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

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Self-hosted web app to view raster & vector layers and annotate

I'm trying to find a self-hosted web app that allows you to view a number of raster and vector layers on a draggable web map, and then to 'annotate' the map by adding points to the map with associated ...
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Rescale raster files in QGIS

I want to construct a surface of predictions in QGIS, using several probabilities I otained previously in R, by constructing GLMM. But I rescaled my variables before constructing GLMM, so I also need ...
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305 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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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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219 views

How to get projection data (.prj) of raster image using GDAL/OGR?

I start with a boundary shape-file (think U.S. states) in lat/long that I convert to some projection, and then rasterize the result as a .tif. What I need now are the raster coordinates of the ...
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39 views

Recording height profile from raster along a polyline shapefile?

I'm looking for the easiest way to record a series of raster values along a 400 meter transect in ArcGIS 10.3.1. I'm working with a LiDAR canopy height model with 3mx3m cells where each cell ...
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23 views

Land cover generation

I am working on a river watershed on QGIS and I need a land cover map. I have a good raster of land use data with 15 m resolution for year 2015, but it covers around the 90 % of the basin. I have ...
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Calculating elevation profile along line from a DEM?

Given a DEM (Digital Elevation Model) and a line (x1,y1) --> (x2,y2) (paired coordinates (x,y)), how can one calculate the elevation profile or cross-section projected on that line? I am looking for ...
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add multiple rasters, each located a branch too deep in separate folders - ArcGIS

I have a year of daily raster datasets (365) that I would like to use the Cell Statistics tool on; however, each raster is located in a separate folder so I cannot add all of them at once. ie: -...
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228 views

Creating a raster file from a shapefile using GeoTools with different colours for different features

The shapefiles that I am processing display information on an operation of a piece of equipment over an area, where the information is stored in steps as polygon features with various attributes and ...
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Arcpy Subtracting rasters error - TypeError: 'unicode' object is not callable

I have a script which subtracts 2 versions of the same raster from each other (one newer than the other) and then extracts the additions & deletions that have happened. I created a simple test ...
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GeoTIFFs made in GDAL don't have min/max range when loaded in Arc/QGIS

I'm creating some floating point rasters in GDAL with the GeoTIFF driver. When I load the resulting images into QGIS or Arc the default symbology puts the min at -3.40282e38 and max to 3.40282e38, so ...
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382 views

Extracting multiple values of raster to polygons using ArcGIS for Desktop?

I was hoping I could get some help on how to extract information from a land use raster using polygons. I have a layer with 157 polygons and a land use raster with multiple land use categories for the ...
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11 views

r.statistics throws invalid reclass rule error despite assigning null to unique value

Trying to run r.statistics on two raster layers, one a layer of distinct zones produced via r.clump (stands) and one a layer of all ones (ones). The areas outside of the immediate region of interest ...
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21 views

Problem with r.grow.distance on GRASS

I would like to use r.grow.distance on a raster map. I rasterised a shapefile (about 50 cities in a region) and we can see them on the raster map. Yet, when I launch r.grow.distance, I have a ...
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487 views

Convert Raster to Numpy Array with only Arcpy and Numpy

All the articles I'm finding including GDAL or PIL(?) which I cannot use. So I am trying to convert a raster I have to a Numpy Array with Arcpy and Numpy and then calculate some statistics on it but ...
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32 views

Applying symbology to raster layer in ArcPy without using symbology layer (layer file)?

I have a raster layer with 3 unique values (1,2,3) and I want to apply a unique color to each using RGB values or hex codes, without the use of a symbology layer (layer file). Is it possible to ...
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117 views

Get Raster Centroid using Arcpy

Purpose:To take an input raster image and clip its shape to a parcel block. In later stages this model will be applied to a loop. Logic: The Model receives an input raster image and calculates a ...
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15 views

Extract lat long point values from EASE2 without reprojection

I have the following file: EASE2 and want to extract the values for this geographic location (148.1, -35.6) #lon lat. How can I do this without the need for reprojecting the ease grid file into ...
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3answers
3k views

Coordinates of raster image from .TAB file

I have got a raster image (tif) from a mapping site and an associated .TAB file. I am trying to correctly map it into CAD/3d model - which I know is set up to the correct coordinates. The .TAB file ...
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388 views

How to store Large Raster Images of Equipotential Surface Generation Using Monte Carlo Simulation?

I have a large (1GB+) raster that I am using as the base for the generation of an equipotential surface. This is to assess the accuracy of DEMs derived from another source. In situ observation is ...
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Using predict function in raster package for applications other than species distribution modelling?

I was wondering if the species distribution modelling technique can be used to analyze other variables such as human movement. For example I have data on whether a person attends a facility (binary ...
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21 views

How to access to the underlying grid table behind Mapinfo's Grid Thematic map?

I created a grid thematic map using "Mapinfo - Map - Create Thematic Map" function. Now I want to know the distribution of the data from the grids. But the "Browse Table" option is not functioning ...
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16 views

Problem in cell dimension assignment from “save as” in QGIS

I am trying to save one raster in QGIS by changing the cell dimensions. I select 30 x 30 as cell resolution, but then the output raster has a resolution of 29.9985 x 29.9985. How can I assign exactly ...
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19 views

Can a Mosaic Dataset have rasters with different vertical units?

