Questions tagged [raster]
Raster is a data format consisting of regular grids of values, usually stored in an image-like format.
2
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0answers
34 views
Add pixels to a raster image
I have a georeferenced raster with water depth values and I would like to add more pixels in order to extend my raster as far as the coastline (like in the picture, dark blue has no values). How can I ...
1
vote
0answers
28 views
QGIS: habitat suitability/combining raster layers
I have created a number of raster layers for different environmental factors (slope, roads, rivers, forest cover) and want to combine them to find areas where the 'ideal' aspects all overlap. For ...
1
vote
2answers
33 views
Cannot read pixel value from DTM raster with QGIS
I am using this DTM:
http://ags.cuzk.cz/arcgis2/services/dmr4g/ImageServer/WMSServer?request=GetCapabilities&service=WMS
At ArcGIS I am able to ready pixel value of the raster but at QGIS it ...
1
vote
1answer
24 views
Substracting raster values from 2 rasters with different cell sizes
I am working with two raster files. The first is a DEM and the second an elevation-correction file. Both files display the same geographic region. My problem is that the cell sizes of both files aren'...
0
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0answers
14 views
How to bind points with polygons extracted from raster using R [on hold]
I have big tiff and load it using raster:
tif = raster(paste0(path))
Next, I can extract all the polygons from the file (using some value P of interesting layer value):
rtp = rasterToPolygons(tif, ...
0
votes
0answers
26 views
How to calculate mean for each raster layer in a stack? [on hold]
I have a data of monthly temperature (with several values in each layer (i.e temperature values for a month)for 31 years (372 layers). Now have to calculate mean for each month for 1980-2010 and save ...
-3
votes
0answers
21 views
Creating 3D image from HGT DEM file? [duplicate]
I tried Displaying 3D raster/vector in GRASS from command line?: Error there is no nviz in my GRASS 7.6.x
Already tried this too: Error m.nviz.image bad server connection
Already see this and the ...
0
votes
0answers
33 views
Digitizing contour lines from a picture in QGIS
I have a map with isobaths (water depth), like in this picture, and I would like to digitize them. Is there any tool or procedure in QGIS that can recognize the lines in the picture and create a ...
0
votes
1answer
63 views
Performing trend analysis with R?
I have data of monthly temperature for 60 years.
I want to analyze the trend for the monthly temperature in R.
How do I construct R Code which would analyze monthly trend over the time series to ...
1
vote
0answers
17 views
How to convert from Large RasterLayer to Formal RasterLayer class in R?
I'm a bit confused about types here. While I'm loading a image:
tif = raster(paste0(path))
I get some "Formal Class RasterLayer" object. But while I change it's matrix of values, for example:
idx &...
2
votes
1answer
39 views
Convert point layer to raster QGIS 3
I have a .csv-file containing x and y-coordinates as well as different variables with attributes (var1 to var3). The csv looks like that:
Loading the data into QGIS with Add Layer → Add ...
-1
votes
0answers
18 views
My TIF files are displaying pixelated..how can I show them as smooth? [closed]
I am trying to display Hurricane Flood Scenarios near a stream/property. I have downloaded TIF files from a coastal vulnerability report. The tif files have no attributes associated with them. They ...
1
vote
1answer
21 views
R: rasterize SpatialPolygonsDataFrame and keep factor field
I want to rasterize a SpatialPolygonsDataFrame and keep the values of a factor column.
Consider the following code (from Processing vector to raster faster with R):
library('raster')
library('rgdal'...
1
vote
1answer
30 views
Making raster layers calculated from point feature congruent?
Raster A and Raster B are both calculated from the same point feature. Raster A results from Natural Neighbor Interpolation in the Spatial Analyst toolbox. Raster B results from Point Density in the ...
3
votes
1answer
69 views
Georeferencing RasterLayer using ArcObjects?
I have a raster derived from a .png which has been drawn into a geodatabase.
