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

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35 views

R Efficient Way to Resample, Crop, and Mask a Raster Image

Does anyone know an efficient way to resample an image? I am currently trying to crop a large image and clip 2 regions from a shape file. From this clipped image, I would like to increase the pixel ...
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32 views

Extracting Mean from Raster and Writing to Table in ArcPy?

I am simply trying to extract the mean of each raster within a geodatabase and write the value to a table. I have done this successfully with another set of rasters, but now I keep getting the ...
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13 views

“Problem loading output layers” error when running algorithms on rasters in QGIS

I am trying to delineate a catchment from SRTM 1arc second data in QGIS. For this, I first try to use the Fill Sinks algorithm and then the Catchment Area algorithm. Both of the operations gives a ...
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23 views

QGIS tiff image loaded but not visible

In QGIS I used the Georeferencer on a jpg image I had prepared in Gimp. But when I load the resulting tiff image into my QGIS project it is invisible, even though an image viewing program can show it ...
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52 views

Using Python to convert line shapefile to raster, value=total length of lines within cell

I have already read the similar question Convert line shapefile to raster, value=total length of lines within cell using R. And I want to realize the function using Python. ===== My attempt ==== ...
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47 views

Not all raster layers redraw

I'm running QGIS 2.12 and have the same issue on 2.8, but it is now worse in this latest version. The issue is that not underlying raster layers (satellite photos loaded in as .tif) are being ...
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88 views

display of raster in QGIS - cells are not rotated

when viewing rotated rasters in QGIS - the overall raster is rotated (as designed), though each grid cell is not. (the nodata value doesn't appear to pick up as the default in QGIS either - ...
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39 views

QGIS raster calculator - crash minidump

I'm new to QGIS and using version 2.10.1-Pisa. I have two raster layers created from ASTER DEM data. I have one for slope and want to create a binary layer where only pixels between 8 and 60 degrees ...
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44 views

Raster Extrapolation in QGIS?

Does QGIS (or different software) have a method to extrapolate raster values to larger area (outer boundary)? I have a boundary(.shp), which is 40 m far from the edge of raster. I want to fill the ...
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33 views

Efficient processing of ST_ValueCount Results in Postgresql

General Problem: I have a table of rasters. The rasters are classified MSI images, so each pixel is an integer indicating the class of the pixel. For a number of regions, I am querying pixel counts in ...
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50 views

Error when I try to convert Corine Land Cover 2000 tiff to shapefile in QGIS 2.10.1 or clip CLC2000 by a polygon

I want to clip Corine Land Cover 2000 tiff by a polygon or to convert it to shapefile in QGIS 2.10.1. So far I have tried the following always getting an error message that 'ascii' codec can't encode ...
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38 views

How to interpolate values for NaN pixels using ENVI?

I'm currently using MODIS data and am running into problems with NaN values in the final product caused by clouds. I'm interesting in a simple way to spatially interpolate (fill in) these NaN values. ...
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43 views

Using QGIS' “network protocol” to import data from OPeNDAP

After looking at the OPeNDAP documentation I assumed I could import data into QGIS by downloading the .ascii file OPeNDAP generates. However the downloaded OPeNDAP .ascii doesn't seem to be compatible ...
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67 views

Area Calculations dont agree after raster to polygon conversion

I have a landsat 8 image [UTM 19s] (30m resolution, so 900m sq per pixel). I need to calculate the total area (hectares) from a land cover type. I take the count of pixels from the attribute table, ...
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125 views

Comparing the use of GDAL to build raster pyramids or overviews versus Arcmap 10.1

I have a large set of imagery that I created a mosaic from in arcmap 10.1. I want to use GDAL to create the overviews because arcmap has issues building the pyramids and never seems to complete. I ...
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45 views

Using Terrain Profile plugin with an interpolated raster

I am very new to QGIS and the goal of this exercise is to view an elevation profile of a river from a set of discrete points taken from surveying records. Steps taken: A vector layer was created ...
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40 views

Raster memory usage in R

I am working with raster/brick data in R and running into memory issues. I am basically trying to use raster objects to perform some simple agent-based modeling, but the objects keep increasing in ...
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85 views

