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

learn more… | top users | synonyms

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
158 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
386 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
147 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
361 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
140 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
305 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
852 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
496 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
3k 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
654 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
75 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
450 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
84 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
114 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
238 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
465 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
101 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
652 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
204 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
674 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
377 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
106 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 ...
5
votes
0answers
349 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
261 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
347 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
507 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..
1
vote
2answers
113 views

Neighborhood analysis based on occurrence of value

How can I do, either in ArcGIS, grass or another tool, the following: for each cell (pixel), if there is at least one cell with value '4' in a neighborhood of 5 cells around it, reclassify that cell ...
4
votes
1answer
2k views

How to resample GeoTIFF images to the same resolution?

I have two geotiff images that I would like to resample the same resolution. If I use ArcGIS this would be easy to do. But using QGIS I don't know how to do this. Some help will be very appreciate. ...
2
votes
0answers
293 views

How to add new raster store and publish for ECW fromat in GeoServer 2.4-RC2?

I am using GeoServer 2.4 RC2 and Tomcat7 on windows xp OS. I have extracted the gdal-data.zip (2.4.0) and geoserver-2.4-SNAPSHOT-gdal-plugin into Tomcat 7.0\webapps\geoserver\WEB-INF\lib. Now ...
1
vote
0answers
341 views

validating the calculation of slope from DEM

my purpose is to calculate and validate slope in percentage of southern california using DEM and landsat data. step 1)i used a DEM file and changed with the float type file to integer type step 2) i ...
2
votes
3answers
473 views

Raster map in different zone () than region ()

I am new to QGIS (just installed QGIS 2.0.1) and am having problems running any spatial analysis tools. I followed the instructions on how to call GRASS tools into QGIS, but when I try to run the ...
2
votes
0answers
96 views

Can Esri ASCII Input files be Aligned with Track Heading in QGIS?

Using QGIS to input Esri ASCII data files, I uploaded many small files, each file representing a second of data: 16 sensors X 25 lines. Each file uploaded creates a small rectangle on my larger map ...
0
votes
1answer
215 views

How to import and patch multiple ASTER files in QGIS?

I'm a new user and just began with GRASS, where I learned to import 30x30 resolution ASTER files and then patch them (the six I'm working with) into one map. On QGIS, it doesn't appear that there's a ...
3
votes
2answers
254 views

How to do regression analysis out-of-memory on a set of large rasters in R?

I am trying to do a regression analysis on a set of large rasters (254,004,000 cells each). Ultimately, I want to run something like the following (or a bit more complex, but let's start simple!): ...
1
vote
2answers
2k views

Convert vector data with irregular points (no grid) to raster with QGIS?

I am aware that how to convert a vector layer to a raster layer is a quite frequent problem and that there are many questions and answers dealing with it. However, none was helpful concerning my ...
0
votes
2answers
911 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 ...
0
votes
0answers
169 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 ...
0
votes
2answers
231 views

How can I fix a geoTiff with an incorrect CRS?

Trying to load and plot a raster (it's a DEM) in R, but having problems. Using R I read in a raster file: library(raster) dem <- raster("DEM_Victoria.tif") # >70 MB print(dem) class ...
3
votes
1answer
863 views

How to cluster Raster data

I have thousands of Raster data concerning the ice coverage at the pole at different times (days) over several years. Now I would like to perform a cluster analysis. I want to split the data into ...
3
votes
1answer
247 views

How to import ESRI Ascii format into GRASS?

I need to take a set of datafiles, generated by our sensor system that reads GPR (Ground penetrating Radar) deviations over a surface as we drive along. I have discrete readings from a set of sensors ...
0
votes
1answer
356 views

Problem with converting rasters to arrays and adding them to main array, then converting to raster via NumPyArrayToRaster : output is NoData values

I have a process that aims to loop through a list of rasters (testing with only 3) covert each raster to an array, add the array to an existing 'template' array, then save the final array back to a ...
0
votes
1answer
43 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
10
votes
6answers
2k views

How do I iterate through every cell in a continuous raster?

See this link for more details. The Problem: I want to loop through a continuous raster (one that has no attribute table), cell by cell, and get the value of the cell. I want to take those values ...
1
vote
2answers
1k views

How to extract subdataset from HDF raster?

I am trying to extract a subdataset from HDF raster. Later on, I intend to make operations such as mosaicking and extracting raster averages from the extracted subdataset. The following code is ...
1
vote
0answers
190 views

Modifying Raster Layer with Python Console

Forgive me if this has been asked somewhere else. I am looking for a way to edit a raster file which has already been loaded into QGIS through the python console (i.e. I would like to edit the raster ...
4
votes
1answer
99 views

Update Grid cell value with Point attribute

I have a 4km gridded dataset with each grid cell value as a measurement of precipitation. I would like to update it with a point shapefile of more precise precipitation values. Aside from ...
0
votes
1answer
128 views

RFE raster images datum conflict

Im using ArcGIS 9.3. I've downloaded RFE images from FEWSNET. And im trying to load them on ArcMap, to clip them using Mozambique's shape. But as the RFE images related to Southern Africa come with ...
1
vote
1answer
133 views

Raster Dataset projection problem

I have a problem connected with my Raster Dataset projection. Two of its bands cannot be shown in some scale - only under 1:1500, when I use 'Zoom to raster resolution' option. Histograms for all 3 ...