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

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Merging Raster: ImportError: No module named _gdal_array

When I try to merge rasters I got following error message: _gdal_array = swig_import_helper() File "C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\osgeo\gdal_array.py", line 18, in ...
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53 views

Floating point calculations in QGIS

How do I manage floating point calculations in QGIS? I have carried out 3 consecutive calculations on landsat bands. I end up with 32 bit floating point rasters on which I can't carry out a 4th ...
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29 views

How do I select specific colors within a raster to create polygons with in QGIS or ArcMap?

We have a few georeferenced zoning map rasters and would like to convert specific zones (colors) to polygons, sometimes multiple zones as different polygons. Our workflow has been in the past to ...
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3answers
77 views

How to reclassify only a part of a raster but keep the rest unchanged (ArcGIS or R)

I'm trying to reclassify only a certain part of a raster...not the entire raster. Here's the problem. I have a LULC raster of the entire US. There are some issues with the raster that I want to ...
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55 views

What format to store/use four band Raster data

I have four band aerial photography - RGBI. I need to share it with my users, a mixture of MapInfo, QGIS, and ArcGIS. What format should I store/serve the data in? GeoTIFF isn't well suited to four ...
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93 views

Why am I getting 'Error 000732 Raster does not exist'?

I am trying to apply symbology to a raster layer via kernel density analysis. When I run the Python script below in ArcMap, I am get the error message below. I have searched and tried the common ...
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61 views

Create Tiles for a raster(georeferenced) to use in leaflet

I have raster, with each pixel containing some data. What i want is to split a large image with each pixel's color is determined by its value, to show on leaflet layer.How to go about this ? raster ...
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102 views

How do I open images georeferenced in ArcMap in QGIS? (.aux.xml)

We have several ArcMap georeferenced images (raster datasets) that we are attempting to open in QGIS without any luck. These are not inside of a geodatabase and are not Arcinfo Binary Grid format or ...
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29 views

Why does heatmap size vary with number of points

I am making three heatmaps based on points over the same area and don’t understand why the number of rows and columns would vary depending on the number of features. The first feature set has 398 ...
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35 views

Extra row and column in a raster after GDAL grid import

I'm exporting an ESRI grid to TIFF format and after that I'm reading this exported raster file into SAGA GIS. However when Saga reads this file in there appears to be an additional row and column in ...
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104 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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54 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 ...
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56 views

ArcScene TIN smooth

I created a TIN with ArcScene out of laserscan point data. I want to smooth the spikes (image below), to get a nice crossover on the elevations of the surface. Do you have any advice how to do that? ...
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35 views

Export raster file geodatabase to jp2 or jpeg?

Can I export or copy a raster from a file Geodatabase and create a output to jpeg or jp2000 formate? I was reading two different helpline on ArcGIS 10.1 and wasn't sure if I was supposed to export ...
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11 views

Raster images at edge of data frame not displaying. How can I prevent then from disapearing?

I have a series of satellite images and as I pan or zoom, the images near the edges of the data frame the stop being displayed leaving small areas with no imagery. It is seems to occur when only ...
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41 views

How do you stop ArcGIS setting Gamma on raster load

I often import raster files using GDAL utilities. When those rasters are added to ArcGIS they seem to have a Gamma Stretch applied and a percent Clip stretch for RGB files. Contrast ids also set to ...
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27 views

Zonal statistics won't work after re-projecting vector layer

I have qgis 2.0. I want to analyze raster information within a buffer of 30 miles around a vector layer of cities across the world. However, both the raster and the vector are in WGS84. I have no ...
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how to digitize areas of a raster and snap to the raster cells?

I need to digitize the extent of an ecw raster image where the RGB value is not black.(see attatchment)ie. not the envelope, just the area where the image is shown without the border areas. The black ...
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56 views

Why am I losing part of my raster when I reproject?

QGIS 2.0 Working with tiff raster file. Reprojections are in WGS84 Mercator. Here is my problem: I am trying to use buffers or urban areas to analyze light intensity on a raster layer. I want 30 ...
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61 views

How to best remove rgb values outside of aerial image?

I have just converted RGB-TIF images to RGB-ECW for reasons of space and performance in ArcGIS. However, after the conversion, there are relics outside of the images which are not nodata values but ...
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89 views

How to iterate GRASS region definition?

I am using GRASS r.skyview command (v.7, Windows) to determine "urban canyon effect" on pollution due to the presence of buildings. The command nicely works, unfortunately I need to process a very ...
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76 views

Multiply a raster list with a field value list in a FOR loop in ArcPy

I'm trying to create a simple map algebra calculation not managed by ModelBuilder, but writing it in Python is trickier than I thought. I have a list of raster in a GDB and I must multiply them by ...
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50 views

How to import R-generated .gri/.grd raster files in grass?

I received data in .grd + .gri format, where the first one is a small text file and the second one (having the same name) is a binary file. I am unable to open them in grass/qgis. Any hint ? Missing ...
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99 views

Clip raster layer with *raster* mask layer in QGIS

Given two input layers 1. The clip layer - an arbitrary layer (though in my case it's a float 1 band geotiff) 2. The mask layer - a paletted raster in which every pixel is either NO DATA or a single ...
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84 views

How to summarize Excel data within the zones of another dataset by using ArcGIS 10.2

I have the following Excel data, I want to summarize the P-value within the zones of map dataset. I have sereached a lot and learned I might need to convert Excel data into XY table, and then into a ...
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69 views

How can I rasterize individual features in a shapefile?

