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

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Converting data from data frame into raster file using R?

I have the following data frame (long, lat, value) (all coordinates are within Colombia): Spoints: x y z 1 -75.67083 7.57916667 7.328901e-19 2 -74.59583 ...
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27 views

Finding and loading global population density raster data into R?

I am using the Bioclim dataset for a maxent project right now, but I want to add demographic predictors along with climatic ones. I have the 19 layer raster data from Bioclim and I'm hoping to use the ...
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30 views

Raster brightness, contrast, saturation in PyQGIS

I'm trying to find a way to change these properties (especially contrast and brightnes) and I've found a QgsBrightnessContrastFilter class, but I can't fugure out how to apply it to my raster layer. ...
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35 views

Crop Raster from using Polygon shapefile in R

I am trying to crop a raster by a polygon in R to the state of Sergipe-Brazil. My raster is a raster brick criated by 7 .tif files which are EVI (vegetation index) time series. Since the EVI archives ...
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Converting from ellipsoidal heights to orthometric heights (EGSA87)

I try to conver from ellipsoidal to orthometric heights with arithmetic function. In input raster 2 i put WGS84.img from \peodata\geoid folder.The results are not right. And now i have the question. ...
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Why do we georeference from the image to the shapefile (and not the other way around)? [closed]

Why do we georeference going FROM the image, TO the shapefile (and not the other way around)?
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27 views

How can I blend DEM rasters with GDAL?

I have several DEM rasters in different projections and at different resolutions. The rasters are not rectangular, but they have appropriate NoData values. They overlap enough that I should be able ...
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36 views

I want to have two raster data sets overlay

I am using ArcGIS 10.3 I have 2 raster datasets with different coordinate systems, but they are the same county (just different databases). When I add them to the same map layer they are far away ...
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66 views

Create polygons of the extents of a Raster in R

I want to create two polygons. One is of the rectangular extents of my raster. I know I can obtain the extent of the raster using r <- raster("band5.tif") e <- extent(r) but don't know how ...
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35 views

How to speed up raster2pgsql?

I'm trying to upload a 37 GB raster dataset to PostGIS. The raster is out-of-db (-R option), so the actual pixel values are not stored in PostGIS. I'm using this command: raster2pgsql -s 25833 -C -I ...
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Find Maximum value per month in rasterstack/brick and corresponding timestamp R

When dealing with raster images, I found the raster and rts packages in R to be very flexible for analysing my raster data unlike ArcGIS. In my learning efforts, I have had to do some ...
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26 views

Importing South African NGI OSM imagery xml file now unsupported by QGIS

Here in South Africa we at our very small company often make use of this simple xml file (downloadable from http://aerial.openstreetmap.org.za/aerial-osm-org-za-tiles.xml) to link to these imagery: ...
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38 views

smallest number of cells classified in a raster

I am using ArcGIS 10.3 and I ran con statement in the ModelBuilder within ArcGIS. I have an output raster (2m*2m) classified into four different classes. The raster has small pockets of 4 classes. I ...
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34 views

Append daily rasters to monthly lists in Python Arcpy

I'm trying to go over a folder of geotiff rasters where the last three digits of the raster name is the julian date and I want to append the correct days to monthly lists (Jan-Dec) and then run Cell ...
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128 views

Selecting multiple attributes, greater and less than

I am trying to select by attributes from a polygon shape file. I need to select areas with a temperature greater than 10 oC and lower than 15oC using gridcode but i can not seem to work out the ...
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31 views

How do I get rid of edge effects while using focal in R to smooth a raster?

I am trying to use R with the focal function from the raster package to smooth raster images. I am working with Radar images that have already been preprocessed. As part of that, some calculations ...
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3answers
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QGIS automatically set transparency for (#000000) pixels and save *.qlr

Starting with FME, i convert some hundreds of geotiffs to jpeg2000. The jpeg2000 writer does not support nodata-values. Adding the data to QGIS gives me these black (#000000) areas when rasters are ...
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45 views

Modify a Raster display just for aesthetic reason

I have one raster display that I want to include in a report that I am working for school. This is a picture of the raster file: This is a river bathymetry and as you can see, on the margins of ...
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37 views

Tin created from raster have different profile graphs?

