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

learn more… | top users | synonyms

2
votes
1answer
190 views

How to multiply raster DEM with a linear graph value

I would like to multiply my Raster DEM with a linear graph value y = mx + C. The graph values look as follows: I want to make a new raster where each cell will represent a damage factor from ...
0
votes
0answers
28 views

calculating mean and standard deviation for raster values using whole pixels within a polygon [duplicate]

i have a raster image and a corresponding shape file. i would like to calculate the statistics of the values within polygons which have a common attribute but only using pixels which are fully ...
1
vote
0answers
33 views

Layers and variables are not coming out in the raster calculator tool window

I have many shapefiles in the table of content but layers and variables are not coming out in the raster calculator tool window. I placed the cursor the left of the Raster Calculator window, dragged ...
3
votes
1answer
433 views

NOAA Nautical Charts .bsb format

Is it possible to load a nautical chart from NOAA into QGIS that has the .bsb format? Didn't have much luck with mrSID format. using QGIS(dev) on ubuntu 13.04
1
vote
2answers
2k views

How to access each raster in a stack with a loop

I have a stack of rasters and I want to access each layer, combine each later with another file and finally export the resulting file as a csv file. Is there any way to do this with a loop? So far I ...
0
votes
1answer
248 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 ...
4
votes
1answer
397 views

Understanding percentage drop-raster (flow direction-tool)

I'm creating a Topographic Wetness Index using a python script (http://arcscripts.esri.com/details.asp?dbid=16750) As I don't want this just to be a blackbox, I'm trying to understand the different ...
1
vote
1answer
790 views

Extract Raster Values by Polyline End Points

I am looking for a way to extract elevations of end points for line data in ArcMap 10.2. I have a road dataset that I want to use as a Network Dataset in Network Analyst. I want to be able to set the ...
5
votes
2answers
173 views

filling up a depression to create new surface

A collegue here has a problem I cannot help with. She has the surface (as raster) of a landslide release area (from AFTER the slide) and wants to calculate the calculate the theoretical/approximate ...
2
votes
1answer
386 views

How can I dynamically trim the informational border off of FAA sectional raster charts?

I'm trying to write a script that can automatically use GDAL to crop the informational border from the FAA's published sectional charts (GeoTIFF) found here: I know that I can use gdal_translate ...
1
vote
0answers
85 views

Sending Raster File in ArcMap, Attributes Gone

On my computer, I opened a .tif file in ArcMap 10.1 and reclassed the values into two categories - this results in a new file. I then send that file to another computer and open it in ArcMap but ...
3
votes
2answers
302 views

The fastest way of generating tiles from raster?

I have some MODIS imagery 250m resolution covering a large area which I generate tiles from using Mapnik and generate_tiles.py script. I need to run this script every day with new satellite images, ...
0
votes
0answers
164 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 ...
1
vote
1answer
143 views

How to work with 16 GB orthophoto raster

I would like to use one GeoTIFF raster in a custom ArcGIS-Engine Application, but my provider gave me 4 orthophotos GeoTIFF 4 GB each, because GeoTIFF is limited to 4 GB. Is there any other way to ...
1
vote
0answers
54 views

Selecting a rectangle box from a raster tiled table in PostGis 2.1

I am new to PostGIS as well as SQL queries for rasters. I have imported a raster .tif file into PostGIS with tiles. I would need to select a bounded rectangle from within this raster using SQL ...
1
vote
0answers
175 views

GDAL and Python: How to “pad the extent” or otherwise handle band.ReadRaster() for area falling slightly outside the image bounds?