I have a large number of polygons that are overlapping. I'd like to create a heat map and plan on using raster calculation to do this. My plan: to give each polygon a raster value of 1, and adding ...
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128 views

Calculate the values of range, sill, nugget in ordinary kriging? [closed]

I am working on temperature data, and I want to interpolate the data to any location that I specify. My programming language is asp.net4 C#. I don't know how can I determine the sill, range, nugget ...
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28 views

Specify single cell value of raster

I'm looking to automate a procedure that will change a single cell value in a raster. I have a known x, y and z, and a raster. I need to change the cell value (closest to my x and y value) to the ...
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25 views

display 3D raster/vector in GRASS 7.0 from command line

I am using GRASS 7.0 on ubuntu linux 12.04 x64. I am working through some GRASS tutorials and am able to get a 3d raster to show up when I use the GUI. However, I cannot get the command line interface ...
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70 views

Polygonize(raster to vector) [closed]

I have been install QGIS 2.0.1.when I use Polygonize (Raster to vector)for convert jpg to shp I get error message such as: C:\windows\123.exe is not recognized as an internal or external ...
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33 views

Building attribute table from raster in ArcMap 10.1

I have a NetCDF file containing the latitude, longitude and porosity for the entire US. I am trying to add another value (wilting point) which depends on the porosity. I wanted to extract the netcdf ...
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Dates are off when opening netcdf file in R

I have a netcdf file with the time dimension that goes from 12/2007 until 12/2010 with monthly time steps. I can see the correct dates in both arcgis and panoply. Panoply tells me this file is a ...
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86 views

Cannot read postgis RASTER into ArcGIS using the interoperability extension, either directly by Query Layer

This post accessing postgis raster data using Query layer in ArcGIS was created in Jul-12. Since then, I have not found any other related-post published. Using QGIS with DBManager ON, my postGIS ...
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61 views

How to load Georeferenced Scanned Maps in R

I have a geo-referenced scanned Map in GeoTiff format, which I would like to load into R. My intention is to plot some vector data (points and polygons) over this map using maptools package. Is ...
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63 views

Cannot upload an IMG file into PostGIS using raster2pgsql

I cannot upload into PostGIS a raster with the following code: raster2pgsql -s 4326 -I -C -M "C:\lyr\gebco.img" -F public.gebco ¦ psql -d test -U postgres -W It says ERROR: Unable to read raster ...
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How to display images as cross sections in 3d

I want to display a base map and several vertical cross sections in 3D. The base map image is easy to rectify as a geotiff. How can I also display the cross sections? The cross sections are at ...
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14 views

How do you distribute values evenly within zones when converting polygon to raster?

I'm trying to convert a (traffic analysis zone) TAZ polygon to raster so that the population values are evenly distributed within each zone. So far, when converting the TAZ polygon, the same ...
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how to specify -t critical dowloading raster with raster2pgsql

I'm trying to download a raster into postgres/postgis. So far I wrote: raster2pgsql -s 3006 -I -C -M -R filename.tif -F -t 463.313x463.313 schema.rastername | psql -h localhost -U postgres -d db ...
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How to obtain stream segments from complemented image(raster data)?

I have raster data in tiff format, i want to extract stream segments from the complement of original raster data. I am able to extract stream segments from original raster data, but not able to ...
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39 views

does Pseudo Mercator Projection causes problem while clipping rasters

I tryed to clip a Raster file using an ESRI shapefile using gdalwarp command, but i always get an empty output file or a wrong clip with wrong location. this the command bellow: gdalwarp -dstnodata ...
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How to buffer raster pixels by their values?

The pixels to the left represent tree locations and their associated crown radii (i.e. pixel values ranging from 2 - 5). I would like to buffer these raster pixels by their crown radius value. The ...
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48 views

Publish rasters stored in PostGreSQL with GeoServer [duplicate]

we are trying to publish some raster images stored in our Postgres database. First, they were generated from satellite images (spectral indexes). Then we uploaded them with raster2psql as tables. So ...
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78 views

QGIS - How can I convert a raster file to a vector file without making same value cells into one polygon?

How can I convert a raster file to a vector file without making same value cells into one polygon? In the attached image, the values "2124", "2269", "2321", "2634", and "2920" are the polygons ...
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how to extract a variable at specific time and depth from netcdf in r

I have the following netcdf file containing 7 variables and 4 dimensions. [1] "file data.nc has 4 dimensions:" [1] "depth Size: 12" [1] "time Size: 37" [1] "x Size: 305" [1] "y Size: 432" ...
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QGIS problems getting layers to line up correctly.

I am trying to add a raster layer and a vector layer to qgis. I have set both of their CSR to NAD83 Oklahoma North State Plane. It doesn't seem to work even with all the files set to those CSR. ...
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66 views

How to extract one band from a three band raster in ArcMap?

I'm fairly new to ArcGIS and I get into trouble extracting a single band layer from a raster image .img in ArcMap that I want to use after in zonal statistics. So far, all help I found is to do the ...
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80 views

Can you change the processing extent in environment settings using python to a shapefile?

I have managed to do this manually at Geoprocessing>Environments>Processing Extent and setting the shapefile in the drop down bar. I was wonder if this could be automated with a python script? My ...
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34 views

TileMill raster-colorizer

I am trying to use the raster-colorizer in Tilemill (v0.10.1) but it is giving me an error. I did set in the advanced section the band to band="1". What else do I have to do in order to use ...
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142 views

How do I get the value of the pixel under the cursor?

Is there a tool or something that will give me the value of the pixel under the cursor? What I've got in mind in something like the eyedropper tool in graphics programs that allows you to ...
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Create line between polygon and nearest raster cell

I need to create a line between polygons (centroid) and the nearest cell of a raster dataset. The polygon and raster do not intersect. Each polygon has a UID. One cell can be linked to many polygons, ...