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

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Is there an analog of PhotoShop's “Magic Wand Tool” in ArcGIS Desktop?

I want to interactively select rasters pixels based on it's values and modify them. Here is example of what this "Magic Wand Tool" should do:
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32 views

Extracting one band from multiple stacking raster layers using PyQGIS? [closed]

I've got 1000 (one thousand) RapidEye raster images. The stacking layers has bands 1, 2, 3 and 4. I need to extract the bands 1, 2 and 3, then save the new file discarding the band 4. I've tried to ...
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1answer
36 views

How to make a single raster which shows the year since the last fire

I am using ArcGIS 10.2.2 to make a single raster which shows the year since the last fire in an area based on the MODIS Maryland University raster layers. I have 15 raster layers all from a different ...
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14 views

Snapping a point into a raster grid

Currently I have a raster grid in the SDE. This raster grid represent certain region (For example: Raster grid for one island). On the other hand, I have point features which are plotted within the ...
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1answer
45 views

Identify the top 10% of raster cells

I have a raster with different risk values for a hazard. How can I identify the top x% (eg. 10%) of the raster cells with the highest values within ArcGIS?
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48 views

Rotating ~90° using Two-Point Equidistant projection with Proj4

I'm trying to rotate a tif raster in R using Proj4's Two-Point Equidistant projection - I think the only way to rotate spatial geometries to custom angles. But I'm finding the operation gets very ...
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1answer
30 views

How to add hypothetical values to a raster?

I have to create Non-Regulatory Products for a few FEMA regions. Right now I am working on the 'Increased Flooding Scenarios' where you add a hypothetical value to the existing Base Flood (1', 2', and ...
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26 views

where are the rasters that make up a layer?

I used raster calculator to add up 12 rasters made up of 0's and 1's to make a fire frequency map. Then I saved the output as a layer (lyr). However, I need the raster output. Did I add it up ...
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2answers
49 views

Create a new GRASS database in R with CRS projection

How to create a new GRASS database in R with CRS projection? I am able to create a new one using the following code but it is not projected require(raster) require(spgrass6) ...
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1answer
38 views

Converting an ENVI raster as point shapefile for editing in ArcGIS?

I have an ENVI raster with multiple classes inside. I tried to export this to a vector so that I can convert it to a shapefile in ArcGis (I want to manually edit/delete points in the raster), but the ...
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1answer
60 views

Clipping a raster with a shape layer fails by returning an empty raster (nan - 0)

I am trying to clip a raster layer by a shape define by a polygon. (A previous question was about a line layer clipping, whereas this one relates to raster layer) The resulting layer is however an ...
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47 views

How to clip raster to polygons in QGIS

I have two layers. The first one is a vector layer with 6 polygons. The other one is a raster layer. I need to have a specific surfacic information for my polygons (avarage slope value). The ...
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16 views

Raster Imagery Performance

I'm currently building a project that will involve using raster imagery in the field on a Windows tablet with QGIS/Intramaps Roam and haven't been able to get a satisfactory understanding of a few ...
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35 views

How to reclassify multiple rasters into 3 categories

I have 120 rasters that I need to reclassify into two categories. All values which are 0 need to be 0, all values between 1-366 need to be 1 and all values above 367 need to also be 0. I have ...
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52 views

Reprojecting a raster file in R

Help! I have a number of rasters from different sources with different projections. I want to reproject the rasters into a common projection (Eckert IV), somehow line the grids up, and then overlay ...
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27 views

Retrieving raster classes as data type in Python Script tool?

