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

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Probabilities matrices and cellular automata in IDRISI

I apologize for asking about such elementary things, but I am utterly new to IDRISI yet am now having to learn how to perform certain tasks with it on very short notice. Am I right that, when Markov ...
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1answer
46 views

Downloading GIS Map for Pakistan into QGIS

I'm looking to add canals and bunds to my raster and have found some GIS maps at: Canals Bunds Bunds Image Network Plan Map Image - looks to contain both canals and bunds I'm not clear on how to ...
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2answers
65 views

How to save imagery from online raster service for offline use?

QGIS allows me to connect to free map services like ESRI's 'world imagery'. I would like to save a certain part of it (decided by map extent) in the highest zoom level available in the service for ...
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51 views

Change the values of NA cells in a raster by using a geographic subset of the raster as a condition

I would like to replace the NA cells that are within a specified extent (here rectangular area defined by drawExtent in the code bellow) of a raster object. My idea was to use the functions ...
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18 views

SAGA Flow Direction input

I have several .adf files making up a DEM in ArcGIS, i want to input this DEM into SAGA to run some different Flow Direction algorithms. Is there a way to convert these files to .asc to allow me to ...
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88 views

How to remove parts of raster layer with QGIS (equivalent of difference tool but for raster)?

I'm trying to get the difference between two raster layers the same way we can do it with the difference tool with vector layers. I'm using QGIS 2.14. Anyone has already done that and can tell me how ...
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2answers
176 views

How can I make QGIS interpret coordinates as long-lat instead of lat-long

I am working with the TRMM 3B31 files on precipitation provided by NASA. When I load them on QGIS selecting the WGS84 projection together with other shape files the maps are displayed vertically, i.e. ...
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1answer
25 views

Mouse-over raster surface to stream values to text file ArcGIS

This is a weird one. I have a user who wants to add a statistical surface to ArcMap and then mouse-over the raster surface and stream those values (z) to a text file. MouseTips can show underlying ...
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41 views

comparing rasters, cells that have changed value

I am attempting to compare two rasters representing a species distribution model for now and the future. The rasters have the exact same extent and cell sizes. here is when is gets tricky, they are ...
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2answers
44 views

PostGIS: MultipolygonZ to floating point raster

I am trying to convert a table of MultipolygonZ geometries to a floating point raster where the pixel values of the output raster will be derived from the Z values of the MultipolygonZ geometries. The ...
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48 views

Create raster with decibel value from Geotiff Intensity using QGIS GDAL python

I have raster with intensity values and I want to create raster with decibel values, I work with QGIS GDAL, I use gdal_calc I do this from the terminal: gdal_calc.py -A input_image.tif ...
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28 views

Multiple raster - same extent - smallest overlapping area

Within ArcGIS (10.1) I have multiple raster files, for which I have to calculate different statistics, based on the total size of the raster. EDIT: The raster have the same extent on a coarse scale ...
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1answer
101 views

Raster style based on percentile QGIS

Is there a way to get similar raster styling in QGIS as ArcGIS does with classified raster data based on percentile scores? In other words, I want an equal number of pixels in one color for my entire ...
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3answers
53 views

Statistical Analysis of Climate Data

I am doing a study on how a changing climate is influencing the spread of an invasive species of moth. I have climate data in the netCDF format which I have made into both rasters and point ...
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1answer
149 views

transpose large netCDF with GDAL, NCL, NCO or CDO

I have a large netCDF file (444GB) that I would like to transpose. The file is flipped with latitude on the x-axis and lon on the y-axis. See pictures of one band below. Not correct Correct: I ...
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18 views

How to make match two same rasters after conversion "Polygon to Raster?

