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

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1answer
35 views

Determining hardware requirements for mosaic dataset operation to work properly?

I've been building mosaic datasets in ArcGIS, but have been having mixed results depending largely on the number of cores on the computer being used to build the mosaic dataset. For example, on a ...
0
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1answer
22 views

Add a random value of the order of 10^-2 to raster layer?

I was doing some raster analysis for smoothing in ArcGIS, one of my task is adding a random value of the order of 10^-2 to a raster layer. Does anybody know how to do it?
2
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5answers
2k views

How to export raster from PostGIS enabled DB as GTiff with gdal_translate

When I want to export a GTiff from my PostGIS DB with this code: gdal_translate -of GTiff PG":host='localhost' port:'5432' dbname='landslide' user='postgres' password='pass' schema='public' ...
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0answers
14 views

Raster Values converted to 3.4e+38 in R

I have read a .grd file into R as RasterLayer which should only contain 1, 0 and NA as cell values. Turns out all the NA cells contain 3.4e+38 as value now. How can I change that and why does this ...
0
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0answers
10 views

How to divide bitmap into differnet layers by RGB color code in MapInfo

I have got bmp file with 7 colors. How to get from this bitmap 7 different vector layers depending on RGB color code? For example first layer is water space with blue color, second is buildings with ...
0
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3answers
74 views

Extracting impervious areas (buildings, rails, pavements) from LAS dataset [closed]

How to extract impervious areas (like buildings, rails, pavements etc.) from las dataset and receive it like a raster? I tried to do it with intensity, but there are many valids with vegetation. I ...
0
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0answers
17 views

Mapserver raster tiles have wrong colors on zoom

Displaying a raster via MapServer on OpenLayers-3 webmap. When zooming in, the resampling or something is behaving weirdly and the colors become very distorted. See image below, the bad tiles should ...
1
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0answers
35 views

Raster package limitations

I am very new to R and to raster package and I was hoping that someone could provide some guidance. I am trying to run a function that averages a series of rasters, 300 to be exact, they are in geotif ...
0
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1answer
28 views

Calculating the number of days above freezing in R

Im wondering if anyone has come across any data source that can be used to calculate the number of days where temperatures are greater than 0 degrees C, 10 C and 20 C at a global scale? I have a site ...
0
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0answers
24 views

Need to compute fragmentation indices within discrete zones

Running arcGIS 10.3 (also have the latest QGIS), win7 64, workstation 16g ram and an intel xeon processor. I'm preferably looking for a simple turnkey solution; very little python experience. ...
0
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0answers
34 views

Is it possible to create a web application that can clip raster images using vector layer shapefile?

I need to create a web application that can navigate through the world or even single country and let the user draw or upload polygon shapefile to clip raster data according to that drawn or uploaded ...
2
votes
1answer
38 views

Export google satallite raster in QGIS 2.12- problem

When I import aerial raster from Google satellite, using the OpenLayers plugin the raster is located in the right place. But when I export it the raster isn't located in the right place: I ...
0
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2answers
290 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 ...
2
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0answers
36 views

how to load raster image in leaflet? [closed]

I want to load a raster base layer in leaflet because the base layer usually needs an internet connection I want to load the raster offline .
1
vote
0answers
44 views

Python error in Qgis 2.14.0

I'm trying to build virtual raster (catalog) following instructions from the documentation in QGIS.. It appears the following error in python code: 2016-04-17T12:13:07 1 Traceback (most recent call ...
0
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0answers
8 views

Using IDW method and its output raster in a web app

I am creating an web app and needs to interpolates between some points- Weather data- (with IDW method) and show the results as a raster (like the output from ArcGIS) so a user can click on raster and ...
0
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0answers
21 views

Extract raster values from RASTERSBRICK using XY coordinates falling within each polygon R

I have a rasterbrick s (10000 raster layers) that actually is a time series raster. Accompanying s is a SpatialPolygonsDataFrame with many sub-polygons which can be identified by names and/or IDs etc. ...
1
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0answers
18 views

