Raster is a data format consisting of regular grids of values, usually stored in an image-like format.
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8 views
Unwanted artefacts working with Raster analysis
I am trying to make a simple slope map from a DEM (tif). I already tried with the different slope-tools in QGIS (GDAL, SAGA, GRASS) and also the 3D Analyst in ArcMap. Boths bring the same result: a ...
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1answer
20 views
How to convert Raster image to Shapefile WITHOUT flipping it upside down
I am using QGIS v 3.2.1 to convert Raster image to Shapefile
Unfortunately the resulting shapefile is upside down.
How to keep resulting shapefile right side up
Here is animated gif (link on GitHub)...
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21 views
Can't get gdal_calc.py to work
I am new to python and QGIS (have some experience with arcpy). I am trying to multiply two .tif files together using gdal_calc.py but I can't get it to work. It just returns the error invalid syntax. ...
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18 views
How to get WYSIWYG of raster layer in print composer in QGIS? [duplicate]
I currently have a base raster layer from OSM Standard used in my project. In the regular editing platform for QGIS, the place identifiers for cities are easily readable.
However, once I enter layout ...
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1answer
23 views
projectRaster() result does not have the same nrow and ncol, but has same resolution
I have a land use land cover (lulc) raster in WGS84 coordinate system shown below
class : RasterLayer
dimensions : 59575, 57541, 3428005075 (nrow, ncol, ncell)
resolution : 0.000509, 0....
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21 views
Vector Tiles VS Raster Tiles for leaflet
I have downloaded many vector tiles in the mbtiles format from OpenMapTiles. The reason I did that is because I will be using them on a station that cannot have an internet connection at all.
I would ...
2
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1answer
37 views
Efficiently read large tif raster to a numpy array with GDAL?
I have been using the Python GDAL API to read tif raster files as NumPy arrays. Previously, I simply read the raster into an array directly with GDAL:
ds = gdal.Open('example.tif')
fullarray = np....
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12 views
Clipping rasters with GDAL
I have this raster (land-and-water.tif):
And this one (land-only.tif, black = no data):
And I need this (black = no data):
I'm trying to do it with GDAL. Here's what I tried so far:
gdaltindex ...
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22 views
Reprojecting raster in QGIS gives nan
I'm trying to reproject raster layers in QGIS. At the moment they are in ESPG:4326 and I want to convert them to ESPG:54009. (Using Save As... and changing the CRS). However, this produces a layer of ...
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34 views
writeRaster() not writing datum information
I am trying to reproject a raster to the USGS version of the Albers Equal Area Conic projection. Following this post, which talks about projecting vectors by adding the +datum=NAD83 and writing it out,...
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20 views
Projection of raster to sinusoidal projection
I have my definitive raster shown below. This raster has the projection as mentioned here
class : RasterLayer
dimensions : 7276, 8330, 60609080 (nrow, ncol, ncell)
resolution : 463.3127, ...
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14 views
Animation by overlapping several raster images using QGIS? [duplicate]
I´m looking for something to help me to make a movie (.avi) out of a series of raster files indicating different years. I´m using soil parameters, so the values are continuous and not discrete.
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10 views
Change raster values in relation to values of another raster in Python
I used 'gdal_rasterize' to create two rasters from shapes (raster 1 and raster 2)
os.system('gdal_rasterize -burn 1 -at -a_srs EPSG:4326 -ts 25000 25000 ' + r'C:\shape.shp' + r' C:\raster.tif')
...
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27 views
How can I access my raster data from PostGIS
I made a PostGIS database where I stored some elevation raster data.
Now I want to get the value of a point from the raster for given latitude and longitude. Therefore I printed out the SRID of my ...
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0answers
17 views
Spatial correlation from multiple netcdfs
Below is my code for calculating correlation of geotiffs:
library(raster)
library(ggplot2)
userpath <- "F:\\userpath"
r <- raster()
A <- stack(list.files(path = userpath, pattern = 'file1*...
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1answer
21 views
Resize rasters to add empty data around edges
I have a set of DEMs that have different extents due to different data being available at each of the sample points these DEMs were generated from. I need to use these to create a set of uniformly ...
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5 views
Setting COLORRANGE for rasters with variable minimum and maximum value in MapServer?
