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

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strange raster calculator behavior in QGIS

I used to work with qgis 2.8.1 in Lubuntu and in windows7. Each time I try to multiplicate a map for a number comprise between 0 and 1 (i.e. 0.1) I get a good results on windows OS, but I get a map ...
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13 views

ArcGIS resampling rasters by maximum pixel value?

I need to resample a binary image of linear features like roads, rivers to a coarser resolution, conceptually combining multiple pixels into a single one. 1 indicates presence of the linear feature, ...
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15 views

Does gdal_calc only support 26 input raster files at a time?

In gdal_calc.py, input files are specified with letters A-Z. Here are two files, input.tif and input2.tif, being averaged into result.tif: gdal_calc.py -A input.tif -B input2.tif ...
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6 views

NetCDF calculations

I have a raster of monthly average temperatures for the state of TX (represented as a grid) for a 50-yr period in the form of a netcdf file. I can display the temperatures but am not sure how to do ...
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21 views

Counting chickens on a scale w/ top down view [on hold]

I am extremely new to QGIS, and just GIS in general. I'm working on a scale project where our end goal is to weight chickens using a hanging scale, then count the number of birds present on the scale ...
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13 views

load raster (geotiff files) to postgis with url

I tried to load rasters to postgis with raster2pgsql but this not satisfy my project because it uses local files. i have 5000 and will be more in future geotiff files in cloud host. is it possible ...
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14 views

Importing large tiled datasets (e.g. Ordnance Survey) into MapInfo?

I am currently using MapInfo and have several large Ordnance Survey datasets, which require updating. They are tiled .tiffs and need to first, be registered as .tab files. Second the .tab files need ...
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20 views

How to update raster color ramp with new min/max values using PyQGIS?

I'm trying to update a single band psuedo color renderer with new min/max values from the python console. All the code samples i have been able to find deal with constructing a renderer from scratch, ...
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20 views

How to fill holes/missing values in XYZ data / a DEM with QGIS?

I have equidistant XYZ point (text) data that I used to create a point grid. However, it's not perfect - there are some holes. I then created a DSM raster from it, which obviously has the holes too. ...
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23 views

Flood fill in python

I am quite new to python and programming in general and I am trying to execute some code from a book. The code I am having troubles with should execute a flood fill function on an elevation raster ...
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1answer
28 views

GDAL raster shifting with python error: 'NoneType' object has no attribute 'GetGeoTransform'

I'm trying to shift a georeferenced raster by 0.5m N and 0.5m W in QGIS using the python console: from osgeo import gdal # Open in read/write mode rast_src = gdal.Open('test_raster.tif', 1) # Get ...
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14 views

Creating a for.loop to randomly extract data from a raster stack within shapefile extents

I'm currently comparing a MODIS time series of about 15 years to determine the effects of pasture management practices on the "greeness" of pastures in a water catchment. So far I've been able to ...
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36 views

Merging USGS DEMs in ArcMap?

I've downloaded some USGS DEMs from the National Map, which appear to be .adf files. I can open them in ArcMap 10.2, but I need to merge them into a single mosaic. To do this, I've created a raster ...
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37 views

Point to raster: QGIS vs ArcMap

I have an equidistant point grid (0.5m) and created a raster from it in QGIS and ArcMap, with different results: QGIS: Raster -> Conversion -> Rasterize Result: raster, with points in the top left ...
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23 views

Computing Area Weighted Average on Rasters Using Raster to Polygon

I am using ArcGIS 10.3 for Desktop. I am trying to compute area weighted averages for polygons in a shapefile using values in a single band raster data set. The approach I am taking is that I am ...
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25 views

GDAL: defining nodata value for gdal_calc.py

This old post exactly describes my question: http://lists.osgeo.org/pipermail/gdal-dev/2011-September/030281.html I want to copy the numpy ma.masked_outside functionality to mask values in my ...
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6 views

Raster loading on arcgis javascript api on user request

In my project, i want to give the user the option to select the date of the raster he/she wants to display, then that raster would be loaded onto the basemap. I loaded daily raster (CREST hydrological ...
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27 views

How to process a big number of raster outputs with r.series?

