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

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Converting worldclim data to 30m resolution

I know that resampling from coarse resolution to fine resolution is bad. Effectively you are making up data. However, if the study area is small are there any other options? Worldclim comes at around ...
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23 views

QGIS 2.8 Raster Layers Moved

I recently downloaded QGIS 2.8 and opened an existing project in it to check how it handled it and make any changes required. This project includes several raster heatmap layers. My problem is that ...
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18 views

How to make a density map from polygons/rasters (ArcGIS)

I would like to make a density map of grasslands. I have a vector layer of habitat classifications, I would like to a density map of grasslands within a specified radius. My thoughts are to: ...
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Raster to polygon with RGB composite using Arcgis

I am trying to convert an RGB composite to a shapefile to use with. The raster to polygon function returns with three shapefiles with "grid_code" of the value of each of these three channels. I am ...
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Extracting the values of a GeoTIFF file that match one particular feature of a shapefile in R

I have a GeoTIFF raster file and a raster that I converted to a QGIS-shapefile. I imported both in R. The shapefile contains 23 features of vegetation classes in Europe. I am trying to extract the ...
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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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18 views

Add information from polygon to raster in R

I would like to add information from a spatial polygon to a new raster. r <- raster(nrow=10, ncol=10) r[] <- runif(ncell(r)) * 10 xym = matrix(c(0,0,0,45,45,45,45,0),4,2,byrow=T) ## create ...
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1answer
27 views

Raster display issue in ArcMap?

A client of ours is having trouble with some raster tiles in ArcMap. They gave me a sample, and I was able to get it looking right with the following workflow: All you have to do is go into each of ...
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22 views

Reduce raster resolution based on cell ratio

I have 2m impervious/non-impervious data. I would like to reduce the resolution to 30m and have the cell value for the 30m data be determined by the ratio or proportion of impervious / non-impervious ...
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18 views

Problem with conversion from raster to polyline (not a single curve)

I have raster file and I need to convert it to line. I used GIS tools Convert Raster to Polyline but the line segment is not straight and it is divided into no of segments, isn't it possible to get ...
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1answer
23 views

Performing raster calculation in ArcGIS Desktop?

I have a raster layer with values between 0 and 10. My second layer consists of 0's and 1's. What I need is my first layer, but with 0's or NoData values where my second layer has 1's?
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Apart from “in-memory” space and physical geodatabase, is there any other method to process raster data?

Using the centroid of the building footprints (tagged residential), I want a count of hydrants within 135m, and a count of hydrants within 270m of every residential footprint. This would be based on a ...
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18 views

Georeference multiple raster layers of same area at once or identically

I have many raster layers that I need to georeference to my existing vector layers. Data types vary between 8 bit unsigned, 32 bit float, and bit 64 float. All have the exact same extent, cell size, ...
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1answer
24 views

Tools for building and exporting high resolution geotiff

I'm having some really nice raster maps in geotiff format. I would like to add some features to these maps as well as then exporting them as tiles for serving the map from a web server. Preferably I ...
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1answer
27 views

Georeferencing uneven/irregularly gridded rasters

I'm trying to take a set of NetCDFs and turn them into georeferenced datasets using GDAL. However, the only Geospatial data is a set of 2-D lat/lon arrays. The projection type is not lat/lon. THe ...
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1answer
33 views

Is there a better way to convert Raster to Point data? Don't need one point for every cell

I need to convert raster data to point data so I can use the points for interpolation via kriging. My problem is that my resolution is 5 ft and I'm working on a whole city. The data I am converting ...
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1answer
12 views

QGIS extend raster layers extension

I want to extend a raster layer to another layer's extension (my input raster layer is smaller). The new raster cells should have 0 value. Is this possible in QGIS?
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1answer
16 views

Raster layer - changing values in raster cells

I have a lot of cells in a raster layer (GeoTIFF) with a -9999 value in it. I would like to update that values to 0. I mean, in vectorial layers would be something like: CASE WHEN band1=-9999 THEN 0 ...
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21 views

QGIS Rasters - Filling no data cells [duplicate]

When making a sum between two raster layers, for every cell, if one of the two cells have no data in that cell, the opeartion is not done in that cell, example: In QGIS raster calculator I do: ...
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1answer
22 views

White Pixel in Raster (CIR) arcmap 9.3

i have to analyse forest cir orthophotos. in high scale resolution, many white pixel appear instead of red ones. i work with arcmap 9.3, win7
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QGIS Raster Calculator, joining two raster

In QGIS raster calculator I do: Plus (+) And I get: The red circle in the middle is like cut in the result, QGIS it's not adding every pixel on each raster, it makes a kind of ...
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How do you symbolise a 32-bit raster in ArcObjects?

For rasters that are ABOVE 16-bit - you cannot apply a colormap - so what is happening when you symbolise in ArcMap a 32 bit raster, it's certainly possible. I'm trying to emulate this funcitonality ...
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How to get the band number for a specific data value?

I have temperature data values which are stored in a raster image and I want to know which band numbers have that data value stored in them. Can anyone please guide me as to how can i do this using ...
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25 views

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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31 views

Use raster memory layer from QGIS processing result

I want to apply subsequent QGIS raster processing algorithms in a python script. I want to use memory layers for intermediate calculation results since I am only interested in the end result. As ...
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22 views

Converting Elevation Raster to Contours [on hold]

I am trying to convert multiple elevation raster files into contour lines, but the contour shapefiles all just end up on top of each other on my map. I can't get them to be where they're suppose to ...
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How to import Esri Raster to IDRISI with NoData value?