Reduce raster resolution and determine pixel inclusion based on % pixel overlap

I'm trying to reduce the resolution of a raster from 1m to 50m using a pixel aggregation (average) method, but I need to set a threshold for inclusion (e.g. 75% of the 1m pixels must fall within the ...
1
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0answers
59 views

Slow performance clipping raster with GDAL

I have a few large LiDAR DEMs that I want to merge. Each DEM has some glitches around the borders which need to be removed in order to get a seamless final product. I manually traced around each DEM ...
1
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0answers
25 views

Curve Number equation

I have a floating point raster of Curve Numbers (70-91) and I'm attempting to use the curve number equation to create a weight raster for flow accumulation, to determine runoff for a single rainfall ...
1
vote
2answers
27 views

Issue running r.region in GRASS command line

I'm currently attempting to use r.region to preform analysis on a specific area of a raster image. I'm receiving Lat/Long data from the step before me, but I'm having issues use that data in ...
0
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0answers
18 views

Finding regions or zones in raster DEM of similar slope or aspect values in ArcGIS for Desktop?

I have a detailed 5m DEM for my study area. I want to find regions or zones where the slope or aspect (or preferably both) varies little. In other words, a nice evenly sloped hillside with a ...
2
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0answers
46 views

Draw raster on top of a Leaflet map

I want to implement a raster layer on top of a Leaflet map that includes the following functionalities: Digital Elevation Model (DEM) terrain height included in each raster cell GPS-Track (I use ...
1
vote
2answers
29 views

Add raster attribute table to raster using arcpy

I have downloaded US soil raster data by state from https://gdg.sc.egov.usda.gov/GDGOrder.aspx at 10m resolution. I am now trying to add a modified raster attribute table to tif that was exported ...
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2answers
61 views

Combining several mask rasters to obtain one single mask with binary values

I have a series of separate rasters which represent the cloud cover over the same area but in different months. Each raster has 2 values: nan for "no cloud" and 255 for "cloud". What i want to do is ...
0
votes
1answer
85 views

Save raster layers in a python script

Is there a way to loop through every selected layer in qgis and save it as a .tif file with the same layer name using a python script? This is the code I am using, but it does nothing at all. It runs ...
1
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2answers
39 views

Arcpy Reclassify by Standard Deviation

I would need some help with the Reclassify tool. I have written a script that produces rasters which I need to reclassify. My problem is, I want the values to be reclassified by standard deviation ...
0
votes
1answer
113 views

QGIS raster calculator wrong output

I am trying to create a mask from a DEM (SRTM tile) using raster calculator in QGIS. I have performed the same operation in ver 2.6 with no problem but in the current version the output is incorrect. ...
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0answers
16 views

How does “Mosaic to New Raster” tools works? How does it treat pixel values?

I'm working with arcGIS. I have mosaicked 8 rasters with values ranging from -408 to 180. The new mosaic shows pixel values ranging from 0 to 180.Then I compared cell by cell values from the original ...
2
votes
1answer
43 views

Merging and splitting raster files in QGIS

I have four .HGT topography tiles (tile1,tile2,tile3,tile4 in the photo below). They are in geographic coordinate system. I would like to merge those four tiles, and then from that merged raster layer ...
-1
votes
1answer
27 views

Fix AttributeError in python code

I got some code that I think should work, but I'm getting this error: Traceback (most recent call last): File "", line 1, in File "c:/users/proxtr~1/appdata/local/temp/tmpgtrnqo.py", line ...
1
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1answer
241 views

Rasterization of point vector in QGis: how to align the resulting raster to an existing one?

I have a point shapefile, with no associated .prj file, that I have to rasterize. Each point should be transformed into a pixel of 30x30 size aligned to the pixels of a Landsat image (the point file ...
4
votes
1answer
39 views

Grid size of a Digital Elevation Model developed from topographic surveyed elevation contour line?