I am new to python and QGIS. I'm trying to take some simple operations (e.g. count, average) over a big number of raster maps from a python script. I'm using the "r.series" algorithm (from processing) ...
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15 views

Maxent species distribution

I am in the process of developing distribution map in MAXENT. My species habitat is subset of another mammal habitat. I have distribution layer digitised for mammal species, rasterised and converted ...
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19 views

Different colors of rasters after loading back to QGIS

I am experiencing this issue longer time but sometimes it is really annoying so I would like to solve it. When I save an image from QGIS - no matter when using Project/Save as image or using Export ...
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24 views

Creating raster depicting landcover/use change in ArcMap?

How would I create a conversion matrix in ArcMap 10.2.2 to display the changes between two rasters (Land Use Land Cover Maps)? I have produced Land Use Cover Change maps from temporal satellite ...
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10 views

fit polynomial function on spectral data

I want to fit a polynomial function (max. 3rd order) on each raster cell over all my spectral bands (Landsat 1-7) creating a new raster(stack) representing the coefficients. I got my data (including ...
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28 views

Point Density produces enormous size rasters [on hold]

I am trying to analyse density of points that represent crime locations in Northern Island. I have shape file containing 92k points. My data is in projected coordinate system (BNG). I tried to run ...
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26 views

Is it possible to put a raster layer on a shifted Chinese basemap using leaflet API?

Recently, we want to develop an application with leafleat and gaode basemap because some features of these products fullfill our basic needs. We want to overlay some raster layers caculated by spatial ...
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1answer
20 views

Extract by Attributes in Model Builder, “Table Name is Invalid”?

I'm attempting to use "Extract by Attributes" in model builder as part of a larger model. I'm trying to pull 6 different attributes out one by one in order to create random points within their areas. ...
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Is the QGIS connection with ArcGIS “mapserver” still working?

I would like to add the Ocean Basemap to QGIS. I also found the other posts and I followed this procedure: http://hub.qgis.org/wiki/quantum-gis/Arcgis_rest Hovewer when I put in the Python console ...
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37 views

Extracting point data for each lat and long from raster file into a dataframe

I have gridded data files ( see sample -each file consist of monthly precip and is label pYYYYMM) https://www.dropbox.com/sh/63z166tjxyu12s5/AAAs3Ccn1zdVoBYMj8Y1o303a?dl=0. I am trying to extract ...
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26 views

How to merge two rasters when are on the same place

I have two rasters in GRASS GIS. first : raster of DMR, raster picture of relief - created from high values second : raster of buildings where pixels of every building have value of high of this ...
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26 views

moving window regression on raster stack in R

I want to perform a moving window regression on every pixel of two raster stacks representing Band3 and Band4 of Landsat data. The result should be two additional stacks, one representing the ...
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34 views

Align vector and raster layers with D3

I have a geocoded raster image that I want to use as the background to a vector map with D3.js. The screenshot shows the layers in QGIS (grey is raster). Here's the markup for the map: <div ...
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31 views

Weighted Overlay final raster to indicate inputs

I have a weighted overlay that identifies the most important areas in a corridor scaled from 0 - 100. I would like to be able to click on a cell and be able to identify which input rasters contributed ...
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23 views

Mosaic to raster 16BIT Error 999999

I am using ArcGIS for Desktop 10.1. I am trying to merge a few 16bit rasters by Mosaic to New Raster. The problem is it makes me do only a 8bit output making me lose pixel data bigger than 255 and ...
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50 views

Directly querying a raster

I've done tons of work within ArcGIS to analyze and process rasters. I'm pretty well knowledgeable on that subject. A question has come in from my coworker who is attempting to populate elevation data ...
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1answer
38 views

How to change sign of z value in a large dataset?

