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

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9
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2answers
251 views

Are “gridded data” and “raster data” the same thing?

I'm working on a project that will involve both "raster data" (aerial imagery and DEMs) and "gridded data" which I understand to be other kinds of numerical measurements taken at grid points, and ...
2
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0answers
62 views

Copying an entire column between layers (tables)

I have a raster layer with probabilities as values and I process them using the Spatial Analyst extension. After the processing the values are modified, however I would like to also have the original ...
2
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1answer
2k views

Spatially join large raster to polygon shapefile

I have a large raster file with elevation data. From this raster, I would like to infer the average ruggedness for different geographic zones (like countries). I have the "countries shapefile" as a ...
3
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1answer
425 views

Area precipitation using IDW

I'm having the following problem with IDW automation. I have a catchment and several gauging stations measuring daily precipitation amounts. I would like to interpolate the precipitation amounts from ...
-1
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2answers
124 views

Counting raster points within boundaries in another layer?

I know this question is similar to some out there, but I have tried all the 'solutions' and none of them are working for me. I am using the latest version of Qgis. I have a raster layer with ...
1
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1answer
203 views

ArcGIS raster data - Group statistics for classification

I'm trying to figure out how to classify a group of rasters. These can't be joined as they have overlaps which must be kept. I was wondering whether there's a way of obtaining grouped statistics - eg ...
2
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1answer
208 views

Efficiently check for equal adjacent values in raster calculator

I have a raster consisting of integer values in each cell. I want to check every adjacent cell in a 3x3 grid to see if any one of the adjacent cells has a value EQUAL to the center cell, and if so, ...
3
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1answer
364 views

Delete single raster from Raster Dataset

Is there any possibility to delete single raster previously loaded to a Raster Dataset?
3
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1answer
106 views

Cell values to No data

I need to set cell values in one raster to NoData based on another raster. Both rasters have the same extent and some cells overlap. For those cells that overlap I want to set them to NoData in ...
0
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1answer
178 views

GRASS GIS related issues! [closed]

(1) How to create a multiband raster from a set of single band rasters (except when somebody talks about doing a r.composite). I attempted creating a raster3D and it turned out that it is not ...
1
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1answer
77 views

Assigning an intersecting line length dependent value to a raster during polyline conversion

I am converting a road network polyline into raster format- my polyline shapefile has an exhaust emissions rate attribute which is in kg/km What I want to achieve is a raster that has (at say 5m ...
2
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2answers
207 views

Searching Open Source tool to load raster data into Oracle spatial

I'm looking for a tool to load raster data into oracle spatial. I found several commercial products but no open source tool. Is there anything available in the open source world?
3
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1answer
3k views

creating a buffer in a raster layer

I've got a raster layer separated into 3 zones, representative of marine park zones. What i'm trying to do is make it so that where zone 1 is adjacent to zone 3, there is a "buffer" between them, of ...
1
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0answers
201 views

How to perform Shapefile to Raster with ArcMap 10.1 while preserving resolution and values?

I am new to ArcMap and I would really appreciate some help. I want to create a new raster using a value in a column of a point shapefile. I have a point shapefile with points equally spaced and each ...
1
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0answers
180 views

Add Raster To Mosaic Dataset: Could not recommend a data source crawler for the specified input

I'm trying to add rasters (TIFF) to a Mosaic Dataset after adding some rasters, the process fails with the message. ERROR 999999: Error executing function Could not recommend a data source crawler ...
4
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1answer
2k views

R - Plotting shapefile with geographical (raster) data

Over the last few days I have been trying to plot a shapefile over data loaded into a data.frame within R. It should be a view of radar precipitation with an overlay of the country borders from a ...
1
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1answer
496 views

Polygon to raster without losing any polygons

I'm trying to convert polygons to raster. But the output raster dataset doesn't have polygons which went into as input data. I need all the date in the attribute to follow with to the raster dataset ...
3
votes
3answers
432 views

