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

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Adding PostGIS raster to QGIS via database manager

When I attempt to add a PostGIS raster to QGIS I get a GDAL error saying I need to set PGHOST. I have set PGHOST with export PGHOST=localhost but still get the error. How can I resolve this ...
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43 views

How to get values to create world file format?

i have researched regarding making world file format and tried to create one using c++ in windows, can somebody confirm if where i am getting the values from are correct? the literature regarding ...
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OSGEO/GDAL and Rotated Pole Grids

I have a netCDF containing a raster in a rotated pole grid. I have a script for converting the desired information to GeoTiff, however it requires projection information in the form of WKT string. ...
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16 views

Geospatially match cells of different rasters - possible?

I have 2 rasters that were originally vector polygons. Raster2 was created from a selection of raster1. After converting both to raster, their cells don't match up (i.e. attribute info for each cell ...
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17 views

Edit an old georeference raster projection in QGIS

I have created a map from a picture. And now I have some more detailed pictures and georeferenced them. Is there any way to quickly access them later on. I mean everything is fine with ...
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16 views

QGIS multiply(add) two raster but divide(deduct) another raster

I am making a parking analysis in one town. I need to obatin the zones where the parking of car is harder because there is less places to park and higher demand of cars.I have three rasters. First ...
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25 views

Load Oracle Spatial Raster using PyQGIS

Able to connect to Oracle Spatial 11g and print tables with SDO_GEORASTER attribute both in QGIS python console and standalone application.I get below error when loading rasters from oracle Table. ...
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31 views

Reading Raster Data with ArcGIS tools in C#

I have a raster data layer as IRasterLayer and I am using C# SDK of ArcGIS. Here is the IRasterLayer. I want to access all the cells I want to edit cell values. After all i need how can i read the ...
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23 views

Saving fields after a raster join with python arcgis

I am working on a raster processing script in which i join a categorical raster with a table that includes some extra data on each category. After much hassle, I have the join working, but I can't ...
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51 views

Calculation of focal statistics at the edges of the region

When I use focal statistics setting the neighborhood of each processing cell to be a circle with 800m radius (map units, not number of cells), how are the statistics calculated in the edges of my ...
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44 views

Load PostGIS or Oracle Spatial Raster Layer using PyQGIS

How do we load Rasters stored in PostgreSQL-PostGIS or Oracle Spatial 11g into QGIS using PyQGIS? I am able to load vector layers from Oracle 11g with below code. What changes are necessary to add ...
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15 views

Specify the NoData pixel from 255 to a lower value pixel value

I have a series of raster files (tif) that extracted using a particular shapefile. However, the output files became much larger (from 2 MB to 200MB). The NoData is now equivalent to pixel value of 255 ...
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23 views

gdal_grid - fails to find layer and field

I'm using gdal_grid for the first time and get this issue: gdal_grid -zfield field_3 -l layer0 OLEX-LAT-190952014.vrt OLEX-LAT-190952014.tiff ERROR 1: Failed to find layer 'layer0' on datasource ...
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28 views

Problem loading tif into raster dataset in ArcSDE 10.2

I have over 1000 raster datasets I need to mosaic into ArcSDE 10.2. I can't use a mosaic dataset because the county I am working for wants to keep the files on an external HD, so the pointers won't ...
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61 views

How to read *.adf files into R?

I want to load .adf files into R. The data is from this page: http://www.fao.org/geonetwork/srv/en/metadata.show?id=14057 I tried the following code that I found after some research in the internet. ...
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43 views

QGIS print composer export excludes one layer

I am trying to export a map from QGIS print composer but the resulting files (I've tried all image, .svg, and .pdf formats) do not appear as the map did in the composer. It is as if one of the raster ...
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15 views

View Oracle GeoRaster in ArcMap

I have imported SRTM DEM into Oracle 11g using FME.The block size is set to 128X128.I am able to view the data in QGIS,Tatuk and play with it using GDAl command line.Unable to view the same in ArcMap. ...
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36 views

Is every cell in flowdirection draining towards an outlet

I have created a Flowdirection map in a defined catchment. I want to find out if every cell in my map is flowing towards the creek/outlet. Is there an easy way to do this? I have created the ...
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33 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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54 views

How to resample a 30m DEM to a 100m slope raster properly?

I need to resample a 30m DEM to a 100m slope raster. Do I just resample the 30m DEM directly to the 100m slope raster? or, do I convert the 30m DEM to a 100m DEM and then create a 100m slope raster ...
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35 views

Assigning score to raster based on cell overlap with other raster and field value

I have a set of rasters that I've assigned scores to individually (scored based predominantly on values of other fields). The scoring scale is the same for all rasters, but the factors that determine ...
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43 views

Where to download rasters for QGIS 2.6

Where can I download sat imagery. I've read that openlayer provide such things but it requires an internet connexion, and I mostly use Qgis with an offline computer. So do you know a way/provider (for ...
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53 views

Visualising a raster PostgreSQL table in QGIS

I have imported a raster tif image into PostgreSQL with this command: raster2pgsql -s 32643 -I -M filepath.tif -F -t 100x100 public.databassename > filepath.sql And imported the output SQL file ...
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How to calculate RMSE, skewness, and kurtosis of raster image?

I'm doing a project to analyze the impact different interpolation techniques plays on DEM accuracy. In order to do so, I need to calculate the RMSE, skewness, and kurtosis. I have: an original ...
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81 views

Difference between raster subsets as defined by another raster

I wish to determine whether there is a relationship between slope and the Corine land cover class pastures. i.e. whether areas defined as pasture have a different slope to non-pasture areas. I've ...
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Unable to execute the algorithm using SAGA LS factor

I tryed to calculate the LS Factor at SAGA, using a slope raster and the area raster, both at the same EPSG, and the error:Unable to execute the algorithm the error means something with the coordinate ...
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27 views

How to shift a raster in QGIS?

