Tagged Questions

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

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3
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2answers
38 views

Running Point To Raster has output coordinate system different from input?

I need to transform a DEM from a Point-Feature-Class (Shape) to raster (GRID). For that I'm using the tool 'point to raster' and it works perfectly. The only problem is that it seems to change the ...
3
votes
2answers
71 views

How can I determine which raster attribute covers the highest area of a polygon?

I'm relatively new to GIS and QGIS but I have a problem that I'm not certain how to solve. I searched here for relevant information but found none. (Or, I used incorrect search terms.) My problem ...
2
votes
0answers
23 views

How to calculate the slope with isolines/raster?

I'm trying to calculate the slope (in %) in ArcGis 9.3, but don't remember how it works. I already did it some time ago, but this time it doesn't work... I used a shapefile with Isolines (see ...
2
votes
1answer
35 views

Open Source counterpart to Euclidean Allocation

I'm looking for a function that can perform something similiar to the Euclidean Allocation process in arcGIS ...
2
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0answers
37 views

Hyperspectral Data in ArcGIS Desktop

The public organization I work for has some archived hyperspectral data (.raw - radiance, non georectified). Has anyone processed hyperspectral data for consumption within ArcMap? If so, what sort of ...
2
votes
2answers
47 views

Find coordinates of given raster value

I would like to get the coordinates of a raster cell with a given value. I suppose many cells can take the same value, in which case several coordinates should be returned. In my first problem I'm ...
3
votes
2answers
29 views

How can I draw an outline around my raster classes

I have a raster created from polygon shapes from a social survey of fishing areas in ArcMap. I have classified my raster to 3 classes High,Low,Medium. I want to draw a border or an outline around the ...
3
votes
1answer
26 views

How to export data from saga or tas into excel?

I want to derive terrain attributes from DEM with saga and whiteBox GAT (SAT). I have problem in exporting data into excel. would you help me?
1
vote
1answer
37 views

Get value of clicked raster cell

When I open a raster file in QGIS (for example a GeoTiff file), I want to quickly check the value of a clicked raster cell. I found there's an 'identify' tool in the toolbar, but when I click with ...
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0answers
11 views

Smooth and boundary clean raster (GRACE) Data

I have some GRACE data that I would like to smooth out and generalize/aggregate the boundaries to look like the maps shown at this website. I've tried playing with filters, converting to integers ...
1
vote
1answer
32 views

Change Data Source of Raster Layer Added to Map Display? Unexpected default

I have a script that I'm using to generate raster maps and automatically add them to the map display, but when they are added they are sourced to a temporary location. I use the same code for ...
1
vote
1answer
38 views

IDW with QGIS from a vector points file within a mask

Given two inputs: A shapefile: points A raster: mask I want to interpolate the points within the extent of the raster except the NoData pixels that i want to use as a mask. NoData pixels are the ...
1
vote
2answers
43 views

getting to grips with raster data: Tutorial needed!

I always have trouble understanding the different characteristics of raster data formats - Bands, RGB, Alpha, Color tables, Classification, Stretching, single color setting etc. Can anyone offer me ...
1
vote
0answers
12 views

how to make mapnik style raster, not just render as solid color

I have set up Mapnik with mod_tile and renderd. I replaced the default osm.xml file with my own xml file, which is shown below. My problem is that all images are being created as solid blue tiles as ...
1
vote
0answers
36 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 ...
0
votes
1answer
18 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') ...
3
votes
1answer
31 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 ...
1
vote
0answers
16 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 ...
0
votes
1answer
42 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. ...
0
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0answers
23 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 ...
1
vote
2answers
37 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
votes
1answer
33 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 ...
1
vote
0answers
14 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
42 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
votes
1answer
25 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 ...
1
vote
1answer
29 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 ...
0
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0answers
20 views

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
votes
2answers
59 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
vote
1answer
15 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.
1
vote
3answers
21 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 ...
0
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0answers
35 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 ...
1
vote
1answer
34 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
votes
2answers
25 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
votes
1answer
37 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
votes
1answer
39 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
vote
1answer
44 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 ...
0
votes
0answers
20 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
votes
1answer
28 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
votes
2answers
69 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
39 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
vote
1answer
33 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
50 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
vote
1answer
38 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
votes
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
vote
1answer
35 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 ...
0
votes
0answers
7 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
41 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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vote
0answers
48 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 ...
0
votes
0answers
22 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 ...
1
vote
1answer
38 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 ...