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

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Making virtual raster with average values [duplicate]

I'm working with many raster files. Is there a way to make virtual raster with average values in each pixel. (QGIS) It's for an NDVI index of summer months over 5 years.
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19 views

How to create ROI in Semi-Automatic Classification plugin QGIS

while trying to classify landsat images, I get the following problem: I click on the pixel I want to define a ROI, but the ROI polygon that the plugin creates appears in a different part of the image ...
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12 views

Using USGS Raster Split but getting errors

I am working on an issue where I am trying to split the 2011 nlcd .img file into counties. I am really just looking at the midwest, so I have state county shapefiles for IA, OH, MN, MO, IL, IN and WI. ...
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16 views

Raster data for maximum temperature

I am looking for raster data for maximum temperature, ideally on a state by state basis (US) to make the file sizes smaller. Data would need to be weekly or daily going back to at least 2010. I ...
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1answer
28 views

Align pixels from two rasters with different cell sizes

I have two rasters in a PostGIS database that I want to be able to compare. The first raster is at 5m pixel resolution and the second raster is at 30m pixel resolution and is on a different grid. How ...
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1answer
16 views

arcpy CSV file to raster attribute table?

Using TableToTable_conversion I can convert a CSV file to a table in a geodatabase, but how can make this table be the default attribute table for a raster in the geodatabase? I can't seem to find ...
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4answers
3k views

How to reclassify a float raster?

I have three rasters which represent distance (in metres) from certain things (bus stops, parks, libraries). I would like to reclassify these rasters so that they get integer values based on the ...
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1answer
39 views

mosaic raster image non georeferenced

I have several jpeg2000 tiles non georeferenced and covering a certain area. I know in qgis you can mosaic image using the merge tool but I have done it only using georeferenced images, which is quite ...
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40 views

How to compute NDSI in ArcGIS for Desktop?

How do I compute a Normalized Difference Snow Index (NDSI) in ArcGIS's Raster Calculator? I have a Landsat 8 scene (hdf4 format) that contains derived surface reflectance band-by-band. Each band is a ...
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1answer
21 views

Compare two rasters in R with the cell value from one replacing the cell value from another

I am trying to create a single raster from two rasters. The first raster is made up of all 0 values and the second is made up of the current date value (formatted in days from 001 to 365). The problem ...
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2answers
3k views

How to reclassify a very large land cover dataset?

Consider the NLCD2001 Land Cover dataset for Alaska (download link). I need to reclassify this dataset so that only pixels of value 41, 42, and 43 are preserved; all other pixel values should become ...
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1answer
492 views

mosaic raster to file geodatabase yields missing raster sections

Since upgrading to ArcGIS 10.1 (SP 1) from 10.0, I've been encountering an issue when running the arcpy.MosaicToNewRaster_management() tool with output to a file geodatabase. I'm principally working ...
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13 views

Creating ROIS in Semi Automatic Classification pluggin Qgis

I am trying to classify a Landsat 8 image using the semi-automatic classification plugin in QGIS 2.6. When trying to define ROIS, I select a pixel of of interest, but the polygon is created ...
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3answers
1k views

How to remove empty classes from legend in ArcGIS Desktop?

I have a classification image with only 12 classes. I'm preparing layout using this image. when I add legend into layout page, a lot of empty classes loaded together with these 12 classes. Totally 255 ...
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5answers
744 views

Fill in NoData gaps in raster using ArcGIS for Desktop?

I have a raster with gaps in it. I want to fill these in with averages of surrounding cells using ArcGIS 10.2 for Desktop. I have tried "Focal Statistics" but it averages EVERY cell and not just the ...
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1answer
50 views

How to calculate raster statistics for each band in qgis

i need to calculate raster statistics for RGBN (4 channels, multiband image) rasters in QGIS. In Arcgis if you use "calculate statistics" in Arcatalog, statistics are calculated for every image band. ...
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1answer
435 views

Simplifying polygons made from binary rasters using ArcGIS Spatial Analyst?

I'm using MaxEnt to produce a species presence / absence raster layer. It works fine but I have to choose a cut off point for what constitutes presence or absence. As a result I end up with a lot of ...
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1answer
116 views

How to recode bands in which max value occur using ArcGIS Desktop?

I have 2 raster images; ras1 (an image with max value) and ras2 (an image with 5 bands). Basically. ras1 image extracted from ras2 images. I'd like to find bands from ras2 in which max value occur ...
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3answers
71 views

Deleting polygon defined area from raster layer in ArcGIS for Desktop?

Which tool do I use in ArcGIS 10.1 for Desktop to exclude areas covered by vector polygon layers from a raster layer? I want to keep portions of the raster layers that exclude the portions covered ...
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1answer
22 views

GlobCover 2009 dataset - importing legend and colormap values into R

Does anyone know how to import a legend for a raster layer (loaded as a .tif) into R such that it can be attached to the raster file itself and used in plotting? In this case, I am using the GLC2009 ...
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1answer
126 views

ERROR 000824 while trying to run IsNull Method outside ArcGIS?

I am trying to perform IsNull function to a raster using PyScripter. This is the code I use: import arcpy import arcinfo InRaster = "C:\\data\InRaster" IsNullRa = "C:\\data\IsNullRa" ...
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1answer
48 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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1answer
27 views

Compare two rasters with raster overlay and replace cell value with variable

I want to compare 2 rasters and when there is a change from 2 to 1 create a new raster that replaces the cell where the change has been detected with the change variable. ## Finds Cells that have ...
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1answer
21 views

How does ST_SnapToGrid work using nearest neighbor interpolation?

I have rasters in a PostGIS database that are not necessarily aligned (some rasters offset from the grid). I want to use ST_SnapToGrid to align all rasters to the same grid but have some questions ...
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1answer
279 views

Can I update the service on ArcGis Server programmatically?

