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
1answer
198 views

Why does georeferencing reduce the image resultion?

I'm trying to use a raster as a base image in my QGIS project. It is a building schematic which is fairly high resolution. Importing this into QGIS, it seems that the only way to re-position an ...
1
vote
1answer
54 views

Needed a free high resolution imagery for Las Cruces, New Mexico area

I'm Looking for a free download Imagery that is a very high resolution and the most recently like the past 3 months. I'm doing to produce a map where our new building being move into next year ? Is ...
1
vote
0answers
164 views

Why are the colors of my WMS layer messed up in QGIS?

I have a raster image on my computer, and I used it to test some geoserver features. (I'll upload images to show you what the problem looks like) I have the same raster, but transferred by wms. And ...
2
votes
2answers
982 views

Most efficient option to create a raster basemap for a web application?

I'm sure this is probably a common problem and many have already found the right answer. I have a large mosaic raster file (a city's ortophoto) in .ecw fromat and we want to use it as a basemap in a ...
0
votes
0answers
316 views

How to convert Raster to points in MapInfo?

I wanted to convert Raster data to point data in MapInfo.Does there any tool to convert? can anyone help me?
1
vote
1answer
87 views

Raster Data to Polygon [closed]

I need to "translate" raster information to a set of polygons. The raster to polygon tool will not work. I created a fishnet with the same resolution of the raster and converted it to polygons. I now ...
6
votes
4answers
2k views

How to convert raster to point in QGIS

I wanted to convert Raster into Point Vector in QGIS. Is it possible? QGIS have option to convert it into polygon but i didn't found any tool to convert it into point. can anyone help me?
1
vote
0answers
67 views

How to Clip a Raster dataset so that it is smooth along a boundary [closed]

I know how to clip a raster, however I need it to be smooth along the edge of a boundary and not jagged as can be seen in the image.
0
votes
0answers
82 views

Interpolation Technique

We have following solar metro logy parameter through satellite data with resolution of 100 Km^2 (10Kmx10Km) Insolation on horizontal surface Diffuse radiation on horizontal surface ...
2
votes
2answers
680 views

Spatial Analysis - Calculate a cells elevation (height) above the nearest stream cell

I have searched for some ideas on how to formulate this analysis, but have come up short. I imagine there is a pretty straight forward answer; any help would be greatly appreciates. Data: DEM, ...
1
vote
0answers
32 views

Map algebra from QGIS python console? [duplicate]

What command do I use to do map algebra on rasters from the QGIS python console?
1
vote
1answer
36 views

Georeferenced labeling

I have a problem with ArcMap that somehow affect georeferencing. So I have three layers, two with .lyr and one is a raster data. The two .lyr datatypes are a border and cities with names. I ...
1
vote
0answers
45 views

What type of calculations must be done for traffic emission for buffers in land use regression?

I have a raster layer that shows traffic emission distribution by kernel density method. Traffic emission will be used as independent variable in land use regression. What type of calculations must ...
1
vote
1answer
285 views

If road lengths are raster layer, how to calculate road lengths for different buffers?

A question related calculation of road layer lengths using raster layer for land use regression. If raster layers are used instead of vector layer for calculation of land use area and road lengths, ...
2
votes
1answer
725 views

How to change layer transparency without changing border lines?

I have a raster image of elevations. I have added a vector shapefile that contains local political divisions. I want to keep the elevation colors, but I want to keep the black lines representing the ...
1
vote
1answer
98 views

Viewshed calculation using SQL

Can i calculate viewshed in MS-SQL server? Viewshed analysis is Raster operation. I have elevation value vector observation as point vectors. Are there any methods to calculate Viewshed (using ...
0
votes
2answers
480 views

Clipping polygon layer into multiple polygons via model builder?

I have a huge polygon layer created from a raster, and over that I have a watershed shapefile. I need to run a land-use regression process on each individual watershed so I'd like to clip and export ...
0
votes
1answer
523 views

How to add raster data to Table of Contents using python?

I can easily add shapefiles to the Table of Contents in Arcmap using the following codes: mxd = arcpy.mapping.MapDocument("current") df = arcpy.mapping.ListDataFrames(mxd, "Layers")[0] path = ...
1
vote
3answers
2k views

Is it possible to open rasters as array in NumPy without using another library?