What DEMs does QGIS support? + DEM data sample

I am working on QGIS rasters. I want to know about DEM file formats supported by QGIS. I know that QGIS can read the GDAL supported formats. but what is GDAL supported format ? Does QGIS support the ...
2
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1answer
2k views

Convert 32 bit image to 8 bit image in QGIS

I want to convert my images from 32 bits to 8 bits. I'm using otb to calculate texture and the raster output is on 8 bits, I'm going to use this information as a layer stack for my multispectral image ...
5
votes
2answers
349 views

10 GB Raster Aerial Image in Quantum and POSTGIS

I have a problem... I have been successful in uploading the raster in postgis but when I access it through Qgis. it does not open even after several hours. I have 10GB aerial image raster and ...
0
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1answer
2k views

How to convert a bil image into grid in ArcGIS?

I've downloaded RFE data from FEWSNET. It's a compressed file which includes .bil files. Now i want to convert this ".bil image" into a grid to use the precipitation data in an area. I'm using ...
2
votes
1answer
361 views

Split single raster within multiple polygons

I have a raster ('slope') which content only one attribute in the table. On the other hand I have a feature which content several polygons (catchments) in the attributes table. I would like to obtain ...
1
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1answer
149 views

How can I turn QGIS into a simple hiking planner?

I'd like to try and turn QGIS into a simple hiking planner. I have found and worked out how to import OS raster mapping at the correct scale and how to add freehand vector lines to the mapping, which ...
1
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2answers
77 views

Adding 'freehand' data to raster mapping in QGIS

Having just worked out how to import raster mapping into QGIS at the correct scale, I'd like to now add useful information to the map like marked routes, labels etc. How can I do this in a 'freehand' ...
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2answers
1k views

How do I import OS raster tiles into QGIS at the correct scale?

I have some tiles of OS raster mapping and their associated TFW georeferencing files. The GR files are in the same folder as the raster data and have the same names, ie TQ21.tif/TQ21.tfw. In QGIS ...
3
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1answer
527 views

Rotating rasters using GDAL Geotransform (and ArcGIS Desktop)

I am working on a GDAL driver for a proprietary grid-format. In some cases, the grids are rotated in order to get smaller file sizes. In my GDAL geotransform array, I do the following (showing a ...
2
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0answers
796 views

Projecting a Raster from WGS84 to planar Equal Area to Calculate Area: How to Select the Cell Size?

I have a broad question on how to calculate the 'correct' cell size for a raster when analyzing an area not at the equator. My goal is to project a land cover raster provided in GCS WGS84 to an equal ...
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0answers
509 views

How To calculate raster land cover inside overlapping buffer zones?

I am working with a raster land cover file that consists of several land cover types (e.g. forest, buildings, grass ect.) in total there is 40 different land cover types. I have 1200 bufferzonen ...
2
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3answers
186 views

How to create a raster from scratch

I realize this isn't a geographic question as I'm not trying to make this into a geographically placed image. But I hope you all will know how to do this. I want to make a raster from scratch. I ...
0
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1answer
56 views

USGS FLT Hdr file interpretation

I have a legacy program that attempts to read USGS 1/3 arcsec data. When I compare results to GDAL, I find that the lat/lon to pixel conversion is off by 1 line. The reason (I think) is because the ...
2
votes
1answer
150 views

Reproject gif.gz raster to WGS84 in QGIS

I am a steep learning curve into QGIS. I have a raster of global fire maps from the modis site: http://lance-modis.eosdis.nasa.gov/imagery/firemaps/firemap.2013221-2013230.8192x4096.gif.gz I would ...
2
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2answers
778 views

gdal_calc.py outputs huge files

I think this is a general enough question to apply to more than just gdal_calc, but perhaps not. When I run gdal_calc.py -A map.tif --outfile=deforestation_00-10.tif --NoDataValue=0 --calc="A >= ...
2
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1answer
280 views

Can I update the service on ArcGis Server programmatically?

