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

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Reclassify ESRI raster using variables from a SQL Server table (connecting with pyodbc)

I am trying to reclass a raster file (representing vegetation and land cover types) using values stored in a SQL Server Express table. I have a set of ~400 species records in the table, with each row ...
4
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1answer
972 views

How do you add a long list of rasters together in Python?

If you have produced a long list of rasters (lets say 50) and want to add them together, is there any shorter way to write in python rather than typing all the inputs, like so: outRas = inRas1 + ...
4
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1answer
506 views

Are there limitations using a PostGIS out-db raster?

I have been trying to import a large raster into a PostGIS 2.0 database and hit a few stumbling blocks. Initially when I tried to import the raster using raster2pgsql, I would receive the following ...
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1answer
148 views

QGis : superimpose 2 rasters georeferenced (adjustment)

I am pretty new in QGis and I encounter the following problem. I have 2 rasters, let's say, "cadaster" and "tranchot". The raster "tranchot" was georeferenced from the raster "cadaster" with QGis. ...
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2answers
637 views

Python problem in conditional combining of multiple rasters and produce one output

I have two rasters for same spatial extent and need to compare both rasters cell by cell and produce one output raster. Each has 10 land cover classes. Based on those 10 classes the comparison should ...
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110 views

How to view Esri GRID format file in wxpython file browse window? [closed]

I'm trying to browse for all kinds of vector and raster data using a filebrowsebutton. The problem is I don't know how to let the browse window see the Esri GRID files (which contains a folder and a ...
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1answer
2k views

GDAL RasterizeLayer Doesn't Burn All Polygons to Raster

I am trying to burn a shapefile to a raster using GDAL's RasterizeLayer. I pre-create an area of interest raster from a different shapefile, given a specific pixel size. This AOI then serves as a base ...
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1answer
1k views

Creating a raster map using Excel file and calculating averages

I am working on my Master's thesis and have thought about using ArcGIS to create a raster map of latitude/longitude (0 to 360 degrees) temperature data (in Excel format). This temperature data ...
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2answers
989 views

How do I use ranges for raster colour map in QGIS

I have a raster layer in GeoTIFF format, with continuous data values between -1 and +1. For the colour map, I would like... >0 to be green = 0 to be grey <0 to -0.25 to be pink <-0.25 to ...
2
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0answers
132 views

3d arcgis raster .tiff image to CFD software

i am trying to export 3d raster image prepared in arcgis to cfd package such as Fluent. I was wondering if any one has experience to convert raster image to autocad 3d format, stl, vrml or any other ...
4
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1answer
254 views

Stripes in Landsat-image after topographic correction (SAGA)

I got stripes in my topographic corrected Landsat images (see second image below). I used SAGA GIS 2.0.8 at xubuntu 12.04 Image and DEM are in the same projection, tried it with EPSG:32636 and ...
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0answers
107 views

Corrupted rasters after import into ArcGIS FGDB

I have been seeing a number of corrupted rasters recently after importing them into file geodatabases (FGDB). The image below left shows a .tif prior to the import, while the image to the right shows ...
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0answers
490 views

How to add ECW support to GDAL bundled with PostGIS Windows

I'm currently trying the new raster functionalities of PostGIS 2.0 and I successfully imported some GeoTIFF file into PostGIS (although it only find one band so it's all black and white for some ...
2
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0answers
448 views

Output raster extents when using the Spatial Analyst Extract By Mask tool to clip a raster

I am using ArcGIS 9.2 and I have a simple python script that does the following : Loop over a polygon feature class (shown in red in the image below) For each record, create a feature layer to ...
3
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2answers
842 views

Rasterize a vector layer in PostGIS

Related to this question asked here on gis.se and this thread on postgis-user, has anyone worked out a good solution for in-database rasterization of a vector layer using PostGIS? It sounds like the ...
6
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3answers
2k views

How to smooth / “reinterpolate” a raster with GDAL?

