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

learn more… | top users | synonyms

0
votes
0answers
5 views

Do projections matter for zonal stat/isectpolyrst?

I have a gridded product (at 5 arc-minute resolution) and I have to summarize the raster cell values that are contained in another polygon layer. The raster product doesn't have a spatial reference ...
0
votes
0answers
9 views

QGIS raster calculator wrong output

I am trying to create a mask from a DEM (SRTM tile) using raster calculator in QGIS. I have performed the same operation in ver 2.6 with no problem but in the current version the output is incorrect. ...
0
votes
0answers
21 views

Raster displaying in ArcGIS

Can anyone please explain this to me? I need the image to be displayed right in any case as I will be using it in different programs. When I open this raster image in an existing ArcGIS map it ...
1
vote
0answers
18 views

Performing Maximum Likelihood Classification in R

I'm trying to perform maximum likelihood classification of landsat imagery using R, I have been searching for a package that implements it but so far I haven't found it. What is the easiest way to ...
2
votes
0answers
23 views

ERROR 999999: Error executing function - Failed to execute (CopyRaster)

ERROR 999999: Error executing function Unexpected operation No spatial reference exists This is a fragment from my log report: ERROR 999999: Error executing function. Database user ...
0
votes
0answers
26 views

Output from arcpy clip management too big

I'm using the function arcpy.Clip_management to clip a raster using the shape from a polygon. The problem is the size of the output is too big. What can I do? Here is my script (in arcmap python ...
1
vote
1answer
24 views

Is it possible to overlay ungeoreferenced raster images in the QGIS Desktop Browser?

Afternoon ladies and gentleman, I work for a company that produces Mining Investigation reports for property in the South West of England and I have spent the last 12 months digitising abandoned ...
2
votes
1answer
25 views

Not able to load any Raster File using QGIS Python

I am trying to run an elementary piece of Python code, that simply loads a dem file as a raster accessing the QGIS Python API. On the embedded console (within the QGIS application GUI), it runs fine ...
1
vote
0answers
22 views

Calculate surface map from PostGIS

We need to create surface maps from the website. The data is stored on PostGIS (2.1) as a table of Point geometries with a field indicating a thematic value. The optimal solution would be to produce ...
0
votes
0answers
31 views

Convert tif raster format to jpg format

Continusly to Convert jpg raster format to tif format, i try to convert tif file to jpg: import arcpy, os , glob outworkspace = r"C:\Project\out\OtherFormat" listOfFiles = glob.glob( ...
2
votes
2answers
33 views

Overlaying Shapefile with projection and raster (without projection but with defined extent) using QGIS?

I'm trying to overlay a shape file into a raster. The raster has no defined projection but it's a global raster with extent 0, -1800 : 3600, 0. I tried "on the fly CRS" transformation and followed the ...
0
votes
0answers
21 views

Cost Distance for urban and roads?

I've been working in GIS for years but I haven't done much raster analysis until recently. I need to create a cost distance for an urban area for a land capability map, and also one for roads ...
0
votes
0answers
38 views

Create web map tiles from large images

I have 70Gb of raster data from drone photography that I need to serve via Openlayers. The data is currently provided as georeferenced jpegs each is 175Mgb in size. What is the best strategy to cut ...
1
vote
1answer
34 views

raster topo map with gaps to DEM

I'm trying to create a DEM from this raster map: I managed to clean all the shapes and text. I tried to write a program which finds the curve pieces and connects them. But, I realized that it is ...
1
vote
1answer
20 views

Iterating through a point layer to create & sum distance rasters

I'm writing an Arcpy program to process data in a layer of several hundred points ('ptsLyr', from file 'ptsFile'), each of which has its own ID ('RecordID') and an associated value, 'radius', that I ...
1
vote
1answer
36 views

Proof low deviations in DEM compared to point dataset

I am not sure how to achieve the following consistently: I have a regular distributed point dataset (surface elevations). From this I derived several DEM using QGIS IDW Interpolation method. Now I ...
1
vote
0answers
23 views

