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

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calculate proportion of polygon greater then 40 degrees in grid cell QGIS

I would like to calculate the proportion of greater then 40 degree slope within my polygon grid cells. I have a Slope Raster layer for my given area and have a polygon that overlays this raster ...
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18 views

Creating clumps of cells in a raster from seeds of 1 cell (in ArcGIS)

I need a process similar to that described in JPD's question: Creating randomly shaped clumps of cells in a raster from seeds of 1 cell/pixel? I have a raster with semi-randomly dispersed "seed" cells ...
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82 views

QGIS 2.0 change the raster band from python command

Does anyone know how to change the band of a multiband raster from the python command line in QGIS2.0? It used to be done with something like rLayer.setGrayBandName(1) in 1.8, but this is no longer a ...
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138 views

How to convert Raster to points in MapInfo?

I wanted to convert Raster data to point data in MapInfo.Does there any tool to convert? can anyone help me?
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60 views

Interpolation Technique

We have following solar metro logy parameter through satellite data with resolution of 100 Km^2 (10Kmx10Km) Insolation on horizontal surface Diffuse radiation on horizontal surface ...
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86 views

Methods to calculate Viewshed analysis

Does anyone know an algorithm to calculate Viewshed analysis? I calculated them in ArcGIS, MapInfo and SAGA GIS. I wish to calculate Viewshed analysis using algorithm or methods which I can use in ...
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34 views

Can´t display two files at the same time

for some reason when I open a raster FIRST and then a shp, I can only see the raster. Then if I open the shp FIRST, and then the raster, I can only see the shp! Is there a bug on QGIS? Or have I ...
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52 views

Updating a raster dataset stored in SDE, without schema changes

The Short(ish) Version: I have some rasters, that are generated nightly, that I need to insert into an SDE instance (10.0), sitting on top of an Oracle database (11.1.0.7). I have many users who ...
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56 views

Creating a mosaic dataset from pre-existing mosaic datasets

I wanted to see if anyone has tried this, or knows of any issues that may arise from performing such a procedure: I have about 20 mosaic datasets already created in separate file geodatabases. I ...
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29 views

Create a mask for a 3 Band Raster Image with surrounding white areas

How do I create a mask in order to clip a 3 band raster image so that the surrounding white area does not display. My thinking is to use Raster Calculator to create the mask or cut all three bands on ...
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40 views

Intersect two rasters with similar scale in PostGIS

I'm working on a project in which we have a ~100x100km grid with ~1x1km cell sizes to which we are trying to aggregate other data, including point, polygon, and raster data. This grid is a collection ...
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60 views

Using Raster Data in a Vector Layer's table in QGIS 2.01

I have a vector layer containing point data representing floor levels. The attribute table contains: Easting Northing Floor Level I also have several water surface levels representing the ...
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114 views

Problem with merging 15 DEM files in ArcGIS

I have 15 DEM files downloaded from USGS website. The pixel depth of each file is 32 bit floating, generic with format FLT. I'm then using data Management Tools > Raster dataset > Mosaics to new ...
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61 views

How to remove Raster from Raster Dataset programmatically?

I have Raster (it is 6 adf files). This raster was added to Raster Dataset in sde database. Geoprocessor geoProcessor = new Geoprocessor(); Mosaic mosaic = new Mosaic(); ...
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202 views

Tabulate area - Spatial Analyse

I am trying to calculate the amount (sqm) of land cover types (forest, water ect.) in 1045 buffer zones, all the same size (500m in diameter).. The buffer zones are polygons and the land cover is a ...
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50 views

Is anyone else working on PostGIS rasters for Ruby?

