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

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25 views

Polygonize only pixel values of 1 from a raster

I have a raster mask that I have created in QGIS (2.2.0) that consist of 0, 1 and nodata values. I would like to end up with a polygon dataset that consist of only the value of one pixels from this ...
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51 views

NAs not allowed error message in attempt to plot raster object in R

I have imported a clipped raster (performed in ArcGIS 10.1) from the National Landcover Dataset into R, but when I try to plot I get the following error message. Error in .readCellsGDAL(x, ...
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23 views

How to reassign the values of a raster, based on the pixels of the raster beneath it?

In ArcMap 10.2.1, I have two rasters. Raster1 shows the extent of a habitat, and each pixel contains a categorical value for its land cover type (values 1-3). Raster1 has the smaller spatial extent of ...
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32 views

How to choose which band is used to calculate DN when converting a raster to vector?

I currently have a raster layer of flood water levels (elevation) which I need to convert to a shapefile for future use. My raster is 4 bands: RGB + one band with values from 0 to 10, representing 10 ...
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21 views

Cannot properly import MODIS MOD07_L2 .hdf files into R using rgdal

I've been trying to accurately import and process some .hdf files from the MODIS Atmospheric Profile product (MOD07_L2) in R for several days now. Still, there's something going wrong during data ...
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23 views

Euclidean Distance Function performed on unprojected data

I am looking to perform a simple multi-criteria analysis on a data set comprised of two criterion: occurence of wildfires and road accessibility. First, the project CRS was enabled with "on the fly" ...
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16 views

Combine overlapping rasters in gdal_calc.py, taking the maximum value from each pixel?

I want to combine 3 overlapping rasters to create 1 raster. Each have the same dimensions, resolution and CRS. I want to populate the new raster with the maximum value from each of the layers. ...
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19 views

Overlaying Line (Vector) Layer on Raster Zones?

I will make my best attempt to clearly explain my problem. I am using ArcGIS 10 I have a raster layer with 3 values that make up zones. For the purpose of this example, lets say these zones are ...
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10 views

How to mask an vector field layer in MapServer?

given this layer def: LAYER NAME "waveswell_sigheight_grid" TYPE POINT CONNECTIONTYPE uvraster STATUS OFF #MASK "water_outline" #I get a "no data received" error in my browser ...
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24 views

Convert colorized/styled vector (KML or qgis-project-origin) to raster and preserve the colorization

I can very rapidly create nice heatmaps (chloropleths actually) using qgis that I can then export as kml's that have the correct colorization when displayed on Google Earth, etc. I'm wanting to ...
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14 views

How to repeatedly mosaic raster in Erdas?

I have found script to mosaic raster in R. But the output raster size is almost 9 times bigger (92mb) than mosaic it in Erdas (12mb). So I prefer mosaic raster in Erdas. But it wastes so much time to ...
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37 views

Bi-Weekly NDVI data into monthly Datasets

I have NDVI data in both Ascii Grid format (0.250 degrees resolution) and raster format twice a month like: ndvi1981_07a ndvi1981_07b I would like to combine these bi-weekly values (average) into ...
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11 views

Oncoming intersection or intersection density

Through the use of Android and its on board GPS module, I am looking to calculate the density of intersections in a given area. Say 1 km x 1km. How would I go about accomplishing this? I am new to any ...
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21 views

How to view a raster in CartoDB?

What is the easiest way to view a raster in CartoDB? From the list of formats that you can upload into CartoDB, I noticed that .tif is available, so I've tried adding a GeoTIFF, but it says that ...
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36 views

How do I convert a .bil (and associated .clr, .blw, .hdr, and .stx) files into georeferenced rasters in R? OR to geotiffs using gdal_translate?

The title says it all. I've got a bunch of .bil files, which I can open in R using the raster command pointed to the path to the .bil file. But I don't know how to efficiently incorporate the ...
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17 views

How do you visualize change in rasters over time in CartoDB?

