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

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185 views

gdal_rasterize -at function still won't capture covered pixels properly

I'm currently using the gdal_rasterize tool in bash. My code looks like this: gdal_rasterize -l $(basename $file .shp) -burn 1 -a_nodata 0 -te -180 -90 180 90 -tr 0.1 0.01 -at -ot Byte $file ...
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2answers
269 views

Break between two raster layers (topographic maps)

I have the following problem [in QGIS]. In displaying two raster layers (topographic maps), a white area appears between the two. If I apply transparency to one of the layers, this white area still ...
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4answers
840 views

Determining gradient of road segment

I've a shapefile of roads data. It contains information about terrain of road segments, i.e., hilly, flat, undulating, etc. I want to determine gradient of every road segment. I know this might ...
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1answer
2k views

How do I add TIFF files to one layer/raster catalog?

We have several TIFF images (already tagged with position information) we want to load as a single layer into the map. It's the first time I dig into this raster/topology thing, but at least I managed ...
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1answer
391 views

Adding Field to Raster

Good day! I have a shapefile which contains X-specific field. I want to add this X-specific field (integer) to a raster dataset. I am using ArcGIS 10. How can I do this? Thanks.
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126 views

Can I avoid runtime raster interpolation by creating an image pyramid to match the zoom scales?

For image quality and performance reasons, it would be best to perform interpolation of my large TIFF image of the world (10GB) beforehand to all the zoom scales I need to display at so that MapGuide ...
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1answer
460 views

How to serve raster mosaic to AutoCad Map 3D from ArcGIS Server without its Image extension?

We are looking for a way to serve all the raster datasets we've collected over the years as a mosaic we have built in ArcGIS so that the AutoCAD department can simply import the mosaic and it will ...
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2answers
322 views

Configuring a WorldImage data store starting from a folder containing tif and tfw files

i have a folder of tif and tfw files and i'd like to show the raster in a map using geoserver. Even reading the geoserver tutorial for this kind of datastore ...
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232 views

What are strengthes and flaws of using grid-cell analysis in GIS? [closed]

I'm going to use grid-cell analysis. What are the strengths and weaknesses?
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625 views

Preventing an Openlayers WMS layer from updating on zoom-change

I'm using openlayers to overlay a raster. When I zoom out, the overlaid layer expands to cover a larger area than was originally requested. I want the tile to be fixed to a particular boundary, and ...
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1answer
1k views

How to convert Geostatistical analyst (GA) file to Raster FAST?

I have been trying to convert a number of Geostatistical analyst files that i were created using Geostatistical wizard in ArcGIS 10. I want to save these files as Raster and use the File Am i ...
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1answer
2k views

How can I extract raster values around points?

I'm using ArcMap 10. I have a point dataset and a .flt raster. For each point I want the sum of the raster values that lie within a certain radius of each point. i.e. I want to extract values within a ...
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1answer
307 views

PostGIS Raster convolution filters

I've looked through the PostGIS raster documentation, but can't find an indication of how to apply a convolution filter to raster data. Does this capability even exist (yet?) There only appears to be ...
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1answer
563 views

OpenLayers ArcGIS Image Service Support

i have ArcGIS Image Server for publishing my raster data to my user. In traditionally way i have been tiling with gdal and it takes a long time besides this it requires more effort for getting true ...
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1answer
154 views

ESRI ISurface.GetElevation is extremely slow compared to GlobalMapper

I'm using ISurface.GetElevation on a Raster to get the elevation for a specific lat/lon. I have to do this for a huge set of datapoints. Currently i'm testing with a dataset of 10.000 items which ...
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1answer
136 views

Blank Vector Selection Dropdown in QGIS GRASS Plugin

I realise there are some issues which getting vectors into the GRASS module in QGIS, but is the behaviour i am getting expected? I have loaded the vector shapefile via GRASS, closed G and reopened ...
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1answer
307 views

How can GRASS export an .flt file?

