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

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GDAL WMS in QGIS 2.4

I'm trying to add in QGIS a layer shown here : propluvia When I watch in my console I see this request corresponding to the layer I need. The server is not able to respond to a getCapabilities ...
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1k views

How to render PostGIS raster with Mapnik XML?

I'm trying to manage raster files from PostGIS, which to be rendered using Mapnik. I used raster2pgsql to load those GeoTIFF images to PostGIS, and I think the loading process turned out OK. The ...
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Mapnik PGRaster Plugin creating 8x8 tiles with visible boundaries

I have used the latest addition to Mapnik PGRaster plugin (https://github.com/mapnik/mapnik/tree/2.3.x) by Strk(https://github.com/strk/mapnik/tree/2.3.x-pgraster) and merged recently. I am able to ...
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434 views

GDAL (Python) Aggregate Raster Into Lower Resolution

I have a (continent-scale) raster with 30m resolution in an Albers equal area projection. Each 30m cell has a value 1-34. I would like to aggregate information from this raster into a 1km grid such ...
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52 views

Error in polygonising raster data with QGIS on Mac

I'm using QGis Chugiak on a Mac and I'm trying to converting a raster layer in a vector data by: Raster/Conversion/Polygonize. So, I select the layer needed from the drop-down menu, I give a name to ...
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80 views

Finding coordinates of the image corner

I have a .bmp image with a map. For creating image i used a Ingeo 4.4 and function MakeImage() What i know: Height an Width of bmp image dpi Map Scale Image Center's coordinates in meters. What i ...
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685 views

Qgis problem clipping a raster .asc file, the output is unreadable

I am currently using QGIS (1.8.0) to prepare files for use in MaxEnt to predict species distribution in a new territory in Argentina. I need to a) cut the raster files (bioclim, and others) to a ...
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54 views

Placing a cost raster in Arcmap Table of Contents in 10.2.2

We have a set of routines that have been used for writing rasters to the ArcMap table of contents from our tools. The code that always worked is this: /// <summary> /// Used for ...
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393 views

Max cell value from a stacked raster

How can I find a max cell value from a stacked raster. Rmax <- maxValue(RAD1998.all[[1]]) works fine but Rmax <- maxValue(RAD1998.all[[2]]) gives NA. Of course not in a stacked raster. ...
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210 views

Smoothing raster map

I have a raster map of US Midwest which is very sparse, i.e. the pixels of interest are few enough to be almost invisble when viewed at a scale where all states of US Midwest are visible. I would like ...
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1answer
59 views

QGIS create raster from cadastre (property lot data) polygon

I have a cadastre (property lots) polygon dataset of a region. Have used rule-base style in QGIS to show different groups of properties in the dataset classified based on their property lot size (ie. ...
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58 views

Get min-max values of a raster and populate two parameters with the values in tool validation script

I am customizing the script tool behaviour of a custom script and would like to get the min-max values from a raster self.params[0] and populate the next two parameters, self.params[1] and ...
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1answer
62 views

How to crop a vector shapefile according to raster?

I am trying to clip a vector shapefile- points according to a DEM in QGIS. I used GDAL function and polygonized the DEM. Then I ran the Vector-Geoprocessing tools-clip in order to crop the vector data ...
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1answer
31 views

How to show number of patches in a neighbourhood?

Given one raster file containing only one zone that indicates patches of vegetation in a city and a shape file containing neighbourhoods for the city, explain how you could create a map that shows the ...
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2answers
297 views

Open Raster stored in ESRI V10.0 Geodatabase in QGIS V2.4

Is there a way to open a raster that is stored in ESRI V10.0 Geodatabase in QGIS V2.4. I can open the vector layer, but there does not seems to be a way to open a raster.
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1answer
79 views

raster files are not exact in extent after clipping

My two layers (chlorophyll-a and Bathmetry) are not exact after I clip my rasters. My bathymetry data (1) is reporting up to 10 decimal places where as chlorophyll-a (2) is only 3 decimal places and ...
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1answer
244 views

How to overlay a county boundary on a raster file?

