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

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1answer
93 views

Wrong coordinates after Usage of NumPyArrayToRaster(…)

My Project I am currently working at should enable cellvalue manipulation on raster files using ArcPy. My Script works fine except I am not getting the right Y-Values (northing values) for the ...
5
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5answers
1k views

Convert line shapefile to raster, value=total length of lines within cell

I have a line shapefile representing a road network. I wish to rasterize this data, with the resulting values in the raster showing the total length of the lines that fall within the raster cell. The ...
1
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1answer
114 views

How can I check the resolution of my .img raster file in ArcMap?

I'm just learning ESRI's ArcMap and I just wanted to know where I can find the resolution of a .IMG raster layer.
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3answers
204 views

Selecting an attribute from a classified raster image

I am trying to select just the black attribute (classified water in the image) but I can not select anything. In the attribute table it lets me select the row, but it will not select in the map. I ...
4
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1answer
125 views

Raster cells with no data being generated by las2dem?

Anyone has an idea where these lines (with no elevation data) come from? They are generated while using the las2dem tool from LAStools. What needs to be done to avoid this? The raw data (.las file) ...
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0answers
78 views

Apply raster contraints on single table with multiple files

I have a raster table (pre-created using CREATE TABLE) containing multiple individual raster files that I append piece by piece to a final table. The table itself is in its own tablespace 'gisdir' and ...
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1answer
234 views

Attaching pictures to polygons in attribute table in batch using ArcGIS for Desktop?

I use ArcGIS and I want to attach a picture of each polygon as raster in attribute table and I have 1900 of polygons. Can somehow attach batch photos as raster that have same ID like polygons? It is ...
0
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2answers
94 views

Con function loop doesn't calculate for all the fifty rasters in a list

I have been trying this for hours and I know it should be easy but I can't make it work yet. I have a list of 50 rasters that I need to change the NoData to "0" values. I have the right arcpy ...
2
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1answer
234 views

Manual (or examples) of r.ros, r.spreadpath and r.spread in GRASS

you can report me references or applications for use of the following modules (GRASS): - r.ros, - r.spreadpath, - r.spread. Thanks so much.
5
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1answer
81 views

Curvature computation for different scales

I would like to assess terrain curvature, i.e. the 2nd derivative of a DEM, on different scales. The most common approach to curvature seems to be the one suggested by Zevenberg (1987) where a ...
2
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1answer
300 views

Extract all unique values from a RGB raster

I have a .png file in RGB format showing the intensity of ship traffic: For my analysis I need to convert it to a one-band raster with values between 0 and 1 where 0 means lowest density and 1 ...
1
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1answer
368 views

Error: Cutline feature without a geometry. > Raster Type

I've got an "Error: Cutline feature without a geometry" on QGIS 2.4.0 Chugiak. I have 2 samples (A raster type and a vector type), they have the same coordinates (EPSG:4253 - Luzon 1911) Then I tried ...
0
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1answer
104 views

How to update raster metadata in postgis

How can I update the raster metadata in postgis? upperleftx | upperlefty | width | height | scalex | scaley | skewx | skewy | srid | numbands ...
3
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2answers
255 views

creating raster based on 'count' of certain property in 8 underlying rasters

I need to build a raster based on 8 raster layers. Data in these 8 layers are divided into 3 classes, (1) K (values 1-1.5), (2) V (values 2-4) and (3) Z (values 5-12). The new raster is raster K, ...
2
votes
2answers
618 views

Get cell size for raster in QGIS

How do you get the cell size of a raster in QGIS? This is a simple matter in Arc, just look at the properties. QGIS has properties, but no raster cell size. Thanks.
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1answer
223 views

Removing disconnected cells in a stream network raster using ArcGIS

I've got a predicted stream network raster with cells values 0 (not a stream) and 1 (is a stream). My end goal is to create a network of connected polylines, but unfortunately there are some areas ...
3
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1answer
427 views