I am trying to convert two .shp files of polygons of same buildings but with different layers of values into raster. When I do conversion from polygons to raster it always generates bit different ...
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42 views

Edit script to use in ArcGIS-R-Bridge

I have an interpolation script running in R which I now want to implement into ArcGIS so I can use it independently with any shapefile. To get to a result I scripted in 3 steps: Original R script: ...
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7 views

Problems with Mapnik raster colorizer discrete not properly assigning values to their stop value

I'm using Mapnik (Python) to convert a raster (float valued) to MBTiles. In general the discrete colorizer is working fine, except for zero values, where it fails to recognize their correct stop ...
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22 views

PostGIS: intersection of a MultipolygonZ and a floating point raster

I am trying to isolate the pixels in a floating point raster (loaded in PostGIS) that intersect my MultipolygonZ table (also loaded in PostGIS) and whose values are less than or equal to the z values ...
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24 views

Combine tool: Does it perform a union or intersect operation?

Can I use combine with different shaped rasters? Does it perform a union or intersect algebra operations with the fields?
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2answers
31 views

How can I alter the value field in a raster?

I'm using ArcGIS. I have a raster with angles in the value field. But the value field is type long integer. I would like to change it to float. Is that possible? Some more details: I've started with a ...
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1answer
25 views

Raster - attribute table, fields - confused

I am a bit confused, as during my studies I learnt that rasters have only one cell value and for some it might be true, as the attribute table is greyed out in ArcGIS. But for others, multiple fields ...
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1answer
45 views

Apply same symbology to many raster layers in ArcMap?

I have many TIFF files (100+) that need to have the same symbology using the unique value option. Is there a quick way in arc 10.3 to do this?
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1answer
33 views

ArcMAP / R: Convert raster pixels to Long and Lat

I have downloaded a raster, which has the following information. Item Data Date 2015-01-03 00:00:00 Product cold partial sst Satellite NOAA-18 Direction Unknown Dimension 1596 x 1617 BPP ...
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61 views

Aligning two raster layers in QGIS?

I am teaching myself GIS in baby steps, I recently acquired aerial imagery (employing RGB and NIR-GB sensors) using a small UAV with the intent of generating a map in a small plot of land. After ...
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14 views

Loading raster image in IGIS?

I am trying to load a raster image into IGIS and have followed the manual. My process_exported a raster image from Global Mapper to Map Tiler, zipped the directories and sent them to Dropbox. ...
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1answer
60 views

C/C++/C# Library for raster to vector conversion

I am looking for an "open source" C/C++/C# Library able to convert raster to vector data (Polygonize). I know gdal_polygonize.py is doing the job, but I can't use Python. Portrace is an other option, ...
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62 views

Changing the cell size and projection of a raster to correspond with the ones of another raster

I have two rasters with different resolution and projection. > r1 class : RasterLayer dimensions : 2510, 5233, 13134830 (nrow, ncol, ncell) resolution : 56, 56 (x, y) extent : ...
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27 views

Using color matching on two geotiff rasters datasets and exporting geotiffs

I have one geotiff (tiff + tfw file) that serves as a basemap for a global zone. Then, I have several geotiffs, one for each zone of this big orthophotograph (50 zones in total). I would like to ...
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1answer
39 views

How do you extract the mean fire frequency (raster) for each point within a given buffer size using R?

I am trying to extract fire data (mean and max fire frequency) for each point within a given buffer size (250m) around multiple points. Currently, my point data is in Lat and Long. For the raster ...
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1answer
11 views

How to extract values from multiple raster dataset from a location point in one single dbf?

Suppose I have 250 raster and my only concern is just a single point. The raster is arranged by ascending date. So if I extract a point value based on the order into one single file then I can graph ...
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1answer
33 views

Create a mapping between polyline and raster in ArcObjects

In my case I have two sources of data: a vector shapefile with a polyline (expressing the path) and a raster with some integer metadata values available for each cell. What I would like to do is to ...
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46 views

Copy resolution extent CRS metadata from one raster file to another using raster R

I have two geotiff raster files, one has all the metadata information and in the other the information was lost. I know that all the metadata information was exactly the same so I want to copy it from ...
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1answer
53 views

