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

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Installing raster resampling module in QGIS 1.8

On the website of Sourcepole, I have recently come across the case of resampling images in Quantum GIS. Because I am rather a beginner in GIS software I would like to ask you for information about how ...
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1answer
413 views

Can I update the service on ArcGIS for Server programmatically?

There is Windows Service. This service adds user raster data to the Raster Dataset in sde database. The Raster Dataset registred on the ArcGis Server. This Raster Dataset also was publishing on ...
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1answer
190 views

(How) can I write string data to a raster with Python/GDAL?

In Python, I have a NumPy array of string values (categories of some variable) that I'd like to write to a raster file (.tif or .img) using GDAL. The impression I get is that it's not possible to ...
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3answers
2k views

Image does not display after clipping raster

I am using ArcGIS 10. I am trying to clip an NLCD layer from a vector polygon. I have used the Clip Raster tool in Data Management and Extract by Mask tool in Spatial Analyst among other things. My ...
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1answer
40 views

Retreive pixel value from raster layer in pyQGIS

I am trying to access the pixel data in all bands from a raster layer in QGis from the Python Console. I have looked at several online resources including ...
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1answer
193 views

Raster map & vector boundaryline data for Istanbul, Turkey

I'm looking where I can download background raster map for Istanbul (street map?), and then a boundary line file of the the 39 Districts in Istanbul. Does anyone have any recommendations?
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1answer
36 views

PostGIS clipping raster with the same color band as the original raster

I am trying to clip a raster so that the clipped raster would have the same minimum and maximum values for the color band as the original raster. For example if i clip the raster with this command: ...
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1answer
27 views

Issues with raster data on postgresql / error:Attempting to get pixel value with out of range raster coordinates

So here is the issue, i am trying to extract values from a big raster divided in 200 or so tiles and applying them to a selection. The points are startpoints, endpoints and midpoints from vector ...
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2answers
416 views

How to set the cell size of a tiff to 1 meter when working in a Geographic Coordinate System?

I am working in a Geographic coordinate system in ArcGIS, and I need to create TIFFs by exporting rasters. THese .TIF file must have a resolution (cell size, or GSD) of 1 m. Is it possible to set any ...
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1answer
38 views

How to order QGIS raster layer style?

I have single band raster files that I am trying to style using Singleband pseudocolour under the Layer Properties, Style settings, and a colour map textfile that I upload for styling. When I upload ...
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3answers
5k views

How to Clip a Shapefile of Circle features using a Raster using ArcGIS 10

I want to keep all the features in the shapefile that lie in the raster region and reject others. How do i do this? Data to be Clipped: Is A Shapefile of 1 mile circles. Data I want it clipped with ...
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1answer
69 views

Finding problematic rasters in large set of rasters using ArcPy?

Just wondering if anyone knows how to quickly find rasters that cause errors when I attempt to process them in cell statistics (as I am trying to sum them). I have many hundreds of rasters and don't ...
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1answer
981 views

ArcMap 10.1 - Tabulate Area tool “doubling up” for Overlapping Buffer Zones

This question is related to a previous question I asked: Raster Version of Spatial Join (one to many) I used the Tabulate Area tool to crosstabulate values between an overlapping "buffrast" raster ...
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2answers
61 views

How to change Raster symbol values (Unique Values) in ArcObjects

I want to change Raster properties symbology using with Arcobjects. Unique Values change as per below attached snapshot. Dim pWSFact As IWorkspaceFactory Set pWSFact = New RasterWorkspaceFactory ...
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1answer
21 views

histogram of raster coordinates in R

I'm trying to generate an histogram of the y coordinates where raster values are 1. Mysteriously the following, different rasters, give me the same histogram. What could I be doing wrong? here are ...
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1answer
384 views

How to calculate zonal statistics from multi-band raster for each polygon using python?