Short: I want to change the resolution of a raster and smooth the gray ramp like shown in the images bellow. The preference is to use GDAL, PIL or Numpy. Description: I'm kriging points into rasters ...
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4answers
3k views

Advanced colour palette for raster data

I'm working with satellite date namely chlorophyll and sst. Each geophysical parameter generally has standard colours to represent them. I'm importing geotiffs into Qgis and I'm having difficulty ...
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1answer
398 views

polygonize and raster tools [closed]

ok simplest question i have asked i think. but im a running QGIS 1.7.4 and there are no other tools in the dropdown menu other than raster calculator. I have seen in a lot of online demos tools below ...
4
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3answers
381 views

How to store raster data outside postgis database

I am able to import raster data easily into the database and view it through QGIS. However, I am unable to view the raster layer in Arcgis. Now I want to know how to create a table with a reference to ...
2
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1answer
420 views

accessing postgis raster data using Query layer in ArcGIS

I tried to load raster file (jpg) into post gis using the syntax provided here "C:\Program Files (x86)\PostgreSQL\9.1\bin>raster2pgsql -I -C -e -Y -F -s 102003 -t 300x300 ras_test.tif ras_test1 | psql ...
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1answer
627 views

Identify Polygons on raster image

I have OS street view mapping as raster images. Is it possible (without the obvious of tracing each dwelling) to identify all polygons on each tile. To clarify, My ultimate aim is to produce a ...
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1answer
590 views

Merging raster data with different resolutions

I need to merge different raster datasets which have one layer and contain discrete values to a layer stack. The resolutions of the data can have any value so not only multiples of the resolutions ...
5
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1answer
880 views

Why do TIF loaded into PostGIS lose their colormap?

I have successfully loaded a TIF image (using raster2pgsql) into my PostGIS 2.0.1 database. I can load the raster image into QGIS and it displays in the correct space. However, it has lost all colour ...
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1answer
430 views

“Display Background value ”0“ raster”

While publish raster layer in geoserver it shows background as black. How to remove the black color. if there is any options to permanently remove the black color.
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3answers
369 views

Unattractive image artefact when exporting from QGIS's Print Composer

When I export my map from Print Composer in QGIS 1.7.4, an odd red band appears across the middle of the image. This happens when I export to both PNG and PDF. Its not visible on the screen before ...
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1answer
1k views

How do I add TIFF files to one layer/raster catalog?

We have several TIFF images (already tagged with position information) we want to load as a single layer into the map. It's the first time I dig into this raster/topology thing, but at least I managed ...
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2answers
458 views

how to remove the color formed on the edge of satellite image?

my AOI requires two scene of satellite image but when I try to mosaic the images using ERDAS imagine, the color of the edge is seen forming black line after mosaic! so please how can I remove the ...
4
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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 ...
2
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1answer
420 views

Building a virtual raster catalog

I am very new to using GIS software so apologies if this is a silly question. I am trying to build a virtual raster catalog to allow me to work with OS address base and codepoint data sets. ...
2
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1answer
2k views

Converting Raster Data to Polygon data

I am trying to convert a raster data to polygon data. Previously I was using the shapefile.py to create point data on individual lat/lon on the raster. But that will create a Huge data and querying it ...
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3answers
2k 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 ...
6
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2answers
642 views

What Open Source (command line/API) method is there to orthorectify and georeference an aerial image given telemetry data?

How can I take an image and orthorectify it automatically with open source software? The information associated with each image is: camera specs latitude, longitude, elevation of the camera ...
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3answers
2k views

How can I mosaic images in ArcMap without it affecting the colour?

This is 4 images (NE, SE, NW, SW) sections of imagery. They have some overlap between them. Working with 1m 3-band orthoimagery. Different parts are sometime flown at different times/sources hence ...
3
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2answers
59 views

Where to look for oceanographical/environmental data for the Arctic (Baffin Bay/Davis Strait area)

I am looking for oceanographical/environmental variables that are available for Baffin Bay/Davis Strait area over the time period of 1995-2011, however, I am not familiar with ...
7
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1answer
130 views

How to improve the display of color images?