I am using GRASS and connecting it to another application. The other application needs an FLT file of the raster map which I should export from GRASS. The other application only reads FLT files. Can ...
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1answer
144 views

Clip GAPAnalysis and save as a new file output strange looking colors

I download USGS GAP Analysis and use a polygon to clip raster from that GAP Analysis. I am wondering why there is a strange looking color when you clipped the raster. If you zoom in, you can see ...
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1answer
445 views

How to use r.patch with two maps having different colortables?

I am using r.patch to combine two raster maps in order to fill in the null values of the other. Is there a way to use r.patch but still maintaining the colortables of the separate raster maps? I do ...
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1answer
279 views

Creating color table file in PCI Geomatica

What is the simplest way to create a stand-alone color-table file in PCI Geomatica (PCT or STR)? I have some classified imagery with values ranging between 0-255 and I would like a way to ...
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0answers
18 views

Zonal Statistic Tool

In ArcGIS, I have a grid 5x5km (I have it both in vector and raster formats) I want to calculate, based on this grid, the zonal statistic (MEAN) of a raster 30x30m pixel size. The raster overlaps ...
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19 views

Raster Precision QGIS

I am using r.patch extension in QGIS to join a number of LiDAR tiles, some of which overlap hence i am carrying out this task before utilising in a hydraulic model. R.Patch works fine, however the ...
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19 views

How do I change the pixel values of raster data from QGIS python plugin

I have been trying my hand at a QGIS plugin. The plug in reads raster layer data into an array, pipes the data to a C++ program, does processing over there, and pipes my results back. After a couple ...
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1answer
33 views

Generate ESRI grid with xllcenter/yllcenter in header

I'm trying to generate ARC/INFO ASCII GRID (*.asc) from point feature class using Create TIN - TIN to raster - Raster to ASCII functions. I'm looking for a way to have the output raster file header ...
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20 views

Selecting cells with values from DEM those are above specific value corresponding to each polygon?

i have a shapefile with 2000 polygons and a DEM. i want to calculate zonal mean for each polygon considering values from DEM which are above a particular value for each polygon. i want to it with ...
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2answers
24 views

How to export vector file in GrassGIS to QGIS

I am using GrassGIS to analyze watershed. I created a stream vector extracted from raster elevation data, how to extract the stream vector file so I can open it using QGIS?
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1answer
35 views

Reclassifying raster analysis (like the one in ArcGIS Spatial Analyst) in QGIS [duplicate]

I am trying to reclassify raster (DEM) in QGIS. I know how it is done in ArcGIS (Spatial Analyst, reclassify option), but I would like to know how it is done in QGIS?. The point of my exercise is to ...
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36 views

Convert a raster with one band into a raster with RVB bands on QGIS?

So yesterday i downloaded a raster tile on a WMS server and exported it with Grass. I get a raster with 3 bands, i treat with the Semi automatic classification Plugin in QGIS and it works perfectly. ...
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21 views

Polygon to Raster: Cells with multiple values

I'm trying to use R to rasterize a number of shapefiles and I'm having trouble dealing with cells on the edge of shapes, in other words the if a cell is partially covered by an NA value and partially ...
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2answers
33 views

Can raster maps be stored in a SQL Server spatial database?

Can raster maps be stored in a SQL Server spatial database? And if so, how? ... I'm aware of VARBINARY and FILESTREAM for images, but can only see GEOMETRIC and GEOGRAPHY for vector data
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17 views

problem with raster calculator syntax [closed]

I am trying to build a raster representing the output from a logistic regression model. i keep getting syntax errors. heres the script: -2.41-(15.97 * "Topographic_Predictors\wadem10m_annsolrad") - ...
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25 views

Raster package limitations

I am very new to R and to raster package and I was hoping that someone could provide some guidance. I am trying to run a function that averages a series of rasters, 300 to be exact, they are in geotif ...
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36 views

Python error in Qgis 2.14.0

I'm trying to build virtual raster (catalog) following instructions from the documentation in QGIS.. It appears the following error in python code: 2016-04-17T12:13:07 1 Traceback (most recent call ...
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43 views

Slow performance clipping raster with GDAL

I have a few large LiDAR DEMs that I want to merge. Each DEM has some glitches around the borders which need to be removed in order to get a seamless final product. I manually traced around each DEM ...
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22 views

