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

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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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55 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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39 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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82 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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53 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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35 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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56 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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62 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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19 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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32 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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45 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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21 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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199 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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43 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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64 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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80 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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158 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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6 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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40 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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31 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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70 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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46 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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30 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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26 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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39 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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81 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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20 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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45 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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57 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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32 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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53 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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56 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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28 views

gdal_grid data from 2 different utm zone

I'm developing a component which grid data over Vietnam region using gdal_grid from gdal. Follow gdal example I've successfully griding data within 1 specific UTM zone. However, for data over the ...
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44 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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87 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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39 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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42 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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115 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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33 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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42 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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35 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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83 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 ...
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173 views

Unserialize socklist error when using rasterEngine in r

Basically, I am running the "rasterEngine" function in R. I want to use parallelization to change values in a raster image (I have around 400 images that I need to work on). However, the rasterEngine ...
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109 views

How to open a raw binary raster in QGIS or R

I have a raw binary raster without a file ending, and no header file. I would like to open this in either QGIS or R and then convert to geotiff, but opening it seems to be a challenge. Here is a ...
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77 views

Is it possible to apply affine transformation (translation) to raster image?

Is it possible to move/translate a raster image in QGIS 2.2 (without using georeferencer) just like it can be done with a shapefile ? If not, alternatively can this be done with ArcGis?
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129 views

Make a raster with pixel scale 100 by 100 meter with gdal_rasterize

I'm asking here, because, I've got great results last time. Here it is the next of my adventure with gdal_rasterize, I want to make a raster picture where each pixel correspond to a square of 100 by ...
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45 views

How to accurately join data based on 1x1 degree grid-cell points to a shapefile

In the data file each row represents a country and a grid-cell at 1x1 degree resolution, and the given coordinates, in longitude and latitude, label the south-west corner of the grid-cell. The ...
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68 views

How to set raster values to NULL?

how can I define values to null? I tried it with the processing reclassify tool but I always get an error log (cannot open the result shape...or something like that).
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38 views

How to raster vector- and shape-files correctly

does anybody know how to convert vector- and shape-files correctly? Doesn't work with tab Raster/convert/vector to shape files. The output always contains strange input-data (wrong and strange ...
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60 views

Error building pyramids/statistics on raster with arcpy

I am building a script to process rasters with the option of adding the extra step of building pyramids and statistics at the end. For some reason, it will not recognize inputs as legitimate raster ...