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

learn more… | top users | synonyms

1
vote
1answer
65 views

ArcGIS, How do I get smoother contours?

I am trying to get nice smooth contours using ArcGIS. I have already smoothed out the DEM using focal statistics, simplified and smoothed the contours. The current result looks like this, which is way ...
2
votes
2answers
166 views

Python Script tools for ArcGIS 10.2 is very slow (get raster properties)

I am using python script tools for ArcGIS 10.2, under Windows 8.1 64bit. When I am using the arcpy.GetRasterProperties_management() command, it's very slow to process the data. For example. I tried ...
4
votes
2answers
161 views

Calculating Shannon's diversity using moving window in R

I have a raster where each pixel is a particular vegetation type. I'm interested in the diversity of vegetation types around each pixel. I'd like to assign a Shannon's diversity index value (see ...
3
votes
1answer
2k views

Count of raster cells as variable in ArcGIS ModelBuilder?

I want to use a cell count of an integer raster as a variable in Arcgis 10 ModelBuilder (and later in a python script), but can't seem to find how to access this information. Is there a (python) ...
0
votes
2answers
46 views

How to clip several raster datasets with a mask?

I would like to clip many images (raster datasets, input) with a mask (shapefile), so I would concentrate only in the images I need for my study area. Is it possible to do with Arc GIS 10,3 ? I ...
0
votes
0answers
12 views

Dynamic polygons grid with specified area based on raster

I'm interested if anyone have idea how to automatically create (maybe in R?) dynamic grid of polygons with specified approx. area (for example around 20000 m2) based raster data or points with values ...
0
votes
0answers
21 views

Converting NAD 83 to WGS 84 in PostGIS

My question is about the best way to convert from NAD 83 to WGS 84 in PostGIS. I have a PostGIS DB containing National Elevation Data rasters. The rasters are in NAD 83 and I would like to convert ...
2
votes
1answer
257 views

Find maximum and minimum value in a list of raster

I trying to write a standardisation script that standardises each raster dataset in a list of rasters by the highest and lowest values found in the list of rasters. The standardisation code is as ...
0
votes
1answer
37 views

Modelling soil texture using ArcGIS for Desktop?

I am doing a project for automated soil mapping using landsat TM imagery, I have 3 output rasters: one for sand percentage one for silt percentage and a third for clay percentage. How can I ...
0
votes
2answers
52 views

Extracting multiple values of raster to polygons using ArcGIS for Desktop?

I was hoping I could get some help on how to extract information from a land use raster using polygons. I have a layer with 157 polygons and a land use raster with multiple land use categories for the ...
3
votes
1answer
903 views

How to align two rasters of exact same cell size, extent in ArcGIS DEsktop?

I have two raster datasets. One is already georeferenced. The second one is not georeferenced but should have the exact same extent and cell size as the first one. It is supposed to exactly overlap ...
-2
votes
1answer
30 views

I need to create a function in R that processes rasters in esri grid format [duplicate]

I have loads of data (6500 files that I need to process and find yearly winter sums/averages/variance for. the format for my naming system is Syyyymmdd_rp. Each file is in the same file folder. I ...
0
votes
2answers
227 views

Getting latitude and longitude raster from DEM using ArcGIS for Desktop?

Could anyone please provide with a way to calculate latitude and longitude from DEM, for each raster cell? In previous posts about this, I have seen that some suggest calculating lat and long in ...
1
vote
1answer
21 views

Mod function in GRASS GIS

What is the equal of ArcGIS Raster calculator "Mod" function (Finds the remainder of the first raster when divided by the second raster on a cell-by-cell basis.) in r. mapcalc in GRASS GIS?
0
votes
1answer
30 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 ...
3
votes
1answer
74 views

Processing large amounts of Rasters in R

I have 6500 processed and clipped rasters that indicate snow levels on a daily basis in the northern hemisphere. I need to create a raster that represents a sum of the snow for the season. The winter ...
1
vote
0answers
15 views

Substract 2 rasters with Raster Calculator in ArcObjects (VB.NET)

I'm having a hard time substracting 2 raster with ArcObjects sdk 10.1. I keep getting a nullreference exception at the gp.execute() method, but I can't figure out where the problem is, I recall ...
1
vote
0answers
26 views

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.
0
votes
0answers
13 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. ...
0
votes
0answers
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 ...
0
votes
1answer
29 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 ...
0
votes
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 ...
5
votes
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 ...
0
votes
1answer
41 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 ...
3
votes
0answers
45 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 ...
0
votes
1answer
22 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 ...
9
votes
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 ...
4
votes
1answer
495 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 ...
0
votes
0answers
15 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 ...
3
votes
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 ...
1
vote
5answers
784 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 ...
1
vote
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. ...
5
votes
1answer
436 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 ...
1
vote
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 ...
0
votes
3answers
74 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 ...
0
votes
1answer
23 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 ...
1
vote
1answer
127 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" ...
0
votes
1answer
50 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 ...
0
votes
1answer
29 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 ...
0
votes
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 ...
2
votes
1answer
280 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 ...
1
vote
1answer
110 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 ...
1
vote
1answer
35 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 ...
4
votes
1answer
435 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 ...
1
vote
0answers
18 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 ...
1
vote
1answer
32 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 ...
2
votes
1answer
37 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 ...
1
vote
1answer
131 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 ...
1
vote
2answers
285 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 ...
5
votes
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?