Rasters are regular grids of values, usually stored in an image-like format.
1
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2answers
125 views
Why is Format of output data grayed out on Save As dialog for Rectify?
I started georeferencing and I could not save my new "rectify" file, I don't know if is because of the raster or I did something wrong. Then I find out that my control layer is not accurate, it ...
3
votes
3answers
199 views
How to extract raster values and create new raster in Qgis?
I want to extract certain values of a raster image in order to create a new raster which then should only contain the extracted/chosen values.
How to do this in QGis?
4
votes
1answer
114 views
Add band to existing GeoTiff using GDAL
This seems like it should be straightforward but I can't for the life of me figure it out.
Given an existing GeoTiff containing a single band, how can you add another band to that GeoTiff? Is the ...
3
votes
1answer
78 views
ArcGIS Raster Symbology - Break contour at 0
In ArcGIS 10, how can I break raster symbology (stretched) at a particular value (i.e. 0). For example, I have a DEM representing both topography and bathymetry and I want a break at the 0 m contour ...
6
votes
2answers
134 views
Breaking apart a polygon layer by unique values, creating many new layers
I have a large dataset of habitat information that I need to calculate distances from animal locations to the closest polygon of each habitat type. The way to do this, that I understand, would be to ...
1
vote
2answers
83 views
Put color for raster data(aspect.tif) on QGIS1.8.0
I create aspect.tif from DEM file.
I could put the values(0 to 360)from contrast enhancement.
I could set color from color map(freakout or Pseudocolor).
In here, the data is shown by only 4 colors.
I ...
1
vote
0answers
103 views
How to use GDAL to burn a selected value from one raster into another?
I think this should be a relatively simple process, but I'm not quite sure how to approach it.
I have a shapefile containing 1000's of polygons. I also have 19 rasters. All of the polygons fall ...
2
votes
1answer
37 views
How to visualize the water equivalent between two raster layers in arcmap 10.1?
I do have two raster layers (interpolated with Empirical Bayesian Kriging), that show the elevation of a glacier in April, and September. I want to show the change in elevation between the layers in ...
4
votes
1answer
66 views
Why does the added raster layer have strange edges?
I'm using Geoserver in conjunction with the google maps API to add a raster layer onto a map. It loads fine, however there's some strange problem with opacity at the edge of the layer where you can ...
1
vote
0answers
129 views
Importing grib, grib2, netcdf to PostGIS
According to grib2 to raster? (grib2 -> raster2pgsql -> PostGIS 2.0 -> GeoServer), it seems like that grib2 can be treated as raster directly. Is it the so called "standard" way?
How about ...
1
vote
2answers
61 views
ArcPad Raster Not Displaying Correctly
I have a hillshade that I would like to use as a background in an ArcPad 10 map. I get everything set how I want in in ArcMap and when I export the map to use on my Trimble the hillshade doesn't show ...
1
vote
1answer
46 views
cannot print listRasters
I'm trying to run this very simple script to check a problem in another more comlpex one.
import arcpy
arcpy.env.workspace= 'C:\\Users\\Umberto\\Desktop\\Prove_Script\\Karakoram\\temporary_01'
rst= ...
4
votes
2answers
185 views
How to extract values from a raster according to Lat and long of the values?
having 12 files with 12 hdrs for one year: these files are raster (projected WGS84,lat long):https://echange-fichiers.inra.fr/get?k=rLSyoavrnifGyH5XrlO
samples = 1440
lines ...
4
votes
3answers
65 views
Where can I find decadal climate and ocean data for Europe?
I would like to find decadal climate and ocean data for Europe that I can download and use directly in ArcGIS. Specifically, I am looking for mean annual temperature, sea surface temperature, and ...
5
votes
1answer
69 views
What GIS software is required to export a GIS map as a hi-res raster image?
I am looking for some (preferably free) GIS software that will enable me to export multi-layered world maps (made up of shape-files and kml files and so on) as hi resolution (21,000 pixels wide), ...
0
votes
0answers
16 views
Aggregation operation on raster files inside a raster database in postGIS Raster
I have a raster database in PostGIS Raster. I want to merge a number of raster files that are imported to the database using average to create another file. In the other words, the mean value of ...
1
vote
1answer
85 views
How to add multiple rasters to a layer file?