I have data in an XYZ format (saved as a .txt file) that I am importing into ArcGIS and then converting to a raster using the point to raster conversion. However the Z field in the data represents a ...
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1answer
24 views

Receiving NULL values from Point Sampling Tool in QGIS

I am using QGIS 2.8.2. My project includes a raster layer of flow depth representing the output from a flood simulation (.DAT file). It also includes a vector layer of points representing the ...
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9 views

Single WMS from single mapfile with several rasters in MapServer

I have several rasters in a single mapfile, I put them as layers like here: LAYER NAME "Layer 1" GROUP "All Layers" TYPE RASTER STATUS ON ...
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1answer
36 views

Is it possible to georeference raster stored in Postgis?

I'm looking to store a huge raster aerial image (400 Gb) into Postgis, but before storing it i like to know how i could georeference or rectify raster stored in postgis ? is there any Qgis plugins ...
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1answer
39 views

Display coastline

I have a raster converted from shape file(tool point to raster). Can anybody prompt, how to display coastline? I can use contours, but are not focused at condition "elevation = 0". Is there any simple ...
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16 views

Extracting many raster values for statistical analysis in JMP

To summarize: We have 28.5 million XY coordinates we would like to compare up to 6 raster values for, and prefer to look at those values in JMP. We are exploring interpolation methods in ArcGIS for ...
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1answer
42 views

QGIS: why does clipping a raster alters cell size?

Using QGIS V 2.2.0 (OS-Windows 8), I need to prepare raster files (ESRI ArcInfo Grids) to be later used in a species distribucion model using MaxEnt. Each of the original raster files (environmental ...
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3answers
34 views

Unable to read raster into R: 'TIFFReadDirectory:Failed to read directory at offset'

I'm getting a weird error when trying to read a raster into R. >r <- raster('myraster.tif') Error in .local(.Object, ...) : TIFFReadDirectory:Failed to read directory at offset 2606110 ...
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4answers
110 views

Checking if polygon fits inside another polygon using ArcGIS or QGIS?

How do I check if one polygon fits inside another polygon? Furthermore how do I automatically check if one polygon fits in other polygons of my shapefile? I have a shapefile with thousands of ...
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22 views

Combine Raster and Feature Class selection

I've been working on a quite complex analysis with ArcGIS 10.2. But now I'm stuck at a problem... I have a raster file and a polygon feature. The Raster file stores information about Zmax, Zmin and ...
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1answer
20 views

Multiply two lists of raster from two subfolder

I have two subfolders, which contains rasters for each country but which express different variables. I am trying to figure out a way to Loop a multiplication of each raster into a folder with its ...
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2answers
113 views

How to automatically calculate maximum cell values contained within polygons?

I've got a dataset made up of a large range of polygons (about 70 or so) which represent structures. I also have raster layers which detail a flood depth across an area. The floods depth raster has a ...
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2answers
42 views

Reading next row of *.txt column inside ArcPy for loop for batch process?

I'm not sure how to approach this problem with python, but in plain english, I'd like to rename rasters with the names given in the *.txt file (see screenshot) and concatenate the basename given by ...
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25 views

Converting lat,lon & solar data in CSV to raster using Python?

I have a csv file with lat,lon and solar radiation data. I am trying to convert it to a grid/raster format so that it can be used with a raster population data set that is in ascii format. How can ...
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24 views

What format are raster data files with data, db, overpict, vect, and WMS folders?

I have a type of GIS data but I don't know what is this type or how to open them. My data are formed by 5 folders: data, db, overpict, vect, and WMS. The main folder (I think) is the first one; it ...
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1answer
28 views

conversion of *.tif file format to *.hdr file format

I have clipped DEM of a region from SRTM data. It is in .tif format. Now I want the same file in header format (.hdr). How can I convert *.tif file to *.hdr file?
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31 views

Georeference a computed tomography image without changing its proportions in QGIS

I have several images obtained from a Micro computed tomography (mCT). The scanned elements are human teeth. In a particular mCT slice, I have introduced a cartesian plot with its X and Y axis. The ...