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

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168 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 ...
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122 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 ...
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377 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 ...
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290 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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2k 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 ...
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209 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 ...
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328 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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282 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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27 views

How can I change the origin (top left corner) coordinates of a raster using PyQGIS?

I am developing a python plugin for QGIS. The purpose of the plugin is to properly open an HDF5 dataset as a raster. Opening and displaying the raster can be done without the need for a plugin, ...
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14 views

PostGIS - raster - bit operations

I have a raster data in the database in separate rows. I would like to select 2 rows and do a bit operation with them (like |, &) and store the result in memory as a query output. Is this possible?...
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20 views

classify colourramp with new min and max value with python

For my script i want to update the existing colourramp of a raster with new min and max value. In my current code is can fill the min and max but can't classify and update the raster. How does the ...
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35 views

Comparing areas of two raster files

I need to compare the areas of two rasters for calculating the percentage parts from another. For example, I have one raster file which shows separated agriculture fields. The value of each field is 1 ...
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58 views

Raster Catalog QGIS; performance

Is there a comfortable way to generate efficient raster catalogs (such as in Arcgis), where polygon tiles are loaded as long as the scale does not hit a threshold value and images are only loaded when ...
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60 views

How to show a 2.5D surface of raster above terrain layer in Cesium?

I'm developing an web application that will show surfaces of rasters and terrain. These rasters are on GeoTiff format. I learned from example cesium can show image overlays earth surface. The ...
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55 views

Size of an object in raster image based on DPI resolution and number of pixels

I'm trying to estimate the size of an object in a raster image, with known DPI resolution. To evaluate the validity of this method, I do as follows: 1) I'm drawing a 0,02 in × 0,02 in black square ...
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20 views

How to generate random points from classified raster layer?

I need to generate random points using a raster layer, which is classified into 5 classes of TPI (terrain position index). This should be a stratified random sampling design, with an equal amount of ...
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21 views

Issue loading PostGIS out-db rasters (either in QGIS or MapServer)

I'm playing with a few different options of storing raster data via PostGIS to visualize (eventually in a web app). The out-db or out-of-database storage seems the best option, but I can't seem to ...
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24 views

Creating a reference raster in R

I need to create global reference raster (100km grid, Eckert IV). Later, I will project other various rasters (with different resolutions and projections) into the resolution/projection of the ...
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52 views

Draw raster on top of a Leaflet map

I want to implement a raster layer on top of a Leaflet map that includes the following functionalities: Digital Elevation Model (DEM) terrain height included in each raster cell GPS-Track (I use ...
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38 views

QGIS raster style rendering incorrectly/unexpectedly

I have a raster of flow accumulation. To style it, when I set manual values for raster breaks in qgis 2.14 it isn't rendering all values below the value I set in the same colour. My understanding is ...
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54 views

ArcGIS Pro 3D rasters?

I am trying to use ArcGIS Pro to create a 3D scene using an elevation surface (.tif) generated from drone imagery. The tif is projected and contains the elevation information, but I cannot get ArcGIS ...
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40 views

Reassigning raster values by looking for nearest pixel in another raster using QGIS?

I have two non-overlapping rasters, A (red hues) and B (blue hues). I want to change the value of pixels in B via a nearest-neighbor search in A; i.e. a pixel in B with a value of 15 looks for the ...
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68 views

Extract values from Rasters in R based on spatial points and spatial polygons

I am trying to extract values from a raster file using the extract command in R mentioned here: http://www.inside-r.org/packages/cran/raster/docs/extract My raster file is unprojected (WGS84 ...
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23 views

Raster and digitized shapefile misplaced in same projection

I have georeferenced .tiff rasters with cadastral borders and corresponding digitized borders in shapefile based on that raster. All that was done in some Mapsoft software. When I insert both in QGIS ...
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34 views

GRASS 7 r.sun aspect in doubt

I'm using r.sun in GRASS 7.0.3 to determine beam irradiance at a site (~ 56N -4W). I have a DEM (a local subset of EU-DEM). I'm using r.sun in mode 2, called from GUI. Typical logging in command ...
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39 views

Extract Mean Raster Value from multiple raster files into Excel

I have a series of non-orthorectified raster files containing NDVI information. I would like to extract the mean value from each raster so I can see a summary of each raster image name and the ...
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47 views

Geoserver ImageMosaicJDBC problem with interpolation setting

I use the ImageMosaicJDBC plugin to connect to an Oracle raster table. Maybe someone can clarify some things about the interpolation settings. There are multiple location where I can define the ...
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61 views

Why azimuth result is wrong for this pyqgis code?

