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

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gdal's polygonize function (via qgis) is not turning monochrome rasters into readable shapefiles regardless of inversion of color scale

I've tried polygonizing this monochrome bitmap as this: and this: and either way it ends up looking like this when (zoomed in) after gdal's polygonize operation: Is there any way I can tell ...
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2answers
60 views

Polygon Data to Fit Raster

I'm working with an NHD Flowline of streams and rivers in NC, and I'm trying to only retain the ones in the raster. I tried to convert to the raster to a polygon and was going to clip them, but in the ...
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498 views

Export raster file geodatabase to jp2 or jpeg?

Can I export or copy a raster from a file Geodatabase and create a output to jpeg or jp2000 formate? I was reading two different helpline on ArcGIS 10.1 and wasn't sure if I was supposed to export ...
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270 views

Polygonize(raster to vector) [closed]

I have been install QGIS 2.0.1.when I use Polygonize (Raster to vector)for convert jpg to shp I get error message such as: C:\windows\123.exe is not recognized as an internal or external ...
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646 views

How to load Georeferenced Scanned Maps in R

I have a geo-referenced scanned Map in GeoTiff format, which I would like to load into R. My intention is to plot some vector data (points and polygons) over this map using maptools package. Is ...
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75 views

QGIS problems getting layers to line up correctly.

I am trying to add a raster layer and a vector layer to qgis. I have set both of their CSR to NAD83 Oklahoma North State Plane. It doesn't seem to work even with all the files set to those CSR. ...
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545 views

Error in raster displays of NoData cells when “zoomed in” past scale 1:3,000,000

I looked around GIS stack exchange and ArcGIS Help pages and didn't find anything on this issue. I have encountered an error in how Arc displays a Raster file (.TIF format) at different scales. At ...
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260 views

How do I use wildcards to work around the GDAL character limit?

I am attempting to use the 'Merge' & 'Create VRT' tools in QGIS 2.0 on a folder with 3000+ raster tiles in. However whenever I try to perform this operation the following error appears: 'The ...
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777 views

How to get polyline features from a raster file using ArcGIS 10.1?

I have a watershed accumulation file look like this: There are several white lines by visual, and I tried the raster to polyline tool and got this: Are there better ways to extract polyline ...
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2answers
109 views

Two r.mapcalc calculations return a much bigger raster cell size than the input raster

I tried the following calculations with a GeoTiff sample, having a cell size of 25m: Calculating the togographic exposure (TOPEX) and estimating the mean topographic curvature Both, the resulting ...
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3answers
160 views

Grouping Multiple Raster Layers

My question is how to create multiple raster layers group, for example when using several aerial photos. I wish to group the layers into one so that I can edit/select as a batch rather than having to ...
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291 views

Import raster into ArcGIS

I received raster data from a grid of 1100 by 1000 meters with a resolution of 1 meter. It is the output of EFC-400 software showing the field strength around power lines. The data is currently in ...
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269 views

How to convert 'RasterBrick' object to 'im' object in R?

During script execution I need to convert 'RasterBrick' to 'im' object. Package 'geostatsp' is supposed to do this job: library(geostatsp) myraster = raster(matrix(1:100,10,10), ...
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2answers
951 views

How to “spatially normalize” rasters of different extents to sum values of overlapping cells

How do I add rasters together that are of different spatial extents? I have many, many features that overlap over a large area (entire east coast) and I am looking to sum them "stacked" where they ...
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45 views

calculate the needed space for a raster pyramide withqgis

how can i calculate (or where can I find information to calculate) the required disk space for a raster map of 36GB which should be in a pyramide of 10 levels ? Regards, D3
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214 views

In grass v.drape works with points but not lines

I got an elevation raster map which I interpolate from a point cloud with v.surf.bspline. Then I digitize a couple of points in a new vector layer. With v.drape I'm able to get a height from the ...
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183 views

GRASS GIS related issues! [closed]

(1) How to create a multiband raster from a set of single band rasters (except when somebody talks about doing a r.composite). I attempted creating a raster3D and it turned out that it is not ...
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361 views

How to change rasterlayer color?