Export background tile map to raster file

In QGIS I managed to display the ship traffic density from marinetraffic.com as a background tile map using the TileLayer plugin. Here is my TileLayer.tsv file: #title credit serviceUrl yOriginTop ...
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1answer
73 views

Creating a raster based on a where clause

I am writing a script that deals with a raster that will need a subset of the raster outputted and the rest of the original raster needs to be "no data". To clarify, say, there is a raster and ...
3
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0answers
38 views

Need to run a Groundwater Analysis Based on Points to a Raster

The title sounds daunting, but this task really isn't. I have well samples over a decade in certain locations through an area. These samples contain a value of that element at that point in time. I ...
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1answer
510 views

Convert raster to polygon based on cell value ranges using ArcGIS for Desktop?

I have a floating point-valued raster which I need to convert to polygon as follows Put the cells with VALUE < 0.5 into (a small/the smallest number of) polygons Cells in the range [0.5, 1] into ...
3
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1answer
771 views

QGIS syntax raster calculator

I'm working with QGIS and I want to reclassify a raster in different ranges. Using the following statement does not work even recognized as valid (2950 <= "dem_tallat @ 1"> = 3050) = 3000 ...
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1answer
177 views

Guidelines for publishing large datasets on QGIS Web Client

Can anybody provide simple guidance to publishing large datasets on QGIS web client? I have a mixture of shapefiles and rasters to display. Biggest shapefile is 230 MB. Biggest raster is 1.4GB. At ...
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0answers
28 views

Exporting QGIS Raster/Vector layers into one PDF? [duplicate]

I have seen a similiar post to this a while back (Is it possible to export GeoPDF from QGIS?), and thought I would try asking it again to see if there has been any improvement or new knowledge on ...
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1answer
273 views

Creating DEM from cross sections in ArcMap?

I have a DEM in arcmap and cross section of a river which flows on the Dem in Hecras. I now the cross sections are more accurate. I want to make a DEM from some of my cross sections and stitch it on ...
2
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0answers
299 views

Retrieve list of all features and values from raster layer (Geoserver and Openlayers)

I'm trying to retrieve a list of all values from a raster layer (GeoTIFF) in geoserver (2.5.x). I tried to modify the code from http://trac.osgeo.org/openlayers/wiki/GetFeatureInfo but I can't seem ...
2
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2answers
32 views

Harvesting pixels using GRASS GIS

having a binary raster map of pixels of interest, a road network, and a target point, my goal is to get a raster map with network pixels having as value the number of pixels of interest they allow to ...
2
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1answer
220 views

How to convert different lidar data formats to raster DTM and measure its geographic position accuracy?

I'm trying to generate a DTM from lidar data and I'm new in the this field. I have different kind of files which describe the same area (different versions): *.dtm *.xyz *.xyz with variable grid ...
5
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1answer
323 views

How can I match the cells of two rasters?

I have many raster files each one containing information that is different from the others (e.g. one contains information on rain, the other on altitude, and another on land use). The cells in each ...
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1answer
377 views

scatterplot of two rasters in R

I am very very new in programming and I want to ask how can I make a scatterplot of two rasters in R and also get their correlation of determination?
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2answers
617 views

Creating spatial Reference to ASCII file

I have produced ASCII files in MaxEnt. These files are able to be loaded into Arcmap10.1 and display as an image, but I cannot interpret them or create them into a polygon for further analysis. I have ...
6
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0answers
149 views

Postgis database query optimisation

I have a set of rasters in DTED format which I load into postgis database using raster2pgsql command line tool. Each of rasters is simply stored in a row and described by rid and a value of raster ...
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1answer
85 views

regression model with randomForest in raster package

I'm learning randomForest classification method in R and I performed land-use classification with randomForest and raster packages. But when I try uesd a regression model produced with randomForest to ...
2
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1answer
621 views

Opening GeoTIFF (georeferenced in ArcGIS for Desktop) in QGIS?