In a nutshell, I'm trying to create a bare-metal tiling utility using GDAL and Python. As you can see in the graphic below, which shows the perimeter of a raster and the OSM-structured tile index, ...
2
votes
1answer
62 views

Calculating statistics for an Image Service

I haven't been able to find much information at all in regards to ArcGIS 10.1 Function Template Chains... I need to be able to load a .rft in my image service and calculate statistics... so I am using ...
3
votes
2answers
400 views

How to solve jpeg2000, jp2. crash & errors on arcgis 9.3.1 windows 7 64-bit

I have several problems at work. One is that jpeg2000 crashes ArcMap but mostly ArcCatalog when trying to read them. This is only occurs on machines with Windows 7 64-bit (we don't have Windows 7 ...
4
votes
2answers
958 views

Is there a Focal Statistics (spatial analyst) tool in ArcGIS equivalent in QGIS?

I'm attempting to use QGIS v2.0.1 to accomplish the same tasks that I can do using ArcMap v10.1 and I'm running into some trouble finding equivalent tools. In ArcMap I am using the Focal Statistics ...
6
votes
3answers
2k views

Best way to clip a large raster ECW file ?

I am trying to clip a large ECW (details below) but the raster file is too big to be processed entirely. Some details of the ECW below Driver: ECW/ERDAS Compressed Wavelets (SDK 5.0) file size: ...
5
votes
5answers
1k views

Impossible to sum rasters because of nodata pixels

I have a set of rasters (.vrt) with daily soil moisture data. I want to sum the pixels of all rasters in order to have a measure by month. However, the whole world is not covered each day, which ...
1
vote
0answers
142 views

Interpolating shapefile of points to grid using Java?

I am looking for a method/prog/library(java) to interpolate points from a shapefile to a grid (file). I have seen arcgis can do that but i am looking for something free. More specific: i have ...
3
votes
4answers
2k views

How can I Destripe Landsat Images?

I am working with Landsat 7 ETM+ SRC-off imagery. I'm doing some land-cover classification for a place in Kenya. My problem is the no-data stripes in the image. Is there a way in which I can ...
1
vote
1answer
146 views

Raster Smoothing python [duplicate]

I want to perform raster smoothing on a DEM file. I want to to assign the elevation of each pixel using the average elevations of its 8 neighbors. The ESRI's "Python scripting for ArcGIS" has a ...
3
votes
2answers
343 views

Partial Map Pixel Projections

I have the following: A PNG or JPG of a random width and height, in pixels, that represents a partial map of the world (i.e. a rectangle of the United States). The four corners of this image are ...
1
vote
1answer
143 views

Problem loading raster QGIS 2.0

I am very new at GIS. I am trying to load a raster so that I can complete a tutorial on georeferencing. The raster file is a jpeg. However, whenever I try to load the raster, it gives me solid colored ...
2
votes
0answers
337 views

Finding coordinates from a nested grid as a numpy array

So this is a pretty basic question, but I'm trying to figure it out. I've written a script that allows a user to read in a raster and provide a cell resolution, and outputs the amount of cells ...
1
vote
1answer
114 views

raster to ascii in QGIS

I have a raster file (DEM or .tif), but I need to transform it into a .txt file (ascii). How can I do this in QGis (Quantum Gis)? Thank you so much!
3
votes
2answers
270 views

Calculating Z-scores in Arc

I am trying to take the natural log and then calculate z-scores on cell values in several composite band GRID rasters in Arc. I am not fluent in python and do not see a way to automate this within Arc ...
4
votes
2answers
757 views

Sum many netCDF rasters

For the first time, I am using NetCDF data files containing daily data about soil moisture at a global level. I want to be able to obtain monthly mean value of soil moisture for each grid cell. ...
3
votes
0answers
459 views

Extract values from raster based on weighted average area using polygon grid

EDIT: I am using Armap 10 sp 5 I have found similar questions but they were either unanswered or somewhat different to what I am asking. I have a raster with cell values 1-5 and a polygon shape file ...
2
votes
1answer
2k views

How to open a “Raster Dataset” in QGIS

I want to open a "Raster Dataset" in QGIS. In ArcMAP I can just add it like shown in the Screenshot (only the raster shows up). If I am trying to do this in QGIS. However there I don't see the ...
3
votes
1answer
574 views

How to join 2D polylines and DEM into 3D polylines?