I want to overlay California county boundary top of raster layer. Here is is my code: data(coastsCoarse) data(countriesLow) library(gtools) library(maps) library(maptools) library(sp) # Raster ...
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1answer
70 views

Convert polyline to presence absence raster in arcpy

I have a polyline that I am converting to a raster in arcpy. This is occuring within a loop and at each iteration I change the processing environment to a different area of interest. In this case it ...
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2answers
37 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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68 views

Raster loaded in ArcMap 10.2.1 not showing decimal places for value

I have an IMG format raster that I am loading into ArcMap 10.2.1. The pixel type and depth, as reported by the Source tab in Layer Properties is 32-bit floating point. The values, as reported in the ...
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1answer
46 views

Extract all raster cells outside a polygon

How does one perform the very simple task of extracting all raster cell values outside a polygon? I've been looking through QGIS for hours with no solution to this simple problem.
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1answer
815 views

How to cluster Raster data

I have thousands of Raster data concerning the ice coverage at the pole at different times (days) over several years. Now I would like to perform a cluster analysis. I want to split the data into ...
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271 views

Save fails on raster object created from NumpyArrayToRaster [closed]

I am trying to save an ESRI grid built from a numpy array and am getting an error I've never seen before: Unhandled Exception: System.IO.FileNotFoundException: Could not load file or assembly ...
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1answer
457 views

SAGA raster calculator, ifelse command syntax problem?

I am trying to get the saga raster calculator in QGIS to spit out all values of a raster that are inferior to 10, and make all other values zero. I think the syntax is correct but I keep getting the ...
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105 views

Problem with batch mode Saga Raster Calculator

I have to do a couple of raster multiplications for which the batch mode would save me a lot of time. But the only thing I get are rasters that contain nothing but nan values. If I multiply the ...
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180 views

Is there any efficient way to create a raster with pixel value representing a unique id calculated based on pixel lat/lon?

I have 10m raster for each state in US. Current pixel value represents something. I want to have 'same' raster but pixel size representing a unique id calculated based on pixel lat and lon. I am ...
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1answer
526 views

QGIS GRASS Missing Dependancy

I want to perform a view shed analysis in QGIS using GRASS 7 r.viewshed. When I double click on r.viewshed in GRASS GIS 7 commands in the processing toolbox of QGIS I get the following message: ...
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61 views

Multiply Rasters with Scalar Numbers as Input in QGIS Modeler

I built a little model in the QGIS modelbuilder which uses the raster calculator with the command gt(a,threshold) I need to run the model with varying thresholds from 2 to 30 so it would be ...
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2answers
586 views

How to import R-generated .gri/.grd raster files in GRASS?

I received data in .grd + .gri format, where the first one is a small text file and the second one (having the same name) is a binary file. I am unable to open them in GRASS/QGIS. Any hint ? Missing ...
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1answer
39 views

Deleting vector lines beyond image extents using QGIS?

I am using QGIS 2.2 I have one vector line layer (roads) that stretches beyond my base image (see below). I wish to have the roads "clipped/trimmed or deleted" right at the edge of the image's ...
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79 views

Easy way to extract raster cells OUTSIDE a vector (Mask) layer in QGIS?