I made some point features in ArcGIS Desktop to build training samples to import to IDRISI. I had 7 classes and convert the feature to raster to build the signature in IDRISI. When I import the data ...
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1answer
30 views

Import GeoTIFF into MapInfo - why “control points”, and how to batch-create TAB files?

OK, so I am largely hostile to commercial software with 'proprietary' formats, but a colleague only knows MapInfo. I have a bunch of GeoTIFFs (produced by gdal-merge of JPG/JGW-filepair hi-res aerial ...
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16 views

Aligning to DEM after TIFF conversion to GRID?

I can convert a TIFF (NASS Cropscape) by using Create Raster in my .gdb or Export to other Format. However, all efforts to align the extent to an existing DEM have escaped me! I have tried Snap ...
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44 views

Unable to save edits. Raster dataset already exist

When I edit my attribute table then I try to save edits but one error mesage appear on my screen "Unable to save edits. Raster dataset already exist". I really wonder why this error message appear?
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2answers
82 views

How to convert a vector map to raster in Qgis?

I am creating a thematic map (vector data) with different classes. How to convert this vector map to a raster map, keeping the classification?
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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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How to draw contour line between certain elevation range?

I have a raster and I want to draw contour lines just between certain elevation range. For example I want to draw contour lines between elevation 700 (m) and 1000 (m) with the interval of 10. So there ...
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Worldfile incorrect? Puzzler: all resources supplied!

Trying to manually create a worldfile for gif images of surface currents supplied by the navy here. I have QGIS and am decent at using it but the world file tool is failing without error on me (even ...
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24 views

What exact format do I need to have for the inputs to make Path Distance work?

I am trying to run the Path Distance tool in ArcGis 10.1. Ideally I would like to utilize Tobler's hiking formula anisotropic approach to slope and a land cover cost surface to calculate the least ...
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How to create a syntesis map ( eg. climatic vulnerability) in Qgis [duplicate]

My final goal is to create a synthesis map of climatic vulnerabilities composed by different thematic variable with different weights. I would like to ask for support for the following issues: For ...
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1answer
28 views

Error adding MrSID raster layer to QGIS for Mac OS X 10.10.2 (Yosemite)

I want to add a MrSID layer to QGIS (version 2.6.1) with a computer running Mac OS X Yosemite. I installed QGIS through macports from the terminal and all python packages through macports, as well. I ...
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1answer
35 views

QGIS change raster tiles properties at once

I have a set of several raster tiles and I need to change the properties of each one, by setting up a transparency for instance. I have found no other solution but changing properties of each one at a ...
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1answer
38 views

Overlay analysis of two raster by attribute?

I have two rasters (one showing land use and the other showing soil texture). I'd like to find the areas where there is a specific land use on a specific soil texture. Is there a way to overlay two ...
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29 views

Metric maps vs topological maps for path finding and UI rendering of indoor floor layouts

I'm building a software to map indoor floor plans of large facilities (like malls). I read through some of the questions on this forum, but my constraints are a little different than the ones ...
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2answers
39 views

How to feed a raster map with values from other raster map

I would like to know if there is a tool able to "feed" a current raster map with the values from other raster map (so the values from the current raster map will be replaced by the ones from the other ...
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1answer
33 views

How to cut a raster into smaller, equal area parts?

I have a large raster file that I need to cut into smaller parts. I already have a polygon shapefile that has the smaller parts that I want to use as an index. The reason for this is that end users ...
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2answers
53 views

How to get cell value along Flow Direction

I have: a flow direction raster where I took off (assigned NoData value) the cells that overlayed the river network (from flow accumulation). a perfectly overlapping raster where I asigned a ...
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SAGA GIS - raster image from Civil 3D

I am a new user of SAGA GIS software. I need to interface the Civil 3D 2015 and Hec Ras software in order to create a flooding map. In order to put in communication the two softwares, I have to use ...
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1answer
20 views

How can I fill the category field in a raster using GRASS

I have a tiff file with land use data. The land use class in in the value field, but the label field is empty. Now I want to find out which is the area covered by each land use class, but GRASS does ...
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Use NASA data (.grd) in ArcMap 10.2?

I am trying to use soil texture data from NASA (http://ldas.gsfc.nasa.gov/nldas/NLDASsoils.php#VIC), but I cannot figure out how to use the .grd file type in ArcMap. I have tried to save as .asc and ...
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Generating ESRI compatible raster reference files in QGIS?

Backstory: employer is GIS incapable and most of the data we work with doesnt play nice with GIS software. That said, we have a client who is very GIS oriented. My boss (not my work) is providing them ...
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1answer
19 views

Turn off the setting of QGIS to produce xml when closing

Every time I open and close a raster layer in QGIS it creates an xml file for that raster when closing. While I do a lot of automatic processing this really bugs me, since I have to add every time ...
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23 views

Assign raster cells presence/absence values depending on whether polygon overlaps with cells

I have a raster of continuous numeric values. A certain portion of said raster overlaps with a polygon of interest. I want to know which cells overlap, and assign values to the raster's attribute ...
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28 views

How to check the value of a single pixel in QGIS?

I was wondering how to check the value of a pixel at a mouse click in QGIS (as of 2.4). In ArcGIS, the "Identify" tool does the job for both rasters and vectors. However, in QGIS, the "Identify" tool ...