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

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Creating Dem from cross sections

I have a question I appreciate that if someone can help me I have a DEM in arcmap and cross section of a river which flows on the Dem in Hecras. I now the cross sections are more accurate. I want to ...
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55 views

regression model with randomForest in raster package

I'm learning randomForest classification method in R and I performed land-use classification with randomForest and raster packages. But when I try uesd a regression model produced with randomForest to ...
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56 views

Raster image does not show up in Data View

I'm a new GIS Student. I created and imported 3 raster files for last week's lab. In our lab this week, we are creating a vector image using the raster data. When I import the 3 raster files, it ...
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89 views

How to know the GSD (grid size, resolution) in meters of an existing raster when working in Geographic coordinates?

I would need to know the GSD or grid size (resolution), in meters, of a raster created when working in a Geographic coordinate system in ArcGIS. Is is possible? Even better, can I set the Cell size ...
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83 views

Raster created by python GDAL interpreted upside down

I am using CRS which has axis in left bottom corner. Code below produce Geotiff which is shown allright in QGIS but when I open it in other software it is upside down. Also gdal_calc takes it as ...
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59 views

Setting resolution for GRASS raster

I am trying to calculate volume using the GRASSplugin. I have my area information in vector format and my depth information in raster. I read that it is important to set the raster resolution before ...
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41 views

DEM error when trying to do topographic correction in GRASS

I'm new to GRASS gis and I'm trying to do a topographic correction (i.topo.corr) of 9 ASTER bands using SRTM dem. I keep getting this error message: ERROR: Illumination model is of CELL type Is ...
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72 views

Flow accumulation raster loading in QGIS 2.4.0 with null values (but flow direction loading ok!)

I have been tasked with creating an open-source hydrology dataset for a community group. To do this I have exported the flow direction and flow accumulation rasters from ArcMap as TIFF files and then ...
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58 views

QGIS create raster from cadastre (property lot data) polygon

I have a cadastre (property lots) polygon dataset of a region. Have used rule-base style in QGIS to show different groups of properties in the dataset classified based on their property lot size (ie. ...
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62 views

How to crop a vector shapefile according to raster?

I am trying to clip a vector shapefile- points according to a DEM in QGIS. I used GDAL function and polygonized the DEM. Then I ran the Vector-Geoprocessing tools-clip in order to crop the vector data ...
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73 views

raster files are not exact in extent after clipping

My two layers (chlorophyll-a and Bathmetry) are not exact after I clip my rasters. My bathymetry data (1) is reporting up to 10 decimal places where as chlorophyll-a (2) is only 3 decimal places and ...
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72 views

Finding coordinates of the image corner

I have a .bmp image with a map. For creating image i used a Ingeo 4.4 and function MakeImage() What i know: Height an Width of bmp image dpi Map Scale Image Center's coordinates in meters. What i ...
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103 views

Problem with batch mode Saga Raster Calculator

I have to do a couple of raster multiplications for which the batch mode would save me a lot of time. But the only thing I get are rasters that contain nothing but nan values. If I multiply the ...
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39 views

Deleting vector lines beyond image extents using QGIS?

I am using QGIS 2.2 I have one vector line layer (roads) that stretches beyond my base image (see below). I wish to have the roads "clipped/trimmed or deleted" right at the edge of the image's ...
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58 views

How can I shift raster layer for making cloud-shadow mask?

I want to make cloud shadow mask in QGIS. I have raster cloud mask and I have to shift it by X,Y coordinates. Is there any easy solution?
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52 views

Determine changes in land cover of isolated features over time?

I have a a study area of 2 Landsat scenes from 2013 which were classified for a specific natural community, and these areas have been isolated and extracted and digitized into vectors so that they can ...
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100 views

POSTGIS Raster - Merge polygon onto raster

I have two tables, SCHEDULE contains polygon geometries and RASTER contains raster tiles I want to take a polygon from the SCHEDULE table and overlay it on top of a set of RASTER tiles that intersect ...
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68 views

How to change the symbology on many image files within a group?

I have a group of raster images from lidar data (so a DEM). When loaded in, they all have different symbology - so their color scheme and color ramp are all different. I would like to create a group ...
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77 views

How do I replace cell values of a raster using values of another raster with differing extent?

I have two rasters (raster1 and raster2). The raster1 extent is smaller than raster2. I want to replace the value of raster2 pixels using raster1 pixels. How can I replace the values?
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124 views

Exporting .tif from referenced mosaic dataset does not use functions in raster dataset

Very frustrating little issue in ArcGIS 10.1 -- I have a referenced mosaic dataset of terrain data that has a series of functions inserted (slope and several iterations of a statistics function to ...
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362 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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440 views

Building attribute table from raster in ArcMap 10.1

I have a NetCDF file containing the latitude, longitude and porosity for the entire US. I am trying to add another value (wilting point) which depends on the porosity. I wanted to extract the netcdf ...
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109 views

Analyzing Raster Data From Vector Layer Buffer

I am using QGIS 2.0. I have satellite images of night-time lights all over earth. I also have a vector shapefile of country boundaries including the largest cities on earth. I want to use buffers to ...
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175 views

How to create a raster with rotated cell orientation from lattice points - ArcMap 10.1

I am trying to create a raster layer from gridded points where the cells have a rotated orientation. Each point is the center of a 1.6 km by 1.6 km cell, rotated to the left. Is there a way to do this ...
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668 views

Why does CON statement give ERROR 010240: Could not save raster dataset to (value) with output format GRID?