I have rasterdataset in gdb. I create layer from this rasterdataset. private static void CreateLayer() { ... IRasterLayer rlMosaicDataset = new RasterLayer(); ...
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112 views

Integer rasters referring to the same scale

I'm using ArcMap 10. I want to display the area of simulated avalanches. I want this area to be divided in different colors depending on the thickness of the deposit. I managed to do that. But I want ...
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1answer
106 views

How can I establish patterns, hotspots and clusters?

AS a crime analyst you need to establish a few maps that would help police to do targeted patrols, I've given data of suburbs, roads, incidents, boundaries. How can I establish patterns, hotspots and ...
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216 views

Help loading Raster to PostGIS 2 .0

Similar questions have been asked, but since my reputation is not enough I am unable to comment on answers. (The following is from an answer by nickves for this question Loading raster data to ...
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450 views

How to batch merge rasters using FOSSGIS tools?

I'm working with QGIS 1.8 (gdal 1.9.2) and GRASS 6.4.3...but on Windows 7. I "just" want to merge my raster. I've got a folder with 50 GTiff raster from Lidar data. The aim is to merge raster ...
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276 views

Working with Interrupted Goode Homolosine data

I'm trying to use Global Land Cover Characterization data from the USGS: http://edc2.usgs.gov/glcc/fao/data_specifications.php It is in the Interrupted Goode Homolosine projection. As I am working ...
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518 views

Define transparent color in singleband pseudocolor raster layer style

Can I somehow define "transparent" color for values higher than 32000 in raster layer? See the style dialog:
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274 views

How to publish raster data in Arcgis Viewer for Flex?

I'm new to ArcGIS for Server and I would like to publish several raster layers (land surface temperature, NDVI etc.). I have uploaded raster to server, but I cannot add it to my ArcGIS viewer for ...
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3k views

Help dealing with a GeoTiff-file in ArcGIS

I'm doing data-analysis on satellite data and my source data is in GeoTiff-file format. What I would like to do with the data is: 1) Open the raster data in ArcMap etc. 2) Change the coordinate ...
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252 views

It seems there is a bug in St_Clip function of PostGIS

The code I am using for clip feature is : raster ST_Clip(raster rast, geometry geom, double precision[] nodataval=NULL, boolean crop=true); I tried clip a shape depends on the polygon from the ...
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290 views

value field name after raster to polygon conversion

When I perform Raster to polygon conversion using tool, sometimes it creates a field named "GRIDCODE", sometimes the field name is "grid_code". Why does it create random name of a field?
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148 views

Algorithm to merge adjacent raster datasets

I am trying to figure out how to merge adjacent raster datasets. Is there any clear algorithms (may be a pseudo code)?
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906 views

Problem with raster calculator [closed]

When working with raster calculator there is an error 000539? The program failed to create a common raster map. I don't know what to do. I did the same in school without any problems. But now, on my ...
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240 views

Setting projection to a geotiff file when it's shown as Unknown

I have a geotiff file that has no CRS in the metadata but I know that the CRS of the raster is WGS 84 UTM 22 N. How can I modify the geotiff file to have the CRS WGS 84 UTM 22 N in the metadata. ...
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220 views

PostGIS raster support

I have the following requirements to manage raster data 1) Convert raster-maps from BSB format to PNG or GeoTIFF 2) Cut the borders of the map 3) Merge individual maps to form a contiguous coverage ...
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368 views

Detect whether there is a spatial polygon in a spatial extent

Given a spatial extent (for example cbind(c(0,0),c(10,10)),I want to see whether there is a part of a SpatialPolygons falls in this extent? How can I do this? Thank you very much!
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283 views

Plotting Smith and Sandwell global seafloor topography grids

Does anybody have any experience with plotting Smith & Sandwell 2-minute Mercator-projected grids in ArcGIS? I've downloaded one in two formats: ers and img. I've found tools for processing .img ...
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3answers
131 views

How to add a float or integer number (i.e 255) to a raster layer?

