Rasters are regular grids of values, usually stored in an image-like format.
0
votes
1answer
24 views
ImageMosaic-JDBC Error
I'm trying to get postgis raster layers in geoserver-2.3.1, with postgresql-8.4, postgis-2.0 and gt-imagemosaic-jdbc-9.1.jar support. I'm going through the tutorial with a PNG raster that i have. In ...
3
votes
1answer
94 views
Visualizing Spatial Query
I'm new to GIS applications and trying to figure out what options I have for visualizing spatial query results that combine raster and vector data using OpenLayers/GeoExt/GeoServer/PostGIS.
A ...
3
votes
1answer
471 views
How to handle time-based raster data in the ArcGIS Server JS API
The TimeSlider functionality in the ArcGIS Server JS API is great for working with time-based vector features - you can scroll forwards and backwards through time to see the vector features which ...
0
votes
0answers
32 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 ...
1
vote
2answers
82 views
Raster Calculator question for Multiple Rasters
I am having trouble for writing script in Python (ArcGIS 10.1). The task is generally divide each raster by 100. I have many of these raster files....
So what I've done is the following:
from ...
0
votes
0answers
14 views
GeoServer/Leaflet - Context menu to change raster [duplicate]
It's my first GIS project and after days of reading, it is still not clear how I should start.
I'm using GeoServer to serve GeoTiff images in WMS to a leaflet application. It works great.
Those ...
0
votes
0answers
24 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.
1
vote
2answers
47 views
Round Raster to next higher or lower int
I am using ArcGIS 10.1.
I am searching for a solution to calculate a raster.
The values are like:
0.2
0.6
5.3
i.e.
How can I now get 0.2 as 0 and 0.6 to 1 and 5.3 to 5? In the end integer numbers.
...
1
vote
0answers
36 views
GetCapabilities Request for WMS
I'm trying to connect to a WebMapServer with the Geotools WMS classes.
My problem is, that the resonse-object "capabilities" doesn't contain all layers.
When I'm doing the request in a browser, I can ...
0
votes
1answer
50 views
How to find locations for hydro power using raster analysis?
I have a stream network and DEM file both in raster format. I need to extract values from DEM to stream network. For the analysis in stream network after that, I need to find out the places for hydro ...
2
votes
1answer
156 views
What are the units of the calculated area from a raster in decimal degree
I'm trying to calculate area for a raster file which contains 2 layers (0 for unsuitable habitat and 1 for suitable). It's been calculated successfully but I don't know what is the unit of the ...
3
votes
1answer
60 views
How to speed up band math in R 'raster' package?
I have some GeoTiff rasters with over 100 bands in total, but they are not huge: resolution is about 1200x600 and total size is less than 7 mb. I'm trying to do a simple NDVI calculation:
raster ...
3
votes
2answers
248 views
Why is Raster Layer not visible?
I have a raster dataset that is not visible in Data View, but it is listed in the Table of Contents.
I have tried viewing it in ArcCatalog but it is not visible there either.
Is there something I ...
3
votes
0answers
62 views
Weighted Average of several raster “zones”
thanks for the visit!
Suppose I have two rasters, A and B. I want to determine the value of a certain "zone" in raster A by taking the weighted average of several other zones from raster B, that ...
2
votes
1answer
46 views
Can Geoserver return the raster value of a lat/lon point
I have a GeoTIFF published by Geoserver 2.2 and being used by Leaflet via WMS. How can I get Geoserver to return the raster value at a lat/long point?
I'm guessing it has to do with using WCS, but ...
2
votes
1answer
40 views
Nearest Neighbor Focal Statistics and Map Algebra
I would like to use a nearest-neighbor type analysis to iterate over a raster. The nearest neighbor analysis will give a cell value of 1 IF AND ONLY IF the cell being analyzed has a cell value larger ...
3
votes
1answer
58 views
Location for floorplan
Is there an application / service where I can put my floorplan of a building en 'position' it on the right place on the earth? (The buildings location).
I found TileMill an application where I can ...
