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
1answer
102 views

How can I establish patterns, hotspots and clusters?

AS a crime analyst you need to establish a few maps that would help police to do targeted patrols, I've given data of suburbs, roads, incidents, boundaries. How can I establish patterns, hotspots and ...
0
votes
1answer
197 views

Help loading Raster to PostGIS 2 .0

Similar questions have been asked, but since my reputation is not enough I am unable to comment on answers. (The following is from an answer by nickves for this question Loading raster data to ...
0
votes
1answer
390 views

How to batch merge rasters using FOSSGIS tools?

I'm working with QGIS 1.8 (gdal 1.9.2) and GRASS 6.4.3...but on Windows 7. I "just" want to merge my raster. I've got a folder with 50 GTiff raster from Lidar data. The aim is to merge raster ...
1
vote
0answers
112 views

Floating Point UniqueValueRenderer

I am trying to build a unique value renderer using ArcObjects .NET. All the samples that I have seen use the attribute table to build the UniqueValueRenderer. However, my raster does not have an ...
6
votes
6answers
667 views

Interpolation of multibeam bathymetry

I'm trying to make a 3D map with multi-beam bathymetry (65536 features, xyz), but it seems that the interpolation methods are too rigid. I need to smooth the data so it looks more natural and ...
1
vote
2answers
414 views

Can I prevent QGIS raster clipper from changing output cell/pixel size?

I have performed a DEM extraction using the clipper tool in QGIS 1.9.0 Master, using a mask layer, the original resolution of the DEM is 20x20 but in the resultant DEM the new resolution is ...
0
votes
1answer
233 views

Working with Interrupted Goode Homolosine data

I'm trying to use Global Land Cover Characterization data from the USGS: http://edc2.usgs.gov/glcc/fao/data_specifications.php It is in the Interrupted Goode Homolosine projection. As I am working ...
1
vote
1answer
341 views

Qgis crash when I attempt to open ECW raster format.

I added Ubuntugis unstable repo and installed Qgis, libgdal-ecw-src, libecwj2-3.3 but still do not work. When I attempt to open an ecw file with Qgis it crash and tells me that there are problems ...
0
votes
1answer
64 views

Adding raster image to Raster field with Python?

I have a feature class with with field that is of Raster data type. I want to add an image to each record in the feature class. Is it possible to use Python to add the image to the Raster field for ...
1
vote
0answers
372 views

How to Smooth Polygons after converting DEM using Raster to Polygon?

I have a DEM SRTM that I classify using Spatial Analyst Tools > Reclass > Reclassify. The result is box shaped so I go to Layer Properties > Display and choose cubic convolution. The result is ...
1
vote
0answers
190 views

How to import binary arcgis maps into R

I have imported arcgis rasters into R. The rasters are binary maps and the legend in arcgis shows this to be binary as the colors are only 0 and 1. Now, when I import the raster into R it is no ...
2
votes
1answer
340 views

How do I convert from points to raster making the point the lower left corner of the cell?

How do I convert from points to raster making the point the lower left corner of the cell? I'm using ArcGIS 10.1. The default for the "Convert Point to Raster" tool is to make the point the centroid ...
1
vote
1answer
288 views

ESRI Raster Remap with Decimals

I have a requirement where the user would like to see the output value in a raster as a decimal. The user will input a series of ranges with a cost associated to them. For instance 0-5, 1.20 ...
1
vote
0answers
51 views

Align OpenLayer raster with OS Mapping Vector

I have an OS Vector map of a town in Ireland. When I load the Google Satellite Raster from the Open Layers plugin, the results are slightly off, by about 2m, probably due to ariel persepective. I'm ...
0
votes
0answers
60 views

How to deal with the situation when two rasters stacked together in arcgis?

