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

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Should large Basemaps be stored in DBMS via ArcSDE?

As I understand it, the SDE Geodatabase provides the technology for Multiuser databases, Versioning, replication and other Geodatabase functionality. In my organisation, this could be useful for ...
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1k views

Convert polygons in shape file to a numpy array?

I have a shape file containing a number of polygons and all attributes being text. I'm trying to import the polygons into numpy as an array where each polygon is represented as unique values. I ...
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196 views

Simple way to compare ranges and distributions of species, looking for correlation and differences between ranges

As a biology student just beginning with GIS, wondered if someone could give me an idea of what tools to go about using to compare the range of 3 species that have trophic effects on one another. I ...
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139 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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2answers
1k views

Can raster files from ArcGIS for Desktop be visualized in Google Maps?

I have raster files created using ArcGIS (Desktop application). On the other side I develop an application using google maps. Can I visualize those raster files somehow on google maps API?
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363 views

How do I use wildcards to work around the GDAL character limit?

I am attempting to use the 'Merge' & 'Create VRT' tools in QGIS 2.0 on a folder with 3000+ raster tiles in. However whenever I try to perform this operation the following error appears: 'The ...
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526 views

Using python to Raster clip the extent to be the same as the display?

I've been trying to figure this out for almost a week now. I am creating a tool which first needs the raster to be clipped out to the current display. I have tried all sorts of things. Below is the ...
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2k views

How can i convert a raster from continuous to discrete?

I have a tiff that is 'invalid' for a lot of tools and will not let me view the attribute table. I think this is because it is "continuous" rather than "discrete". Does anybody know how to convert it ...
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87 views

How to stop transfer of large raster into arcsde geodatabase

I have just realised that I will not have enough space on my harddrive to accomodate a raster which is being copied into an arcsde geodatadatabase. I am afraid, that if I stop the process in ...
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430 views

What are common mistakes when creating mosaic datasets?

I have a set of images taken from a unmanned air vehicle, they have lat/lngs when properties are clicked in windows, but when they are imported into ArcGIS they have no spatial reference or coordinate ...
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2answers
93 views

How can i combine the colours of one raster with values from another

I have two Tiffs with data from the same area. One is in colour and when I use the identify shows a 'color index' number (eg. 141), then Color(a,r,g,b)(eg. 255,90,255,0). The other tiff contains a ...
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540 views

Converting files for use in fragstats

To use my data in fragstats i need to convert it into a signed integer grid. I have the data in a raster format and have tried 'right click>data>export data> and setting the format to 'Grid' and it ...
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How to determine if point is surrounded using raster processing?

I am attempting to improve a currently extremely cumbersome vector/python process for a natural hazard model. At the moment we have a lengthy script which generates distance/bearing lines from a given ...
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1answer
407 views

White lines in merged GeoTIFF files after ImageMosaicing on GeoServer

I have merged 21 GeoTIFF images using GDAL utilities. Each image is the result of merging 500 smaller tiles. I am using ImageMosaic in Geoserver but I am getting a mosaic that contains white lines and ...
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1answer
327 views

Raster topo map “collars” overlap

I am using QGIS 2.0. I have downloaded USGS 1:100,000 topographic maps which show adjacent areas. The topographic maps were digitized with the borders (I've seen them called "collars", I think) as ...
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269 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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504 views

R, rasterVis and RGL: how to prevent reflective surfaces?

I have been experimenting with digital terrain model files in ESRI ASCII grid raster format. Despite zero experience with this type of data I found it very easy to load into R, as per code below. The ...
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141 views

Finding percentage of feature in a raster

I am attempting to find the percentage of polygon features at a 5 meter resolution that are located inside each 25km raster cell. I am looking to assign percentages to each cell based on the ...
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2answers
330 views

Copy rasters slow, increases file size

I have a folder with ~1200 aerial photos in both jp2 and tif format, of which I need about 380. I wrote a python script to get the names of the files I need, which works fine. But when the script ...
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1answer
607 views

Summarize values from a raster brick by latitude bands in R

I would like to sumarize (sum and/or mean) values from layers on a raster brick based on latitude bands (been using raster package). Been looking at the package documentation and didn't find a way to ...
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2answers
492 views

How to find the second highest value in a rasterStack in R

I have a rasterStack of rasters representing count data. I want to return a single raster whose values are the index of the raster with the second highest value for each cell. (I used which.max for ...
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311 views

How to cut multiple neighboring raster images

I'm looking for a way to cut a larger number of neighboring aerial raster images (each sized 1x1 km, resolution 10 cm per pxel) into four smaller raster images (size 500 x 500 m). I haven't done this ...
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113 views

Qgis raster interpolation shift

Using Qgis 2.0.1, I'm attempting to interpolate a large point dataset (n > 400K) to a raster surface. I'm using the IDW option in Raster>> Interpolation>> Interpolation, and the resulting ...
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2k views

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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638 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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178 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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757 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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1answer
511 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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268 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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48 views

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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427 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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451 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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226 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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2k views

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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564 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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123 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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70 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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2answers
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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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619 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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41 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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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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318 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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1answer
881 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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1k 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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687 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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1k 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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263 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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158 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): ...