I know that it is possible to open a raster as an array in NumPy using GDAL, but I want to skip GDAL and use NumPy only, as it is cooler handling rasters with NumPy as matrices. There is a similar ...
1
vote
1answer
131 views

Load Raster Values into Shapefile [duplicate]

I have a shapefile containing many points. Some of these points fall within an area for which I have raster data. I would like to load the values of the raster which underlie each point into the ...
4
votes
3answers
150 views

How to show cell boundaries on a raster?

I am trying to recreate a situation where each cell from a raster dataset has a black border as seen in this image. Any ideas?
1
vote
1answer
72 views

Re-sizing Raster file pixels

I have 2 JP2 aerial imagery files that are incorrectly sized. They are 100x larger than the other aerial images but correctly geo-referenced (starting x, y co-ordinates). I believe the issue is their ...
3
votes
0answers
240 views

Image classification for a study site falling over two adjacent Landsat 8 scenes (qGIS or ArcGIS)

This question concerns work-flow rather than specific methodological problems. I will be using GRASS to classify Landsat 8 images to create a vegetation map for a study site that happens to fall over ...
1
vote
1answer
438 views

How to get custom color palette in rasterVis plot3D in R?

I am trying to insert an RColorBrewer palette to visualize an elevation raster in R using the rasterVis function plot3D. The rasterVis reference document shows the following parameters: plot3D(x, ...
2
votes
3answers
816 views

How to Iterate through Bands of Raster using ArcGIS 10.1 ModelBuilder?

I have a large number of rasters with 3 bands (R,G,B). What I want to do is add all 3 bands of each raster together to end up with a single band image with the summed R,G,B values in each pixel but ...
2
votes
1answer
106 views

Raster layer calculator

In PCI Geomatic, I have two raster layer.raster1 identified like %1 and raster2 like %2. if (%1 <= 10) then %2 = 60 elseif (%1 > 10 and %1 <=50) then %2=80 elseif (%1 > 50 and %1 ...
1
vote
0answers
189 views

Touch up tool for rasters?

I was wondering if it were at all possible to manipulate/massage rasters (eg Geotiff) using Qgis plugins or Grass?? By manipulate, I mean manually smooth off interpolation artefacts, blended surface ...
1
vote
1answer
761 views

Why does CON statement give ERROR 010240: Could not save raster dataset to (value) with output format GRID?

I am receiving the following error when trying to run the following code: import arcpy from arcpy import env from arcpy.sa import * arcpy.CheckOutExtension = "Spatial" env.workspace = ...
2
votes
1answer
2k views

ArcPy findAndReplaceWorkspacePath not working with Raster Datasets

Situation: I am working on creating a Python script that will replace workspace paths for every layer in a map document in order to fix broken layers after a data migration. The script works except ...
1
vote
1answer
389 views

“dataset does not exist or is not supported” using large GRID raster

I am trying my hand at arcpy for the first time to create a conditional raster from a set of threshold values. I have 3 large GRID format rasters (mos_zb3, mos_zb4, pca_finb2) I am trying to feed into ...
0
votes
1answer
107 views

QGIS proximity raster with extent beyond original coverage?

I need a raster coverage of distances from points outside the geographic region of interest, and am having trouble doing this with QGIS. Questions like this one (Calculating distance to points in ...
1
vote
2answers
180 views

Grass GIS 6.4.3, How to create a .PTS file

I'm trying to export a raster map in order to use it in the Flo-2d program. This program needs a .pts DTM file, do you know how I can create it? Alternatively, I can use a XYZ file looking like this ...
4
votes
2answers
3k views

Loading PostGIS raster layer into QGIS

I am unable to load a PostGIS raster layer into QGIS. I have looked through previous posts Loading raster from PostGIS DB into QGIS and Cannot add the PostGIS raster layer with QGIS but was not able ...
2
votes
0answers
51 views

Wrong pixel sums within buffers in Esri ArcGIS 10.0

I have a raster of Zambia, 100m² resolution (about 650mb). Buffers (single) at 1,2,3,4,5,10,15,20,25,30,50 km. I'm running "zonal statistics as table" in the model builder for all buffers (actually, ...
1
vote
0answers
329 views