I want to calculate the zonal statastics from multi band raster for a polygon layer. When I am using this snippet of code: vectorlayer=qgis.utils.iface.mapCanvas().layer(0) rasterfile = ...
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1answer
79 views

Creating polygonal windows for spatial analysis in r

I am attempting to normalize a spatial point pattern using a population density raster in r. My problem is that the function I am trying to run is recognizing the "white space" around the raster I am ...
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1answer
789 views

Converting DEM to Floating Point Raster (FLT) using QGIS?

I am looking to convert a .DEM exported from AutoCad to a floating point raster file type (.FLT) utilizing QGIS to implement in HEC-RAS Mapper. This is accomplished easily in Arc using the ...
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1answer
45 views

Modify a Raster display just for aesthetic reason

I have one raster display that I want to include in a report that I am working for school. This is a picture of the raster file: This is a river bathymetry and as you can see, on the margins of ...
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2answers
534 views

problem to open a netCDF and create a raster file

I want to open a netCDF file and create a raster with ArcMap 10.2. The file contains the mean monthly temperature for Switzerland. I found it in meteoswiss web site. I tried to open it with the ...
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1answer
46 views

What is the most efficient way to get a table or attribute table of a float raster?

I'm starting with a stretch point raster. Ultimately I want to get a mean value of values with larger zones and then rate the zonal mean stretching from 0-1 and output rank/zone to a table or layer ...
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19 views

Map netncf-file with different years and save the different layers in shapefiles

Download from this website the following netncf-file: cru_ts3.23.1991.2000.pet.dat.nc.gz. This is a monthly raster with data from all over the world from january 1991 to december 2000 I am using ...
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1answer
1k views

Problem in importing raster data from PostGIS to Geoserver

I am using Opengeo Suite 3.0.2, PostGIS 2.0.3 and PostgreSQl 9.2. I am trying to import raster data from PostGIS to Geoserver but facing an error. I follow this tutorial link to import the raster ...
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25 views

Clipping raster brick object in R

I have MODIS NDVI TIFF files for a year I want to first clip it with a irregular polygon (not by its extent only) of my study area and save it as a multi band raster in TIFF format The TIFF image are ...
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46 views

What method does QGIS Merge Rasters tool use?

I am trying to merge rasters in QGIS and want to set a priority order for merging so that the values from the highest priority raster are used in overlap areas (the “FIRST” merge/mosaic method, I ...
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1answer
38 views

Cutting raster using ArcGIS for Desktop?

I would like to cut a raster file that I have. Here I attach a example of how it is original: And this is how I would like it would be. (I have cut the image on Paint): Can someone give me a ...
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3k views

r - increase speed of crop, mask, & extract raster by many polygons

I'm extracting the area and percent cover of different land use types from a raster based on several thousand polygon boundaries. I've found that the extract function works much faster if I iterate ...
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0answers
34 views

Cut only a river of a raster file [duplicate]

I have one raster file which has a river that passes in a land. I want to "cut" only the river and save it to another raster file but I do not know how to do it. Can anyone give me any suggestion? ...
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1answer
32 views

Export RAT (KEA driver) to Shapefile

I have a dataset of rasters (driver kea) whose has, let's say, 20-30 attributes in their RAT. I'm realizing how to have these attributes in shapefiles (without using proprietary software). I've read a ...
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1answer
24 views

5x5 raster filter in ArcGIS?

Normally, I am using the 3x3 lowpass filter if I need to filter a DEM. However in one case, for better results in curvature calculations, I would like to do a 5x5 filtering. How is this possible in ...
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73 views

Creating new field in Raster Attribute Table with corresponding values from another raster

I have a raster layer that represents surface temperature for the State of Arizona. I also created a raster using the interpolation function to represent air temperature for the State of Arizona. I'm ...
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1answer
648 views

how to create a new raster from one field of a raster with several fields in a RAT

I have a raster with an attribute table containing many fields. I want to create a new raster from one field using ArcGIS 10.1.
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1answer
39 views

display historical map without georeferencing?

I have a historical map of Rome that was published as 46 separate sheets. I'd like to scan these sheets, mosaic them together, and display them as a single map. I've tried to georeference a few of the ...
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1answer
31 views

How do I get rid of edge effects while using focal in R to smooth a raster?

