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

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Exporting a raster with renderer enabled to file

I have a problem when trying to export a layer with renderer to a file. Basically, what I have at start is a correct IRasterDataset. Then I define a stretch renderer in form of IMultiPortColorRamp and ...
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31 views

How to calculate average value of a raster, that is clipped by multiple polygons?

I am using QGIS 2.12.0. I have a raster of coherence value (SAR interferometry) and a land use shape. I wish to calculate mean coherence value for those areas with a specific land use. I split land ...
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10k views

How to calculate raster statistics for polygons?

how can I calculate sums, averages etc of raster-points (multi-band) per polygon of a vector-layer. I was told that this is called "zonal statistics". I tried that with QGIS first. There is a way to ...
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19 views

Grid buffer in QGIS

I do have a raster file (grid) which I have processed before with the SAGA kriging tool. Is it possible to buffer this raster file a little bit (expanding the interpolated result) of 1 or 2 grids? I ...
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125 views

Free open satellite or other remote sensing data for night time?

I usually work with daytime satellite images to do some image classification (mostly Landsat data from the USGS EarthExplorer). Right now I'd like to check at some night time images to work on city ...
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30 views

problem when doing algebra with raster layers in R

I'm trying to combine bioclim raster layers to create the following layer. (Q) = AnnPrec/[(Tmax+Tmin)*(Tmax-Tmin)]*1000 For that, I import a bioclim stack: envirc = ...
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17 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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40 views

Spplot SpatialPolygonDataFrame and SpatialGridDataFrame

I have to plot in the same graph something like this: Then, I have elements from SpatialPolygonDataFrame class and others elements from SpatialGridDataFrame class. When I try to plot them in the ...
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21 views

Error 010422 when combining rasters

I have 17 rasters, some of which overlap one another. I wish to combine them such that where the rasters overlap the sum of their values is taken. I have tried combining them using raster calculator, ...
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35 views

How do I change my “no data” values to get “true” values in raster calculator in Qgis

I have two rasters and I want to subtract the values from one of the layers. The first raster is a altitude raster and the second raster is depth values for a lake. I would like to subtract the depth ...
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2answers
436 views

problem to open a netCDF and create a raster file

I want to open a netCDF file and create a raster with ArcMap 10.2. The file contains the mean monthly temperature for Switzerland. I found it in meteoswiss web site. I tried to open it with the ...
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28 views

QGIS Raster Calculator syntax

I have tried this several different ways and get lots of NaN. I need to specify that in my raster 'test1', I want a certain set of values to equal 1 and the rest to equal zero. For instance, I want ...
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68 views

Raster statistics for polygon areas PostGIS

I'm trying to get zonal raster statistics for each polygon area. I have used the following method from this site: SELECT bufid, (ST_SummaryStatsAgg(ST_Clip(rast, geom, true))).* FROM rasttable, ...
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1answer
223 views

Calculate tree cover over certain area from raster data

Last year Hansen et al. published Global Forest Change map as set of raster data available in TIFF format. Basically those are 30-meters resolution satellite images with pixel values ranging from 0 ...
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2answers
1k views

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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1answer
31 views

How to extract all pixel values in a raster file

I have a image difference from ArcGIS, which i have performed a remap function on. The layer is a temporary layer and does not have an attribute table, i need all the pixel values to do a frequency ...
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2answers
872 views

Scriptable alternative to ArcScan (particularly vectorising lines within tolerances)?

Sadly the answer to Can you access ArcScan from a python script? suggests that it is not possible to script ArcScan from within a python script. Therefore, does anyone know of any alternatives to ...
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530 views

Digitizing raster in ArcGIS Desktop?

I have the raster below which I want to convert to a set of vector lines: As you can see, there are small breaks in the lines and some bits are double-width. I want to be able to reliably import ...
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390 views

How to fix “Raster layer: Provider is not valid” error when loading PostGIS rasters?

I compiled and installed the current QGIS master as usual and I imported some raster data into my postgres 9.3 database with postgis 2.0.2 extension. Whenever I try to import the raster data into qgis ...
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23 views

gdalwarp error cropping raster

I'm getting an error from gdalwarp using the following code: gdalwarp -cutline input.shp -crop_to_cutline -dstalpha input.tif out.tif Error: *** Error in 'gdalwarp': free(): invalid pointer: ...
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3answers
58 views

Merging georeferenced images that have overlapping information?

Having trouble to mosaic two overlapping .tif files. I need to merge these two images together into one resampled raster image. Unfortunately I cannot do this with my ability and resource available to ...
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98 views

Huge file size after averaging two rasters

After I average two raster files (singleband gray, initial size ~700MB each) through QgsRasterCalculator() with formula "Raster1@1/2 + Raster2@1/2" the size of the resulting file is 2.9GB. Is there ...
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78 views

Error while comparing two raster layer in R

I have got a geographic point distribution with N prehistoric settlements with a size of x and want to compare the distribution with an economic simulation, which produces M settlements (Usally N > ...
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1answer
178 views

What exact format do I need to have for the inputs to make Path Distance work?

I am trying to run the Path Distance tool in ArcGis 10.1. Ideally I would like to utilize Tobler's hiking formula anisotropic approach to slope and a land cover cost surface to calculate the least ...
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1answer
389 views

About FAPAR calculation?

I want to calculate FAPAR in different land cover types using max and min value of NDVI. I have a raster image with 9 Land cover types and max, min value of NDVI in each land cover type but I don't ...
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338 views

MapServer map file shows Raster image as white

I'm using PAN image for raster publishing but the output in browser shows a full white image? Please give me the solution? My map file is ass follows: MAP NAME "terra" # Map image size SIZE 600 600 ...
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1answer
60 views

GRASS GIS temporal raster individual layer statistical summary

I have created a temporal raster in GRASS GIS which has 90 layers. I would like to extract the mean of each raster layer and export it as text file. Right now I have to export the rasters as GeoTiffs ...
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1answer
48 views

How to create azimuth raster layer by pyqgis?