I want to program a python script tool in ArcGIS where the user should be enabled to input a classified raster and, based on this raster, the classes should be selectable. EDIT: As is suggested in ...
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42 views

Extract values from Rasters in R based on spatial points and spatial polygons

I am trying to extract values from a raster file using the extract command in R mentioned here: http://www.inside-r.org/packages/cran/raster/docs/extract My raster file is unprojected (WGS84 ...
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25 views

Clip multiple raster error using Semi automatic classification plugin (SCP)

So I have to clip 25 raster layers of NDVI using a shapefile and the SCP plugin. This error keep showing error has occured while executing Python code: Traceback (most recent call last): ...
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19 views

Raster and digitized shapefile misplaced in same projection

I have georeferenced .tiff rasters with cadastral borders and corresponding digitized borders in shapefile based on that raster. All that was done in some Mapsoft software. When I insert both in QGIS ...
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19 views

Refining a Viewshed

I have been tasked with finding the observable area of a canoe route based on a drainage, stream and contour file. First, I made the drainage a line file and then merged it with the stream. I then ...
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2answers
43 views

whats wrong with my exported raster reclassify map in grass?

I'm trying to export a reclassify map in grass to a Geotiff format to pass it to DinamicaEgo platform. I have 6 classes in grass but when I export it, the exported map show me 255 classes and they ...
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17 views

Create Point Layer from Raster [duplicate]

How would I create an evenly spread Point layer (Qgis), where each Point is located in the middle of a raster cell from a given raster layer?
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1answer
21 views

Vector to raster conversion: Gaps within the vector boundary

Is there a tool in ArcGIS that will make the output raster completely encompass the vector boundary? Somewhat similar to select by attributes where all overlapping features however minuscule is added ...
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2answers
60 views

How to change Raster symbol values (Unique Values) in ArcObjects

I want to change Raster properties symbology using with Arcobjects. Unique Values change as per below attached snapshot. Dim pWSFact As IWorkspaceFactory Set pWSFact = New RasterWorkspaceFactory ...
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2answers
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Georeferenced image not displaying

I used Georeferencer to georeference a jpg map and saved as tif. I used Thin Plate Spline, Cubic Spline, and LZW as settings. The tif shows fine in OSX Preview. gdalinfo reports Driver: GTiff/GeoTIFF ...
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217 views

Displaying numbers of single band raster layer in QGIS without additional vector layer?

I wonder if there is a raster symbolizer in QGIS with a label option, that renders the cell values as labels of single band raster layer, a scalar field. The standard raster symbolizer dialog in ...
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48 views

Problem with ST_Union

I have loaded some rasters into Postgis. I did a lot of ST_XXXX (scale, snap to grid,resample) magic to make them aligned. After executing: select r1.rid,r2.rid ...
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1answer
36 views

How does GeoServer/RasterSymbolizer ramp interpolate?

I want to encode data using a colormap using GeoServer/RasterSymbolizer, by mapping data using the full 24 bits in RGB. I am thinking of the following scheme: <ColorMap type="ramp"> ...
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1answer
67 views

Altering elevation of specific cells in raster layer of QGIS?

I'm looking to alter the height of some cells within a raster and it's been suggested that I do this by creating a polygon layer and use that as a mask to alter only the heights of cells within the ...
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1answer
35 views

Matching Decedal Average NDVI and Worldclim Data

Ive never used NDVI (or EVI) datasets in R. Does anyone have any resource I could use to access a decadal average NDVI dataset for the globe. It would be preferable if this dataset was also comparable ...
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1answer
27 views

transformations from a sphere using R for raster and polygon data [duplicate]

I am planning on using the MODIS burned area products which were produced by Maryland University. These come as either polygons or rasters. In the user guide it says A shapefile version of the MCD45 ...
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2answers
53 views

Filling only the deepest sinks/depressions in a DEM

I am trying to come up with a workflow that will extract the location of surface mines from a DEM. My original thought was to fill the depressions in the DEM and then subtract the original DEM from ...
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57 views

Get counts in grid cell for multiple values

I have 500+ polygon shapefiles with nationwide coverage. Each shapefile has possible record values of 0-4. I want to get the value that intersects each grid centroid and then get a total count for ...
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1answer
28 views

Fixing Pixelation in DSM [duplicate]

I ran las dataset, then las to raster using max for DSM. Two and a half hours later I have 3 areas showing pixilation using higher level coloring. See enclosed image. I found on web that seamless ...
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2answers
29 views

Raster conditional tool unexpected results. What's wrong?