Table of statistics of rasters input in QGIS

I work with QGIS GDAL,I have many raster image 'geotiff' with one band for many dates, I want to create a table that contains statistics for all rasters that I have. I tried the algorithm 'raster ...
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52 views

QGIS 2.14 open raster crash [closed]

I am using QGIS 2.14 on Mac OS X 10.11.3; every time I try to open a raster file, in any format, QGIS crash, any suggestions?
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39 views

Correlating raster layers

I am trying to correlate contaminant data with other variables. For instance I want to see if high values of contamination coincide with topographic lows in my elevation raster (DEM). All the layers ...
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1answer
48 views

How to insert raster in PostGIS from java JDBC

I have been looking for a solution to store dynamically generated raster data into PostGIS from java and PostGIS JDBC. I am working with geotools toolkit but i am unable to find any documentation ...
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1answer
26 views

Create MosaicDataset with 12 Bits

I'm using ArcGIS 10.3.1, and I want to create a mosaic dataset, but my rasters are in 12 bits, and a mosaic doesn't have this option. What can I do?
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1answer
31 views

Combining overlapping polygons to make a raster

I'm working in Arcmap10.3. I have some polygons layers that over lap that I want to merge to one polygon layer. Then I want to convert it to a raster in the end. I want the top layer of the 4 input ...
3
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1answer
102 views

Identifying value of closest non-NA pixel

I have a raster representing a large landscape, where pixel values indicate particular land classes. I have been using the "distance" function in Package 'raster' in R to calculate the distance from ...
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1answer
36 views

Is there an 'average' algorithm for st_resample()?

Currently, the docs for ST_Resample() give options for NearestNeighbor (English or American spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. ref: ...
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37 views

Is it possible to use a raster::click event within an interactive leaflet map?

Data Download: https://www.dropbox.com/s/f849ra8l6umo9d8/crops.tif?dl=0 I have various raster images of the world that I would ultimately like to plot within an interactive leaflet map; an example is ...
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19 views

Merging Raster Images Changes Its Coordinates

I'm trying to merge raster files (Landsat images) for the island of Sumatra, Indonesia. When I upload each raster file to check if I have all of the island covered, I get this: However, when I use ...
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1answer
55 views

How to avoid unexpected values in border of slope raster in QGIS

I have a DEM like After calculating slope with QGIS, it's showing the following result So, how can I remove the unexpected value at the edge of this DEM? Which is showing almost 90 degree ...
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27 views

Contour Extraction from Scanned Raster Image in Qgis

I have a scanned raster image containing contours and rivers. I am trying to use qgis to extract these contour and river polylines for analysis. As a start I was thinking of the following process ...
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What to do with polygons that were created from a raster file? [closed]

I need some suggestions. I'm working in Arcmap 10.3. I used a NDVI landsat product to find patches of row crops. I then extracted these cells and turned them into shapefiles. I want to measure the ...
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1answer
42 views

QGIS Has Rendering Error on JP2000 Raster. Works in ArcGIS

I've got a large .jp2 raster file that was created using 'Mosaic to New Raster' in ArcGIS. I'm trying to open it in QGIS 2.8.6 (I've tried 2.8.14 as well) and am getting a vertical line that won't ...
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36 views

Convert from unsigned (8 bit) integer to short integer grid

I'm looking to convert a unsigned integer grid to a short integer grid for use in TauDEM. The unsigned integer grid has values ranging from 0 - 4.
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54 views

Clipping raster with Postgis raster

I'm using Postgis 2.1.5 on Ubuntu 15.04. In my system there is a second disk mounted with the raster data as /media/name1/data/rasters/*.tif. The *.tif are good looking when I watch the metadata with ...
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50 views

Georeferencing Raster automatically fails

While trying to auto register a raster image in georeferencing - using a wms raster layer as reference - I get the simple error message "Failed to auto register". Thereby the Link Table remains empty. ...