0
votes
0answers
137 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 ...
1
vote
2answers
437 views
QGis problem with raster transparent
I am new to QGIS. I found the problem impossible to solve the parts of raster data that are in TIFF format should be made transparent. What do I do?
4
votes
4answers
113 views
How to display a “Save As” dialog for raster files?
I'm writing a QGIS plugin in python. I need to show a "Save as" dialog window in order to allow the user to select the path of the output raster file. Do I need to create a QFileDialog and manually ...
1
vote
0answers
510 views
Conversion to Raster issue in ArcGIS 9.3.1
Trying to convert a polygon to raster in ArcGIS gives me an error... I am wondering if there is another way around to do this? I am using ArcGIS 9.3.1.
The error i am getting is number 9999 when I ...
22
votes
6answers
28k views
What are Raster and Vector data in GIS and when to use?
What are raster and vector data in the GIS context? In general terms what applications, processes, or analysis are each suited for? (And not suited for!)
In answering someone's question today, I ...
5
votes
1answer
62 views
Georeferencing a jpeg in QGIS but the scale is way off
I've gone through the really helpful walk-through(s) of how to georeference a jpeg in order to make it a layer, but after inputting the coordinates (either by typing in actual coordinates or clicking ...
6
votes
3answers
758 views
Raster: How to get elevation at lat/long using python?
I was wondering if anyone has some experience in getting elevation data from a raster without using ArcGIS, but rather get the information as a python list or dict?
I get my XY data as a list of ...
5
votes
1answer
130 views
ModelBuilder: How to extract data by date, export to separate tables and interpolate tables to rasters
I've been using ArcGIS for a couple years, but when it comes to model builder I've only worked with very simple models. I'm hoping someone that is much smarter than myself can help me in building a ...
0
votes
0answers
14 views
publishing postgis raster in geoserver [duplicate]
I have stored a table of raster file through raster2pgsql in postgis. When i connect it to the geoserver and publish it, the bounding box limits are described illegal. Also the raster images are saved ...
4
votes
1answer
75 views
Create points around the edge of viewshed results?
Is there a tool or module, or multiple tools, in ArcGIS that will allow you to automate the creation of points around the outer edges of a viewshed?
What I am trying to do is gather data about the ...
2
votes
2answers
77 views
Merging Raster Datasets of Different Resolutions
I have two DEMs in .tif format and I am looking to merge the two. The main problem with merging these are that they are different resolutions (one is 10m and one is ~20m). Also, another problem with ...
2
votes
0answers
56 views
How to create raster attribute table to a raster data using gdal python?
I classified a remote sensing data and saved it as a raster using Gdal python. I want to create a raster attribute table for this classified result.. my classified raster has five classes with ...
3
votes
1answer
126 views
An error in raster calculator in Arcgis
I wrote and ran this formula in raster calculator in ARCGIS. But the following error gets me into trouble. Does anyone have a suggestion to overcome this? Here is the formula I wrote and the error ...
3
votes
1answer
115 views
How to import QGIS Raster into PostGIS
I have created a IDW heatmap using QGIS 1.8.0 and need to import the raster into PostGIS 2.0.1. QGIS saves the raster layer as a .asc file.
How do you import the raster into PostGIS as a Raster? What ...
2
votes
1answer
54 views
MrSid => GeoTiff
I have a MrSid file that I would like to convert to a GeoTiff. Is there a way to do this on a Mac running Mountain Lion? I know it can be done on Windows and Linux using the LizardTech command line ...
1
vote
0answers
551 views
two results of IDW in ArcMAP are different
i added the following points to ArcMAP using "Add XY Data".
x,y,z
7,39,117
27,17,122
27,61,123
46,36,136
52,14,138
55,46,141
56,56,137
65,24,144
65,36,145
Changed raster output size in "options" ...
2
votes
0answers
133 views
How to sort entries in raster legend?
How do I reorder the Value field in a raster? There is no up or down button in it.
