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

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579 views

combine raster with another raster mask file - gdal

I have 2 rasters in GeoTiff format. One has all of the land and water and the other is a mask file that shows either 0 for water or 1 for land. I basically want my output to just have the land values ...
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2answers
377 views

How to Calculate Custom Zonal Statistics?

I have a vector polygon shapefile outlining counties for which I have a raster of nighttime-luminosity data. I've been able to compute Zonal Statistics in ArcGIS 10.0 using Zonal Statistics as Table ...
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1answer
161 views

How to create a raster with rotated cell orientation from lattice points - ArcMap 10.1

I am trying to create a raster layer from gridded points where the cells have a rotated orientation. Each point is the center of a 1.6 km by 1.6 km cell, rotated to the left. Is there a way to do this ...
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0answers
36 views

TIF file creation from shapefile in GRASS?

Does anyone have any idea how to get around this problem? I've been looking for a solution to no avail. I'm trying to convert a shp file to a grid, and the tif is hanging up. Output raster layer: ...
7
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3answers
657 views

R - How to sampleRandom() from large raster without NA values

I have a number of vary large rasters which need to be randomly sampled with the return value being a matrix of x, y, and value. The raster package sampleRandom(raster,n, na.rm=TRUE, xy=TRUE) will do ...
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1answer
181 views

How to find matching pixel values in seperate rasters

I am looking to scan two separate rasters, capture the pixel information, then draw a polygon of the matching pixels. any thoughts? I am at a loss. Edit: I have two aerials, both are in ...
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1answer
448 views

How to extracting raster data to multiple polygons?

I have a reclassified raster dataset (10 classes) and I want to find out the area of each class contained within multiple (hundreds-to-thousands) polygons. I have all the polygons in the same ...
2
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2answers
129 views

How to translate (reposition) a .tif raster layer?

I'm starting to use QGIS for my thesis (environmental physics) and have to admit I'm pretty ignorant about it - I've always used Mathematica or Matlab. My problem is: I have a raster layer, in .tif ...
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0answers
182 views

PostGIS Raster: raster2pgsql was not found in /usr/lib/postgresql/9.3/bin

I have installed sucessfully Postgresql-9.3-postgis on Ubuntu 12.04, following this instructions: http://trac.osgeo.org/postgis/wiki/UsersWikiPostGIS21UbuntuPGSQL93Apt Having done that, I have ...
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1answer
411 views

Equivalence of EPSG:3857 for MapInfo 9.5

I have a raster projected on EPSG:3857 with QGIS. I have image registration in Mapinfo but there is no projection for EPSG:3857. Do you know the projection that I need to use?
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1answer
619 views

Creating Random Points in ArcGIS 10.1

I would like to create random points across my study area (which is a DEM raster) using the Feature Class> Create Random Points. However, I need to select/copy/move/delete these points and re-arrange ...
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2answers
126 views

How to reduce Polygon to Raster (Conversion) bit depth?

I have a polygon featureclass that I am trying to convert to raster format at a low bit depth (i.e. <8 bit unsigned). The FC contains 50,000 polygons which have five values: 1,3,5,7,9. I have set ...
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0answers
115 views

Strange black pixel on edge when generating with gdaldem -hillshade

I'm getting a strange result when I'm generating an hillshade with the gdaldem hillshade command. Here is my command (see the compute_edges parameter): ...
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2answers
724 views

How to clip an Openlayers OSM Background to a Vector Boundary?

I'm new to QGIS. In my project i have two layers: one is my vector (city boundaries) and the other is the OSM (obtained with the plugin). How can I cut the OSM along the edges of the vector? I want to ...
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1answer
112 views

Which File to load from National Hydrography Dataset?

Start-over beginner here. I'm using QGIS 2.0 on MacBook with OS X 10.8.5. I downloaded a National Hydrography Database file. Unzipped, it is titled NHD11032_NM.gdb. I try to add the layer as a vector ...
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2answers
93 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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1answer
75 views

Raster to Surface

I have a raster and I have been asked to modify some pixel values in it. Is there an open source way to do this? I would guess that I have to create a 3d surface, then manipulate the surface, then ...
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2answers
732 views

Calculate area covered by a particular raster layer within polygons in QGIS

I am trying to extract information on vegetation cover within a set radius of point locations (my sites). I have succeeded in creating a new vector layer of circles with a 5 km radius around my sites. ...
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0answers
126 views

Whats the best way to create bathymetric contour lines?

