

Calculate mean value of polygon from raster in PostGIS

I started with a NetCDF .gri and .grd raster file of the UK provided by a colleague. I clipped it in R to be only London, exported and converted to a ASC file, and then imported it to PostGIS using ...
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16 views

Sampling raster by line in QGIS

I am quite new to GIS, and was wondering if you might be able to help me out? I have a raster layer for gradient as well as a line created from GPS tracking points(using the point connector tool). Is ...