I have created a TIN file from a Raster one, but the profile graph from TIN is different from the Raster. Here I attach a image where in the left is a profile graph from the raster, and on the right ...
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32 views

ArcGIS Pro 3D rasters?

I am trying to use ArcGIS Pro to create a 3D scene using an elevation surface (.tif) generated from drone imagery. The tif is projected and contains the elevation information, but I cannot get ArcGIS ...
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47 views

extract() function from r raster package returns different cells if “weights” parameter is TRUE or FALSE

I am trying to extract cell values from a RasterLayer based on a SpatialPolygons object. I create the raster with library(raster) rasterValues <- matrix(rnorm(20),4,5) r <- ...
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28 views

How to clip MrSID Files in R and export to GeoTiff?

I would like to use R to: Read in an MrSID raster (.sid format) Clip the extent using a shapefile Save the new clipped raster as a geotiff I am fine with steps #2 and 3, but I can't find any ...
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48 views

How to use ModelBuilder to run tool extract by mask on many rasters in ArcGIS for Desktop?

I'm trying to extract the same part of multiple rasters (Landsat scenes) using a polygon so I can do a time series. I've been trying to do it in ArcMap 10.2 ModelBuilder but the following error ...
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28 views

Does raster intersect polygon in ModelBuilder?

In ArcMap, I'm building a model which is iterating over ArcGrid rasters. I only want the steps to run where the raster intersects with a certain polygon. How do I add this condition to ModelBuilder?
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67 views

Why do I get “Insufficient memory for image” although there should be enough RAM?

QGIS reports "Insufficient memory for image 1403x716", when I want to load a raster. The problem begins after 1 hour of work. Had somebody had such problem? System win7 64 bit, 16GB RAM, Intel Core ...
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34 views

Creating a Grid For Raster When Measuring Land Cover In Accuracy Assessments

I am assessing the accuracy for the 2011 National Land Cover Map (NLCD). Each pixel for the NLCD measures 30m x 30m. For my reference data, I'm using two sources: 1) Google Earth (~20 m ...
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Repeatedly losing data sources for raster layers in ArcGIS for Desktop?

I have several raster layers that keep losing their data connection whenever I add a new layer from running a tool. I repaired the data source, but this keeps happening every time I run a tool. Is ...
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45 views

Distance to nearest cell with value “x”

I would like to create a raster where each cell equals the distance to the nearest cell >= the value of the source cell plus a constant. In the example below, the input raster has a grid size of 1m x ...
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17 views

Zonal smoothing on a specified area of a raster?

Is there any way to smooth a specify an area on a raster, such as a DEM, and smooth it? For example, I'd like to smooth out the artifact highlighted in the red box. What is the best course of ...
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30 views

How to get the pixels from a geotiff file in gdal python for a given polygon?

I use python and GDAL under apache to make a webservice. I have a GeoTIFF file and i want only a subset of the data, everything inside one polygon defined by a buffer of a line (coord is the input ...
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26 views

Raster to TIN error

I have a big raster file (6,5gb) that I am trying to convert it to TIN format. What happens is that after 15-25 min of processing I get this error message Can someone tell me how can I fix this? ...
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How to save symbology for raster and also its associated 'value' (using unique values)?