I am doing a project about petroleum geology. There are several formations needed to add attributes (e.g. name, thickness and age). I have the raster data of thickness, so I created a raster catalog ...
2
votes
1answer
842 views

combine raster and polygon values in R

My question is similar to this one Get Raster Values from a Polygon Overlay in Opensource GIS Solutions but I think I need another step. I have a polygon layer of ecoregions which I brought into R ...
1
vote
2answers
396 views

Set Blend Width on Mosaic Dataset, ArcGIS 10

I've made a mosaic dataset of some thermal imagery. There are three overlapping images, seen here: As you can see, there is a discontinuity (jagged edge) between the two images on the right, and a ...
4
votes
1answer
675 views

Replace NA's with 0 for raster data using R

I am new in R. How can I replace NA's with 0 for my raster data which have spatial information?
6
votes
1answer
435 views

Histogram Matching Python

I am trying to do histogram matching using Python to improve the mosaicking process of multiple overlapping rasters. I am basing my code on that found at: ...
0
votes
1answer
124 views

show dwg,as background not as vector

I have some dwg files that i need to show as background on my map, but the DWG is not need to be vector layers, i need only to show them with out the need of using. if i am trying to convert it to ...
3
votes
0answers
128 views

Can extracting raster values work in polygons' CRS without raster resampling?

I am trying to extract raster values using polygon layer with different CRS. Raster is in WGS84 (EPSG:4326) and the polygons in UTM (EPSG:23031). 1. If I want to work in the projection of the ...
0
votes
1answer
331 views

Define transparent color in singleband pseudocolor raster layer style

Can I somehow define "transparent" color for values higher than 32000 in raster layer? See the style dialog:
1
vote
1answer
125 views

GeoTIFF without projection?

I have encountered a GeoTIFF raster files with EPSG:4326 (WGS84), i.e. no projection defined! Is this normal? I would expect raster to be in Projected Coordinate System. Raster is a grid of pixels so ...
1
vote
2answers
205 views

Exporting raster data from QGIS in chosen projection

EDIT: it is seeming like some of the time my last method will lead to a correct projection, some of the time it will not. Unsure what's happening there but at least trial and error will get me ...
2
votes
2answers
672 views

Clip_management to raster extent outputs larger raster than raster extent

Using Python and ArcMap 10.0 SP5, I'm trying to reproject and clip a large input raster to exactly the same grid as a smaller target raster (same extent, pixel sizes and projection). The problem is ...
3
votes
1answer
301 views

Sensitivity analysis for coarse scale GIS epidemiological model?

I am working on an epidemiological model with disease incidence rate as dependent variable and environmental factors as independent variable. Disease data is available at county scale whereas ...
0
votes
0answers
102 views

Copy Raster Tool and 1bit to 8bit

I have a bunch of 1 bit rasters (700+) of scanned maps that I need to convert to 8-bit rasters. It's the only way Geosoft will recognize the spatial coordinates of the TIF as they don't deal in 1bit ...
0
votes
1answer
725 views

Geoserver with ECW image file

I am trying to show ECW ortophoto as base layer in openlayers. So i found this thread on GIS SE: Geoserver 2.1.1 with ECW (v3.3) support 1. Download Geoserver 2.1.1 from ...
1
vote
3answers
231 views

How to use the GeoServer REST api to get a PNG representation of a layer?

Does anybody know if I can retrieve by REST service in GeoServer an raster representation of layer? Just like in for ex. ArcGIS REST Api: When I send: ...
0
votes
0answers
20 views

Scale factor (constant not linear stretch) GDAL [duplicate]

I need to re-scale a geotiff with gdal. I'm aware that gdal_translate has a -scale function, but i need to actually apply a constant (eg value(x,y) * 100) instead of scale the pixels to within a ...
1
vote
0answers
853 views

Create a jgw file for jpg image.

I converted ecw file into jpg file with IrfanView, to display the jpg as base layer in openlayers. I understood that I need to create a jgw file to display the jpg file. I found this example: ...
4
votes
1answer
121 views

How to make raster cells with a certain value stand out in QGIS?

I would like to make my raster cells glow in QGIS. If I have a dataset where only a few pixels has a value, they can be pretty difficult to spot (unless I know where to look). Stretching helps a bit, ...
2
votes
1answer
177 views

Right raster zonal statistics for NDVI at county scale?