In this code I want to obtain azimuth from a single point to each pixel center, but when run it, in raster created azimuth result for each pixel is wrong, what is correct code? from osgeo import gdal,...
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87 views

Adding a custom color scale for a sp.points layer to levelplot() legend

I'm wondering how I can add a customized color palette that I used to display a sp.points layer in a call to levelplot (lattice plotting) in the rasterVis package in R. I used a function that Dave X ...
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88 views

R Efficient Way to Resample, Crop, and Mask a Raster Image

Does anyone know an efficient way to resample an image? I am currently trying to crop a large image and clip 2 regions from a shape file. From this clipped image, I would like to increase the pixel ...
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50 views

Extracting Mean from Raster and Writing to Table in ArcPy?

I am simply trying to extract the mean of each raster within a geodatabase and write the value to a table. I have done this successfully with another set of rasters, but now I keep getting the ...
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24 views

“Problem loading output layers” error when running algorithms on rasters in QGIS

I am trying to delineate a catchment from SRTM 1arc second data in QGIS. For this, I first try to use the Fill Sinks algorithm and then the Catchment Area algorithm. Both of the operations gives a "...
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51 views

QGIS tiff image loaded but not visible

In QGIS I used the Georeferencer on a jpg image I had prepared in Gimp. But when I load the resulting tiff image into my QGIS project it is invisible, even though an image viewing program can show it ...
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51 views

Not all raster layers redraw

I'm running QGIS 2.12 and have the same issue on 2.8, but it is now worse in this latest version. The issue is that not underlying raster layers (satellite photos loaded in as .tif) are being ...
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107 views

display of raster in QGIS - cells are not rotated

when viewing rotated rasters in QGIS - the overall raster is rotated (as designed), though each grid cell is not. (the nodata value doesn't appear to pick up as the default in QGIS either - -2.9999e+...
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85 views

QGIS raster calculator - crash minidump

I'm new to QGIS and using version 2.10.1-Pisa. I have two raster layers created from ASTER DEM data. I have one for slope and want to create a binary layer where only pixels between 8 and 60 degrees ...
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100 views

Raster Extrapolation in QGIS?

Does QGIS (or different software) have a method to extrapolate raster values to larger area (outer boundary)? I have a boundary(.shp), which is 40 m far from the edge of raster. I want to fill the ...
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42 views

Efficient processing of ST_ValueCount Results in Postgresql

General Problem: I have a table of rasters. The rasters are classified MSI images, so each pixel is an integer indicating the class of the pixel. For a number of regions, I am querying pixel counts in ...
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104 views

Error when I try to convert Corine Land Cover 2000 tiff to shapefile in QGIS 2.10.1 or clip CLC2000 by a polygon

I want to clip Corine Land Cover 2000 tiff by a polygon or to convert it to shapefile in QGIS 2.10.1. So far I have tried the following always getting an error message that 'ascii' codec can't encode ...
2
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0answers
84 views

How to interpolate values for NaN pixels using ENVI?

I'm currently using MODIS data and am running into problems with NaN values in the final product caused by clouds. I'm interesting in a simple way to spatially interpolate (fill in) these NaN values. ...
2
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87 views

Area Calculations dont agree after raster to polygon conversion

I have a landsat 8 image [UTM 19s] (30m resolution, so 900m sq per pixel). I need to calculate the total area (hectares) from a land cover type. I take the count of pixels from the attribute table, ...
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295 views

Comparing the use of GDAL to build raster pyramids or overviews versus Arcmap 10.1

I have a large set of imagery that I created a mosaic from in arcmap 10.1. I want to use GDAL to create the overviews because arcmap has issues building the pyramids and never seems to complete. I ...
2
votes
0answers
76 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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67 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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109 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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95 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 ...
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57 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 ...
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28 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 ...
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122 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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0answers
129 views

Merge raster tiles in PostGIS

I have several raster tiles that are adjacent and non-overlapping, so they form a mosaic. I am trying to merge two adjacent rasters using PostGIS but am getting an error that they do not have the same ...