I am receiving the following error when trying to run the following code: import arcpy from arcpy import env from arcpy.sa import * arcpy.CheckOutExtension = "Spatial" env.workspace = ...
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28 views

Searching 'select by color' for raster or map data

I'm planing to create an online map component with which the user can create/draw polygons based on underlying raster data. Is there some library / tool / procedure existing which enables the ...
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89 views

Counting points in a raster

Is there a way to select points in a raster dataset by raster classification? I have a floating point raster created from the points, classified into 4 ranges by standard deviation. I want to find out ...
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723 views

ArcMap 10.1 - Tabulate Area tool “doubling up” for Overlapping Buffer Zones

This question is related to a previous question I asked: Raster Version of Spatial Join (one to many) I used the Tabulate Area tool to crosstabulate values between an overlapping "buffrast" raster ...
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11 views

Creating polygon layer from raster

I am using ArcGIS 10.2 in order to create soil management zones for farmers. when I use the raster to polygon tool it creates small triangles out of the polygons and jagged edges that are very ...
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21 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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29 views

Attribute table is missing in raster after using extract by mask tool

Every time I use the extract by mask tool, the rasters that are created don't have an attribute table (i.e it's greyed out). Does anyone know what is causing this and why these rasters essentially no ...
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51 views

How to separate details by color from raster?

How to separate details by color from raster? Is it possible in ArcGIS or any other software? I have tried Spatial Analyst. I want to use RGB .tiff image which is scanned map. It consists of all the ...
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20 views

How to make Feature to Raster tool run faster

Suppose you have a feature class that you need to convert to a very detailed raster (where each cell size is quite small). With a cell size of 0.0092908447 in the Feature to Raster tool, the procedure ...
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36 views

How to get projection data (.prj) of raster image using GDAL/OGR?

I start with a boundary shape-file (think U.S. states) in lat/long that I convert to some projection, and then rasterize the result as a .tif. What I need now are the raster coordinates of the ...
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20 views

How to specify raster name and how to designate the saved name of a created raster

import arcpy from arcpy import env from arcpy.sa import * arcpy.CheckOutExtension("Spatial") env.workspace = r"G:\GHY_568\project" mystery_creek = r"G:\GHY_568\project\Mystery_Creek.shp" ...
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Use of OTB BandmathX

I have a couple of three-band satellite images that I want to apply an expression to and get a three-band output. The expression is of a simple form: output_pixel= (input_pixel*d^2)/cos e After ...
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35 views

Rasterize gives weird image

ro<-readShapeSpatial("roads") ra<-readShapeSpatial("railways") co<-readShapeSpatial("LIE_adm0") u<-union(union(extent(ro),extent(ra)),extent(co)) rast<-raster(u,res=1) ...
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59 views

Extract values from raster by using polygons

I am working with multiple raster files that cover all of united states. The file format of the rasters - GeoTIFF. I have around 100 geotiffs that I need to process. Then I have another shapefile with ...
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55 views

plot 3D graph based on raster pixel values

I am new to raster data. I have a raster tif file with population density value in each grid cell. I am interested in plotting a 3D graph based on raster values in ArcGIS or R. The similar graph is ...
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25 views

How to turn a vectorgraph into raster correctly?

In QGIS2.8 version, I added several points in a point vectorgraph. When using the grid - > Conversion - > rasterized vector , The results turn out into a black figure. How to turn a vectorgraph into ...
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59 views

Creating an R factor raster in RUSLE Soil Loss equation with multiple input rasters

I am attempting to obtain the rainfall erosivity "R" factor for the RUSLE Soil Loss equation using rainfall PRISM 30 year history data. I have both monthly and annual data that comes into ArcMap as ...
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39 views

Reduce raster resolution based on cell ratio

I have 2m impervious/non-impervious data. I would like to reduce the resolution to 30m and have the cell value for the 30m data be determined by the ratio or proportion of impervious / non-impervious ...
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65 views

What exact format do I need to have for the inputs to make Path Distance work?

I am trying to run the Path Distance tool in ArcGis 10.1. Ideally I would like to utilize Tobler's hiking formula anisotropic approach to slope and a land cover cost surface to calculate the least ...
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55 views

How to cut a raster into smaller, equal area parts?

I have a large raster file that I need to cut into smaller parts. I already have a polygon shapefile that has the smaller parts that I want to use as an index. The reason for this is that end users ...
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75 views

using raster.predict for Cubist model, factor levels list

I would like to thank in advance any help or advice. Let me know if I need to provide more reproducible data/code. I am working on a Cubist prediction model for soil texture, using continuous and ...
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57 views

Intersection of two Raster objects

I have two raster objects r1 (in grey and green) and r2 (in pink) that I want to intersect with R. I tried with the R function intersect from the raster package but it only intersect the extent of the ...
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71 views

Converting raster presented in KML to polygon using ArcGIS Desktop?

I have spent quite a lot of time Googling which brought me many places including this site, but I haven't found the resolution. I have a KML that presents a PNG. Radio Mobile generated the files and ...
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39 views

How can I avoid a specific area of raster?

I have a raster polygon. I need to avoid certain area (another raster) from that raster. I need to avoid a watershed sub basin area that has its area on other basin also. How can I remove that basin? ...
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20 views

Geospatially match cells of different rasters - possible?

I have 2 rasters that were originally vector polygons. Raster2 was created from a selection of raster1. After converting both to raster, their cells don't match up (i.e. attribute info for each cell ...
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29 views

Specify the NoData pixel from 255 to a lower value pixel value

I have a series of raster files (tif) that extracted using a particular shapefile. However, the output files became much larger (from 2 MB to 200MB). The NoData is now equivalent to pixel value of 255 ...