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

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how to use gdal_rasterize? how to know which attribute to burn with ogrinfo?

I have a vector layer I need to rasterize. I guess this is a basic operation, but I haven't found the information I need yet. First, I have reprojected the vector shapefile: ogr2ogr -s_srs ...
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17 views

Change default raster style of newly created rasters in QGIS

If I do calculations on rasters with the raster calculator or other tools, the resulting rasters displayed in my canvas are always in the same default style (singleband gray, black to white...) so ...
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16 views

Add raster layer

This is my code whenever i try to load .tif image it shows layer is not valid,QgsRasterLayer always return invalid layer (I am using linux 12.04). QString myFileName = ...
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10 views

How to group a multiple rasters in MapServer?

I had a map files for each state (raster file) of India. Now I want group all mapfiles to show a single raster or single map file? How I can do in using qgis or any platform?.
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38 views

Is there raster equivalent to vector Intersect?

The intersect tool that is used on vector data cannot be used on raster data. What tool can I use for my two rasters that does the same as the Overlay > Intersect tool?
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12 views

Determine changes in land cover of isolated features over time?

I have a a study area of 2 Landsat scenes from 2013 which were classified for a specific natural community, and these areas have been isolated and extracted and digitized into vectors so that they can ...
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11 views

Merge/mosaic categorical rasters in QGIS/GDAL

I am attempting to make yearly bins of some monthly MODIS data for all of the US. The cells of the raster are defined with Julian dates indicating the date at which a burn event took place. After ...
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2answers
37 views

Use Values from Raster Statistics (e.g. sum of all cells) in Raster Calculator

I need to do calculations on raster layers which require the sum of all cells of the raster. I've used the zonal statistics tool for that but it gets a little annoying to do those extra steps (run the ...
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1answer
31 views

Con() does not recognize raster values

I have a problem when using the con() argument. What I want to do is to remap all raster of a raster file ("Red_SL") cells with values larger than 40 to the new value 5. All other values should be ...
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21 views

Iso Cluster tool in script failing to open clip raster

I have been coding in Python for only a few months, so maybe I'm just overlooking a minor detail as a newbie. I have written the script below for a class project. It is supposed to clip two rasters, ...
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18 views

Problem with adding mosaic layer via arcpy

I have a mosaic layer that I want to add to my map in ArcMap. When I add this layer manually (i.e the "Add Data" button), a raster image, a boundary, and a footprint are added to my table of contents. ...
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20 views

Cannot get 2 raster files of same cell size to align ArcMap 10.2

I have two raster files that are the same cell size but I cannot get them to align properly. (I want the black to line up with the pink) When creating the black raster file (from using polyline to ...
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113 views

How to find the projection of an image?

Instead of georeferencing the image and deforming it, I'm trying to find the projection used by the author of the image. I've got tens of these distribution maps to digitize. The idea is to avoid ...
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3answers
36 views

Use GDAL command line to copy projections

I have two images, a georeferenced Tiff and a second Tiff without a reference. The second image is a copy of the first, but it lost its reference. Now, I want to copy the reference from the first Tiff ...
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2answers
44 views

QGIS Raster Calculator: Need values to be set to 0 instead of no data

I have a landcover map with different values for the landuse options e.g. 190 for commercially used areas. Now I want to extract only these areas using the Raster Calculator with the expression ...
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3answers
46 views

Zonal Statistics as Table Tool

I have a slope dataset. I have a polygon shapefile with territory within the extent of the slope map. I have to calculate the real surface area of this shapefile using the zonal statistics as table ...
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how can i obtain mean of 30 bands from the help of raster calculator in QGIS API with python? [on hold]

class BankAccount(object): def __init__(self, initial_balance=0): self.balance = initial_balance def deposit(self, amount): self.balance += amount def withdraw(self, ...
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29 views

Raster Calculator

I have a slope dataset. How do I calculate the real surface area for this slope dataset using the raster calculator. This is the example I was given: orthogonal area of a raster cell in square ...
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10 views

Raster Analysis Grid (Interpolation) Crashes

Upon clicking on "Grid (Interpolation)" QGIS crashes. I running QGIS 2.2.0-Valmiera on a Mac with OS X 10.9.4 Thank you for any trouble shooting guidance
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32 views

Polygonize Missing Polygons

Polygonize is not capturing all of the pixels in an image that has been converted to 0s & 1s. The pics below show -original geotif -geotif recalculated to 0s & 1s -polygonize output As the ...
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1answer
50 views

data source for worldwide cross-sections of topographic and bathymetric for woodworking art project?

i am a decent r programmer and statistician, i am able to work with data sets pretty well. i am less familiar with GIS tools, but if given a shapefile i can certainly plot political borders and ...
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22 views

Positioning and tracing polygons over an image

On QGIS 2.0 - I want to add an image (TIFF or whatever) then resize and correctly position it over a satellite image (openlayersplugin). Then, the task is to create a new shape file layer and draw ...
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25 views

polygon to raster - not all polygons rasterized

I have a building footprint shapefile (polygons) that I want to convert to a raster. I use the Polygon to Raster tool, and specify a cell size by importing from another raster (which is 24m x 30m). ...
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21 views

R giving error when attempting map algebra

I'm trying to manipulate some downloaded rasters using R, and keep getting the same error when I try to do any type of map algebra. The example below uses a raster file downloaded from ...
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36 views

ERROR 000824 while trying to run IsNull Method outside ArcGIS?