This is more of an answer looking for a question, really. If you're writing Ruby (and especially ActiveRecord) code and want to use those tasty pixels from PostGIS rasters, you've probably had to deal ...
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125 views

Trying to build pyramids for large raster

I finally was able to make a slope with a rather large 5m DEM. But now I it usually wont finish drawing. When ArcMap asks to 'build pyramids' it always freezes sometimes instantly after accepting ...
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60 views

Using arcpy.GetRasterProperties_management gives strange results

I have a loop which goes through folders and do some raster operations. Inside this loop I checked for a raster properties using arcpy.GetRasterProperties_management with NODATA parameter. And then ...
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74 views

Compare cell value of a row

How can I compare the cell value of row(n) with cell value of row (n+1){where n = 1, 2, ...} import arcpy arcpy.env.workspace = "C:\RG\Kings County\Test.gdb" inFC = arcpy.GetParameterAsText(0) inFC ...
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142 views

QGIS 2.0 cannot open TIFF

I've just installed QGIS 2.0 on my Windows 7 computer. I'm trying to open a raster and the system reports this message: Cannot open TIFF file due to missing codec. How can I solve it? Thanks in ...
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96 views

How to create a raster dataset from a known decimal extent?

I have an input raster pInputRaster. I want to create a new raster dataset called pOutputRasterDS that is the same width, height and cellsize as my input raster dataset (I'm not worried about ...
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37 views

How to select raster layers for averaging based on values in another layer?

I wonder if anyone have some ideas about how to solve this geoprocessing situation: 1: I have a raster layer called mixlyr_apr (representing depth values) 2: I have a series of raster layers called: ...
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102 views

QGIS GRASS Rasteranalysis (r.los)

I want to determine the area around a wind turbine from wich the object is visible. I want to use r.los in GRASS i get this error: (German) r.los input=dgm@sichtbarkeit coordinate=534228,5406743 ...
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156 views

QGis: merge point and line vector themes to create single raster

I have two vector shapefiles with different geometries: point theme with depth attributes and line theme with contour of water body (zero depth). How can I build the raster from this two different ...
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69 views

Vector/Raster Intersection - Speedup and replacement for ST_Centroid

I have some raster data which is the altitude above sea level and also some vector data which represents building outlines. What I want to do is grab some buildings outlines and fetch all the raster ...
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50 views

Creating raster from raster subtraction

I am trying to create a raster from the subtraction of two other rasters. I am aware the process involves several steps, therefore I would like to know: What is the command for raster subtraction? ...
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42 views

RasterCalc multiple band operation

I have a 3 band image and for EACH BAND I need to reclassify the -26872 to a 0. Is there a way to do this using rasterCalc? ...something like: eq(xxx@1 xxx@2 xxx@3, -26872, 0) I have just explored ...
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67 views

QGIS merge rasters error

I've been trying to merge some raster tiles at work and I've been getting an error message saying I don't have the correct permissions. This works fine on my home pc. Any obvious reasons for this? ...
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133 views

How to create a raster mosaic from many asc files

I am trying to create a raster mosaic (in ArcGIS 10.1) as I am working with many asc files - I am trying to put all the different tiles together in order to run a view shed analysis. I have been told ...
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129 views

Assign spatial reference for 1000 different ECW raster datasets using 1000 different *.prj files through python programming or .net

I am having 2000 ECW raster datasets without spatial reference and also I have 2000 *.prj files in another folder. I know only the way as right click on raster datasets-->properties-->Spatial ...
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92 views

How can you calculate mean value per segment in Idrisi?

I have a segmented image and the original NIR/R/G bands in Idrisi Selva. I would like to calculate the mean NDVI per segment in Idrisi. There are so many tools, I'm not sure which would do the trick. ...
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79 views

Floating Point UniqueValueRenderer

I am trying to build a unique value renderer using ArcObjects .NET. All the samples that I have seen use the attribute table to build the UniqueValueRenderer. However, my raster does not have an ...
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54 views

How to deal with the situation when two rasters stacked together in arcgis?

I am doing a project about petroleum geology. There are several formations needed to add attributes (e.g. name, thickness and age). I have the raster data of thickness, so I created a raster catalog ...
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90 views

Copy Raster Tool and 1bit to 8bit

I have a bunch of 1 bit rasters (700+) of scanned maps that I need to convert to 8-bit rasters. It's the only way Geosoft will recognize the spatial coordinates of the TIF as they don't deal in 1bit ...
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68 views

QGIS: “No data” raster value for missing rows conflicts with data?