I am creating a Mosaic Dataset (ArcMap 10.3) that contains LiDAR dems from a number of different US states. The data is in different coordinate systems (UTM, State Plane meters, State plane feet), ...
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231 views

Attribute table is missing in raster after using extract by mask tool

Every time I use the extract by mask tool, the rasters that are created don't have an attribute table (i.e it's greyed out). Does anyone know what is causing this and why these rasters essentially no ...
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52 views

Precipitation data raster

I'm using the TRMM 3B43 precipitation data. I have downloaded individual NetCDF files depicting yearly accumulation in mm for each year from 2000 to 2015 (16 files). I have imported each file into ...
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33 views

Sum area of specific poly attributes within raster grid cell

I have a polygon layer (A) containing several different land use types (road, building, etc). I also have a different GIS layer (B), a raster of NLCD land use/land cover. I would like to sum/...
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43 views

How to define season by month and average data

I have 10 year NDVI data i.e. two values per month. I would like to average values within a season e.g Season A (January, February and March) per year and plot a graph. y axis=average ndvi value, x ...
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179 views

How to model a geodesic grid in PostGIS?

Abstract I've decided to use PostGIS for a hobby game project. It requires a lot of units allocated on the surface of a planet. I'd like to model not only the units (simple points), but also their ...
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172 views

Generating an image representing inland surface water using QGis and OSM data

I'm trying to generate a raster image representing surface water for a given bounding box. I'm using OpenStreetMaps data as my input for water bodies, and I'm using QGis on Ubuntu to process this data....
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Intersecting vector data with raster data in PostGIS?

I have Open Street Map [OSM] data imported so that I can access the geometry of buildings. I have also loaded SRTM digital height data from NASA from a GeoTIFF raster. I have projected the raster into ...
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How can a statistically significant difference between rasters be calculated?

so after some gruelling use of MaxEnt I have four occurrence probability rasters for the four quarters of the year, each one is about 70MB+. I want to test whether they are significantly different ...
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361 views

Issues calculating range with QGIS 2.0 raster calculator

I would like to calculate a simple range using the QGIS 2.0 Raster Calculator, but am getting strange results. I believe I am not using the correct syntax. To get all values between .003-.5, I ...
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kernel density estimation-mask layer-arcgis

I have a vector layer with points (road accidents) and another polygon layer which is the area in which occured these accidents. I ran kde where I changed the environments-raster analysis (I added as ...
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1answer
41 views

QGIS Oracle-Spatial-GeoRaster-Plugin not working

I am having trouble with Oracle-Spatial-GeoRaster-Plugin in QGIS (running on Windows 7 Professional N 64bit). The connection to my database on an external Oracle-Server obviously works as it shows the ...
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22 views

How to create raster layer directly from numpy array in QGIS, without saving to file?

I have managed to create a numpy array from a raster file using commands from the gdal library, and now I would like to load that raster as a layer without saving it first. It seems like there should ...
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869 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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41 views

How to make a loop that interates over large raster cells in R go faster?

I am trying to add +1 to the cell value of certain cells in a raster. I have the cell numbers of the cells on which I'd like to perform said computation saved in a vector. I have a working code but ...
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Rasterizing in R - how do resolutions work? (e.g. population within a circle)

I'm creeping into building surfaces - useful for a number of public health projects - and can't seem to make sense of what's happening with the resolution and raster building process to get what I ...
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1answer
209 views

Why am I losing part of my raster when I reproject?

QGIS 2.0 Working with tiff raster file. Reprojections are in WGS84 Mercator. Here is my problem: I am trying to use buffers or urban areas to analyze light intensity on a raster layer. I want 30 ...
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89 views

Max value of overlapping Polygons

Licence: Advanced Version: ArcMap 10.3 In my shape are thousands of overlapping polygons. My goal is, to generate a new output in which the biggest overlapping value represents a new polygon/...
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5k views

How to modify single Pixel values in QGIS?

I would like to modify a raster (pixel values) in QGIS. The plugins "value tools" can easily provide me with the value of the pixel of my raster. However I don't know how to modify it. I have found ...
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1answer
4k views

How to create attribute table for raster data?

I have raster dataset for rainfall but its not having attribute table. How can I create tabular data using the same raster file? How to join it back again to it? Software used is ArcMap 10.1.
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How can I change the origin (top left corner) coordinates of a raster using PyQGIS?

I am developing a python plugin for QGIS. The purpose of the plugin is to properly open an HDF5 dataset as a raster. Opening and displaying the raster can be done without the need for a plugin, ...
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360 views

How to use GDAL to burn a selected value from one raster into another?

I think this should be a relatively simple process, but I'm not quite sure how to approach it. I have a shapefile containing 1000's of polygons. I also have 19 rasters. All of the polygons fall ...
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Resolution changes when exporting raster from GRASS to Arcmap

I have a raster file of rainfall (floating) in GRASS that I want to export and open in arcmap. If I look for the raster file in GRASS, it has Rows: 140 ...
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Clipping a raster layer with a shapefile on mac

I am trying to clip a raster layer using the raster clipper function. However, for some reason this is not working for me and I haven't been able to find the answer anywhere. I choose my raster ...
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Receiving higher values than should be possible in stackApply SUM for Frequency calculation in R

I am currently working on creating a frequency raster for a country based on multiple Rasters of the same day through following years and where the previous values are reclassified to 1's and 0's. The ...
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Scanning a raster by moving windows. Output rasters off by a cell. ArcGIS, python

I'm working in extracting smaller rasters from a bigger one (yellow). I'm using only python, some numpy maybe. I succesfully extracted a patch from a big raster, secuentially, by moving windows. So I ...