I have a raster in ArcMap (built using sum function in cell statistics), and only want to show the water parts of it (band 128). In doing so I only need to show multiples of 128, however there are ...
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28 views

Percent coverage of a polygon in a raster grid

I have a wooded area polygon and a study area grid of cells with 300m resolution. I would like to calculate a raster which shows the amount of each grid cell covered by the polygon. The density per ...
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36 views

Zonal Statistics with very large mosaic in ArcGIS

I have the complete National Elevation Dataset from USGS in over 3000 ArcGrid files (coming to almost 190 GB), and a polygon shapefile of Colorado counties. I'm trying to use ArcMap Zonal Statistics ...
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52 views

Loop over pixel data using Python in ArcMap

Further to my question on SO I'm trying to check the validity of bitmaps. Mainly for transparent or black pixels. I'm new to ArcMap, and I now know that Python scripts can be run from Arc. Any ...
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43 views

QGIS georeference raster to world file (WLD)

I am trying to georeference a raster (jpg). I can easily create a geotiff, but when trying to use the QGIS georeferencer to create a wld file instead, something goes wrong. I have the target CRS set, ...
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53 views

Is there a tool to shrink/grow raster data edge by n pixels

Looking for an open source tool to grow/shrink raster edge by n pixels. I noticed Grass has r.grow but hoping there might be a way to do it with GDAL, PostGIS or python library. More information: I ...
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Reassigning raster values by looking for nearest pixel in another raster using QGIS?

I have two non-overlapping rasters, A (red hues) and B (blue hues). I want to change the value of pixels in B via a nearest-neighbor search in A; i.e. a pixel in B with a value of 15 looks for the ...
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21 views

Clipping raster Data: Converted from GeoPDF to .tff. to .lyr

Program: ArcGIS 10.3 Need: Trying to get a free basemap for georeferencing a historic map so that I can overlay it in my project area. Attempted to use ESRI's USGS National Basemap so that I could ...
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2answers
33 views

TIF with TFW not opening and NO spatial reference

I will receive tif files with the associated tfw. I always thought that these would open correctly in Arc. When I check the spatial reference on the tif it states undefined. So I try to add it myself, ...
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17 views

Dynamic style for DSM layers in geoserver

I have lots of raster layers to show DSM under GeoServer 2.8.2. The input file is the one band TIF served with ImagePyramid plugin. Could I set a dynamic style which related with min and max values ...
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34 views

NDVI polygon from NDVI raster

I am currently working with NDVI data. I found this format which seems to be preferred by our clients: Our maps are made in ArcGIS, I've tried running classification but classes won't allow me to ...
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24 views

Intersect with Raster data

I have ArcGIS 10.2.2 I have raster data over a whole state but am looking at just analyzing a specific county. I downloaded county polygons to overlay over the raster data to determine the area I ...
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75 views

Raster calculator: Insufficient memory available for operation

I use QGIS 2.14 (Windows, 64bit) and try to do some raster calculations with EUNIS habitat data, filter for specific habitat types, files are about 3 GB. RAM: 8 GB (7,85 GB usable) Virtual RAM: 8043 ...
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108 views

How to update raster pixel values based on another raster with conditions in QGIS?

I have 2 land cover rasters. I want to update parts of the first raster with values from the second using QGIS. The workflow should be like this: 1. Select values equal to 30 and 34 in the first ...
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35 views

Erode pixel areas in QGIS

I try to resize Pixel segments exported from eCognition. The goal is to erode the segments for one pixel of the boarder. So for example if the segment is 30px x 30px the result should be a new area ...
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I got the tiles of a raster and I would like to create the original raster

I got the tiles of a map named txt 2x0x0.png 2x0x1.png ... 2x1x1.png 2x1x2.png ... 2x45x1.png 2x45x2.png The first part is the zoom, the second the row and the las the column number. Is it ...
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Probabilities matrices and cellular automata in IDRISI

I apologize for asking about such elementary things, but I am utterly new to IDRISI yet am now having to learn how to perform certain tasks with it on very short notice. Am I right that, when Markov ...
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46 views

Downloading GIS Map for Pakistan into QGIS

I'm looking to add canals and bunds to my raster and have found some GIS maps at: Canals Bunds Bunds Image Network Plan Map Image - looks to contain both canals and bunds I'm not clear on how to ...
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65 views

How to save imagery from online raster service for offline use?

QGIS allows me to connect to free map services like ESRI's 'world imagery'. I would like to save a certain part of it (decided by map extent) in the highest zoom level available in the service for ...