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

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1answer
99 views

How to properly combine and export (as raster) vector lines on top of raster

I have a georeferenced TIFF with building plans on it. I then laid topo lines on top of it. it looks right in QGis. I now want to export this as an image (i.e. with the topo lines overlaid). How do I ...
2
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2answers
512 views

Handling hundreds of raster tiles in ArcGIS 10

I have 650 individual raster tiles (MrSID format) representing aerial imagery of a county. Each one is approx. 72 MB in size. As with a lot of aerial imagery, I use this as a base image for other ...
0
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1answer
65 views

Find Distance within each Raster contiguous cell block

I was asked to find for each Individual Contiguous Forest Block the distances INSIDE of each where it would be the farthest (aka the most isolated) from each forest cell block's respective edges. I ...
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0answers
33 views

Can I tell QGIS to load/show only a part of an image?

can I tell QGIS to load/show only a part of an image without to extract this region as an extra/ new image?
2
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1answer
167 views

Smooth out lines in QGIS

I have taken a raster image and coverted it to a vector file. It is an OS map which shows field boundaries etc. As the vector file has been created from the pixelated raster file the lines are ...
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3answers
587 views

Is there an iOS app to display several offline raster maps with transparency?

There are several iPhone apps displaying offline maps. Some of them can show custom maps, for instance loaded as MBTiles or sqlite files. Galileo-app does this pretty well. But it is only possible ...
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1answer
5k 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 ...
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2answers
8k 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 ...
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0answers
75 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 ...
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2answers
127 views

How to get information about only one data point?

I have a vector-point shapefile. The data are not dense (about 1 x 1 degree). Lets say that every point includes value of average wind speed. I would like to create a interactive web-map so that ...
3
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3answers
2k views

Creating DSM and DTM from a LAS using a freeware solution

Is it possible to export a surface and terrain model files from an aerial, LiDAR point cloud (LAS) set? I am using SAGA GIS for very basic operations, but I couldn't find this option (and I have a ...
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2answers
119 views

Copy Jp2000 from Mosiac Dataset turns white

I am trying to copy a raster to jp2000 from another File Geodatabase that I created as a Mosaic Dataset. It came out as a whiteout in the middle. I don't know what it cause this. See screenshot : ...
0
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1answer
149 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 ...
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1answer
77 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 ) Don'...
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1answer
306 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 ...
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0answers
133 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 ...
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2answers
75 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 ...
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2answers
907 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. ...
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1answer
630 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 the ...
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1answer
343 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 ...
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1answer
55 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 ...
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4answers
566 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 ...
3
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1answer
342 views

Combining Geological Grids and extruding between them?

I have a situation where I have 3 Geological grids, each showing a different horizon + the Seabed Grid. I need to extrude between these grids in order to make the 3D polygon for the geological ...
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2answers
614 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 ...
2
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1answer
502 views

Convert a KML ImageOverlay to World Files with GDAL

I have many raster outputs from an Open Source radio transmission topographic path tool called SPLAT, georeferenced in KML image overlay format. I have figured out an easy way to use tools to ...
0
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1answer
356 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 ...
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1answer
730 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 ...
2
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3answers
446 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 fix,...
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1answer
78 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 ...
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2answers
2k 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 ...
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1answer
490 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 ...
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2answers
3k 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 ...
2
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0answers
208 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 ...
3
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0answers
161 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 ...
3
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1answer
2k 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 ...
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1answer
649 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? ...
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1answer
993 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 ...
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1answer
603 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 ...
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0answers
90 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 ...
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3answers
547 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 ...
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0answers
361 views

ArcGIS Mosaic to New Raster() tool seems to interpolate data gaps on one computer/version but not another?

i have a group of raster files in .tif format that I want to mosaic together into one .tif. I've noticed that I get data gaps along the seams when I do Mosaic to New Raster() on my home computer (...
2
votes
1answer
200 views

Why am I losing part of my raster when I reproject?

QGIS 2.0 Working with tiff raster file. Reprojections are in WGS84 Mercator. Here is my problem: I am trying to use buffers or urban areas to analyze light intensity on a raster layer. I want 30 ...
2
votes
1answer
343 views

How to best remove rgb values outside of aerial image?

I have just converted RGB-TIF images to RGB-ECW for reasons of space and performance in ArcGIS. However, after the conversion, there are relics outside of the images which are not nodata values but ...
2
votes
1answer
353 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 ...
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1answer
465 views

Multiply a raster list with a field value list in a FOR loop in ArcPy

I'm trying to create a simple map algebra calculation not managed by ModelBuilder, but writing it in Python is trickier than I thought. I have a list of raster in a GDB and I must multiply them by ...
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2answers
1k 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 ...
2
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1answer
5k views

Clip raster layer with *raster* mask layer in QGIS

Given two input layers 1. The clip layer - an arbitrary layer (though in my case it's a float 1 band geotiff) 2. The mask layer - a paletted raster in which every pixel is either NO DATA or a single "...
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2answers
224 views

How to summarize Excel data within the zones of another dataset by using ArcGIS 10.2

I have the following Excel data, I want to summarize the P-value within the zones of map dataset. I have sereached a lot and learned I might need to convert Excel data into XY table, and then into a ...
3
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1answer
498 views

How to count and rasterize polygon overlaps in QGIS?

I have a large number of polygons that are overlapping. I'd like to create a heat map and plan on using raster calculation to do this. My plan: to give each polygon a raster value of 1, and adding ...
2
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1answer
2k views

Calculate the values of range, sill, nugget in ordinary kriging? [closed]

I am working on temperature data, and I want to interpolate the data to any location that I specify. My programming language is asp.net4 C#. I don't know how can I determine the sill, range, nugget ...