There is Windows Service. This service adds user raster data to the Raster Dataset in sde database. The Raster Dataset registred on the ArcGis Server. This Raster Dataset also was publishing on ...
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2answers
385 views

How to georeference a raster based on identical, already georeferenced raster

I have two identical rasters, one has been georeferenced, the other has not. I would like to georeference the second raster automatically using the first one. I do not want to create links by hand and ...
1
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1answer
540 views

identify percentage of raster cells within a polygon

As per the title I want to determine the population inside multiple polygons according to different land use zoning (High Residential, Low Residential, National Parks etc) that's in raster format. ...
0
votes
1answer
184 views

How to delete raster dataset from sde base programmatically

I use sde database, registered with ArcGis Server 10.1. Sde connection is direct. Database container is postgres. There is a raster dataset in this sde base. I can open this sde database ...
0
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1answer
144 views

Rotating raster grids using ArcObjects changes cell size in ArcGIS Desktop?

I am using ArcObjects, namely RasterGeometryProc, to apply rotation on grids. The transformation works fine. However, when looking at the grids properties in ArcGis, the cell sizes has changed. ...
2
votes
1answer
206 views

Change Values of Georeferenced Raster

I am using QGIS to georeference B&W images. I have now done this and would like to set the black surround of the image (as a result of the georeferencing) to transparent but this does not work as ...
0
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1answer
545 views

Polygonize.py: AttributeError: 'NoneType' object has no attribute 'CreateDataSource'

Given a topographic raster tif of an european country where elevations are simplyfied to either 0, either 200. How to create a polygon ? Comment: With the following polygonize.py command: ...
4
votes
3answers
943 views

Is there a Raster Equivalent of the Split tool?

I have the DEM of a State in ERDAS Imagine (.img) format. I have a shapefile containing the counties of that state. I want to split the whole raster into DEMs of the individual counties. The counties ...
0
votes
1answer
582 views

How to conditionnally assign a new value to pixels of a raster image?

Given a topographic GIS raster of one country crop.tif: Given a know pixel value such as elevation (z) is +73 : $ gdallocationinfo crop.tif 1 1 -valonly > 73 Given an elevation threshold n = 50 ...
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2answers
434 views

Gdal: How iterate through all pixels of a raster image?

Given a topographic raster image. How to iterate through all pixels of this raster image ? Solution preferably with gdal, in console. Some other libraries/script could be installed. Related: ...
2
votes
1answer
407 views

How to work with flt & hdr files

I have been working on a vector-based spatial analysis in R using shapefiles. I wish to use some environmental data that is downloadable, however it is only available in raster format (FLT & HDR ...
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1answer
510 views

Gdal: How to get a pixel's value from raster image?

Given a topographic raster image. Given a pixel's coordinate in pixel/lines or geocoordinate. How to get it's pixel value ?
2
votes
1answer
118 views

Revert back from RGBA raster to original 1 band raster cell value

I have a number or single band raster grids that have been converted to RGBA (png). I no longer have access to the orignal single band raster data but have the png files. Is there a way to convert the ...
0
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0answers
86 views

Vector/Raster Intersection - Speedup and replacement for ST_Centroid

I have some raster data which is the altitude above sea level and also some vector data which represents building outlines. What I want to do is grab some buildings outlines and fetch all the raster ...
2
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0answers
250 views

How to render a transparent raster layer on top of one or more vector layers with PyQgis?

I been trying to render a map with a 3 vector layers and one raster layer. The idea is that the raster layer should be on top of the other 3 vector layers. The problem is that even when I add the ...
0
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1answer
312 views

How to change rasterlayer color?

I have rasterdataset in gdb. I create layer from this rasterdataset. private static void CreateLayer() { ... IRasterLayer rlMosaicDataset = new RasterLayer(); ...
5
votes
2answers
1k views

How to calculate the number of cells with a given value?

I have a raster file where all cells have values between -3 and 7, no data value is -9999. Have can I calculate the number of cells with a specific value e.g. 6? Can I use the calculator?
1
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1answer
4k views

Import PDF to qgis

i have a PDF containing a region of Baltimore city that contains lots of polygons in it. you can download it from here: ...