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

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PostGIS clipping raster with the same color band as the original raster

I am trying to clip a raster so that the clipped raster would have the same minimum and maximum values for the color band as the original raster. For example if i clip the raster with this command: ...
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32 views

QGIS: Merging raster files produces error

I'm trying to merge (Raster -> Miscellanous -> Merge) four raster files into one. Each file has same CRS and are saved as .tif files. Merge produces error: "The process crashed some time after ...
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19 views

Add information from a raster nc-file to a polygon shapefile

DATA Download from this website the following ZIP file: NUTS_2006_60M_SH.zip and save all the NUTS_RG_60M_2006 files. In what follows I refer to this as "NUTS3 regions". Download from this website ...
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1answer
21 views

Combine function on ArcGIS for Desktop?

I am trying to use the combine function on ArcGIS 10.3 for Desktop. I have two raster files that have the same values and I want to combine them in order to compute an accuracy assessment through ...
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12 views

Global Raster over GPS Data

i want to build a global raster over all GPS coordinates. The cells should be like 20x20 metres... I want to write an java application and 'work with'/adjust that raster later on. For example to get ...
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89 views

Why am I getting two different outputs from Python and C++ using GDAL?

I am trying to gather information from a *.tif file using the GDAL libraries. When I open the *.tif file using both the Python API, and C++ API, I encouter two completely different answers. Here are ...
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38 views

What is a raster attribute table?

I've seen raster attribute tables mentioned in several places here at GIS.SE and at ESRI websites. However, I don't understand what is a raster attribute table (RAT). The resources I found so far ...
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115 views

ArcPy Script Tool takes 30min - Ideas to accelerate the (raster) process

I developed an arcpy script tool that takes as input multiple rasters, a criterion to select specific cells from the raster which are then intersected with a point shapefile. At the end a value is ...
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26 views

Control points in IAdjustXForm for georeferencing of raster (ArcObjects)

I am trying to create a georeferencing tool using ArcObjects in VB.Net. Though only a little text is available on this topic in forums as well as from ESRI; I found an esri article that states the use ...
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16 views

Using the extract function in raster package for R with polygons

I have a shape file that contains some polygons and an unprojected raster. I'd like to extract the cells within the polygons using R, so I use code like this: # Load my polygons MyPoly <- ...
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60 views

How to generate a buffer outside polygons having a given pixel value?

For example, I would like to build a 20-m buffer (represented in yellow in the image below) outside polygons having a value of 2 (represented in green) and to assign the value of 3 to buffer cells. ...
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16 views

Code to sift through many rasters and find rasters with errors using python [duplicate]

I would like a code to go through hundreds of rasters and print the names of the rasters that are problematic/don't work. I am trying to use the in cell statistics however I keep coming up with errors ...
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53 views

How can I align perfectly 4 topo sheets?

I have 4 topo sheets and i want then to align perfectly Would I have to georeference each image again? Or is there a more simple method?
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32 views

Is it valid to resample a raster from 1m to 3 feet?

I know that in general it is not a good idea to up-sample. I am curious if it would still be be a "bad idea" with a minor change like this from 1m resolution to 3 feet? Going to 3 feet would not ...
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19 views

Calculating the distance between points and parts of a underlying raster set

I need your help with a calculation of the distance between points (cities in this case) and forest (raster data). Is there a possibility to collate to every city the distance to the nearest forest ...
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17 views

How to unckeck automatically the “No Data Value” predefined on raster background on QGIS 2.14?

I'm trying to import a bunch of rasters, but there is a parameter predefined on the TIFFs, where says that No Data Value should be marked. But I need this unchecked. I opened the metadata, and found ...
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1answer
22 views

QGIS raster no data value changed to -inf when viewing at smaller scale

I have a raster with some no-data cells. I want to visualise raster values using a colour map and set the no data values to transparent. I am attempting to do this using the transparency tab in the ...
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3answers
69 views

Extracting impervious areas (buildings, rails, pavements) from LAS dataset [closed]

How to extract impervious areas (like buildings, rails, pavements etc.) from las dataset and receive it like a raster? I tried to do it with intensity, but there are many valids with vegetation. I ...
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27 views

Error message received when cropping raster with clipper

QGIS 2.10.1 Pisa Message -> Error: Computed -srcwin 8208 142185 0 0 has negative width and/or height. Tried with several different files and types of raster files [GeoTIFF, MrSis, ECW], the same ...
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2answers
35 views

How to Call ArcHydro Tools in Stand Alone Python Script

I am currently using ArcGIS ArcHydro tools to perform 'Catchment Polygon Processing'. However, it is proving time consuming to perform this for multiple rasters. How might a write a python script to ...
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1answer
69 views

Finding problematic rasters in large set of rasters using ArcPy?

Just wondering if anyone knows how to quickly find rasters that cause errors when I attempt to process them in cell statistics (as I am trying to sum them). I have many hundreds of rasters and don't ...
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53 views

Find NoData values inside a polygon area from a raster

I have a raster (representing a polygon in black) which contains NA values (represented by white pixels) that are located inside the polygon and outside the polygon. How can I get the index value ...
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28 views

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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29 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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37 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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19 views

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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44 views

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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1answer
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 ...
3
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1answer
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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36 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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22 views

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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1answer
30 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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38 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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1answer
131 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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33 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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85 views

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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39 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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33 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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1answer
50 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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51 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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68 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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23 views

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 ...