I have a raster dataset with both Topographic and Bathymetric stored in it. What is the best way to create exact contours of the lake-bed? This becomes tricky when I want to make the contour for depth ...
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2answers
436 views

TIFF/Raster to Point shapefile question

Apologies in advance if this question is incredibly basic, but I've been googling around and I just don't know where to start. I've downloaded some nighttime luminosity data from NASA, and the data ...
2
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1answer
280 views

Hillshade tool in ArcMap returns terraced, pixelated image

I am applying Hillshade tool (ArcMap 10.1) to SRTM in Caucasus Mountains (border between Russia and Georgia). It gives me weird image with 'terraces' (see attachment). I reprojected SRTM from WGS-1984 ...
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2answers
247 views

How to identify valleys on DEM in ArcGIS 10.1 [closed]

First, What is the best and easiest way to identify valleys in a DEM raster? Second, how do you create a least-cost pathway for each valley in a region based on low angle slope and proximity to ...
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1answer
94 views

How to get Name of IRaster object using ArcObjects?

I have an IRaster object as output from a function. I need to be able to get the name of that raster. Is there a way that I can do that? I know that I can't mask an IRaster as an IRasterDataset. If I ...
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1answer
104 views

Retrieving raster/coverage width and height in pixels from GeoServer

Is it possible to retrieve the original width and height in pixels for a coverage in GeoServer using either the Python API or REST? I could not find anything in the documentation regarding how to ...
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3answers
1k views

Creating spatially projected polygon grid with ArcMap

i need to create a grid with 1x1 square kilometres cells in ArcMap. The operation located in Data Management Tools -> Feature Class -> Create Net is almost what i need but in the parameters, i can't ...
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1answer
116 views

GeoServer raster tiles are individually contrast-balanced: how to turn this off?

I'm running GeoServer locally as a servlet (in JBoss), and I'm serving a GeoTIFF file through the WMS protocol. In a webpage running an OpenLayers map, I have the GeoTIFF-WMS layer overlaid above an ...
2
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1answer
132 views

R - Efficient way to segment rasters into sub-regions and sample… without using extract()

My question is: Is there a more efficient way to sample from a sub-region (defined by a shapefile read into a spatial object) of multiple rasters without having to use extract() for each region on ...
2
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1answer
651 views

extend the size (area) of raster

My problem is that I would like to multiply two rasters using raster calculation tool. Both rasters have values 0 and 1, but the covered area of first raster is bigger (100 x 100 miles) then the area ...
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2answers
30 views

working with hydrography raster the cost array ignores the end of water

We have our maps laid out using hydrography maps from NOAA. We had to run the graphics through several steps to create the water feature raster. I have a process that pulls in that raster, sets a ...
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2answers
119 views

How to automate creation of toe of slope from DEM?

I was looking for an automated process to "identify" the toe of a slope from a DEM and ran across this ESRI thread and technique: I am at Step 7 but have no idea how this is accomplished. I get it is ...
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1answer
93 views

How to calculate the sum of all cells in a raster layer upstream of a specific point?

I have a rainfall map which covers large area. However, I'm interested in the total value of rainfall over a specific subcatchment. If I don't have the shapefile which defines the boundary of this ...
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1answer
1k views

How do I fill gaps in a raster to zero value cells?

I am trying to add some forest elevations to a DEM using ArcView. I have converted a polygon feature class of a forest into a raster with the same resolution as my DEM. Then I reclassed the forest ...
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2answers
235 views

Rasters added to mosaic dataset only display at large acale

I have a set of 357 rasters in .jp2 that I've added to a mosaic dataset. All but 7 of them display properly, but the 7 only display at larger scales, around 1:6500 and under. I've tried adding them ...
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1answer
261 views

If I convert a TIN to a raster in ArcGIS will results from the two versions of the surface be comparable?