I have a series of satellite image rasters. I need to show the change over time of these rasters. Would the best way be to change the basemap with the click of a button for each? Has anyone got an ...
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23 views

Qgis Server, show Oracle Georaster dynamically

I have an Oracle Spatial database and I use rasters (SDO_GEORASTER). I can render some rasters on a web page with Qgis Server : when I render the maps on the webpage, it come from a qgis project ...
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15 views

gt:VectorToRaster in Openlayers

i would like to opa vector table using "gt:VectorToRaster" a WPS function in Openlayers. my vector table is stored in Postgis 2.1 and published in geoserver. i need the code to do this, can you help ...
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64 views

R plot raster with real colors

I'have a raster image from Scran25 IGN. In Qgis, it opens perfectly but in R (with rgdal or raster packages), I do not know how to keep the original colors like this exemple? I have tried ...
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37 views

rasterize table polygon postgis 2.1

I would like to rasterize a postgis 2.1 polygon table, but I don't undersand how to create the SQL function syntax for ST_AsRaster. My vector table has 3 fields: gid, recharge, and geom. The SQL ...
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24 views

GeoTIFF Mosaic/Crop/Translate: Easiest Method in QGIS?

I routinely have to mosaic multiple GeoTIFFs together, extract a rectangular area, and save that area as a JPG with a world file. Typically I've been using commercial software for that (Geographic ...
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24 views

QGIS-Merge or create virtual raster files without losing definition?

I am new to QGIS and relatively new to GIS (so please be aware I am not that familiar with a lot of technical terminology). I am trying to merge several tiff files as either a virtual raster or a ...
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47 views

How to calculate a population weighted centroid using a raster and shape file in QGIS?

I am very new to QGIS so please help me with a step by step answer. I have a raster file with population count and a shape file based on a large population and shape file. I have successfully created ...
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5 views

View information raster data in postgresql

I download and use raster2pgsql.exe import tiff image into postgresql. Can i use the query to retrieve the information of the image does not? Information such as: date of capture, capture time.
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27 views

The difference when querying raster and vector

Hi everyone I have two queries have the same meaning but different results. Why is there a difference?. Queries are true? query 1: query 2:
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25 views

Is there a Raster2pgsql GUI?

Has anyone ever attempted to create a raster2pgsql gui (like the shp2pgsql gui). As I am sometimes lazy to use command line, this could be a very nice to have.
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33 views

qgis's georeferencer renders my white map with a translucent blue tint, can I prevent this?

I'm running QGIS 2.0.1-Dufour on MacOSX and when loading a PNG or TIFF into qgis as a raster its always getting rendered with a blue tint. Here's what it looks like before being loaded into QGis's ...
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25 views

Rasterizing vector contour data: Python error message

would anyone know why qgis kicks up this error message (image attached) when using v.to.rast.attribute? the rasterise related to a contour set. i duplicated it twice to create 3 copies. the first ...
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40 views

Arcpy raster calculation producing random no data cell in output

I've been trying to get the raster calculation below to work using python: import arcpy from arcpy import env import os from arcpy.sa import * arcpy.CheckOutExtension("spatial") KSat_mm = ...
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39 views

time processing

I am computing NDVI for Landsat TM in grass 6.4.3 in raster map calculator, and time processing is many hours and finally tke message is "failed". trying to find a solution I discovered that it ...
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26 views

Disable option in QGIS which picks 4th band as alpha band

Is there a way to disable that function? As somebody who works with 4 band orthoimagery on a daily basis, it is annoying to go to the transparency options every time I load an image to disable the ...
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21 views

Slope regions from elevation points using QGIS 2.0

I am using QGIS to create a layer of slope region polygons (e.g. less than 30% slope, 30-50%, more than 50% categories). My data comes from point elevations and I interpolated using SAGA b-spline ...
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24 views

rasterize a geography polygon using postgis 2.1

I am still bit new to Postgis 2.1. I am trying to rasterize a polygon, meaning that I have a polygon of Syria and I want to create an empty raster that contains the shape and geography reference of ...
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65 views

Issues creating slope raster layer from a point layer

I'm trying to create a slope raster layer using QGIS 2.0 on Windows XP. I started with a points layer with the Z elevation attribute. I then used the interpolation plugin to create a DEM. But, ...
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15 views

extracting values from maps and inserting into a summary table

I have several maps that I am working with. I want to extract the values (1, 0 and NA) from the maps and place them all into a summary matrix. Since I have so many maps, I think its best to do this as ...
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31 views

How to draw rotated symbol RASTER type layer in Mapserver?

