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

learn more… | top users | synonyms

1
vote
0answers
338 views

TIN to Raster Tool, output elevations are 3.40282e+038 and -3.40282e+038, tried calculate statistics didn't work

I have an input TIN file that I created using Create TIN. The elevations are all correct. When I convert the TIN to Raster using the tool, my output elevations are 3.40282e+038 and -3.40282e+038 ...
2
votes
0answers
73 views

Can I clip raster maps by vector boundaries on fly while serving them via geoserver?

I have a lot of georeferenced raster topographic map sheets which contain not only map itself, but some sketch elements like legends, stamps outside the map frame. I want to make seamless coverage ...
2
votes
0answers
50 views

Extract MultiValuesToPoints yields identical value for each band

I'm attempting to extract hyperspectral remote sensing data to a point featureclass using the ExtractMultiValuesToPoints ArcGIS tool. The value of each band (228 bands) should be appended as a field ...
5
votes
1answer
808 views

Raster vs Grid vs Lattice terminology?

I have a question about GIS terminology - what is the difference between grid and raster and grid and lattice - in theory?? I thought, that raster is regular network and value is in the cell and the ...
1
vote
1answer
115 views

Analyzing Raster Data From Vector Layer Buffer

I am using QGIS 2.0. I have satellite images of night-time lights all over earth. I also have a vector shapefile of country boundaries including the largest cities on earth. I want to use buffers to ...
0
votes
0answers
174 views

Choose what zoomlevel to read from for mbtiles file in GDAL

GDAL is supposed to read MBTiles files and to do so, it selects the highest zoomlevel available. However, is there a way to choose another zoomlevel? i.e. override the default and go for a lower one? ...
1
vote
1answer
74 views

How to read the count of the cells with data with non “no-data” values ,in QGis?

How to read the count of the cells with data with non "no-data" values ,in QGis
1
vote
1answer
75 views

QGIS Grid Division/Grid Product etc. results are wrong projection

I have several raster grids, all 4320 columns, 2160 rows in WGS 84 projection. They are loaded from ESRI ascii files. When I use the Processing Toolbox to carry out arithmetical transformations on the ...
1
vote
2answers
501 views

convert data.frame with no lat-long info to a raster

coders, I need to read in a .txt file into R and later do some spatial analyses on it. I’m working in R. 3.0.2 on a Windows server. I load the following libraries (probably more than I need): ...
2
votes
1answer
142 views

PostGIS Raster: Outputting raster into GDAL supported file?

I have import a raster into my postGIS database via raster2pgsql. My raster tiled to 100x100. Now I'm trying to export (output) the raster to GDAL supported file (for example: PNG). Following the ...
7
votes
2answers
252 views

Finding specific pixel values ​​in ArcGIS using Python

I have a raster file containing some integer values. I need to find all pixels whose values are not defined in list like this one: l = [1,2,4,8,16,32,64,128]. Is there any easy way to solve that ...
4
votes
1answer
697 views

How to calculate total number of data cells in raster?

I am using ArcGIS 9.3 and python 2.5. My code is shown at the bottom of this post. I have a raster containing fire intensity information at 200m cell resolution. I run the script and the first count ...
5
votes
1answer
457 views

Create a point at the highest value in a raster ArcGIS 10.1

I am trying to find the location of the highest value pixel in my Direct Solar Radiation Raster. I can see the extent of the data in my raster but don't know where the highest value pertains to. Is ...
1
vote
0answers
132 views

Importing GPS coordinates to extract multiple DN values in ERDAS

I have a set of GPS points (stored as a csv for now) and would like to import these points to ERDAS to find the DN values associated with each location. I am able to import a SHP to ERDAS but the ...
4
votes
1answer
888 views

How to extract pixel value counts from a raster in QGIS?

How does one go about obtaining a summary of the counts of cell values within a raster in QGIS? I know QGIS is doing this, in order to provide the summary statistics and histogram in the properties of ...
1
vote
1answer
218 views

Convert point to grid: Numbers of cells differ

In R I am trying to aggregate points data to a grid. The data for the grid (G-Econ) comes as a csv-file. In this file each row represent a grid-cell at 1x1 degree resolution and the given ...
1
vote
1answer
73 views

Should large Basemaps be stored in DBMS via ArcSDE?