I tried to open a georeferenced geotiff created in ArcGIS for Desktop in QGIS. I could open them but they are not in the right spots. These raster datasets contains .aux .rrd .tfwx .tif.aux.xml ...
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0answers
51 views

Update Raster extent

How do you update raster's extent after you export the raster ? I forgot to enable the Date Frame rather than it's original Dataset?
4
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2answers
463 views

Visualization of a field in Leaflet

In a Leaflet app I want to overlay raster data (technically speaking, a field) on a web map. The data consists of triples < lat,lon,value >, where value is in range [0,1], for example: ...
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2answers
78 views

PostGIS raster write support in R

I want to push/write some generated raster layers to my postgres database directly in R. In theory this could be supported by the rgdal package, but sadly it isn't. In the latest version only copy, ...
2
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2answers
343 views

Arcpy Slope Analysis Script

I'm trying to run slope analysis in ArcGIS. I have written an ArcPy script that converted feature layers to raster files. Now I have a list of rasters (each with a unique name) in the table of ...
3
votes
2answers
100 views

OpenWind Zone of Visual Impact transparent pixels?

How do you make pixels which are not visible from a point be made transparent and the pixels which are visible opaque so that I can overlay the raster over a map to see clearly where you can and ...
2
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0answers
138 views

geoserver and openlayers select rectangle pixel values

I'm running a geoserver (2.5.x) with 1 raster file (GeoTIFF) as a layer. From my application I can access a single pixel value when clicked (through WMS), but what I'm really interested in is to get a ...
3
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2answers
461 views

QGIS ASCII Grid output problem

I have this .asc file of maximum temperature of a local place. This file is a result of vector to raster (GeoTIFF) conversion then GeoTIFF to ASCII grid conversion, both using QGIS. Here is a snippet ...
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2answers
498 views

Overlaying Raster image with Google Maps in OpenLayers3

I am trying to overlay Google Maps with a raster image layer in Openlayers3 and am new to this. Can anyone help by providing the steps involved in performing this task?
2
votes
1answer
286 views

Subset multiband tiff file using Python in ArcGIS for Desktop?

I have a multiband (1140) raster file in tiff format that I want to subset. Each band represents a prediction of monthly rainfall (12 bands for each year) over a 95 year period (12*95=1140). I need to ...
5
votes
1answer
217 views

What are the PostGIS Raster Constraints used for?

My question is quite basic, but I have not found a simple explanation of why raster constraints are useful. I have worked with rasters in PostGIS for a while but only recently I realized that I do ...
2
votes
1answer
37 views

Looking for smallish raster of global elevation data

I'm trying to find elevation data for the whole globe for a simple mapping application and I'm not having any luck. I really don't want anything fancy, just something like a 4000x2000 raster of ...
4
votes
1answer
33 views

raster statistics by line shape (vector)

I have a georeferenced area where I created 7 raster maps (classified with suitability values from 1 to 5) as I have 7 factors to check e.g. natural reserves, floods, slopes etc. From there I did a ...
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vote
1answer
463 views

How to load postgis raster layers into R?

It is easy to get Vectorlayers into R from a PostgreSQL+PostGIS solution. library(rgdal) dsn="PG:dbname=plots host=localhost user=test password=test" plots = readOGR(dsn,"Plots") But how to do the ...
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49 views

How to get transparent nodata values in GeoExplorer?

I have a single-band raster image with NoData values set to 0. Is it possible to get them transparent in GeoExplorer?
2
votes
1answer
286 views

Loading raster in postgis and link it with an existing table

Relatively new to PostGIS and I am currently exploring the options to make one of my PostgreSQL Tables spatial. Essentially I want to store a raster object in a table that also contains essential ...
3
votes
1answer
526 views

make a raster from dataset (csv)

I was trying to make a raster from an dataset (https://www.dropbox.com/s/jsm1x06lnzfbqty/data.csv?dl=0) code: inter1= read.table("c:/data.csv", header=TRUE) #convert to spatial points ...
3
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1answer
47 views

Fast editing in raster calculator — adding lots of images together

I need to add pictures together to make one raster. In one session there are about 150 - 200 images (named randomly - see syntax example) There are about 50 sessions (named randomly) Is there any ...