I have generated a Digital Elevation Model from elevation contour line. I got these elevation contour line at 20 cm interval from DGPS survey. What would be the grid size of generated DEM in "m". ...
1
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2answers
159 views

Installing raster resampling module in QGIS 1.8

On the website of Sourcepole, I have recently come across the case of resampling images in Quantum GIS. Because I am rather a beginner in GIS software I would like to ask you for information about how ...
2
votes
1answer
196 views

(How) can I write string data to a raster with Python/GDAL?

In Python, I have a NumPy array of string values (categories of some variable) that I'd like to write to a raster file (.tif or .img) using GDAL. The impression I get is that it's not possible to ...
3
votes
3answers
2k views

Image does not display after clipping raster

I am using ArcGIS 10. I am trying to clip an NLCD layer from a vector polygon. I have used the Clip Raster tool in Data Management and Extract by Mask tool in Spatial Analyst among other things. My ...
2
votes
1answer
201 views

Raster map & vector boundaryline data for Istanbul, Turkey

I'm looking where I can download background raster map for Istanbul (street map?), and then a boundary line file of the the 39 Districts in Istanbul. Does anyone have any recommendations?
1
vote
1answer
40 views

PostGIS clipping raster with the same color band as the original raster

I am trying to clip a raster so that the clipped raster would have the same minimum and maximum values for the color band as the original raster. For example if i clip the raster with this command: ...
0
votes
1answer
32 views

Issues with raster data on postgresql / error:Attempting to get pixel value with out of range raster coordinates

So here is the issue, i am trying to extract values from a big raster divided in 200 or so tiles and applying them to a selection. The points are startpoints, endpoints and midpoints from vector ...
3
votes
1answer
39 views

How to order QGIS raster layer style?

I have single band raster files that I am trying to style using Singleband pseudocolour under the Layer Properties, Style settings, and a colour map textfile that I upload for styling. When I upload ...
0
votes
3answers
5k views

How to Clip a Shapefile of Circle features using a Raster using ArcGIS 10

I want to keep all the features in the shapefile that lie in the raster region and reject others. How do i do this? Data to be Clipped: Is A Shapefile of 1 mile circles. Data I want it clipped with ...
2
votes
1answer
71 views

Finding problematic rasters in large set of rasters using ArcPy?

Just wondering if anyone knows how to quickly find rasters that cause errors when I attempt to process them in cell statistics (as I am trying to sum them). I have many hundreds of rasters and don't ...
0
votes
2answers
68 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 ...
0
votes
1answer
23 views

histogram of raster coordinates in R

I'm trying to generate an histogram of the y coordinates where raster values are 1. Mysteriously the following, different rasters, give me the same histogram. What could I be doing wrong? here are ...
0
votes
1answer
87 views

Creating polygonal windows for spatial analysis in r

I am attempting to normalize a spatial point pattern using a population density raster in r. My problem is that the function I am trying to run is recognizing the "white space" around the raster I am ...
0
votes
1answer
46 views

Modify a Raster display just for aesthetic reason

I have one raster display that I want to include in a report that I am working for school. This is a picture of the raster file: This is a river bathymetry and as you can see, on the margins of ...
2
votes
1answer
47 views

What is the most efficient way to get a table or attribute table of a float raster?

I'm starting with a stretch point raster. Ultimately I want to get a mean value of values with larger zones and then rate the zonal mean stretching from 0-1 and output rank/zone to a table or layer ...
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0answers
19 views

Map netncf-file with different years and save the different layers in shapefiles

Download from this website the following netncf-file: cru_ts3.23.1991.2000.pet.dat.nc.gz. This is a monthly raster with data from all over the world from january 1991 to december 2000 I am using ...
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0answers
38 views

Clipping raster brick object in R

I have MODIS NDVI TIFF files for a year I want to first clip it with a irregular polygon (not by its extent only) of my study area and save it as a multi band raster in TIFF format The TIFF image are ...
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vote
2answers
55 views

What method does QGIS Merge Rasters tool use?

I am trying to merge rasters in QGIS and want to set a priority order for merging so that the values from the highest priority raster are used in overlap areas (the “FIRST” merge/mosaic method, I ...