I'm trying to make a .lyr file to bring into ArcMap with arcpy.mapping. I can bring a single raster into a .lyr with the script below. I'm unsure how to proceed to get multiple rasters from the same ...
2
votes
2answers
210 views
How to georereference a TIFF file which has already a spatial reference?
I have a TIFF file of Poland and a self drawn vector map of Poland. The vector map has no spatial information.
I am intending to reference the TIFF exactly to the shape of the self drawn map.
My ...
4
votes
1answer
121 views
Use csv file as raster file and stitch them together
I'm having an issue trying to stitch together 100 32bit Tiff files (coming from thermal imagery video and extracted as 32bit Tiff).
I used Hugin to mosaic the pictures extracted from the video which ...
3
votes
0answers
110 views
shortest distance between a raster and another raster
i am using arcgis 10.1
i want to calculate the shortest distance between a raster and another raster. i have a bathymetric raster and an underlying fault plane raster. for each bathy raster cell, i ...
4
votes
1answer
134 views
How can I avoid reprojection gaps when merging DEM rasters?
I have two raster DEMs in same resolution I want to bring together. I was using the merge-function in SAGA, GRASS and QGIS but I always get the following result:
What do I need? Where could the ...
1
vote
2answers
291 views
QGIS Raster Calculater Syntax
I am trying to use the raster calculator in QGIS to combine a number of rasters. I want to calculate a mean, this is easy:
(raster_1@1 + raster_2@1 + raster_3@1) / 3
I then want to create a max. ...
0
votes
0answers
132 views
Output of QGIS raster clipper not as expected?
My goal is to clip a raster with a polygon in QGIS 1.8. Based on an article I read, this should be a pretty straightforward task. However, the output appears to be empty. The raster produced is the ...
1
vote
0answers
145 views
Raster calculator error 000539 - cannot create weak reference to 'classobj' object
I was - like many times before - trying to clip a raster with the raster calculator (raster * 1 with shapefiles as mask). Now - the following error keeps popping up:
ERROR 000539: Error running ...
3
votes
1answer
62 views
Get rid of raster grid cells that are less than 1
I'm using QGIS to work with raster data. I have a raster dataset of a country where each grid cell is assigned a number 1-100. However, the raster is in the format of a rectangle based on the extent ...
6
votes
1answer
91 views
How to reclassify raster data by their sign?
I want to do the following: I have two data raster sets with different units and values. One results from measured metric data, the other from modelled grid values. What I want to compare is simply ...
3
votes
0answers
57 views
Geoserver Raster layer cropped by polygon?
I've got a Geoserver raster layer which represents a satellite image. I use the Geoserver WMS to display the raster in OpenLayers. I want to display only parts of the raster - those within a certain ...
0
votes
0answers
67 views
Can't Find Raster with Android QGIS [closed]
I can't seem to use QGIS android file system to find input files on my xoom. I have stored Alaska raster on both sdcard and sdcard2, but I can't find it with QGIS.
I managed to solve this problem ...
0
votes
0answers
205 views
How to resample a raster in QGIS?
I've got a boundary file that I would like to resample the raster file from a 30m grid to a 10m grid inside the boundary file. When I try and do it in Qgis or Grass all I get is one big raster cube ...
7
votes
2answers
173 views
How to create a solar intensity map for a garden plot?
I'm interested in creating a raster surface that depicts the average solar intensity per unit area for a small garden plot. I imagine the inputs into the model would be the following:
Plot ...
1
vote
0answers
26 views
When a raster is described in general as either a double or an integer how do conversions work for that type
I know a raster format is essentially a grid of cell values that may have values associated with color, but I'm unsure of how the primitive types factor into the format. In addition if I need to write ...
3
votes
1answer
268 views
How to re-project ease( Equal Area Scalable Earth) grid with a ~25 km cylindrical projection to WGS84 0.25 degree?
I have nc (NetCDF) files for global soil moisture.
From the metadata, the projection is cylindrical and the resolution is 25 km (it is based on authalic sphere based on International 1924 ...
1
vote
1answer
57 views
How do I create rendered vector field in qgis
Perhaps I am misunderstanding the "vector field renderer" and "VectFieldCalc" plugins, but I have no idea how to make a vector field of arrows, with directions and magnitude. I have the data loaded ...