I want to create an azimuth raster layer base of single point shapefile, for this I write below code that create a memory point layer that each point in memory layer is center of each pixel and have a ...
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2answers
41 views

How to bulk upload raster datasets to ArcGIS Online as separate discrete layers?

I have 18 raster datasets which I need to publish through ArcGIS online to allow users to turn on/off each layer and toggle transparency. I have the data stored in a file gdb as below: I am looking ...
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2answers
157 views

How to speed up this script in QGIS?

I am a new in PyQGIS, I want to create a Point layer from a raster layer. In table of point layer created, there is 3 fields by name of "X_coord", "Y_coord" and "Azimuth", each point in Point layer ...
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164 views

How to calculate raster statistics for each band in qgis

i need to calculate raster statistics for RGBN (4 channels, multiband image) rasters in QGIS. In Arcgis if you use "calculate statistics" in Arcatalog, statistics are calculated for every image band. ...
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27 views

Why do collinear ground control points create larger residuals?

When georeferencing a raster image of a long corridor, why do collinear ground control points cause larger residuals? Say I am using the georeference function in ArcMap, and I have 6 ground control ...
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42 views

Use function spplot

Does anybody know how to plot with "spplot" fuction two elements of diferents classes?. One element from "SpatialPolygonDataFrame" class and other from "raster" class.
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208 views

Make several rasters more uniform

I have imported some rasters that is supposed to be continuously connected but instead they create some sort of bordered grid between them. I may assume that this is a matter of calibration between ...
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291 views

Is there an efficient way of sending a large raster image?

Rather simple question: I have two large raster images that are stored in ArcSDE. I need to send these images to someone else, and post it on their ftp site. What is the most efficient way to send ...
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1answer
380 views

Can I update the service on ArcGis Server programmatically?

There is Windows Service. This service adds user raster data to the Raster Dataset in sde database. The Raster Dataset registred on the ArcGis Server. This Raster Dataset also was publishing on ...
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11 views

How to avoid the quilt effect when displaying imagery from multiple source

In the context of creating my own imagery viewer (for educational purpose), I would like to learn about the process used to create seamless transitions between satellite imagery tiles coming from ...
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33 views

how to extract line features from a raster

I have a raster of land cover types where roads are represented by pixels (1 pixel = 25m x 25m = 625 m²). Is there a way to extract line features (here roads) from a raster ? ## Create raster as an ...
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35 views

How to automate the QGIS Raster Interpolation Plugin using python console?

I have a rainfall data from 1961 to 2015 for each day of this years. I need to create a raster for each day with this configuration. Do you know how to automate this using this plugin and python?
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27 views

R: raster stack (time series) loop pixelwise and write layer number of value occurence into a single output layer

I have a raster stack of gridded RFE 2.0 rainfall data (time series of one year = 365 layers). Now I wanted to identifiy on which date during the year the first rainfall occurs for each Pixel. The ...
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40 views

High res monthly satellite maps including ice cover

I have some old month by month NASA satellite maps showing the world in 2004 at 5400x2700px. I've noticed NASA has newer cleaner versions of these maps at ...
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1answer
19 views

Calculate the frequency of classes of neighbouring raster cells

I'm struggling with a problem when working with a raster dataset of biotope types: For each cell I would like to find out the frequency of classes in the adjacent cells, e.g. from the 8 neighbouring ...
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1answer
55 views

Problem with importing GeoTif files in QGIS

I have installed the new version of QGIS (2.12) and the newest OSX version (El Capitan). When I tried to open GeoTif files with QGIS, it always crashed! Then I tried an older version of QGIS (2.8) and ...
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1answer
46 views

Storing and updating large amount of raster data

Large amount of data = ~10TB of rasters (multiple projections) with the possibility of this data growing. The basic architecture I'm planning at the moment is having 2 clusters of GeoServer--one ...
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1answer
193 views

ArcGIS, How do I get smoother contours?

I am trying to get nice smooth contours using ArcGIS. I have already smoothed out the DEM using focal statistics, simplified and smoothed the contours. The current result looks like this, which is way ...
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27 views

How do I create a raster file from a geopandas dataframe storing lats, longs, values, and geometries

From a text file with time, lat, long, and cf values, I create a pandas dataframe (cf_df). Then I use the lat, long values to create a geoseries and create a geopandas dataframe from the original ...
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66 views

ArcMap aerial raster image exposure is off

I have some aerial raster images and I want to create tiles for web. So I added images as layers in Arcmap and as the result some images were overexposed with different lightness. For comparing I ...
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16 views

Import raster using raster2pgsql with out-of-db option not working

I am using raster2pgsql to import DTED data into postgis database. I would like the data to be out-of-db, I am using the command as follows. raster2pgsql -R /home/gis/elevation/DTED/area.dt2 ...
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1answer
181 views

Receiving NULL values from Point Sampling Tool in QGIS

I am using QGIS 2.8.2. My project includes a raster layer of flow depth representing the output from a flood simulation (.DAT file). It also includes a vector layer of points representing the ...
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1answer
964 views

Problem in importing raster data from PostGIS to Geoserver

I am using Opengeo Suite 3.0.2, PostGIS 2.0.3 and PostgreSQl 9.2. I am trying to import raster data from PostGIS to Geoserver but facing an error. I follow this tutorial link to import the raster ...