As I understand it, the SDE Geodatabase provides the technology for Multiuser databases, Versioning, replication and other Geodatabase functionality. In my organisation, this could be useful for ...
1
vote
1answer
761 views

Convert polygons in shape file to a numpy array?

I have a shape file containing a number of polygons and all attributes being text. I'm trying to import the polygons into numpy as an array where each polygon is represented as unique values. I ...
4
votes
1answer
130 views

Simple way to compare ranges and distributions of species, looking for correlation and differences between ranges

As a biology student just beginning with GIS, wondered if someone could give me an idea of what tools to go about using to compare the range of 3 species that have trophic effects on one another. I ...
0
votes
0answers
111 views

How to split a raster into multiple rasters using QGIS?

I would like to know how to split a raster into multiple rasters in a single operation using QGIS. Although I can clip the raster image, it would be better to split it using a single operation. I am ...
2
votes
2answers
550 views

Can raster files from ArcGIS for Desktop be visualized in Google Maps?

I have raster files created using ArcGIS (Desktop application). On the other side I develop an application using google maps. Can I visualize those raster files somehow on google maps API?
0
votes
1answer
242 views

How do I use wildcards to work around the GDAL character limit?

I am attempting to use the 'Merge' & 'Create VRT' tools in QGIS 2.0 on a folder with 3000+ raster tiles in. However whenever I try to perform this operation the following error appears: 'The ...
3
votes
2answers
412 views

Using python to Raster clip the extent to be the same as the display?

I've been trying to figure this out for almost a week now. I am creating a tool which first needs the raster to be clipped out to the current display. I have tried all sorts of things. Below is the ...
1
vote
1answer
1k views

How can i convert a raster from continuous to discrete?

I have a tiff that is 'invalid' for a lot of tools and will not let me view the attribute table. I think this is because it is "continuous" rather than "discrete". Does anybody know how to convert it ...
2
votes
1answer
74 views

How to stop transfer of large raster into arcsde geodatabase

I have just realised that I will not have enough space on my harddrive to accomodate a raster which is being copied into an arcsde geodatadatabase. I am afraid, that if I stop the process in ...
2
votes
0answers
280 views

What are common mistakes when creating mosaic datasets?

I have a set of images taken from a unmanned air vehicle, they have lat/lngs when properties are clicked in windows, but when they are imported into ArcGIS they have no spatial reference or coordinate ...
1
vote
2answers
81 views

How can i combine the colours of one raster with values from another

I have two Tiffs with data from the same area. One is in colour and when I use the identify shows a 'color index' number (eg. 141), then Color(a,r,g,b)(eg. 255,90,255,0). The other tiff contains a ...
1
vote
3answers
347 views

Converting files for use in fragstats

To use my data in fragstats i need to convert it into a signed integer grid. I have the data in a raster format and have tried 'right click>data>export data> and setting the format to 'Grid' and it ...
1
vote
1answer
1k views

How to Create Cost Surface Raster for Least Cost Path Analysis?

I have a DEM raster and would like to carry out a cost path analysis. Among other factors such as slope, proximity rivers etc. I would also like to take elevation into consideration. According to ...
8
votes
4answers
306 views

How to determine if point is surrounded using raster processing?

I am attempting to improve a currently extremely cumbersome vector/python process for a natural hazard model. At the moment we have a lengthy script which generates distance/bearing lines from a given ...
3
votes
1answer
315 views

White lines in merged GeoTIFF files after ImageMosaicing on GeoServer

I have merged 21 GeoTIFF images using GDAL utilities. Each image is the result of merging 500 smaller tiles. I am using ImageMosaic in Geoserver but I am getting a mosaic that contains white lines and ...
2
votes
1answer
204 views

Raster topo map “collars” overlap

I am using QGIS 2.0. I have downloaded USGS 1:100,000 topographic maps which show adjacent areas. The topographic maps were digitized with the borders (I've seen them called "collars", I think) as ...
0
votes
0answers
188 views

recording pixel value with Python script in ArcGIS 10.x

A scripting newbie question... I'd like to write a Python script for ArcGIS 10.x that would record the pixel value for all pixels in a raster. Furthermore, I'd like to only record a given value once ...
8
votes
3answers
383 views

R, rasterVis and RGL: how to prevent reflective surfaces?