[PARTIALLY SOLVED]: I was on the wrong track I need to use a UVRASTER, see this part of the docs But doing leaves with with another question about how to get the angle correctly, please see this ...
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47 views

How to get RasterToPolygon working

We have a process that is almost working except for this one call ... This is the one tool function that is requiring a FeatureClass and I found code that I thought would work. Unfortunately all I ...
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27 views

R equivalent of GRASS r.grow?

What is a good R equivalent of the GRASS function r.grow? The closest I've been able to find is the script suggested by whuber in response to Creating randomly shaped clumps of cells in a raster from ...
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33 views

Assign a particular projection for un-projected raster/vector files in a folder/sub-folders

We are having 1000's of raster images/vector (shp,tab,dxf) files in a folder/sub folders. Is it possible to check the projection of those and if it is an un-projected one? WGS 1984 has to be ...
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38 views

QGIS 2.2. raster color ramp

I have just upgraded from QGIS 1.8 to QGIS 2.2 and I am missing very much 1-band raster color ramp plugin that I had easily colorized my DEMs by using pre made color brewer such as DEM screen or DEM ...
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23 views

glm with raster data: species decline~ ndvitrend

I have species decline data (number of population per year, over a period of 23 years) out of ndvi data for these 23 years I calculated the trend, and mapped it. now i'd like to relate the negative ...
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44 views

Why does merge/mosaic four DEMs into one give ERROR 01042?

I'm unable to merge 4 dems into one using ArcGIS Home 10.2. Raster Calculator, adding them, gives me the error: RuntimeError: ERROR 010422: Error in processing the environment mask. I created a ...
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22 views

Is the “1-band raster colour table” plugin available in QGis 2.0?

I used to use the "1-band raster colour table". Is it still available in QGIS 2.2.0? It seems like I can't install it (I don't find it in the list of plugins available, even after installing the BC ...
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33 views

How to crop an image into more than 80 small sections automatically in R

I'd like to crop an image into 15 sections in R. The image projection is Geog lat/long, extending 87 to 120 degree in East and 45 to 55 degree in North. I want to separate it by every 2 degree. So I ...
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63 views

Opening netcdf in arcmap as a raster with uneven coordinate spacing?

I have SMOS CATDS 2010-2013 daily data that is in EASE-grid netcdf format. I have 100 sites that I need specific daily soil moisture values for from this dataset. I have daily AAFC CATDS soil ...
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24 views

Display one of many rasters in Web Map

I would like to interactively add a georeferenced tif to my webmap. Use case is: I have a raster catalog of georeferenced tax maps. I would like to be able to select those tax maps (there are ...
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27 views

Regression analysis - creating dataset

I have a vector-based dataset of soils/parent material. The statistics have already been done, with coefficients for each category of parent material. I am not sure how to use this information to ...
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33 views

Raster projection problems

How would I go about specifying the following projection in Arc and QGIS? After defining this, how would I then go about changing the spatial reference to ESPG 27700? The following are the details of ...
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28 views

Calculating raster values from center to edges to represent normal distribution

Edit for simplification/clarification: What I want to do is take a raster and calculate cell values from center to edges such that the center has an arbitrarily determined high value which decreases ...
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42 views

Error: .asc is not a supported raster data source

I am new using QGIS and struggling with this error "...... .asc is not a supported raster data source" when trying to add a ."asc" file as a raster. I downloaded the files from ...