Raster is a data format consisting of regular grids of values, usually stored in an image-like format.
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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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19 views
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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15 views
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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15 views
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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1answer
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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26 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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1answer
21 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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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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55 views
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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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
25 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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17 views
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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0answers
18 views
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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22 views
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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1answer
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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21 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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6 views
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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42 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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0answers
27 views
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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20 views
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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0answers
27 views
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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22 views
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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28 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
32 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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0answers
27 views
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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28 views
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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29 views
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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1answer
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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1answer
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 ...
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1answer
21 views
How to use gdal_grid with VRT?
Hi folk's it seems to be that I'm to stupid to use gdal_grid. I' have
file called dgm-10-epsg-32633.csv with equidistant samples 10x10m in this form.
X,Y,Z
386700,6068670.000,.000
...
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2answers
27 views
QGIS dividing a raster by a polygons layer
I've got a raster image and I want to divide that raster by a polygon layer. There are just 7 polygons in the layer so i need to obtain 7 raster images as output.
How can this done in QGIS?