I am trying to perform IsNull function to a raster using PyScripter. This is the code I use: import arcpy import arcinfo InRaster = "C:\\data\InRaster" IsNullRa = "C:\\data\IsNullRa" ...
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37 views

Raster Calculator Blurring Image Results

I am trying to run a NDVI analysis using raster calculator on Arg Map 10.2.1 and the results create blurry or bleeding image, almost as if the map has been dipped in water. I am using the default ...
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23 views

raster overlap count

Would it be possible to simply detect and count overlaps between raster files, i.e. not polygons against rasters, using arcpy? By default I don't have the spatial analyst extension for ArcMap 10.1 but ...
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41 views

gdal2Tiles output differs from MapTiler

I'm in need to process a large batch of Landsat images with MapTiler and since the version I'm using (1.0 Beta 2) does not support multiple input files, I created a simple python script that calls ...
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19 views

How to calculate average raster values around a set of points (ArcGIS or R) [duplicate]

I have a 30-m elevation raster as well as a set of points that overlay the raster. For each point, I want to calculate the average elevation within a 5-km radius of the point. One way I was ...
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29 views

POSTGIS Raster - Merge polygon onto raster

I have two tables, SCHEDULE contains polygon geometries and RASTER contains raster tiles I want to take a polygon from the SCHEDULE table and overlay it on top of a set of RASTER tiles that intersect ...
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32 views

QGIS: Need to remove unwanted white bands when raster layer are overlapping

In my project when raster layers are overlapping a white band appears the edge of the top layer. How can I remove it and obtain a seamless overlapping of the raster ? (I have try to built a vrt with ...
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1answer
16 views

QGIS: how to identify a visible raster layer among large view (composition of rasters)?

I have QGIS project loaded with many raster files. For a given area, (ex: under my mouse pointer), I am looking for way to identify which (raster)layer provides the visible data. To start, I will ...
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32 views

How to do loops on raster cells with python console in QGIS?

I'm new here and beginner with python. I'm looking for a solution to my problem for some hours but now you are my last chance... I'm using the python (2.7.5) console in QGIS (2.4.0). Is there a ...
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31 views

analysis of srtm data for gaps

I need to analyse the SRTM DATA (1025 X 1025) of a particular terrain which has gaps or voids. Could anybody suggest a solution to find the percentage of gaps or voids in the SRTM data? I would like ...
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29 views

Create global raster layer with latitude values of each cell in QGIS

I have a raster with a 0.0083 degree resolution (WGS 84) of which I need the area of every single pixel. An easy but compute-intensive approach is explained here but as I need to work with bigger ...
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18 views

Text in POSTGIS Raster

Is it possible to add text/annotation to a raster generated in Postgis raster? Specifically I need to do this within the database if possible and am looking for an option that does not require an ...
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25 views

Polygonize only pixel values of 1 from a raster

I have a raster mask that I have created in QGIS (2.2.0) that consist of 0, 1 and nodata values. I would like to end up with a polygon dataset that consist of only the value of one pixels from this ...
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1answer
37 views

Projection mismatch when plotting precipitation with ggplot

I'm trying to plot accumulated precipitation in Brazil for a given period, see code below: Load packages library(raincpc) library(SDMTools) library(raster) library(ggplot2) library(rgdal) ...
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49 views

NAs not allowed error message in attempt to plot raster object in R

I have imported a clipped raster (performed in ArcGIS 10.1) from the National Landcover Dataset into R, but when I try to plot I get the following error message. Error in .readCellsGDAL(x, ...
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84 views

LiDAR data density, returns per square meter

How can I compute a raster showing the number of return points per square meter using SAGA GIS or other open source software? My goal is to obtain a mask which would show me the places (cells) ...
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18 views

Conservation International Hotspot Data

I am creating a Heat Map and need Conservation Internationals's Biodiversity Hotspot Data in GIS form. I have tried to find the data online, but have since been unable. Where would I be able to find ...
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71 views

Mapnik + OpenStreetMap + Shapefile with Raster Images + Mod Tile + PostGIS

I am new to GIS. I have a Shapefile (.shp, .shx and .pbf). The .pbf file contains path to PNG files located on my machine only. I was able to save the Shp data to PostGis via Shape2Gis tool. Now ...
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54 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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23 views

How to reassign the values of a raster, based on the pixels of the raster beneath it?

In ArcMap 10.2.1, I have two rasters. Raster1 shows the extent of a habitat, and each pixel contains a categorical value for its land cover type (values 1-3). Raster1 has the smaller spatial extent of ...
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2answers
23 views

What is the source of horizontal and vertical striping in USGS DEMs?

When processing 30m and 10m DEM data downloaded through the National Map Viewer from the National Elevation Dataset, we noticed horizontal and vertical striping not only in the produced results, but ...
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26 views

How I can sum 360 raster files in a folder with the Arcgis raster calculator?

In a folder I have 360 precipitation raster files and I want to sum them all to the raster calculator
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31 views

How to choose which band is used to calculate DN when converting a raster to vector?

I currently have a raster layer of flood water levels (elevation) which I need to convert to a shapefile for future use. My raster is 4 bands: RGB + one band with values from 0 to 10, representing 10 ...
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21 views

Cannot properly import MODIS MOD07_L2 .hdf files into R using rgdal

I've been trying to accurately import and process some .hdf files from the MODIS Atmospheric Profile product (MOD07_L2) in R for several days now. Still, there's something going wrong during data ...
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57 views

QGIS: Multiply Raster Value with Pixel size

i'm working on a map with population densities. My raster data contains values as [People/square meter] for each cell. I have per capita values of energy demand etc. which I want to multiply with the ...
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Choosing the map scale (1:nnn) for the given raster dimension

Starting points: let define the raster image size, say: 1800x900 pixels I want draw my own raster image map - by drawing polygons e.g. like "draw line from pixel with coordinates x100y100 to pixel ...