Curve Number equation

I have a floating point raster of Curve Numbers (70-91) and I'm attempting to use the curve number equation to create a weight raster for flow accumulation, to determine runoff for a single rainfall ...
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15 views

Reduce raster resolution and determine pixel inclusion based on % pixel overlap

I'm trying to reduce the resolution of a raster from 1m to 50m using a pixel aggregation (average) method, but I need to set a threshold for inclusion (e.g. 75% of the 1m pixels must fall within the ...
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2answers
28 views

Add raster attribute table to raster using arcpy

I have downloaded US soil raster data by state from https://gdg.sc.egov.usda.gov/GDGOrder.aspx at 10m resolution. I am now trying to add a modified raster attribute table to tif that was exported ...
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15 views

How does “Mosaic to New Raster” tools works? How does it treat pixel values?

I'm working with arcGIS. I have mosaicked 8 rasters with values ranging from -408 to 180. The new mosaic shows pixel values ranging from 0 to 180.Then I compared cell by cell values from the original ...
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19 views

Map netncf-file with different years and save the different layers in shapefiles

Download from this website the following netncf-file: cru_ts3.23.1991.2000.pet.dat.nc.gz. This is a monthly raster with data from all over the world from january 1991 to december 2000 I am using ...
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31 views

Clipping raster brick object in R

I have MODIS NDVI TIFF files for a year I want to first clip it with a irregular polygon (not by its extent only) of my study area and save it as a multi band raster in TIFF format The TIFF image are ...
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2answers
47 views

What method does QGIS Merge Rasters tool use?

I am trying to merge rasters in QGIS and want to set a priority order for merging so that the values from the highest priority raster are used in overlap areas (the “FIRST” merge/mosaic method, I ...
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0answers
22 views

Adding rasters to mosaic dataset?

I'm working with an ArcSDE geodatabase v 10.0 in SQL Server 2008R2. I added more than a dozen of rasters w/o problem. Server: WIN 2008R2 12GB RAM SPACE: 1TB Created a mosaic dataset (empty) w/o ...
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1answer
36 views

PostGIS clipping raster with the same color band as the original raster

I am trying to clip a raster so that the clipped raster would have the same minimum and maximum values for the color band as the original raster. For example if i clip the raster with this command: ...
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26 views

Control points in IAdjustXForm for georeferencing of raster (ArcObjects)

I am trying to create a georeferencing tool using ArcObjects in VB.Net. Though only a little text is available on this topic in forums as well as from ESRI; I found an esri article that states the use ...
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19 views

Calculating the distance between points and parts of a underlying raster set

I need your help with a calculation of the distance between points (cities in this case) and forest (raster data). Is there a possibility to collate to every city the distance to the nearest forest ...
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17 views

How to unckeck automatically the “No Data Value” predefined on raster background on QGIS 2.14?

I'm trying to import a bunch of rasters, but there is a parameter predefined on the TIFFs, where says that No Data Value should be marked. But I need this unchecked. I opened the metadata, and found ...
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1answer
29 views

Finding and loading global population density raster data into R?

I am using the Bioclim dataset for a maxent project right now, but I want to add demographic predictors along with climatic ones. I have the 19 layer raster data from Bioclim and I'm hoping to use the ...
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1answer
36 views

How to speed up raster2pgsql?

I'm trying to upload a 37 GB raster dataset to PostGIS. The raster is out-of-db (-R option), so the actual pixel values are not stored in PostGIS. I'm using this command: raster2pgsql -s 25833 -C -I ...
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33 views

How do I get rid of edge effects while using focal in R to smooth a raster?

I am trying to use R with the focal function from the raster package to smooth raster images. I am working with Radar images that have already been preprocessed. As part of that, some calculations ...
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68 views

Why do I get “Insufficient memory for image” although there should be enough RAM?

QGIS reports "Insufficient memory for image 1403x716", when I want to load a raster. The problem begins after 1 hour of work. Had somebody had such problem? System win7 64 bit, 16GB RAM, Intel Core ...