I have a DEM raster (High: 53441, Low: -3444, unit: cms) with negative values, and I want to make all values 100 or less to be 100. I've tried Raster Calculator, and also python. I've got the same ...
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0answers
33 views

GRASS 7 r.sun aspect in doubt

I'm using r.sun in GRASS 7.0.3 to determine beam irradiance at a site (~ 56N -4W). I have a DEM (a local subset of EU-DEM). I'm using r.sun in mode 2, called from GUI. Typical logging in command ...
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3answers
128 views

Get rivers from a DEM raster

I am new to spatial analysis and even newer to hydrology. I have a 30arc DEM elevation raster and I was wondering if I can use it as an input to get the approximate presence of rivers in a ...
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32 views

Overwrite the mosaic raster generated using gdal_merge.py?

Is it possible to overwrite the raster generated using gdal_merge.py? When I ran the command: % gdal_merge.py -init 255 -o out.tif in1.tif in2.tif it works fine, but if I ran the same command and ...
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1answer
47 views

Changing coordinate system says that geotransformation is invalid?

I am planning on using the MODIS burned area products which were produced by Maryland University. These come as either polygons or rasters. In the user guide it says A shapefile version of the ...
4
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1answer
57 views

Get raster value at specific point (arcpy)

I have an arcpy script creating thousands of points in a feature layer, based on a river network. At creation time, I'd like to use the value from a (large) elevation raster corresponding to the new ...
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1answer
61 views

Wanting extract to produce sensible answers for NAs in R

So, I'm working on extracting values from multiple different rasters in R. However, some of our data is marine, some terrestrial. Some rasters cover both, but a few are ocean only or land only. At ...
3
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1answer
58 views

Build a table with columns of raster values from multiple raster datasets, using Python, GDAL, or PyQGIS?

I have a series of raster datasets, clipped to the same extent, with matching cell resolutions, each of which represent land surface temperatures (LST) captured by the MODIS sensor. Each raster ...
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1answer
75 views

aggregating using 'gdalwarp -average' resulting in incorrect values

I'm trying to aggregate data up from 0.05 to a coarser 0.25 resolution and am having trouble getting gdalwarp to work correctly. From comparing the original input data with the aggregated data and ...
2
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1answer
34 views

Why is ArcMap reverting 4-band raster settings?

ArcMap keeps redrawing my 4 band false colour image in standard 3 colour bands. As you can see below I have my 4 band data set to auto display as (4,1,2 - infrared, red, green). When I bring in an ...
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1answer
46 views

Extract Polygons out of a raster

I want to extract every row from a .shp from a raster (Extract by Mask). With the following code i get 4 output raster, wich concludes every row. import arcpy arcpy.CheckOutExtension('spatial') ...
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60 views

Geographic vs. projected raster cell size area

I am wondering the best way of knowing how to define the area of each raster cell in global data. Specifically, I downloaded all ~400 tiles of MODIS land cover data, mosaiced them into one, and now am ...
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2answers
67 views

Open source option to ArcGIS tool MosaicToNewRaster_management in python?

Is there any open source option in python to mosaic rasters to one raster? The equivalent of the MosaicToNewRaster_management in ArcGIS.
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41 views

IR as 4th band in RGB composite (ArcGIS)

In Symbology tab of a raster in ArcMap, in the section of Pan-sharpening, there is an extra option to check at the bottom: "4th-band Infrared Image" along with its weight: I guess I have to add ...
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17 views

Extracting coordinates and climatic conditions of grids where species polygon overlaps with the climatic layer in R?

I have species’ shapefiles and climatic raster files. The climatic file is in 50 * 50 km equal area grid. Now, I want to calculate the climatic conditions in each grid cell where species polygon ...
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1answer
38 views

How to replace raster values in one Raster with another [duplicate]

I have two raster files in ArcGIS 10.1, raster 1 and raster 2 all with values and similar spatial resolutions, and overlay in some areas. I want to replace values in raster 1 with those in raster 2 ...