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

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How do you set sea level elevation to white in terrain analysis?

I have ASTER files I am working with to create a shaded relief background for some other vector shapefiles. In experimenting with different color-elevation options, I am unable to have the Terrain ...
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25 views

Weighted Overlay with “nodata” cells

I´m currently conducting a suitability analysis with the weighted overlay function. One relevant criteria is the proximity to highways. If the wind turbine is located up to 300 m away from the ...
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13 views

Show raster data in WEB

I have downloaded Landsat8 image and use matlab to processing temperature and vegetation. Then I insert data into PostGIS. I used QGIS to display the results but i want show in web. How to display the ...
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15 views

Error: .asc is not a supported raster data source

I am new using QGIS and struggling with this error "...... .asc is not a supported raster data source" when trying to add a ."asc" file as a raster. I downloaded the files from ...
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37 views

Is there any method to choose the value of each pixel according to land cover

I have 2 images; one is land cover image (imgA) and monthly mean temperature image (imgB). I'd like to choose value of each pixel from imgB corresponding to imgA. WhaT I expected is each pixel of ...
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42 views

extract shapefile attributes from raster colors

I have two layers: a shapefile with states and counties (shp) a raster file (with colors and some text and borders, but not a perfect map) (tiff) I want to use the colors in the raster file to ...
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33 views

ArcGIS model builder: How to reclassify 16,000+ rasters and do weighted sums on these rasters per year?

I've been trying to build a model in model builder (ArcGIS 10.1) which can do the following task: I have a folder full of ca. 16,000 raster files (.asc) representing mean temperatures for each day ...
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17 views

Problem with polygon overlay in raster stats using gdal

I am using the raster_stats module in python to calculate the mean carbon value for different sets of polygons. Here is the code that I am using: africa_sat = ...
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31 views

Reading a raster map cells values in C#?

Suppose I have a raster map file (TIFF, TGA, JNG... etc) loaded with geo-info manifested by the cells values. I need to read the values of the raster map cells "programatically" in a C# program. P.S: ...
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29 views

How can I save and re-apply symbology properties for a classified raster in ArcMap 10.2?

I have a classified raster which has the desired symbology configured in ArcMap, and I want to apply this symbology to other similar rasters. So I use the Save option on the Symbology tab, intending ...
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17 views

How to create a circle vector layer with 12 sectors with Python and to save average value of underlying raster in each sector?

Hi I am writing a code with Python 2.7 using Arcpy 10.1 and I guess I am doing stuck with a silly problem that lies under my eyes. I have created a grid of points (with "Create fishnet" function) over ...
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33 views

Eliminate 0 Values From Raster

Arcgis 10.2 I currently have a raster file that I want to turn into a set of polygons. This will help me to create specific buffers around certain points. The extent of my values are 0, and 1. When I ...
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27 views

Comparing/Correlating NDVI Rasters with other index Raster

So, I've created two rasters. One for NDVI and one for another index for surface water from the same orthorectified World-View 2 image. I can visually see how the indexes are inversely proportional. ...
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63 views

using Python to calculate NDVI, output as a Geotiff

I need a script that can calculate NDVI from two separate input Geotiff files, then output the results as a Geotiff. I wrote following script, most of which is borrowed from various on-line sources ...
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24 views

Trouble Creating Raster Catalog in SDE [closed]

I would like to create a raster catalog in an enterprise geodatabase/sde connection. For SDE is a config keyword needed, the defaults which appear are geography and geometry, neither of these bypass ...
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8 views

Unserialize socklist error when using rasterEngine in r

Basically, I am running the "rasterEngine" function in R. I want to use parallelization to change values in a raster image (I have around 400 images that I need to work on). However, the rasterEngine ...
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43 views
+50

Raster slightly displaced after exporting from PostGIS database

With the following queries I've exported a raster (GTiff) from my postgis database: 1.Creating a large object: WITH buffer AS ( SELECT id, ST_Buffer(geom,50) AS geom FROM ...
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28 views

How to export a IDW raster while keeping the search radius data

I want to export my IDW rasters that I made in ArcGIS to QGIS, however when I export my raster, the values are there but are no longer displayed. They are stored within each cell and are not ...
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64 views
+50

How to translate .bil files in a batch mode with QGIS?

I have some .bil files that I would like to convert into ASCII Gridded XYZ format files. It seems to work well with the Raster>Translate tool of QGIS when I process one file at a time. But I would ...
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23 views

How to open a raw binary raster in QGIS or R

I have a raw binary raster without a file ending, and no header file. I would like to open this in either QGIS or R and then convert to geotiff, but opening it seems to be a challenge. Here is a ...
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22 views

Is it possible to apply affine transformation (translation) to raster image?

Is it possible to move/translate a raster image in QGIS 2.2 (without using georeferencer) just like it can be done with a shapefile ? If not, alternatively can this be done with ArcGis?
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28 views

Calculate the coordinates upper right corner from the center [closed]

How do i calculate the coordinates upper right corner from the coordinates of center? if there's an example that would be really helpful.
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Create a common scale for different raster layers in GRASS, SAGA or QGIS

I have a number of layers that represent the temperature variability of the water in a lake. They have been generated trough interpolation and have different values as they represent temperatures ...
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39 views

change spatial resolution

I have two types of image, one of them is a TRMM image with 0.25 degree cells and the other one is a MODIS image with 1 km spatial resolution. How can I change my TRMM image resolution to 1 km ...
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1answer
52 views

Re-project raster image from Mercator to Equirectangular

I have a raster image of the world map in Mercator projection, square 1:1 format. I want transform the image into an Equirectangular projection accurately. I assumed from my research that GDAL would ...
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15 views

Make a raster with pixel scale 100 by 100 meter with gdal_rasterize

I'm asking here, because, I've got great results last time. Here it is the next of my adventure with gdal_rasterize, I want to make a raster picture where each pixel correspond to a square of 100 by ...
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Need to make a 'donut' then put that in a featureset [duplicate]

I am hoping the minds here can do much more than ESRI support ever could. :) I have the need to apply a delay to a raster map for movement through water by ships. The delay example would be a lock ...
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1answer
26 views

Why is Mosaic or Mosaic To New Image causing a 1-pixel gap between adjacent images?