I've found some really nice color ramps for portraying rasters, but in ArcGIS and QGIS, they don't seem to be easily usable for a finished product because their complexity causes obvious steps rather ...
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1answer
444 views

Creating a constant elevation raster with multiple attributes

Is it possible to create a raster with a constant value with multiple attributes? Such as: rowid value count Name 1 630 36000 Forest 2 630 75000 Anthro 3 630 2600 ...
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2answers
950 views

Creating a multispectral image from scratch

I want to make a multispectral image from cero to do some tests on it. Something really simple like 5 completely uniform bands with salt and pepper noise on them or a square of different values at the ...
3
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1answer
152 views

Assigning Probability to cells

I am working with the image below and I am trying to find how many pixels are in the grey corners of the image, and I want to assign them a probability of 5%. The bottom layer is my DEM and the top ...
3
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1answer
317 views

Vector to Raster for Smoothing purposes

I have a vector file that represents transit scores by CT of a city. It shows harsh boundaries where one CT has great access to transit and right beside that CT is one that has extremely poor access. ...
3
votes
1answer
375 views

Creating a Raster Filter

I am looking to create a raster filter which reclassifies single or contiguous pixels less than, for example, 30 pixels (shown in white below) into another class (shown in black). The filter, ...
3
votes
1answer
316 views

Why does QGIS Polygonize ignore the no data value?

I'm running into an issue georeferencing a number of PNG image files. The files simply contain an image where each pixel is either transparent or a single color, forming a coverage mask. In the past, ...
9
votes
3answers
3k views

Best method to aggregate 1m DEM mosaic to 10m DEM

I have a mosaic of a 1m LiDar derived DEM. I need to output a subset of the data as a 10m DEM. I am currently using the aggregate tool in ARCGIS 10 to produce a mean value for each new 10m pixel. ...
4
votes
3answers
1k views

Convert an arbitrary meta-data-free map image into QGIS project

My background: experienced programmer, amateur historian, complete beginner to GIS (so I'm using QGIS). I did learn to use the QGIS georeferencer tool though. The input: suppose I have an image like ...
4
votes
1answer
825 views

Raster data on PostGIS

I need to publish raster and vector data through GeoServer WMS service and I have already chosen PostGIS as datasource to keep vector data. Now I would like to know what is the best practice to work ...
5
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1answer
588 views

Raster processing with Python or Arc raster calculator

I have 4-band NAIP imagery that require the following processing steps: Convert to 8 bit unsigned B/W Reverse (note not inverse) the image, so that dark values appear light and light values appear ...
3
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2answers
997 views

Image does not display after clipping raster

I am using ArcGIS 10. I am trying to clip an NLCD layer from a vector polygon. I have used the Clip Raster tool in Data Management and Extract by Mask tool in Spatial Analyst among other things. My ...
3
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1answer
262 views

how can I obtain the areas where my rasters overlap, using Qgis?

I have a bunch of raster files showing the distribution of different species of mammals, and I would like to obtain the areas where they overlap, the areas in whitch more than one species can be found ...
2
votes
1answer
412 views

How to add EPSG:5235 to QGIS?

First of all I should say I am new to EPSG and QGIS world.Then I want to Georeferced Raster image to EPSG:5235 in QGIS. But in Qgis I can't found above EPSG. How I add this EPSG to Qgis ? Pls help ...
2
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1answer
642 views

Loading Raster and vector data In MapGuide using Maestro

I am new to Mapguide , working on it for my summer Internship.I have Installed it perfectly. Now the task is to load vector data and Raster data in map Guide (mainly have to load *.shp files and *.tif ...
3
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1answer
164 views

storing jpeg in spatialite database

How to store jpeg file in spatialite blob column so that spatialite gui and Qgis can recognise the format and show the image. I have created in memory jpeg from raster bands using jpeglib and stored ...