I have a series of rasters picturing the same phenomenon/product eg. the accumulated precipitation and I use the same mapfile for all. Naturally the minimum is always zero but maximum is variable from ...
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23 views
Flood TIFF layer does not show full max and min values [on hold]
I have set up a raster layer using a TIFF file for surface water flooding. The layer indicates the minimum and maximum flood range of 0.102624m – 0.47962m under the Layer Properties Histogram, but I ...
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1answer
28 views
Running a function on subset of a raster image instead of whole image in R
I have a wide swath raster image. I want to detect cloudy pixels based on criteria such that a pixel in raster layer only consider its 25*25 neighborhood not the entire image.
My problem is here that ...
2
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0answers
48 views
Identification of roof peaks on a Raster in Qgis
I am trying to map all the flat roofs of a city. After processing my data I have a huge raster with the zones that are flat (=1) and not flat (=0).
I can overlap the roof polygons over this raster and ...
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1answer
21 views
Converting 13 band .tif images to RGB using QGIS?
I have sentinel 2 images. Each image has 13 bands (bands are not individual images). I wanted to convert them to only RGB images and store them in a file to use for another purpose.
I have tried
...
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2answers
74 views
Correlation between raster pixels within each polygon
I have two raster layers with the same extent, CRS, and resolution, and a shapefile consisting of a number of polygons. I would like to calculate the Pearson correlation between the two rasters within ...
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15 views
Clip raster by mask layer gdalwarp error in QGIS
I've been trying to find why my gdalwarp isn't allowing me to clip a raster to the shape of a shapefile.
GDAL command:
gdalwarp -ot Byte -of GTiff -cutline /Users/johnmorris/Desktop/Geodata/...
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1answer
12 views
How to merge single band chunked raster tiles with ST_Union in PostGIS
I have written the code below to select specific polygons and determine which grid tiles they intersect via a lookup table. Then depending on the grid tiles I want to merge the associated raster tiles ...
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2answers
24 views
How to assign raster layer's colors to polygons in QGIS?
I have a georeferenced raster file showing parcels of a town with different colors (yellow for the category single-household residential, green for agricultural areas, etc.). I also have the shapes of ...
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12 views
Could not list layers for this store, an error occurred retrieving them: Failed to create reader from file:
I am trying to add an ImageMosaic Store in GeoServer from orthomosaic .png files (4096 by 4096 pixels, 2000 by 2000 metres) with associated .pgw and .prj files and I get the following error:
...
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1answer
25 views
Apply mann-kendall analysis on stacked raster in R as a function
I want to run a mann-kendall trend analysis with pre-whitening on a stacked raster and then save the resulting tau, sen-slope and p_value. I am currently doing this by looping through every pixel but ...
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0answers
21 views
Saving rasters in Arcpy loop
I'm trying to do Map Algebra on a bunch of rasters by iterating through a for loop and saving them in an empty geodatabase. However, they aren't saving properly. Only the last raster is created and it ...
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37 views
Reclassifying raster with ArcPy? [closed]
I have a raster which originates from a large tiff file being clipped and resampled. The resulting raster resampled_raster retains the same projection and opens up just fine in arcmap.
I would like ...
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0answers
13 views
How to get WYSIWYG of raster layer into layout mode in QGIS? [duplicate]
I currently have a base raster layer from OSM Standard used in my project. In the regular editing platform for QGIS, the place identifiers for cities are easily readable.
However, once I enter layout ...
0
votes
1answer
40 views
Filling no data value in raster using ArcGIS Desktop?
I have a raster with no data values, I want to give them values according to values around them. If a no data pixel is surrounded by 8 pixels whose values are 1 then the no data pixel should adopt ...
1
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1answer
37 views
How to extract values from .tiff file using R?
Maybe a rather simple question, but I could not find an answer. I am trying to extract long, lat, value from a .tiff file of a map of Africa with long/lat and soil acidity as the values.
Here is some ...
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0answers
15 views
crosstab() rasters in R
I am having a hard time understanding the contigency table produced by crosstab() between two different rasters.
Say the command is
crosstab(r1,r2)
[r1] [r2] Count
0 0 3456
1 41 ...