ArcGIS Split Raster tool results in black rasters

I have a rather large raster that I am trying to split into small tiles in PNG format to upload to Autodesk Infrastructure. I came across the Split Raster tool and thought it would do exactly what I ...
2
votes
1answer
20 views

can i comparing landsat 7 and landsat 8 thermal band?

can i comparing landsat 7 (band 6) and landsat 8 (band 10&11) thermal band? because landsat 8 only have 100m spatial resolution, so the output looks more general or blurr than landsat 7 thermal ...
0
votes
2answers
30 views

How to extract values from raster at points with many different rasters and points

I have a folder containing 100 DEM rasters. I have a point file containing thousands of points. I need to collect raster values at all of these points. Only some of the rasters intersect with the ...
2
votes
3answers
67 views

Plotting Netcdf data. How to get right projection?

Maybe it's very easy for someone to fix, but I'a a new one in R, so I really need help. I/m trying to plot data containing lat, lon and variable (nmf2). The grid isn't a regular one, so there are some ...
0
votes
1answer
46 views

Explaining ArcGIS Raster to Polygon output?

I want create a new shapefile with selected fields found in a raster which depicts landcover. I first attempted to run Raster To Polygon. However, some class names no longer appear, as shown here: ...
0
votes
0answers
17 views

Adding polygon attribute to a gdb raster

I am working with the gSSURGO soil database which has many tables with data and one raster file. I managed to join the tables to the raster, so now I click on my map and can see all raster attributes. ...
1
vote
1answer
18 views

Get Raster Values from a Polygon Overlay in ArcGIS

I have the same problem as Curlew in Get Raster Values from a Polygon Overlay in Opensource GIS Solutions and thecrashlandingdodo in Step-by-step: How do I extract Raster values from Polygon overlay ...
0
votes
0answers
36 views

Converting DEM to Floating Point Raster (FLT) using QGIS?

I am looking to convert a .DEM exported from AutoCad to a floating point raster file type (.FLT) utilizing QGIS to implement in HEC-RAS Mapper. This is accomplished easily in Arc using the ...
0
votes
0answers
12 views

Pixel based transparency or “Lighten” on geoserver

This is similar but different from this question. I'd like to statically assign a transparency of one raster based on another raster. For example, say I had a raster of aspect in a spectral gradient ...
1
vote
1answer
94 views

How to make maps out of imagery?

I am working for a client and we chose to use OpenGeoSuite as our system. Our client will be flying a plane over farm land capturing images that we need to put in our system. From my understanding ...
0
votes
0answers
15 views

Add QGIS raster layer to Google Maps API

Is it possible to add a hosted QGIS Raster layer into a Google Map? Thanks.
1
vote
0answers
15 views

Problem with QGIS raster interpolation from a point shapefile after duplicating the shapefile

Let me explain a problem I had with QGIS to see if somebody else has experience it. I created a raster from a point shapefile through the Raster-> Interpolation menu with no problems. After that, I ...
2
votes
2answers
37 views

Extract from raster by tightest rectangle mask without Nodata

I'm using ArcMap 10.2.2 and I have a raster that has Nodata around the edges. How can I extract the tightest rectangle from this raster that does not include Nodata? The screenshot may help ...
0
votes
1answer
35 views

chi-squared for two rasters in R

I am kind of new with statistics. I have two raster with categorical values and I want to get chi-square. How can I do this using R? Rasters have the same region and same resolution. Is chi-square ...
3
votes
0answers
24 views

Automate Exporting of Rasters Using Renderer in ArcGIS

It is possible to export rasters in ArcMap by right clicking the layer-> Data-> Export: You can then click 'Use Renderer' check box to ensure the image you export uses the current ...
0
votes
0answers
28 views

Euclidean Distance with Weighted Values

I am currently dealing with a dataset which consists of about 2700 points stochastically placed in a study area of about 650,000 sqKm. I am trying to create a distance raster for these points, which I ...
0
votes
0answers
33 views

Problem to visualize raster data from PostGIS in QGIS

I have two multiband raster files and i'm trying to load these data into PostGIS using raster2pgsql. Here is the syntax that i used: raster2pgsql -c -s 4326 -I -t 100x100 *.tif ...
0
votes
0answers
19 views