I’m having a problem with specifying “no data” in a raster dataset in QGIS 1.8.0-Lisboa. QGIS does fine in interpreting pixels I don’t have rows for as “no data” if I set Layer Properties -> ...
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81 views

Why does a shapfile shift after transformation?

I have a shapefile created in the raster package (ER_14.3_2000_poly). > #read in a raster file > ER_14.3_2000<-raster('E:/Ecoregions Models/Outputs/ER_14.3/ER_14.3_ConsensusMap3.asc') > ...
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204 views

How to fill in the parameters for kernel density estimation?

I am desperately trying to calculate animals home range with kernel. Unfortunately, the result is obviously incorrect and I cannot identify my mistake (I would like to post a screenshot but its not ...
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57 views

ArcGIS API for Silverlight: Retrieve all Data From a Raster layer?

Is it possible to use ArcGIS api for silverlight to get the data in each cell of a raster layer and store them in an array?
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79 views

Copy Raster Catalog from .mdb to .gdb, but only within a certain extent with arcpy?

I am stumped again, this website has really helped me before so here is another shot. I am trying to copy a raster catalog from a personal geodatabase to a newly created file geodatabase but only ...
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159 views

How can I calculate raster cell area for upslope contributing area

I am new to spatial analysis, and urgently trying to follow this tutorial to generate a topographic wetness index for my area of interest: ...
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149 views

Use a WMS raster in ArcGIS 10 and combine with vector layer as an

I have connected to a WMS server which provided a raster images which are a LIDAR surface elevation map. http://data.gov.uk/dataset/lidar-digital-surface-model-wms I also have a vector layer which ...
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159 views

Manually edit cell value in DEM in Arcmap10?

Is there any chance that I could manually pick a group of cell in DEM, then edit the value of them in Arcmap 10? I know about the Aris Grid Editor for Arcmap but it requires licence and it's too ...
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53 views

Problem with Georeferencer not scaling TIFcorrectly

I am trying to use QGIS and the Georeferencer to digitize paper maps but I am unable to get the raster to rotate afte I pick my control points. Below is a brief outline of the steps I used to ...
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31 views

QGIS: Unable to project raster layers correctly on a Toshiba Tecra 64# Win7

I know how to project a raster, I can do it on other machines. On this particular machine the raster loads but are no where near the correct position as if the datum is on another planet.
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76 views

Display raster outlines

I guess mine is a very simple task, however I don't know how to solve it. I m trying to display the outlines of a raster created from a polygon shp. What I would like to come up with is an image where ...
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85 views

Searching Pixel Location (idrisi) on Another GIS

I'm Searching similar command Pixel Location (like idrisi) on Another GIS, I, need create raster file with values ​​lat, long by separately... Update: I need a raster file where the value of each ...
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105 views

Why Stacking rasters return all values as NAs?

I have several rasters that I want to do some calculations ,basically calculating the moving average. dir2 <- list.files("D:\\2010+2011", "*.bin", full.names = TRUE) ...
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62 views

Four band raster - ColorInterp of the IR band

I have a four band aerial photography raster. The bands contain Red, Green, Blue, and IR data. Using GDALInfo we get something like this currently: Band 1 Block=2933x1 Type=UInt16, ...
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717 views

How to resample a raster in QGIS?

I've got a boundary file that I would like to resample the raster file from a 30m grid to a 10m grid inside the boundary file. When I try and do it in Qgis or Grass all I get is one big raster cube ...
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471 views

why preview image is blank for ImageMosaicJDBC (postgis raster) layer?

I follow http://docs.geotools.org/latest/userguide/library/coverage/pgraster.html to publish a ImageMosaicJDBC layer in geoserver. the layer seems published ok and saved, but the preview of this layer ...