I have a raster file but am only interested in the cells outside a certain polygon. This polygon is very iregular and scattered across the raster. Is there any easy way to extract only the cells ...
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60 views

levelplot index issue

levelplot with static index works fine but not in a for loop. What's wrong with my code? Static index: png(paste("1998",outlist[[1]],".png",sep="")) levelplot(RAD1998.all[[1:4]]) dev.off() ...
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984 views

Extracting roads out of Landsat raster images

For a study into the expansion of road networks in the rainforest I am trying to extract roads out of Landsat images. We already have sharp and cloud-free composites on which the roads are clearly ...
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2answers
90 views

Reclassify a rasterList and sum the reclassified value from each Pixel

I'm trying to write a script in arcpy which reclassified a List of Rasters. This rasters are made by another tool before so there is already a loop. Actually I get the error 000582 and before this ...
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1answer
383 views

AttributeError: 'unicode' object has no attribute 'save'

I'm trying to multiply my raster to 100 from my ListRasters. I've adapted the code (especially the for loop portion) also from this site. Now, I'm encountering an error at the last line, when saving ...
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1answer
168 views

Highest DEM pixel in polygon

I'm working with QGIS and have a big DEM raster layer with height information and a vector layer with many polygons, representing 1 x 1 degree tiles. Now I want to find for every polygon the highest ...
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1answer
127 views

QGIS raster clip error: Cutline not of polygon type

I have a raster file and want to clip it, but I'm getting this error: "ERROR: Cutline not of polygon type" what does this error mean and how can I resolve it?
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55 views

Align & Sum Grids in Python

I have two grids. One, call it A, is 4320x2160 cells and spans the whole globe. The other, call it B is 8640x3432 and spans the circumference of the globe, but is clipped toward mid-latitudes. Both ...
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103 views

PostGIS Raster functions not working

Hopefully I have a simple question that I'm not phrasing correctly in google. I'm trying to learn about storing and producing rasters in PostGIS. There are tons of examples and documentation online ...
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1answer
79 views

Java how to create geotiff from points

I have an array of objects where each object has three fields: lat, lon, and category. It is essentially pixels that have been given a land use category. I cannot figure out how to turn this data into ...
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1answer
276 views

How can units be defined in QGIS for the Rasterize tool?

I am using QGIS 2.4 (Chugiak) via the kyngchaos build for OS-X. My question is--when using the Rasterize tool to convert a point vector layer to a raster and using the "Raster resolution in map units ...
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4k views

Raster mosaic not displaying raster values ArcGIS 10

I have eight DEM tiles that I downloaded from the USGS National Elevation Dataset. The individual rasters are displaying correctly, but when I try to combine them in a Raster Mosaic I get arbitrary ...
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1answer
942 views

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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1answer
81 views

Error reading large virtual raster with rasterio: “Cannot invert degenerate transform”

I've created a virtual raster using gdalbuildvrt, which covers a large extent (England) at a high resolution. The data is fairly sparse, focused around the coastlines with no files covering inland ...
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Looking for a QGIS solution to make aerial imagery ArcSDE compatiable

Would like to avoid having to use 3d Analyst and use free raster tools in QGIS or elsewhere to make aerial rasters ArcSDE compatible. This 18 page work flow is what I am trying to use. Any suggestions ...
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74 views

Speeding up loading raster

I georeference a tif image and then I clipped that image in a mosaic. I did a index of these images but when I load them is very slow(7 seconds or more to display the first tile). How can I do to go ...
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143 views

Correlation between point feature (disease) and elevation

I have a problem! How can I calculate the correlation between point feature and Dem raster? Hypothesis: disease prevalence in high altitude is more than low altitude. I must do this in ArcGIS 10 and ...
5
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1answer
720 views

R raster Package Moran's I interpretation

I am using raster package to calculate the local Moran's I . The example gives the range of Moran's I between - 1 to 2.47. On my own data I have see the value range -3.070423 - 7.228558 How can ...
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1answer
320 views

How to count and rasterize polygon overlaps in QGIS?

I have a large number of polygons that are overlapping. I'd like to create a heat map and plan on using raster calculation to do this. My plan: to give each polygon a raster value of 1, and adding ...
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2answers
3k views

How to count and rasterize polygon overlaps in ArcGIS Desktop?

How do you take a vector layer with overlapping polygons and turn it into a raster where each cell counts the number of polygons containing that cell? We are looking at polygons of fire burn areas ...