I am currently doing a modeling project at county scale in which I have disease rate as dependent variable and environment variables (such as temperature, NDVI and evapo-transpiration) as the ...
1
vote
2answers
137 views

Batch Fuzzifying with ModelBuilder

I am trying to run the Fuzzy Membership on simultaneous rasters in ModelBuilder and I am running into the problem (or bug) where it allows me to change the "Membership Type" but ends up defaulting to ...
2
votes
2answers
293 views

SPOT NDVI time series

I have 423 spot.vgt ndvi from first April 1998 till 31 Dec 2009. I want to know how to stack these NDVI to have one image for time series analysis? Or better to ask how is it possible to analyze a ...
2
votes
2answers
1k views

How can I use GDAL to batch define a projection?

I have a fodler with 1500 ECW rasters, no spatial reference information defined. Can I use GDAL to batch define a projection for all 1500 in the folder?
1
vote
1answer
326 views

Having issues removing white background from Raster images

I've got an issue with 4 raster layers that I have converted from kml files into layer files. It would only allow me to convert them if I used ground overlay and now the 4 raster images are ...
0
votes
0answers
76 views

QGIS: “No data” raster value for missing rows conflicts with data?

I’m having a problem with specifying “no data” in a raster dataset in QGIS 1.8.0-Lisboa. QGIS does fine in interpreting pixels I don’t have rows for as “no data” if I set Layer Properties -> ...
0
votes
2answers
114 views

How can I see average of raster value over certain area, marked by mouse?

I have a raster in Quantum GIS and I am just exploring it. How can I see average of raster value over certain area, marked by mouse? In other words: How can I select particular area in QGIS? How can ...
3
votes
1answer
66 views

Speeding up raster to point set function

I have written the following function that takes a raster (always non-skewed) and returns a set of points. As I'm executing it millions of times in my queries, I'd like for it to be super-optimized ...
4
votes
3answers
755 views

Loading raster data to postgis

I'm a newbie in GIS technology and need some help in loading a rainfall radar raster data into PostGIS. The raster image is shown here: What I need is to store in the database the radar ...
2
votes
1answer
855 views

How to overlay two raster layers

How to match two raster layers, I have one raster and a shapefile and I want to convert the shapefile into raster BUT I want it to have the same cellsize and its cells overlay (same positions) to the ...
5
votes
1answer
1k views

ArcGIS - make linear regression across multiple raster layers

I have a series of 5 rasters which represent a value for 5 consecutive years. Is there a way to create a linear regression for each cell over the 5 layers and output the slope? The result would be a ...
2
votes
2answers
571 views

Select maximum values from list of raster layer : ArcMap10

I have 10 raster layers. Each layer has the dimension of 100 columns x 100 rows and actually are temperature values from year 2000 to 2010. I want to ask ArcMap to produce a raster layer that ...
1
vote
1answer
170 views

Aggregating a raster to fit a polygon grid

I am working at the scale of 10 square km grid cells for the UK, and have a polygon layer of the Ordnance Survey 10k grid cells in ArcGIS. I have another layer of the human footprint index, also for ...
3
votes
2answers
183 views

Resolution difficulties in Grass

I have gone through similar questions to mine here, but I didn't find a solution. Please help! When cropping a raster image by using g.region & r.mapcalc, I get a new image but the resulting ...
1
vote
2answers
463 views

Parallel Computing and Raster Operations in ArcObjects gives cryptic error

This is a problem I have been struggling with for awhile. The code below takes 1-3 input feature layers (pFLayer) that were stored into a list called pFeatureLayerCollection, casts them into ...
1
vote
2answers
183 views

Read raster value at mouse position

I have raster layer imported in QGIS. How can I read value of the variable represented by the raster at mouse position? I just have a new raster layer and I want to read values at random places to ...
0
votes
0answers
89 views

Why does a shapfile shift after transformation?

I have a shapefile created in the raster package (ER_14.3_2000_poly). > #read in a raster file > ER_14.3_2000<-raster('E:/Ecoregions Models/Outputs/ER_14.3/ER_14.3_ConsensusMap3.asc') > ...
0
votes
0answers
46 views

How to reclassify raster data on a scale of 0-1? [duplicate]

I have various raster layers generated after using euclidean distance tool. How can I reclassify them on a scale of 0-1 instead of 1-10, etc?