Merging rasters in Openlayers

I'm using Openlayers 2.13 and GeoServer 2.5.2 and I want to merge rasters. After short searching on Internet, I haven't proper, not even close, solution for this. How can i handle this? Thanks in ...
0
votes
1answer
36 views

Using Polyline to Raster tool in ArcGIS

Pretty basic question; In this Polyline to Raster tool, there is a field called "Value Field" I am not sure what to put for this field. My polylines are ZM, so there is Z information for the line, I ...
1
vote
1answer
19 views

Clipping a Raster into 5x5(25) equal tiles through the use of arcpy?

I am curious to find our if there is a way to create a python code that enables you to clip a raster into equal parts example: 5x5(25) tiles with the use of arcpy? From what I can think of you would ...
1
vote
2answers
48 views

Where do I get Elevation Data for Scotland?

So I am new here and I arrived here because I have been searching for quality elevation data for the entire Scotland but I have not succeeded yet. Kindly help if you know where to get the data Raster ...
-3
votes
0answers
14 views

Raster and vector dat [closed]

To what extent is the debate about the relative advantages of vector and raster formats IRRELEVANT in light with recent advances in GIS?
1
vote
1answer
22 views

QGIS raster from interpolation not scaled correctly

I am using the interpolation plugin in QGIS to interpolate values within a boundary. I start with two layers; 1) my points and 2) a polygon for the area of interest. Then I go to ...
2
votes
1answer
30 views

ClipRaster with three inputs

1) How can I clip raster with checked "Use Input Features for Clipping Geometry? I don't want to specify X, Y Min/Max for the Output Extent. I want to run a simple Clip Raster script that includes 3 ...
0
votes
0answers
17 views

is it possible to create gis web application that can clip raster images using vector layer shapefile?

I need to create a web application that can navigate through the world or even single country and let the user draw or upload polygon shapefile to clip raster data according to that drawn or uploaded ...
0
votes
1answer
28 views

True color combination using Resourcesat-1?

I am working with an image from India. According to the metadata, I am working with an image acquired by the AWiFS sensor from Resourcesat-1: ...
0
votes
0answers
16 views

Computing View Distance in One Direction from Point on Elevation Raster in PostGIS?

I'm a software developer just getting into GIS, so please forgive me if I don't use proper lingo, or if I use proper lingo incorrectly! I have a raster of elevation data. For a given point in the ...
0
votes
0answers
12 views

How to create Raster from 2d double array

How i can create a Raster file (tiff image) using a 2D double array : double[][] pixels i tried to start from a raster data set using the function which i found in the arcgis java help system. but ...
0
votes
0answers
27 views

Problem rendering raster in QGIS

I have a problem with some Landsat 8 bands combination. I created a multiband (1 to 7) file in order to avoid the creation of several files with combinations and instead, have all the bands in one ...
1
vote
0answers
39 views

Does interpolation create a vector or raster?

I have been reading about interpolation and am trying to understand whether interpolation results in a vector or raster. Say I have a layer of points and I am interested in creating a raster that fits ...
3
votes
1answer
70 views

Is it possible to add a raster file as layer from an URL?

I have several geoTIFFs stored on a server that I can access through http. I would like to add them as raster layers analogous to adding a local raster file through the "Add Raster Layer" button, but ...
2
votes
1answer
16 views

Combining several raster files generated from polylines

Maybe I'm just missing the point somewhere... I'm working on a path distance analysis, specifiying the cost layer. For this I have built a model, where I have roads and trails, both polylines, that I ...
1
vote
1answer
35 views

The truth value of a raster is ambiguous. Invalid use of raster with Boolean operator or function.

I'm having trouble with an if/else statement in my for loop. I have a raster Vmax with a constant value, another raster V which has a value of 0 in the beginning and will change during execution of ...
1
vote
2answers
24 views

Merging raster data in QGIS using wildcards

I have a problem merging raster data sets in QGIS, and I have searched various forums, but have not found a solution yet. An "ordinary" merge, for example merging the raster files ...