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27 views
Separating overlapping polygons into a new shapefile
I am currently working on building a model so that my process is easier to follow so the solution would preferably be something I can add to modelbuilder.
I have a shapefile of polygons that represent ...
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1answer
19 views
Extracting raster values and creating new raster in QGIS is not working as intended
I am trying to extract certain values from a raster image in order to create a new raster which should then only contain the specified values. I have a single band raster showing forest loss from 2000 ...
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0answers
24 views
Opening National Land Cover data?
How do I open the National Land Cover data in QGIS 3.0? Attached is an image of the files. It looks like it's an .rrd file.
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2answers
31 views
TypeError: 'int' object is not iterable in reclassifying raster using arcpy
I am trying to reclassify a raster, using arcpy in Python. My code is below
from osgeo import gdal
import arcpy
from arcpy import env
from arcpy.sa import *
raster_file = 'M:/tgopalakrishna\Data\...
1
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1answer
66 views
Lost pixels during a raster merge with gdalbuildvrt
I'm trying to merge some rasters with gdalbuildvrt in a python script:
rasters = glob.glob('/{0}/ndvi_masked/*.tif'.format(path))
gdal_cmd = 'gdalbuildvrt -q -vrtnodata "0" -overwrite {0}.vrt'....
4
votes
1answer
39 views
How can I estimate a Least Cost Path in Google Earth Engine?
I'm using Google Earth Engine to estimate walking time based on slope, using the Google tutorial and this example based on a DEM. My code actually runs, but I don't know what units the output raster ...
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2answers
30 views
Adjusting the extent of raster
I have a netcdf file which I converted using Make NetCDF Raster. Unfortunately, the x and y are not, I think, properly define. One way to solve this is by correcting the extent (I am not sure here) ...
1
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2answers
26 views
Creating precipitation raster map in GRASS GIS?
I am trying to create a potential erosion map of my basin for which I require a rainfall distribution map. I have 3 stations' rainfall data for the year 2007- 2015.
How do I create a rainfall map in ...
3
votes
1answer
34 views
Raster representation in arcpy/numpy
I have a .tif raster file which contains integer values at 1, 2, 3, 4 and 5. Importing this file into ArcMap also shows a number of cells with Nodata value where the above classes are not present.
I ...
4
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2answers
81 views
Generating random points inside raster boundary using R?
I have a projected raster shown in the image below (left). I want to generate random points inside the raster like the middle image. However, the result I am getting is the same as the image on the ...
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0answers
40 views
Creating rasters with exactly 1km x 1km resolution in QGIS?
I am using QGIS 2.18.11. I want to create grids with cell size that is exactly 1km by 1km using Raster>Conversion>Rasterize(Vector to Raster) and Raster>Grid(Interpolation). My area of interest is ...
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1answer
19 views
Copy raw rasters referenced by a Mosaic Dataset in ArcGIS Pro 2.2.1
Is there a tool in ArcGIS Pro 2.2.1 that allows me to select and copy the raw underlying rasters referenced by a Mosaic Dataset to a folder?
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30 views
Rasterio Raster merge - horrible result
I am merging .DEM files from CUGIR NY repository, and need to merge files into one larger image for the whole of NY city. I use python 3.6 + rasterio; It works perfectly for all but one file - "The ...
1
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1answer
25 views
Reprojecting raster between laea and lon/lat alignment issues
This is a follow-up post to a recent question on StackOverflow. I'm now facing a GIS problem rather than a coding one.
I'm working with a DEM from this source, which has the following projection ...
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2answers
38 views
Clipping a raster with shapefile and export the raster with shapefile extent
I am clipping a raster file with a shapefile grid and I want to save each raster subset individually with the polygon spatial extent.
To select the extent of each polygon, first I select the polygon ...
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0answers
11 views
mosaic rasters retaining original symbology
I am trying to produce an animation of surface runoff flow in ArcGIS 10.4 showing buildings change their colors when runoff of certain depth hits them (e.g., when flow depth<=10 cm, building remain ...
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19 views
Identifying source of reference mosaic dataset in ArcPy?
I want to check the source mosaic dataset for a reference mosaic dataset within Python.
Using:
arcpy.Describe(reference_mosaic).referenced
I can confirm that the reference mosaic is indeed a ...