How to tell if map service is fully vector or raster?

sorry if this is a duplicate, but I was wondering how to tell if a map service (in web browser) is vector based or raster based? What I think to understood so far is that Google Maps for example is ...
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45 views

Efficiently calculate distance between raster patch edges

I have a binary raster which I've classified into patches using raster::clump. I now want to efficiently calculate the edge-to-edge, i.e. minimum, pairwise distance between patches. I am currently ...
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41 views

Spatial Analyst tools adding extra column of NoData

I've got a script tool in ArcGIS that runs Curvature and Aspect from Spatial Analyst, and the outputs of both contain an extra column. I've attempted to set the extent in the both the tool and the ...
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23 views

Sampling raster by line in QGIS

I am quite new to GIS, and was wondering if you might be able to help me out? I have a raster layer for gradient as well as a line created from GPS tracking points(using the point connector tool). Is ...
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84 views

clipping raster changes raster values?

I am working with BIOCLIM temperature/precipitation layers and I have noticed that when I clip the global raster down to a specific region, something happens and the raster value at a specific point ...
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33 views

Combine Raster and Feature Class selection

I've been working on a quite complex analysis with ArcGIS 10.2. But now I'm stuck at a problem... I have a raster file and a polygon feature. The Raster file stores information about Zmax, Zmin and ...
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56 views

Calculate cover loss between years using r.mapcalc

I am working on forest cover raster data for 2 years and am interested in areas with >5% loss in forest cover. I am pretty new in GRASS GIS, so any suggestions for how to create a difference map of ...
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41 views

Help Summing Raster cells to equal circles with a specific sum

So I have this application user density data that I've collected. Each gps point has a user density associated with it (for example: 150 users within a 1 km radius, which calculates to users/[pi*R-sq] ...
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161 views

How to run Focal Stats on specific values in python

I'm a beginning programmer and am new to the site but it has helped me quite a bit so thank you! I'm trying to recreate a raster calculator operation using python scripts but am having a hard time ...
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138 views

Different obs. when I extract raster values from polygons in R

I have two raster layers with the same projection, extent and resolution: r1: class : RasterLayer dimensions : 33434, 89431, 2990036054 (nrow, ncol, ncell) resolution : 0.001447053, ...
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133 views

Large Rasters in ArcGIS & MapInfo

My geoscientists like to work with MapInfo and ArcGIS. I require a common 1 band raster format that can hold obscene amounts of data without damaging the data (compression). I have tried .tif and ...
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47 views

Raster Copy: Output bit size does not match specified value

Using ArcGIS (Map/Catalog) 10.0. I have a raster file (kdens) developed from point data using the kernel density tool. It is 32-bit float file format. I need this file converted to a polygon ...
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66 views

ArcGIS 10 restricted WEIGHTED Flow Accumulation

I have a question very similar to one asked by wxfox4god on 12th June 2013 ("Arcmap 10 restrict Flow Accumulation") that was answered by whuber. (I have had to post it as a new question as I do not ...
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53 views

How to create raster from table containing cell values in PostGIS?

I am having a table with integer values. These values are in between 0 and 2. I want to create a raster out of that table with integers as cell values. Or else how to create polygons out of that table ...
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44 views

Where to find QGIS geoprocessing results?

Is there a way to access in QGIS 2.6.1 something like the Geoprocessing Results window found in ArcGIS? The History and Log window in QGIS appears to show the geoprocessing results from SAGA, OTB ...
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82 views

How to re-grid a raster using area-overlap weighted averaging?