I have a series of adjacent PNG images, and I'm trying to merge/mosaic them into a single seamless image. The images have clean "cuts" between them, with no overlaps. However, when I use either the ...
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36 views

How to display a raster using Javascript API

It's all a proof of concept for myself and my learning but I have definitely hit a brick wall here! Here's what I've done and can get to work. I have written a Python script that: Sets its ...
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1answer
17 views

Associate points with polygon QGIS 2.2

I want to associate a point layer with a polygon layer so that I can do zonal statistics. In the image below, the polygon layer represents roughly the metro area of a certain city. The point ...
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2answers
54 views

Conversion of point grid to a raster with open source tools (Gdal, QGIS …)

I'm looking to do something which seem simple to me, but I haven't found a solution since 2 days I looked for. I've got a Postgis DB with lot of points (WGS84) spaced of 100 meters which cover a ...
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How to normalize multiple PNG rasters with differing colormaps

I have a series of adjacent rasters which comprise a digital elevation model. Unfortunately they have been given to me as PNG files, rather than Esri Grids. The only key that I have to the actual ...
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22 views

I'm converting a raster to TIN and a large section of it didn't convert properly (ArcGIS 10)

I've got a DEM for a pretty large area and I need to create a TIN. I'm using 3D Analyst Tools > Conversion > Raster to TIN. The process runs without any error messages, but a large section of the TIN ...
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How to accurately join data based on 1x1 degree grid-cell points to a shapefile

In the data file each row represents a country and a grid-cell at 1x1 degree resolution, and the given coordinates, in longitude and latitude, label the south-west corner of the grid-cell. The ...
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2answers
30 views

Delete numerous NoData rasters from database

I've got >1000 rasters in a folder with about 10% containing no data. I'm looking for a method, preferably through ArcGIS (also open to QGIS, GDAL, etc.), to run through the folder and delete all of ...
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53 views

Mosaic Aerial Photography Tiles to a Seamless Raster

I've got about 6 different Aerial Photography datasets I am managing at the moment. All of them are made up of tiles covering a large area. Some of these datasets contain up to 2000 tiles. All the ...
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43 views

Find the minimum elevation pixels from an elevation raster using arcpy

I want to create a python script to find the minimum elevation pixels from an elevation raster (aster,srtm) using arcpy and arcmap 10.1. The purpose is to reclassify these pixels. I have tried but I ...
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1answer
18 views

How to set the output extents of rasterization in QGIS

I am trying to rasterize a bunch of vector based shape files in QGIS. All these files are covering certain types of ground use in a city (houses, street, open field,...). I need these files to be ...
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43 views

How to remove black box around georeferenced grayscale image in QGIS?

i'am trying to georeference a grayscale image (*.tif) in QGIS 2.2.0 Valmeria. It is working but QGIS draws a black box around the georeferenced raster image. If i use the option set 0 transparent, not ...
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9 views

Edit a classified grid file (.grc) to improve accuracy

I have a .grc file (classified grid file) which contains some clutter information, forest, sea, woodland, etc... I need to alter the data in some area to improve accuracy. Basically a larger forest or ...
3
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1answer
40 views

Expand raster extent and set expanded values using nearest neighbor sampling

I have run a hydrodynamic model which has given me a grid of surface elevations throughout a bay. I am trying to process the results in ArcMap (or QGIS if needed). My goal is to take the current grid ...
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29 views

How to set raster values to NULL?

how can I define values to null? I tried it with the processing reclassify tool but I always get an error log (cannot open the result shape...or something like that).
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1answer
21 views

Clipping several raster layers to the same exact size QGIS

I'm new to QGIS, sorry if this is a newbie question... I need to clip about 40 different raster layers from one vector layer (that has the boundaries of 4 neighboring countries) but I need them all to ...
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2answers
32 views

Road-construction (alignment) tools

Are there any tools available in any GIS environment for route alignment? To be specific, the tool should take a DEM and road-construction parameters -- distance and gradient, roadfill, drainage ...
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30 views

Point-sampling rasters using R? [duplicate]

I need to be able to sample many raster files (imported from GeoTIFFs) using a previously defined set of spatial points, using R. What's the best way to do this?
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Automating the production of GPS-compatible map tiles from georeferenced raster maps

I have a set of TIFF maps that I want to load onto Garmin GPS 62s units. The maximum size for each tile on the GPS is 3Mb and less than 1 million pixels. I manually produced one tile, following this ...
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23 views

How to raster vector- and shape-files correctly

does anybody know how to convert vector- and shape-files correctly? Doesn't work with tab Raster/convert/vector to shape files. The output always contains strange input-data (wrong and strange ...
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2answers
67 views

ArcGIS - Extract by Attibutes in Model Builder

I have a model which at one point uses the Extract by Attributes tool to produce a new raster with just the areas containing the maximum values of the first. I would think that the SQL expression ...
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2answers
86 views

Extract Raster from Raster using Polygon shapefile in R

I am new to R and using the raster package. I have a problem extracting polygons from an existing raster file. If I use extract(raster, poly_shape) function on the raster it always creates a list ...
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1answer
41 views

Why do layers appear in the wrong order in QGIS 2.2?

I have a problem with in which order my vector and raster layers appear in QGIS. I have raster that I want to be the background of my other layers (vector). I place the vector layers on top in the ...