I got a simple question but could not find a satisfactory answer yet: I have a road network in 2D/PostGIS and a DEM. I want to turn the road network into 3D by retrieving the Z-value from the DEM. ...
4
votes
1answer
74 views

Raster Calculator Bug at start

I use ArcGIS 10.1 on a Windows XP. ArcGIS completely shuts down when I attempt to launch the "Raster Calculator" tool. Has this happened to someone else? Any ideas on how to solve this annoying issue? ...
3
votes
1answer
397 views

Selecting raster values at random locations in a raster in python/arcgis

I have a large dataset of integer rasters, and was hoping to find a way to generate a "random" selection of pixels for four of the rasters, while making sure all 5 classes, which I've specified based ...
0
votes
1answer
79 views

What tool breaks up raster cells into individual values based upon contiguity?

The green values have a COUNT attribute of 13418. I will want to use a tool that lumps the COUNT attribute and reclassifies based on values. But first it appears I will need to break up the raster ...
3
votes
0answers
102 views

Add attribute table to a raster in postGIS

I would like to add attributes to a raster stored in a postgis database. I use the following command to insert the raster in the database: raster2pgsql -s 4236 -I -C -M ...
1
vote
0answers
212 views

GDAL in Java fails on ReadRaster()

To summarize, trying to read a raster keeps giving me an UnsatisfiedLinkError that makes sense, but looking into the compiled GDAL jar, I don't know how to fix. gdal.AllRegister(); TheFile = ...
0
votes
0answers
427 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 ...
2
votes
1answer
95 views

How to select a part of a land cover type a certain amount of feet away from another land cover type

I have raster Landcover type Urban combined with Forest all within the county raster perimeter. I want to make a layer of only the forest cells that are more than 500 feet from an urban cell, so that ...
1
vote
2answers
603 views

Error .ecw is not a supported raster data source

I am a user from Spain and a I have recently installed QGIS 2.0 in my computer which has Ubuntu 13.04 and when I try to use an .ecw file it says: Error, .ecw is not a supported raster data source. I ...
2
votes
0answers
187 views

python.multiprocessing and “FATAL ERROR (INFADI) MISSING DIRECTORY”

I have a question which is closely related to this old question here: python.multiprocessing and "FATAL ERROR (INFADI) MISSING DIRECTORY" I have also looked at this, which seems to relate ...
4
votes
1answer
603 views

How to delete coordinate system from raster file with prj.adf?

How can I delete the coordinate system from a raster file like .adf which is multiple files? I found a file with tha name "prj.adf" so if I delete this file is it enough? In shapefiles usually Ι ...
4
votes
2answers
352 views

Problem loading SID to geoserver

I have a folder with .sdw and .sid files I want to server using geoserver. I've followed the instructions here which basically means to install GDAL extensions and binaries on the geoserver machine. ...
1
vote
1answer
97 views

Why is my raster offset after I use a tool such as Reclassify?

I'm using ArcGIS 10.1 and have noticed a strange problem. Often,though not always, when I use a tool such as Polygon to Raster, Reclassify, or Mosaic to New Raster, the resulting raster layer is ...
4
votes
0answers
318 views

How to convert a raster (array) to a NetworkX graph and do a * search?

I want to use a slope-raster for a a_star path analysis in NetworkX. I am using Python for this project. My test raster looks like this First I read in the raster with GDAL input_raster = ...
0
votes
1answer
230 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), ...
0
votes
0answers
276 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 ...
5
votes
1answer
434 views

Legend of a raster map with categorical data

I would like to plot a raster containing 4 different values (1) with a categorical text legend describing the categories such as 2 but with colour boxes. I've tried using legend such as : legend( ...
1
vote
0answers
16 views

the layer attribute table is not consistent with the pointvalue

The point value of my grid is right, but the output value ranges from -2147483648 to 2147483647. I haved tried to recalucate statistics, but it didn't work..