Saga Reclassify grid problem

I am using Qgis 2.1 ver. 5f5cd4c (64 bit version on win7 64) OSGeo installed. I was trying to reclassify a DEM in EPSG:32614. I used the SAGA's Reclassify algorithm in the processing toolbox. I ...
3
votes
1answer
160 views

Create a band mask based on pixel locations, not in pixel values

I have this image loaded in QGIS, with two possible values for the pixels: 1 = orange, 2 = blue For simplification, assume it represents a province of a country. I want to extract just the part of ...
2
votes
1answer
315 views

netCDF-java has trouble reading this netCDF file(format) and fetching values from the latlon dimension

I'm developing an application where I need to extract variable-values from netCDF files. I'm processing several different formatted netCDF files and now one format seems to be creating some issues. ...
1
vote
1answer
179 views

QGIS Grass Plugin fails with r.cost.vect

I tried the following in QGIS with the Grass Plugin: r.cost input=preCostSurface@albi start_points=OSMroads@albi output=cost0109 max_cost=0 And I get the following error: Dev note: Adapted sites ...
0
votes
2answers
129 views

Count the area of rasterdata in specific shapefile polygons (residential density in different districts)

I'd like to count the exact area of three different residential classes (low, medium, high) by district of a shapefile which contains 225 districts. like: district 1 has: XXX sqm low, XXX sqm medium, ...
1
vote
1answer
847 views

Map Algebra - Grass GIS (r.mapcalc) merge two raster with NoData value

I have a slope raster and a road raster. The black pixels in the road raster are NoData values and the pink pixels have a value of 1. They don't cover exactly the same area. I want to create a new ...
1
vote
0answers
59 views

Selecting a bounded area within a raster

I am new to postgresql. I have imported a 256kb sample raster (.tiff) into postgres with tilesize 100x100. Now I need to select the area (rectangle) from the center of the image using sql query. Then ...
3
votes
1answer
94 views

How to use Plus tool in ModelBuilder?

I want to have the sum of at least 2000 raster combined to one raster layer using ModelBuilder (Plus tool). I think I'm missing something here. This model does not work.
0
votes
1answer
116 views

How to display NoData of a raster in QGIS

How can I show raster pixels with NoData value in QGIS? In ArcMap there is a button to choose the color for the NoData value. Is there something like this in QGIS?
2
votes
4answers
138 views

Is there any free resource to get international raster data (other than USGS)?

I am looking for any raster database that allows free downloads of any kind of raster data pertaining to Damascus, Syria and the surrounding Turkey area. I'm trying to avoid USGS since it requires a ...
2
votes
1answer
212 views

How to multiply raster DEM with a linear graph value

I would like to multiply my Raster DEM with a linear graph value y = mx + C. The graph values look as follows: I want to make a new raster where each cell will represent a damage factor from ...
0
votes
0answers
28 views

calculating mean and standard deviation for raster values using whole pixels within a polygon [duplicate]

i have a raster image and a corresponding shape file. i would like to calculate the statistics of the values within polygons which have a common attribute but only using pixels which are fully ...
1
vote
0answers
34 views

Layers and variables are not coming out in the raster calculator tool window

I have many shapefiles in the table of content but layers and variables are not coming out in the raster calculator tool window. I placed the cursor the left of the Raster Calculator window, dragged ...
3
votes
1answer
525 views

NOAA Nautical Charts .bsb format

Is it possible to load a nautical chart from NOAA into QGIS that has the .bsb format? Didn't have much luck with mrSID format. using QGIS(dev) on ubuntu 13.04
1
vote
2answers
2k views

How to access each raster in a stack with a loop

I have a stack of rasters and I want to access each layer, combine each later with another file and finally export the resulting file as a csv file. Is there any way to do this with a loop? So far I ...
0
votes
1answer
289 views

Import raster into ArcGIS

I received raster data from a grid of 1100 by 1000 meters with a resolution of 1 meter. It is the output of EFC-400 software showing the field strength around power lines. The data is currently in ...