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

learn more… | top users | synonyms (1)

0
votes
1answer
34 views

How to Calculate Area in Raster data in Arcgis 9.3

I run Supervised Classification on Spot image and now how to claculate The Area of different classes with out converting To shape file . because converting to polygon create too much polygon which is ...
0
votes
0answers
81 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 ...
2
votes
3answers
931 views

How to publish ECW images to ArcGIS Server?

When I am going to publish mxd (containging image.ecw) to ArcGIS Server, the following error appears: Confiquration image.ecw. MapServer can not be started. Server Object instance creation ...
3
votes
3answers
1k views

NoData values recognised in raster in ArcGIS but not following symbology rules

I have a GeoTIFF raster in ArcGIS, which can be downloaded from the following two links: http://www.rtwilson.com/downloads/MODIS_MOD04_16-06-2006_Subset.tfw ...
0
votes
1answer
98 views

Convert MapInfo raster file (.tab) to use it in QGIS and/or ArcGIS

I am trying to convert raster files from MapInfo (.ecw, .jpg, .TAB) in order to use them with QGIS or ArcGIS. I have access to all 3 softwares. I have tried Data interoperability tools in ArcGIS but ...
1
vote
2answers
185 views

How to create a raster (topo to raster) with non-rectangular shape?

I'm using Arcmap 10, I need to create a raster from contour lines. These contour lines were clipped out with a certain shape with the purpose to modify them only within that shape and then create the ...
0
votes
0answers
49 views

How to convert a shapefile to binary grid?

I have a polygon shapefile with a UTM projection which I read into MATLAB: % available from http://sharesend.com/zhqsdc9x s = 'C:\path\to\shapefile.shp' % Read the shapefile shp = shaperead(s); ...
1
vote
0answers
19 views

QGIS 2.01 - raster transparency not working properly

I have loaded a color raster image (aerial orthoimagery) into a QGIS project. The layer is visible but very transparent (in the enclosed image the vector polygons are below the imagery), but when I ...
6
votes
3answers
432 views

Suggestions for an efficient way to store raster files for lab use?

I'm trying to create a repository for our raster files from various sources and Im exploring the possibilities on how to store them and deliver them in our local intranet. I have come across rasdaman ...
2
votes
1answer
376 views

Output of QGIS raster clipper not as expected?

My goal is to clip a raster with a polygon in QGIS 1.8. Based on an article I read, this should be a pretty straightforward task. However, the output appears to be empty. The raster produced is the ...
0
votes
1answer
28 views

Cannot display Oracle raster images using QGis

I am dealing with QGIS 2.2 and the plug-in Oracle spatial georaster. Apparently the connection to the database can be made, as the raster images are listed once you press 'Connect', but when try to ...
0
votes
0answers
28 views

IDW Interpolation Raster clipping

I used the CLIPPER tool under the 'Raster' menu to clip my interpolation raster with a polygon. the resulting output is not displaying anything even though the process completes without any errors. ...
1
vote
1answer
24 views

How can I assign Raster2 pixel value to Raster1 where they overlay?

I want to assign Raster2 pixel value to Raster1(Bigger) where they overlay. Both of them have the same cell size. How can I accomplish this process in ArcGIS Desktop? (Like Raster Calculator ) ...
0
votes
2answers
42 views

how to specify -t critical dowloading raster with raster2pgsql

I'm trying to download a raster into postgres/postgis. So far I wrote: raster2pgsql -s 3006 -I -C -M -R filename.tif -F -t 463.313x463.313 schema.rastername | psql -h localhost -U postgres -d db ...
1
vote
1answer
59 views

Calculation amount or number of certain pixel-values in a raster

It seems pretty simple but until now I could not find a proper solution: In a given raster i want to know the number or ratio of e.g. red pixels. Edit: to be more precise: I have a number a arial ...
2
votes
1answer
153 views

how to create an outline polygon (footprint) from raster data with postgis?

how can I create a polygon, containing the actual outlines (aka footprint) of a raster file with postgis? I just need the outlines of the data containing parts of the raster. ST_PixelAsPolygon ...
1
vote
0answers
21 views

Is there any GRASS command to measure the distance between a point in rastermap and another in vector map?