0
votes
0answers
26 views
Generate Adjacency Table from a Region Grouped Raster Layer
I’ve searched high and low to no avail looking for any existing tools, scripts, ArcGIS geoprocessing steps that will output an adjacency table something like this:
VALUE,ADJ_VALUE,LENGTH_EDGE (m)
...
1
vote
1answer
23 views
MapInfo displays a JP2 raster weirdly - why?
We have some JP2 files created with FME 2013. They work just fine in ArcGIS, MapModeller and QGIS. But when viewing it in MapInfo (11.5) we get what looks rather like a 60's drug trip.
Zooming in ...
0
votes
0answers
62 views
R Raster package: write NetCDF with time dimension
I am writing a rasterbrick with multiple layers to a netcdf file using the raster package in R:
writeRaster(gridfile, "Data", "CDF", overwrite=TRUE,
...
5
votes
5answers
870 views
How can I align two non-coincident equi-resolution raster grids?
I have two rasters: a digital elevation model (DEM) and a Landsat band. The grid resolution of both is 30 m, but the grids are not coincident (see image: the dark raster on top is the DEM; the light ...
1
vote
0answers
52 views
Reclassifying a raster based on values in another raster
I am attempting to create a new raster based on the values of two rasters I have already created. I am using ArcGIS 10.1
Raster1 is an area with my true values.
Raster2 was created by reclassifying ...
1
vote
0answers
27 views
Rasterlayer divide
i´m new to qgis at all. I´m a blender user and found that beautiful NZ heightmaps at koordinates.com wich are CC 3.0 and free to use.
I want to use this maps for heightmap displacement if i can ...
1
vote
1answer
63 views
R: data.frame to raster object error
I have a data.frame consisting of a points with an associated continuos value and their X,Y coordinates. Altough it's not stored anywhere it's projection is a Lambert conformal conic. I think this is ...
1
vote
1answer
133 views
How to merge different classes/clusters in one single raster in arcgis 9.3?
I've created a signature file with 8 clusters and performed an unsupervised classification. Later I have grouped values (spatial) classes together to form 4 classes I needed (in symbology) but that ...
3
votes
2answers
60 views
Buffer of different radius - Intersect with raster
I have a polygon shape with buffers. However, the buffers are of different size from 4m radius to 15m. In total I have 7 different buffers.
I have a landcover raster and I would like to extract ...
2
votes
1answer
26 views
Problem Joining FAA raster charts
I am new to GIS and I am trying to place the North and South Salt Lake City aeronautical charts in QGIS. The problem I'm having is that there is a black section where the two charts should touch. Am I ...
1
vote
2answers
122 views
“Extract by Mask” changing raster pixel values…or not?
I am using ArcMap 10.0 and am confused by my Extract by Mask output rasters.
I hope to eliminate the black background from three Landsat ER Mapper images so that I can mosaic them. Originally I ...
5
votes
5answers
254 views
How to find the minimum extent of a given pixel value of a raster?
I am wondering if there is a way to find the minimum bounding extent for a raster with a particular value. I clipped a raster from a global image and the extent is set as the global extent with a lot ...
10
votes
7answers
2k views
How do I create a shapefile showing footprints of Rasters?
I have around 1,000 satellite images in tiff format, and I want to create a shapefile which will serve as an index to the rasters. This is something similar to a raster catalog, but I do not want to ...
8
votes
1answer
114 views
What is some theory on the number of GCP when georeferencing?
Just wondering, is it always better to have more than 3 GCPs? Should the GCPs be spread out evenly? Where can I find some general resources on the theory of this? Other than trial an error, which ...
1
vote
1answer
36 views
Difference in raster size using raster2pgsql
I use the PostGIS-build-in raster2pgsql to load SAGA-raster into the db. I tried to grid them into 100x100-tiles, just as seen in the code:
/usr/lib/postgresql/9.2/bin/raster2pgsql -s 32632 -a -F ...
4
votes
0answers
73 views
Assigning costs to a road network : use raster or vector?
I have a road network in a PostGis database (db_routing). In another database (db_environment), I have some spatial features of the surrounding environment (trees as points and water bodies as ...
