Tagged Questions

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

learn more… | top users | synonyms (1)

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19 views

set extent for jpeg programmatically

I feel like this should be easy, but how can I set coordinates for a jpeg image using Python? I have a python add-in that draws a polygon and then uses its geometry to post a query request to a REST ...
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1answer
11 views

Problem in adding raster layer from arcpy

I am using the following code to add the raster layer using arcpy in arcmap def AddRasterLayer(path,layerName): layer=os.path.join(path,'new'+str(layerName)+'.lyr') ...
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1answer
17 views

1m cell size equivalent value in decimal degree

I'm doing re-sampling pixel size in ERDAS 2014,I'm using input image(Indian terrain) in GCS_WGS_84 projection. Now I have to keep out put cell size as 1m,what is the 1m equvivalent value in Decimal ...
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0answers
8 views

Extract values to point - values not being extracted

I have a single band raster. When I use the information select tool I can see pixel values. I also have a shape file made up of points sitting over the raster. I want to extract the pixel values from ...
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20 views

how to batch reclassify rasters with percents range

Using Model Builder I need to reclassify slope rasters with percents range value. I have read and ask here batch reclassify rasters with different elevation ranges, but I still need more explanation. ...
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20 views

Clipping MrSID raster image, without decompressing clipped raster, in ArcGIS Desktop? [duplicate]

I am using ArcView ArcMap10 and when I clip a raster using tools/data management tools/raster/clip. The Clipped file ends up much larger than the original file. Specifically I am trying to clip a ...
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1answer
21 views

How to take cosine squared of raster using python

I have an equation y = cos^2(x) where x is a raster. How can I write this equation in python?
2
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1answer
21 views

Build raster with multiple attributes based on 3 input rasters

I am trying to make a new raster based on three input rasters which have the same cell size and the grids align perfectly. I now want to construct a new raster, which for each cell, has three ...
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0answers
8 views

Image pyramid have wrong colors in Geoserver (but the tif-files looks fine)

Just want to start off with saying that I'm fairly new to geoserver and the fix to this may be very simple. So have managed to create an image pyramid out of a ~7 GB ECW file. The files are fine ...
4
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0answers
25 views

Building a Mosaic Dataset with rasters that are not georeferenced. Whats the workflow?

I have 68 aerial jpegs that I would like to use in a Mosaic Dataset. They have not been georeferenced. My question is in regards to whether I should georeference them and then rectify and save them in ...
2
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1answer
20 views

Failed to execute floating raster to integer raster

im facing a problem in converting Floating to Integer Raster by using"spatial analyst tools (arc toolbox) > math > Int" . However, it shows warning of "error ERROR 999998: Unexpected Error. Failed ...
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1answer
18 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 ...
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0answers
7 views

Pixel Value Recording Script Efficiency

I have been working on a script to read pixel values and print the values out to a text file. This is currently working but takes around two hours with a 6.6gb file. This is to replace an older script ...
2
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1answer
32 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 ...
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1answer
12 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
18 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 ...
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0answers
31 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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0answers
15 views

Convert NDVI map into shapefile [on hold]

I have NDVI raster file. I want to convert raster file into shapefile.how to clip shapefile ?
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1answer
22 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 ...
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2answers
23 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
29 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.
4
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1answer
34 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 ...
1
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1answer
33 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 ...
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0answers
9 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 ...
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1answer
23 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 ...
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2answers
61 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, ...
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2answers
33 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.
1
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1answer
25 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 ...
2
votes
1answer
32 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 ...
1
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1answer
33 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 ...
2
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0answers
20 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 ...
1
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1answer
29 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 ...
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0answers
5 views

How to implement gs:storeCoverage with GeoServer scripting

I was wondering if it is possible and how to implement the service gs:storeCoverage using the scripting facility (e.g. with python or groovy). The reason I ask is that gs:storeCoverage is not of ...
2
votes
1answer
37 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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0answers
40 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
18 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
35 views

Creating Dem from cross sections

I have a question I appreciate that if someone can help me 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 ...
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0answers
17 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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1answer
19 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 ...
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0answers
19 views

WPS: how to write output to a raster layer in GeoServer

In GeoServer vector-based Web Processing Service (e.g. gs:Import), we can have the output saved to a GeoServer Layer, as described in the documentation. Outputs Name Description Type ...
2
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1answer
47 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
votes
1answer
65 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 ...
0
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1answer
32 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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0answers
33 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 ...
3
votes
0answers
40 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 ...
1
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1answer
11 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
41 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
19 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 ? Thanks.
4
votes
2answers
52 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: ...
0
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0answers
15 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, ...