I have a question about WinGRASS 6.4.3. Is there any GRASS script command to measure the distance between a point in rastermap and another in vector map? I have a raster map and a vector map. Raster ...
1
vote
1answer
99 views

Export ArcGIS Model to Python - Iterate Rasters, Collect Values, Calculate Values

I want to batch process a large number of raster files, calculate some values and properties and export these to a .csv or .xls. I managed to get a good working model that does this perfectly. ...
0
votes
2answers
34 views

Polygon Data to Fit Raster

I'm working with an NHD Flowline of streams and rivers in NC, and I'm trying to only retain the ones in the raster. I tried to convert to the raster to a polygon and was going to clip them, but in the ...
1
vote
1answer
60 views

Extracting data from a raster to a polyline based on start and end points?

I have a polyline shapefile with the attributes seen above. startx and starty represent the coordinates of the beginning of each segment of a polyline. endx and endy represent the coordinates of ...
0
votes
0answers
19 views

What information, Open Attribute table of stream segment shows?

I have delineated the watershed from DEM data. I have converted the stream segment(raster) to vector lines. In the attribute table of this vector lines, there are 3 columns, CAT, VALUE, LABEL, what ...
-1
votes
2answers
53 views

Polygon shapefile to Raster with Mask and Extent

I have a polygon shapefile (Vesijärvi lake). The lake has many islands, bays and inlets. When I look at the attribute table, there are actually two adjacent features: Northern lake and southern lake. ...
1
vote
1answer
36 views

How to perform a standard deviation stretch on a raster in QGIS

Is there a way to perform a (2) standard deviations stretch on a raster image in QGIS 2.2? I have found the raster styles menu, but the help says there is no help in my language (English) and whilst ...
0
votes
4answers
86 views

Best tutorials on raster data formats and raster manipulation [closed]

I am looking to improve my understanding of raster formats and how to manipulate them. I don´t really want to go into the mathematics of it, but really want to know the differences between the ...
1
vote
1answer
103 views

Scanned Transparent Map Overlay

We have a flat file of 50 Geology maps that have a transparent overlay with faults and drill holes. I have them scanned and georeferenced as TIF images and they will be used in ArcGIS 10.0, 10.1 and ...
0
votes
1answer
16 views

Is rid=2 significant in PostGIS raster structure?

It seems that in most, if not all, examples with raster appear to include the WHERE rid=2 statement in the query. http://postgis.net/docs/RT_ST_Value.html Is there something about the rast structure ...
1
vote
1answer
53 views

Floating point calculations in QGIS

How do I manage floating point calculations in QGIS? I have carried out 3 consecutive calculations on landsat bands. I end up with 32 bit floating point rasters on which I can't carry out a 4th ...
1
vote
1answer
47 views

QGIS Quickly switching overlapping raster images

I'm new to QGIS, and haven't used arcGIS in about 5 years, however I've just seen someone using arcGIS and was able to quickly switch between overlapping rasters when checking registration. The top ...
0
votes
1answer
37 views

Merging Raster: ImportError: No module named _gdal_array

When I try to merge rasters I got following error message: _gdal_array = swig_import_helper() File "C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\osgeo\gdal_array.py", line 18, in ...
2
votes
3answers
77 views

How to reclassify only a part of a raster but keep the rest unchanged (ArcGIS or R)

I'm trying to reclassify only a certain part of a raster...not the entire raster. Here's the problem. I have a LULC raster of the entire US. There are some issues with the raster that I want to ...
1
vote
1answer
55 views

What format to store/use four band Raster data

I have four band aerial photography - RGBI. I need to share it with my users, a mixture of MapInfo, QGIS, and ArcGIS. What format should I store/serve the data in? GeoTIFF isn't well suited to four ...
0
votes
0answers
29 views

How do I select specific colors within a raster to create polygons with in QGIS or ArcMap?

We have a few georeferenced zoning map rasters and would like to convert specific zones (colors) to polygons, sometimes multiple zones as different polygons. Our workflow has been in the past to ...
0
votes
2answers
93 views

Why am I getting 'Error 000732 Raster does not exist'?