There is Windows Service. This service adds user raster data to the Raster Dataset in sde database. The Raster Dataset registred on the ArcGis Server. This Raster Dataset also was publishing on ...
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1answer
109 views

In qgis using python, how can I get multiple pixels from a raster based on a vector point file

I just started working with qgis, and for the life of me I cannot figure out how to solve this problem: I have several points of interest, these are stored in a shape file (just simple points). I ...
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1answer
34 views

Merging USGS DEM files in ArcMap?

I'm trying to merge my DEM files into 2 separate files, one will have 4 files and the other will have 3. I've been reading every post from when someone asked this before for over an hour and I'm still ...
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1answer
432 views

raster tile - find the correct tile for a given coordinate

I have a large raster map which I loaded into postgis with 1000x1000 meter tiles... the corresponding table has about 200 rows, each row representing a tile. I want to get the raster value for a ...
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0answers
17 views

How does `ST_Union` treat NULL values in a raster?

My question is about how ST_Union of rasters containing NULL values are handled. For example suppose I have two rasters that intersect but the values of the intersection are NULL in one of the ...
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1answer
30 views

How to extend raster data for larger boundary?

I am working on serveral raster data, but some of them are not fill data exactly with intended boundary (as shown in the picture below). What i want to do is firstly extend the raster data to intended ...
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1answer
36 views

Bleeding/fuzzy edges when adding raster to mosaic in ArcMap

I'm a relative newcomer to ArcMap but have done my best to try solve this alone - to no avail. I need to create one layer from three raster tiles that show presence/absence (0/1) of woody vegetation ...
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1answer
130 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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2answers
283 views

Rasters added to mosaic dataset only display at large acale

I have a set of 357 rasters in .jp2 that I've added to a mosaic dataset. All but 7 of them display properly, but the 7 only display at larger scales, around 1:6500 and under. I've tried adding them ...
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3answers
2k views

Reproduce raster with same extent, and same number of columns and rows?

I have two raster A and B. A and B have the same grid size but different extent. How can I make A have the same number of columns and rows, as well as the spatial extent of B?
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1answer
147 views

How can I create an animation with raster data in qgis?

I have 4 raster images showing different coniditions of air flow distribution at different times. I'd like to create an animation to show the change from image 1 to image 4. How can I do this? I tried ...
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1answer
743 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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1answer
26 views

Output Raster r.cost.full values

I am having troubles interpretating the output of r.cost.full. Currently i am working on a project comparing some arcgis tools with qgis tools (workflow and output). One of my examples is to make a ...
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32 views

Why does @data@values slot for RasterLayer only contain logical(0) and not the actual values?

Trying to get to the bottom of why, when I read in a raster of NDVI, the @data@values slot does not contain the actual values until I set them manually. For example: NDVI <- ...
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8answers
19k views

Get boundary of raster image as polygon in ArcGIS Desktop?

I have a rectangular raster image in ArcGIS. My question is: how can I produce a polygon which is just the extent of the raster image? That is, I want to have a polygon layer with a single ...
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1answer
170 views

How to stack rasters for ecological analysis?

The attached image shows two different forest openings. Each opening has the following layers associated with it: Point shapefile 1 = A red X which represent a large "legacy" tree in the gap Point ...
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1answer
596 views

Managing sizes of input rasters for raster calculation in ArcGIS Desktop?

To calculate any formula (conditional statements/relational operation etc) in the raster calculator in ArcGIS using two different sources of raster images, I'd like to know input rasters must be the ...
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0answers
45 views

Reduce population density grid from 10km to 1km

I've a 10km cattle density grid, the units are head/sq. km. I would like to convert the grid to 1km and maintain the units.
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1answer
23 views

Workflow for updating raster using polygons of different attributes

I require a specific output but it is proving difficult for me to work out a workflow. I have: 1) polygons of new housing developments (356, non overlapping) 2) a 25m raster of land cover I want ...
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1answer
30 views

Properly placing my raster over a shapefile on my map

I have an ASCII file that I converted to a raster. My heading on the ASCII file is: NCOLS 156 NROWS 720 XLLCORNER -170989.3011812 m YLLCORNER 1417628.464462 m CELLSIZE 1 ...
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1answer
313 views

How to build an attribute table in a 3-band raster?

I have a 3-band (RGB) raster file from CORINE and the attribute table hasn't been built. When I try to execute the command BuildRasterAttributeTable I get an error that only single band rasters are ...
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24 views

Raster (Tiff) to KML for Google Earth Overlay - QGIS

I am trying to convert some raster files to KML in QGIS for overlay in Google Earth. They are really huge Tiff files as I processed them from 3 meter DEM datasets. I have been searching the web and ...
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24 views

Zonal Statistics for multiple rasters

I'm trying to create a timeseries of raster data (one layer per year) by polygon (Administrative regions). Is there any way in QGIS to perform Zonal Statistics for multiple years (without having to ...
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1answer
21 views

Mosaic rasterstacks based on minimum of certain layer?

I am trying to mosaic 42 remote sensing rasterstacks (with 250 bands) based on the criterion that in overlapping areas, the pixel should be taken that has the most nadir viewing angle Beside my ...
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2answers
19 views

Unable to set raster surface resolution in ArcScene?

I have a 3-band subset of a Landsat image which I want to display in ArcScene (of ArcGIS version 10.2.1). The image is 30 meter resolution and I am draping it on a 25m resolution Aster DEM. But have ...
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1answer
699 views

Why is Orthorectify button not active in Image Analysis Windows in ArcGIS10?

I wanted to Ortho rectify GeoEye HR imagery using existing RPC and IFSAR DTM in Image Analysis. According to ArcGIS Resource center ...