6
votes
2answers
143 views
Extracting roads out of Landsat raster images
For a study into the expansion of road networks in the rainforest I am trying to extract roads out of Landsat images. We already have sharp and cloud-free composites on which the roads are clearly ...
3
votes
0answers
74 views
Build Raster Attribute Table with GDAL Utilities
Is there a way to build a raster attribute table using one of the GDAL utilities? I know you can view it using gdalinfo and I have successfully created one using Python, but it would be so much ...
2
votes
1answer
54 views
Are there any open source distribution raster merging functions within JTS or GeoTools
I'm looking for something similar to the combine function from the ISelectionSet interface from ArcObject's SDK 10 .NET framework on a more scaled down level. Ergo, I don't plan on using that ...
1
vote
1answer
72 views
Set certain amount of pixels to 1 inside of a polygon (GRASS)
I have a rather coarse vector map with polygons and want to calculate a (sufficiently) finer raster map defined by spatial extension and resolution. Every polygon of the vector map has a value ...
1
vote
3answers
61 views
Apply rotation before FeatureToRaster_conversion
I am converting polygon shapefiles to rasters. With arcpy I am using the function FeatureToRaster_conversion.
gp.FeatureToRaster_conversion(InFeatures, InField, OutRaster, InCellSize)
This function ...
2
votes
1answer
126 views
Saving rasters in a Python for loop fails only on last iteration
I'm a newcomer to Python scripting and I'm having what's seemingly a very simple problem but one that's stumped me enough to send me posting to these forums for the first time.
I'm using a for loop ...
3
votes
1answer
491 views
ArcGIS 10 - Raster cell values and raster attribute tables - reassign raster cell values from another attribute
It seems like this should be relatively easy to accomplish, but I've been messing with this issue off and on for a couple days and have not successfully figured it out.
Problem: I have a large (size ...
2
votes
1answer
111 views
USGS GeoTiff extent via GDAL
I have 2006 land cover GeoTiff from the USGS site (for a county in VA, USA). The projection is Albers Conical Equal Area Units. The download came with an HTML metadata file that tells me the geo ...
0
votes
0answers
88 views
UTFGrids for raster data and incorporation into existing MBTiles files
I've been rendering a raster vegetation model (at 30m resolution) through TileMill with good success. Our specific vegetation model has many attributes associated with each pixel, although there are ...
1
vote
0answers
50 views
jagged edges in mosaic DEM
I encounter edge issues when trying to mosaic USGS NED DEMs in ArcGIS 10.0.0. After projection and aggregation, I attempt arcpy.MosaicToNewRaster_management(). I've reproduced the same results using ...
3
votes
1answer
103 views
parallelization of raster mosaic
I would like to create a raster mosaic of the national USGS NED 30m DEM (~50 GB). I'd like to leverage parallel processing using python multiprocessing module where possible. I'm using ArcGIS 10.0. My ...
0
votes
0answers
35 views
I need advice in using QGIS Lisboa 1.8 (vol 2) [duplicate]
Possible Duplicate:
I need a advice in using QGIS lisboa 1.8(vol 3)
My previous question was not clear, so again my question is:
In an urban area with polygon and dots, how could I display ...
11
votes
2answers
310 views
Converting ascii windspeed files to rasters
I have been trying to convert windspeed files to rasters without success. It was discussed in an Arcgis forum which I followed. This involved replacing semi-colons with spaces and adding a header.
I ...
5
votes
1answer
91 views
GDAL/OGR Determine if dataset is raster or vector
I am writing a script using the GDAL/OGR Python bindings and it is possible that the user may provide a raster dataset or a vector dataset as input. If the user provides a vector dataset, the script ...
1
vote
3answers
325 views
How to subset raster image using gdal?
I have read pixel values of an raster image using GDAL libraries in visual studio 2010(vc++).
Now I have to crop the image (subset) according to the grid given in shape file.
I have got a code for ...
3
votes
1answer
123 views
An error in raster calculator in Arcgis
I wrote and ran this formula in raster calculator in ARCGIS. But the following error gets me into trouble. Does anyone have a suggestion to overcome this? Here is the formula I wrote and the error ...
2
votes
1answer
104 views
ArcObject 10.1 Java : Raster Analysis
I have been working with ArcObjects Java for a short time and have not been able to find a solution to the following problems:
How to get the Raster object from a IRaster reference?
IRaster raster = ...