I have been experimenting with digital terrain model files in ESRI ASCII grid raster format. Despite zero experience with this type of data I found it very easy to load into R, as per code below. The ...
4
votes
1answer
106 views

Finding percentage of feature in a raster

I am attempting to find the percentage of polygon features at a 5 meter resolution that are located inside each 25km raster cell. I am looking to assign percentages to each cell based on the ...
1
vote
2answers
230 views

Copy rasters slow, increases file size

I have a folder with ~1200 aerial photos in both jp2 and tif format, of which I need about 380. I wrote a python script to get the names of the files I need, which works fine. But when the script ...
0
votes
1answer
451 views

Summarize values from a raster brick by latitude bands in R

I would like to sumarize (sum and/or mean) values from layers on a raster brick based on latitude bands (been using raster package). Been looking at the package documentation and didn't find a way to ...
2
votes
2answers
307 views

How to find the second highest value in a rasterStack in R

I have a rasterStack of rasters representing count data. I want to return a single raster whose values are the index of the raster with the second highest value for each cell. (I used which.max for ...
1
vote
1answer
243 views

How to cut multiple neighboring raster images

I'm looking for a way to cut a larger number of neighboring aerial raster images (each sized 1x1 km, resolution 10 cm per pxel) into four smaller raster images (size 500 x 500 m). I haven't done this ...
1
vote
0answers
92 views

Qgis raster interpolation shift

Using Qgis 2.0.1, I'm attempting to interpolate a large point dataset (n > 400K) to a raster surface. I'm using the IDW option in Raster>> Interpolation>> Interpolation, and the resulting ...
0
votes
1answer
697 views

How to get polyline features from a raster file using ArcGIS 10.1?

I have a watershed accumulation file look like this: There are several white lines by visual, and I tried the raster to polyline tool and got this: Are there better ways to extract polyline ...
2
votes
0answers
404 views

Why does Topo to raster tool stall in ArcMap 10.1?

I'm having the following problem - An 8 mile by 4 mile set of 2 foot contours. Whenever I start the topo to raster tool, I get a constant loop of the tool running. And running, and running, and ...
0
votes
1answer
115 views

How to force deletion of corrupt ArcSDE Raster?

ArcSDE 9.3 / ArcGIS Server 10.0 / ArcCatalog Advanced 10.0 After an unsuccessful attempt at creating a mosiac, ArcCatalog refuses to allow deletion of the corrupt Raster file. The Mosiac creation ...
0
votes
0answers
415 views

gdal python set projection of a raster - does not work

Gdal 1.9.2, ECW driver: ECW/ERDAS Compressed Wavelets (SDK 3.x) I am having problems with the script that supposed to set projection of the ECW to EPSG:27700, i.e. the British_National_Grid. Please ...
2
votes
1answer
360 views

OpenLayers 2.13 : How to display a local tiled raster?

I am trying to display (on OpenLayers 2.13) a local tiled raster I made with gdal2tiles.py. Unfortunately it's all blank or pink. Here is my layer definition: var tiles = new ...
1
vote
0answers
187 views

Why doesn't the mosaic to new raster tool or the mosaic tool work when I try to use them?

I am trying to mosaic 4 raster datasets of elevation together using the 'Mosaic to new raster' tool in ArcGIS 10.1. I have even tried using the 'mosaic' tool and it still doesn't work. The errors that ...
2
votes
0answers
44 views

Is it possible to preview a raster catalogs raster field in a Windows form?

What I want to achieve: The attribute table for an ArcGIS Raster Catalog contains a raster field. When a raster field cell is clicked with the mouse, a preview window displaying the raster associated ...
5
votes
1answer
294 views

Is there a way to find out which pixel values are around the current pixel?

I would like to write a cycle which takes a current pixel, look at the surrounding pixels, choose the pixel with max/min value and skip to that pixel...and so on. Is there in arcpy such a function ...
8
votes
1answer
360 views

Where is this raster offset being introduced in the QGIS processing toolbox?

I'm using the (awesome!) processing toolbox in QGIS 2.0 to reclassify some NoData values in a raster from -9999 to 0, but at some point in the process there's an offset of about 0.2 degrees being ...
3
votes
1answer
153 views

Rasterlite db with multi table

When working with Spatialite DBs, I can store multiple tables in single DB. But now I want to store multiple raster tables on a single Rasterlite DB. I tried QGIS for conversion but it converts only ...