I am trying to use R with the focal function from the raster package to smooth raster images. I am working with Radar images that have already been preprocessed. As part of that, some calculations ...
2
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1answer
403 views

How to extract percentage of land cover from a raster according to multiple shapefiles?

I have a raster map that represents land cover of a region, and different shapefiles (total 120) in the same region. I want to know the percentage of every land cover for each shapefile. For example, ...
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0answers
21 views

Adding rasters to mosaic dataset?

I'm working with an ArcSDE geodatabase v 10.0 in SQL Server 2008R2. I added more than a dozen of rasters w/o problem. Server: WIN 2008R2 12GB RAM SPACE: 1TB Created a mosaic dataset (empty) w/o ...
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3answers
114 views

ArcPy Script Tool takes 30min - Ideas to accelerate the (raster) process

I developed an arcpy script tool that takes as input multiple rasters, a criterion to select specific cells from the raster which are then intersected with a point shapefile. At the end a value is ...
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0answers
30 views

QGIS: Merging raster files produces error

I'm trying to merge (Raster -> Miscellanous -> Merge) four raster files into one. Each file has same CRS and are saved as .tif files. Merge produces error: "The process crashed some time after ...
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17 views

Add information from a raster nc-file to a polygon shapefile

DATA Download from this website the following ZIP file: NUTS_2006_60M_SH.zip and save all the NUTS_RG_60M_2006 files. In what follows I refer to this as "NUTS3 regions". Download from this website ...
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2answers
86 views

Why am I getting two different outputs from Python and C++ using GDAL?

I am trying to gather information from a *.tif file using the GDAL libraries. When I open the *.tif file using both the Python API, and C++ API, I encouter two completely different answers. Here are ...
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1answer
261 views

Calculate tree cover over certain area from raster data

Last year Hansen et al. published Global Forest Change map as set of raster data available in TIFF format. Basically those are 30-meters resolution satellite images with pixel values ranging from 0 ...
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1answer
21 views

Combine function on ArcGIS for Desktop?

I am trying to use the combine function on ArcGIS 10.3 for Desktop. I have two raster files that have the same values and I want to combine them in order to compute an accuracy assessment through ...
8
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1answer
434 views

How to fix “Raster layer: Provider is not valid” error when loading PostGIS rasters?

I compiled and installed the current QGIS master as usual and I imported some raster data into my postgres 9.3 database with postgis 2.0.2 extension. Whenever I try to import the raster data into qgis ...
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2answers
60 views

How to generate a buffer outside polygons having a given pixel value?

For example, I would like to build a 20-m buffer (represented in yellow in the image below) outside polygons having a value of 2 (represented in green) and to assign the value of 3 to buffer cells. ...
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1answer
12 views

Global Raster over GPS Data

i want to build a global raster over all GPS coordinates. The cells should be like 20x20 metres... I want to write an java application and 'work with'/adjust that raster later on. For example to get ...
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1answer
38 views

What is a raster attribute table?

I've seen raster attribute tables mentioned in several places here at GIS.SE and at ESRI websites. However, I don't understand what is a raster attribute table (RAT). The resources I found so far ...
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3answers
169 views

PostGIS polygon clip inaccurate using ST_Clip and ST_Union from tiled raster

I have a RGB raster tiled at 128x128 in PostGIS enabled database. I am trying to clip from the raster using a polygon as follows: SELECT ST_AsGDALRaster(rast,'GTiff') FROM ( ...
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23 views

Control points in IAdjustXForm for georeferencing of raster (ArcObjects)

I am trying to create a georeferencing tool using ArcObjects in VB.Net. Though only a little text is available on this topic in forums as well as from ESRI; I found an esri article that states the use ...
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1answer
53 views

How can I align perfectly 4 topo sheets?

I have 4 topo sheets and i want then to align perfectly Would I have to georeference each image again? Or is there a more simple method?
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16 views

Using the extract function in raster package for R with polygons

I have a shape file that contains some polygons and an unprojected raster. I'd like to extract the cells within the polygons using R, so I use code like this: # Load my polygons MyPoly <- ...