I have converted a TIN to a raster. I found that the top of a bund wall shifts laterally in position between the TIN and the raster into which it has been converted using the TIN to raster tool in ...
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1answer
358 views

Use of Raster Calculator in ModelBuilder

I have the following equation: 3000*(1-exp((-0.000664)*input raster)) I want to make a tool to use this equation on raster images. I want to do this with the Raster Calculator with the help of ...
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1answer
52 views

Can I export an imagery directly to a geo-referenced raster form File|Export Map in Arcmap?

While using File|Export to export an imagery to raster, is there a way to have it geo-referenced in a way that if I load the exported raster into the map, the image sits exactly in its place without ...
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0answers
249 views

converting vectors to raster (burning streams)

I converted my stream vector to a raster file (using polyline to raster conversion tool). I anticipated that I would get a No Data row in the raster file attribute table, so that I could use a ...
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1answer
3k views

Is there a way to export online ESRI basemap layers to raster?

I have been working on polygonizing the vegetation areas in some counties from imagery. When I have the mosaic raster locally I can easily get the polygons using Image Classification Toolbar. But when ...
2
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1answer
55 views

How to choose an area (of mxn metres) within a raster that have values above a certain range

I've got a raster of concentrations of iron on Mars and I want to be able to choose several areas of either m by n dimensions in metres, or just any area in m^2, that encapsulate regions that have ...
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2answers
2k views

How to make RASTER from irregular point data without interpolation

I was trying to make a raster image from an irregularly spaced point database. The data looks like- > head(s100_ras) x y z 1 267573.9 2633781 213.29545 2 262224.4 2633781 ...
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1answer
984 views

How to perform a Cost Path analysis in ArcGIS 10.1?

Is it possible to model the easiest pathway through a landscape between many points (rather than just two)? I want to carry out a cost-path analysis, I would like to display the easiest pathways ...
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1answer
112 views

gdal_rasterize using a “string” as src_datasource

I would like to use a string as src_datasource for gdal_rasterize program. Is it possible to use something like a WKT definition to translate a single point to a raster? Somethink like ...
2
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2answers
1k views

Iterate through multiple Raster files and compute statistics using Zonal Statistics

I have a large number of raster images. What I'd like to do is to compute statistics on different sections of these raster files using a polygon. I think everyone is suggesting Zonal statistics. ...
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0answers
72 views

Color blending/compositing in web mapping frameworks?

The color/layer blending capabilities of QGIS 2 produce marvelous results. Blended rasters are especially nice to look at. Blending is, to me at least, a better way of combining layers than mucking ...
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3answers
457 views

Cache generation failed. Progress gets stuck at 0%

I'm trying to publish a map service containing a large .tif raster (48GB). I managed to publish a small cached raster successfully (for testing), but when I tried to publish the large one, the cache ...
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1answer
188 views

Wrong values in Feature/Point to Raster

I've got an XY dataset that I'd like to convert to a raster, based on the ETrel_whol field. The ETrel_whole field includes NaNs and ranges from 0-1. I would like to convert this to a raster, with a ...
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1answer
83 views

How to build and pass remap for floating point raster without getting Reclassify ERROR 010255?

I am receiving the following message when executing my python script: ERROR 010255: String remap must be used with a string field. My input raster is floating point and I would like to ...
2
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1answer
96 views

How do I create smaller maps for publishing from multiple tiles representing a large map using QGIS?

I am completely new to cartography and QGIS - I'm a writer, editor and acceptable designer (Adobe Creative Suite). I wish to produce PDF tour guides featuring maps that display a route. One version ...
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3answers
902 views

Merging hundreds of Aerial Photos into one big file?

I have tried to merge my 405 Aerial Photos into one. I have FME and ArcInfo 10.0 at my disposal on Windows 7 64bit. I have tried the following: create a mosaic; export all images from a ...
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0answers
33 views

Warping Rasters in QGIS

There seems to be a bug warping rasters in the new QGIS version 2.0 When you have to option of target and Source SRS, the Coordinate reference system does not get automatically writen into the box ...