I am trying to apply symbology to a raster layer via kernel density analysis. When I run the Python script below in ArcMap, I am get the error message below. I have searched and tried the common ...
0
votes
1answer
59 views

Create Tiles for a raster(georeferenced) to use in leaflet

I have raster, with each pixel containing some data. What i want is to split a large image with each pixel's color is determined by its value, to show on leaflet layer.How to go about this ? raster ...
1
vote
3answers
1k views

QGIS Raster Calculater Syntax

I am trying to use the raster calculator in QGIS to combine a number of rasters. I want to calculate a mean, this is easy: (raster_1@1 + raster_2@1 + raster_3@1) / 3 I then want to create a max. ...
1
vote
0answers
35 views

Extra row and column in a raster after GDAL grid import

I'm exporting an ESRI grid to TIFF format and after that I'm reading this exported raster file into SAGA GIS. However when Saga reads this file in there appears to be an additional row and column in ...
6
votes
3answers
2k views

Raster mosaic not displaying raster values ArcGIS 10

I have eight DEM tiles that I downloaded from the USGS National Elevation Dataset. The individual rasters are displaying correctly, but when I try to combine them in a Raster Mosaic I get arbitrary ...
1
vote
2answers
99 views

How do I open images georeferenced in ArcMap in QGIS? (.aux.xml)

We have several ArcMap georeferenced images (raster datasets) that we are attempting to open in QGIS without any luck. These are not inside of a geodatabase and are not Arcinfo Binary Grid format or ...
3
votes
0answers
104 views

How to compute surface of raster or any point using ARCGIS?

I have a raster image whose values are a digital elevation model of terrain. I need to know the surface type (topographic characterization) of particular points along transects of this DEM. How to ...
0
votes
0answers
29 views

Why does heatmap size vary with number of points

I am making three heatmaps based on points over the same area and don’t understand why the number of rows and columns would vary depending on the number of features. The first feature set has 398 ...
2
votes
0answers
53 views

Move Scale Rotate raster in Qgis

I have some archaeological scanned raster that they have a north arrow and a scale bar. There is no grid, no coordinate system.I would like to put those files in a general map. I don't care about the ...
1
vote
1answer
56 views

ArcScene TIN smooth

I created a TIN with ArcScene out of laserscan point data. I want to smooth the spikes (image below), to get a nice crossover on the elevations of the surface. Do you have any advice how to do that? ...
1
vote
2answers
50 views

How to import R-generated .gri/.grd raster files in grass?

I received data in .grd + .gri format, where the first one is a small text file and the second one (having the same name) is a binary file. I am unable to open them in grass/qgis. Any hint ? Missing ...
0
votes
1answer
35 views

Export raster file geodatabase to jp2 or jpeg?

Can I export or copy a raster from a file Geodatabase and create a output to jpeg or jp2000 formate? I was reading two different helpline on ArcGIS 10.1 and wasn't sure if I was supposed to export ...
2
votes
1answer
41 views

How do you stop ArcGIS setting Gamma on raster load

I often import raster files using GDAL utilities. When those rasters are added to ArcGIS they seem to have a Gamma Stretch applied and a percent Clip stretch for RGB files. Contrast ids also set to ...
0
votes
0answers
11 views

Raster images at edge of data frame not displaying. How can I prevent then from disapearing?

I have a series of satellite images and as I pan or zoom, the images near the edges of the data frame the stop being displayed leaving small areas with no imagery. It is seems to occur when only ...
1
vote
1answer
267 views

Map Algebra - Grass GIS (r.mapcalc) merge two raster with NoData value

I have a slope raster and a road raster. The black pixels in the road raster are NoData values and the pink pixels have a value of 1. They don't cover exactly the same area. I want to create a new ...
0
votes
0answers
27 views

Zonal statistics won't work after re-projecting vector layer

I have qgis 2.0. I want to analyze raster information within a buffer of 30 miles around a vector layer of cities across the world. However, both the raster and the vector are in WGS84. I have no ...
3
votes
3answers
79 views

how to digitize areas of a raster and snap to the raster cells?

I need to digitize the extent of an ecw raster image where the RGB value is not black.(see attatchment)ie. not the envelope, just the area where the image is shown without the border areas. The black ...
2
votes
1answer
89 views

How to iterate GRASS region definition?

I am using GRASS r.skyview command (v.7, Windows) to determine "urban canyon effect" on pollution due to the presence of buildings. The command nicely works, unfortunately I need to process a very ...