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

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347 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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1answer
527 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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277 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 = 'E:/Research_Work/data/processing_data/...
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2answers
395 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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5k 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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260 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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1answer
634 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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122 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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3k 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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182 views

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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86 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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1answer
1k views

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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614 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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0answers
295 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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93 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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2answers
576 views

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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1answer
164 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
2k 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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335 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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1answer
177 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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2answers
738 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
98 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
744 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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159 views

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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1answer
849 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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2answers
61 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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1answer
2k 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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207 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
590 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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1answer
959 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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720 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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102 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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234 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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222 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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2answers
781 views

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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64 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
132 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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7k 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
903 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 TOC,...
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2answers
360 views

Clipping a raster file into the multiple shapefiles

I splitted the single shapefile into the multiple shape file based upon their attributes. Now I want to clip the raster file into the each splitted shape file. How can I do it at once? I am using a ...
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2answers
624 views

Update raster value to reflect total number of points within cell- python

I have what should be a fairly simple task, but I can't seem to figure out how to do it. I have to do it in python/arcpy/gdal/whatever because I'm trying to automate this process for a hundred or so ...
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1answer
326 views

How to obtain the width and height of an image using arcpy

This Stack Overflow question shows how to obtain the pixel dimensions of an image using Python. Is it possible to find an image's height and width using arcpy and ArcGIS? arcpy.Describe would seem ...
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1answer
181 views

How to isolate certain raster values using raster calculator?

I have a one band grayscale image. It has values 0-63 within the band. I need to isolate some of those values. Is there a way to do this in the raster calculator? QGIS 2.2//Windows 7
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1answer
365 views

Gdal creating raster rotated wrong way

I have been trying to read in a stack of images for a timeseries and created an output raster that contains the max pixel values of the timeseries. The arrays were created using numpy img_stack = np....
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1answer
961 views

QGIS DEM (Terrain models) Mode Slope creates wrong data [duplicate]

I have a DEM raster file downloaded from the USGS site. The file can be downloaded here. I am trying to create a slope raster in percent with the DEM tool in QGIS. The GDAL command is the following: ...
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2answers
282 views

How to use the raster calculator in the processing modeler of QGIS

I am trying to create a easy way to do raster analysis by building a model for two way raster calculations. I have two raster layers that I want to combine into a single raster. For now I've done this ...
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0answers
755 views

Precision for an FGDB raster dataset?

I would like to know the precision for an ArcGIS raster stored within a file geodatabase (FGDBR format); I can't seem to find this information anywhere in their documentation (apologies if I have ...
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1answer
442 views

Renaming multiple rasters with ModelBuilder gives errors 000622 and 000878?

I have 101 raster images stacked inside a folder. The Rasters are of arcinfo grid type (*.asc) while having a long string name 'NW2D_T100_05_base_depthXXX.asc' where XXX ranges from 000 to 100. What ...
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1answer
80 views

How to deal with empty corners in raster when calculating fragmentation index

I have clipped buffer area around coordinate from one big raster (forest cover). Such created raster was loaded in R where PatchStat function (library SDMTools) gives fragmentation index. After ...
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2answers
61 views

Creating Many Uneven Buffers

Qgis 2.2, Windows 7 I am looking to create buffers around city lights (the raster). Currently, I have simple polygon buffers around the point layer (oecdminusa), but this is not accurately capturing ...