I have two rasters r and r2 with different resolutions. I want to re-sample (re-grid) r2 to be the same as r using area-overlap weighted averaging:If an r grid cell is covered by more than 1 ...
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117 views

Python Script to iterate numerous, single-band rasters for arcpy.CompositeBands

I have a large collection of single-band geotiffs (NIR, Green, and Red) that I would like to composite using a Python script. The goal is to iterate through multiple folders in a main directory, ...
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219 views

ImportError: No module named gdal qgis2.8.1

i am using QGIS 2.8.1 (32 bit) in windows 7). I imported two DEMs and trying to merge (QGIS>Raster>Miscellaneous>Merge)them. Unfortunately it gives me import error as below. Traceback (most recent ...
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97 views

Adjusting heights within a DEM raster for visualisation

Problem I have a bathymetry DEM which I want to display in 3D (ArcScene or Fledermaus). The data set is one single raster but looks like it is a mosaic of several smaller datasets. The problem is ...
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302 views

Calculate Euclidean distance to raster WITHIN multiple polygons

I am using ArcGIS 10.1 on a Windows x64 system. I am working in a study area where I have 360 000 locations of about 50 territorial animals. I have a shapefile containing 125 sometimes overlapping ...
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175 views

Arcpy script for summing pixel values in loop can't handle large number of rasters

I want to sum the pixel values of large numbers of rasters of different extents (ArcMap v10.2). 16GB RAM. I have the following code (with help from this site) which solves the different extent ...
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63 views

How to change values in a raster file at particular positions?

I have a collection of coordinates which comes from a QGSGeometry object. The shape is a polygon. example: qgsGeometry [[(75.2172,17.6566), (75.8499,17.9613), (75.5218,17.2113), (75.2172,17.4574), ...
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120 views

ArcMap - Export raster symbology to a raster function template programmatically

I would like to programmatically export symbology for a raster dataset as a raster function template xml file, as can be done by clicking the export button in the symbology tab of the layer properties ...
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412 views

Working with AIG Raster format in ArcGIS for Desktop?

I downloaded a specific layer which has the format "AIG" as you can see in the screenshot. It has no projection so I applied "Define Projection" on it. I searched for the projection and found the ...
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111 views

Geoserver : create a rasterized polygon / dynamic fill for polygons with features from database

I decided to post here because I couldn't find any answer to my problems on the internet. So I am using geoserver 2.7-SNAPSHOT, everything is working fine but I need to implement a new function or ...
2
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0answers
29 views

What are the problems of loading overlapping (or the same) tifs into postgis?

I am still early on the Postgis learning curve. I have an existing table in Postgres - it looks like this: create table "public"."mytable" ( "rid" serial primary key, "rast" raster, "filename" ...
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71 views

Looking for a tool like (IDW) for raster

I am looking for a tool that gives the same outputs like the IDW, but for rasters instead of points. I have a Corine land cover raster layer in ArcMap 10.2 with different friction values, displaying ...
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77 views

Subtracted 2 DTM layers to find the height of trees but all we have is the pixel values, can I convert this to height?

For a piece of coursework we have an aster layer that captures the tops of trees and a panorama layer that sees ground height (both are raster) so we have subtracted one from the other to get tree ...
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105 views

How to calculate the slope with isolines/raster?

I'm trying to calculate the slope (in %) in ArcGis 9.3, but don't remember how it works. I already did it some time ago, but this time it doesn't work... I used a shapefile with Isolines (see ...
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139 views

Hyperspectral Data in ArcGIS Desktop

The public organization I work for has some archived hyperspectral data (.raw - radiance, non georectified). Has anyone processed hyperspectral data for consumption within ArcMap? If so, what sort of ...
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236 views

Retrieve list of all features and values from raster layer (Geoserver and Openlayers)

I'm trying to retrieve a list of all values from a raster layer (GeoTIFF) in geoserver (2.5.x). I tried to modify the code from http://trac.osgeo.org/openlayers/wiki/GetFeatureInfo but I can't seem ...
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107 views

geoserver and openlayers select rectangle pixel values

I'm running a geoserver (2.5.x) with 1 raster file (GeoTIFF) as a layer. From my application I can access a single pixel value when clicked (through WMS), but what I'm really interested in is to get a ...
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79 views

What are my options to handle Raster Clipper ERROR 6: ADRG driver doesn't support 4 bands?

I have a tif file which contains 4 bands (RGB + alpha). The clipper does not work and gave me the message below; ERROR 6: ADRG driver doesn't support 4 bands. Must be 3 (rgb) bands. Any patch file ...