Is there any code to add a float or integer value with a raster layer? I can easily do mathematical operations between two raster data. But I am unable to do the same between float or integer number ...
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348 views

Incorrect spatial extent for imported hdf image on ArcGIS

I imported an hdf image onto ArcGIS but I cannot make correct projection of it. Also, it does not have correct spatial extent (please see the enclosed figure, the small one is projected under WGS84). ...
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1answer
24 views

r.report giving only per-class cell count

I'm trying to extract the count of each pixel value in a raster, like in this question: How to extract pixel value counts from a raster in QGIS? However, when I run r.report (from QGis (2.10) ...
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1answer
23 views

Specifying number of columns and rows in a raster file

ArcGIS 10.2 I want to produce a raster file with a specific number of rows and columns - 300x300. This needs to be reproducible on multiple data sets/locations - so fixing the extent of the file ...
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2answers
47 views

PostGIS - store 2D elevation data

I am new to PostGIS. How can I store 2D elevation data? I have uniform raster and for every [x,y], height is set. I want to be able to use this in my queries (something like SELECT height FROM data ...
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1answer
51 views

Overlaying grids with a polygon to determine the average value of the overlapping grids for that polygon

I would like to add the average, minimum and maximum value of, let’s say soil moisture (variable "value" in my case), to each NUTS3 region (= a NUTS3 region is a polygon of a certain small area in ...
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1answer
54 views

Geoserver renders reprojected raster only as transparent images

Trying to reproject WMS layers in geoserver from the default of EPSG:4326 to EPSG:3574 Using the default projection works fine. url = ...
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2answers
30 views

How do you insert values into custom fields when adding to a Mosaic Dataset table?

I have a mosaic dataset (file geodatabase) with an additional field added to it (id that is integer) and I'm trying to accomplish in ArcPy what I can do manually--which is: Add a new raster (single ...
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1answer
41 views

How can i import raster image to GRASS GIS without losing RGB Values?

I am using GrassGIS 6.4.2, How can I import raster data to GrassGIS without losing RGB Values? The raster image format is TIFF, the below commmand is using to import raster image: r.in.gdal ...
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1answer
41 views

Adding pixel value data from a raster layer to a number of buffer polygons ArcGIS

I have created a layer of polygons with buffers around my points of interest, all of the same size, in Arc GIS. I also have a raster layer of nighttime lights with pixel values between 0 and 63 ...
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46 views

Extracting Data from Raster based on Aspect Raster file

I have 2 rasters, ones shows aspect and another shows date of snow thaw. I want to extract the date of snow melt based on values from the aspect raster. For example I want all the snow thaw dates from ...
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14 views

error 00289 while projecting raster

I tried to project satellite image of pixel size 2.5m*2.5m. It's in wgs84 UTM zone 44 North. I tried to project it to nepal_87 but failed. The error massage displayed was 'error-000289,failed to alter ...
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2answers
53 views

Adjusting extent of raster?

the coloured file contains landuse information and it needs to have the same number of columns and rows as the DEM in the background for further processing. i can't get it to work - "clip" and ...
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1answer
66 views

mosaic raster image non georeferenced

I have several jpeg2000 tiles non georeferenced and covering a certain area. I know in qgis you can mosaic image using the merge tool but I have done it only using georeferenced images, which is quite ...
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1answer
69 views

Compare two rasters with raster overlay and replace cell value with variable

I want to compare 2 rasters and when there is a change from 2 to 1 create a new raster that replaces the cell where the change has been detected with the change variable. ## Finds Cells that have ...
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1answer
34 views

Properly placing my raster over a shapefile on my map

I have an ASCII file that I converted to a raster. My heading on the ASCII file is: NCOLS 156 NROWS 720 XLLCORNER -170989.3011812 m YLLCORNER 1417628.464462 m CELLSIZE 1 ...