I'm looking for a tool or a plug-in for QGIS that would allow me to shift rasters to new coordinates. An equivalent of ArcGIS' Shift tool would be the best option. I know I can edit the world file ...
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27 views

Rasters change pixel size and range of values when imported into QGIS

I have observed that when I import rasters into QGIS their pixel size changes and also, the full range of the raster's value does not appear. For instance, I may have a raster with values ranging from ...
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28 views

Error converting a raster to polygons

When I am converting a raster using the polygonize tool, I get this error: ERROR 4: 'C:/Users/Vitor/Desktop/Cartografia EE_Portimo/COS RASTER/cos_raster_reeditada.tif' does not exist in the file ...
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22 views

How can i perform area calculations in a raster file?

I would like to know if is possible and how can i calculate all areas or parts of it in one raster? Can i do it using the raster calculator? All help is appreciated, Best regards
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54 views

Python Script tools for ArcGIS 10.2 is very slow (get raster properties)

I am using python script tools for ArcGIS 10.2, under Windows 8.1 64bit. When I am using the arcpy.GetRasterProperties_management() command, it's very slow to process the data. For example. I tried ...
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14 views

Raster2pgsql overview method

What is the method used by Raster2pgsql to create overview? I couldn't find details in the docs. Nearest neighbor isn't a very good choice for the dataset I'm working on, but that seem to be the one ...
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53 views

Arc - how do I find the coordinates of the centroid of a raster?

How do I find the coordinates of the centre / centroid of a raster? I have tried Zonal Geometry but this does not give me the coordinates. I need to find the centroids of two rasters and create ...
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32 views

Got different cell sizes from a rasterised data

I'm trying to rasterize the Land cover data of Nigeria which was obtained from FAO database. During the process of rasterizing the land cover data, I used the following information which gave ...
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44 views

Overlaying two raster images with no spatial reference

I have two images (X-Ray and Neutron Tomography Scan) of a human bone fragment. I want to use ArcGIS 10.2 to accurately overlay (geo-reference) these two images which have no spatial coordinates. any ...
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17 views

Open and split a 4 channel RGB picture

How can I split an 4 channel rgb pic in qgis? With the value tool I can see 4 channel. I tried to use the RGB to PCT tool but I always get an error (File "C:\PROGRA~1\QGISBR~1\bin\pct2rgb.py", line ...
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71 views

Mapinfo : How to cut a raster with a vector layer?

With mapinfo 12, i would like cut my raster layer .tab with one of my vector layer. How to do this basic task with mapinfo? Is it possible with mapinfo to convert .tab raster table toward any ...
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Transparency on black/white raster after clipping in QGIS?

I'm new to this forum and QGIS. I'ld really appreciate it if you could help me with my problem, since I couldn't find any solution online but people experiencing the same issue. It seems as if this ...
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28 views

Mosaic to New Raster not allowing correct overlap

I am not sure what exactly is causing hiccups for me - how I processed the data (removing the white edges in 3rd party software), the bit depth (8bit), the file format (png to support transparency), ...
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21 views

Slope tool output has artifacts

So I've tried using the slope tool for a DEM using an appropriate Z-factor and the output is smooth, but it seems to be over-estimating slope angle. I would prefer to reproject the DEM (to NAD 83 UTM ...
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3answers
29 views

Raster algebra to tiled maps on a sever with open source solutions

Let's say I have a collection of data in raster format. It changes daily. Once each day I would like to do some fairly complex raster algebra on these datasets. I would like to be able to do the ...
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64 views

Reprojecting a population raster from LAEA to lonlat

I have a population density raster from the EEA which is based on the CORINE land cover 2000 data. ...
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58 views

Raster calculator to create single raster with 4 values from two binary rasters

I have two binary rasters showing habitat suitability (0 = unsuitable, 1 = suitable) under current and future climate scenarios. I am trying to create a raster showing: 0 = cells that are not ...
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73 views

Load the raster image which is in TIF format using QGIS API

I am quite new inthe field of GIS. I am interested in is to load the raster image which is in TIF format using QGIS API I have followed the steps given the in the follwing link to load shape file ...
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73 views

Save rasters created by loop operation to different directory?

I have a set of rasters. I crop them all using FOR loop. Then, I want to save new-created rasters in new directory, not in my actual directory. For one raster it is easy: writeRaster(raster1, ...
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How to get background maps to show in QGIS Cloud mobile version?

we're a group in Denmark, trying to publish some maps for use on a mobile device, but although our background maps show up in the desktop version, we can't get the mobile version to show them - What ...
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64 views

Remove clumps of pixels in R

I would like to remove isolated pixels (or clumps of pixels <9) from my raster image. library(raster) # create some raster data r <- raster(ncols=12, nrows=12) set.seed(0) r[] <- ...
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Isolation and interpretation of vineyard multispectral data

I have 3 band multispectral raster imagery over a vineyard from which i have created a number of indices e.g. NDVI. The data is fairly high resolution (5cm/pixel) so shows a lot of along vine and ...
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40 views

How do you calculate a new field for a raster table based on value from a joined table?

I need to know whether it is possible to calculate a new field for a raster table based on a value from a joined table. Ideally I'd like to be able to accomplish this task without having to add table ...
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39 views

QGIS virtual raster - insufficient permissions

I'm trying to create a virtual raster in QGIS 2.6.1 64b on Windows, but I get the message: "The process failed to start. Either the invoked program is missing, or you may have insufficient ...