I also have the spatial reference and extent coordinates where I want to georeference the raster.
Is there a way to ...
1
vote
0answers
34 views
Raster projected in Google Earth Engine showing weird values within R
I classified a raster in GEE and I am trying to work with the same within R. I have 7 land cover classes and when I view the output in R, I get something that does not make sense. Please see the ...
0
votes
0answers
13 views
gdalbuildvrt does not add all the bands needed [closed]
I have 7 rasters (.tif) and I want to merge their bands into one file.
I use gdal as following:
gdalbuildvrt -separate $Database_outdir/emissions.vrt $Database_outdir/CO.tif $Database_outdir/NOx....
0
votes
1answer
24 views
Draw RasterLayer to map
I request a .PNG from a rest API, store it and create a IRasterLayer.
My problem is I'm trying to draw it to the focus map with the RasterLayer.Draw() method, but does not look like I'm doing it ...
2
votes
1answer
23 views
Find the coordinates of the max n values of a raster layer
I have a Geotiff file which is published as a raster layer in Geoserver.
I need to be able to calculate the coordinates of the max n values that are inside a given polygon.
I have found a WPS called ...
1
vote
1answer
14 views
Adding scale bar to raster overlayed on ggmap Google Maps object
I am trying to plot a predicted surface (raster layer) over a ggmap object that contains base imagery from Google Earth. I have produced the map that I want however, I am struggling to add the legend ...
1
vote
0answers
15 views
How does buffering objects in a raster data set differ from buffering in a vector data set? [closed]
How does buffering objects in a raster data set differ from buffering in a vector data set?
What are the steps on making a raster buffer?
0
votes
0answers
13 views
Clipping a raster by latitude and longitude extent in ArcMap
How do you clip a raster by latitude and longitude in ArcMap? I have a planetary DEM of Mars: The datum is D_Mars and the xy coordinate system is Equirectangular_Mars. I want to clip this raster ...
10
votes
2answers
316 views
Remove border lines of SRTM tiles rendered as hillshade
I have downloaded several SRTM DEM raster tiles from https://dwtkns.com/srtm30m/, and created hillshade versions from the tiles. However, upon closer inspection, the hillshade tiles now have border ...
0
votes
0answers
14 views
Intersect multiple binary rasters based on certain criteria in ArcMap
I have multiple binary raster image (0.1). For example if I have n images, how can I extract the pixels that has the value of 1 and frequently occurred " the same pixels" in 70% of the n images (for ...
3
votes
1answer
55 views
r.surf.contour for large area
I have a vector file containing contour with 2m accuracy, covering a large area (All Hong Kong).
I tried to generate an elevation raster map with the file, by first rasterized the vector, using v.to....
-1
votes
1answer
33 views
Calculating new raster metrics without polygonizing in R?
I have an enormous number of large rasters representing tree canopies. Every individual canopy has a unique number that is assigned to each pixel that is part of the tree. I am working with R and the ...
2
votes
1answer
39 views
Configuring lidR catalog to overwrite raster output (with different extension)?
I have a small issue with configuring the lidR package for parametrizing the extracted raster files with grid_metrics() function.
My question is how to set in the catalog options that:
be able to ...
0
votes
0answers
9 views
GeoServer rasters disappear with ColorRamp, no null value transparency
I'm having trouble getting GeoTIFFs to display like anything nice. Two main problems I'm dealing with:
Using default "raster" SLD style, I can get the raster to appear in map (but null displays as ...
2
votes
1answer
40 views
USGS Relief map (GeoTIFF raster) misaligns with vector layers (QGIS)
I'm trying to correct the alignment of three layers (described below), but I'm not entirely sure how to go about re-projecting raster layers to my other layers. Ultimately my goal is to clip the ...
1
vote
0answers
38 views
Reclassify pixel values of defined area to neighboring values - GRASS, SAGA or QGIS
Is there any function in GRASS, SAGA or QGIS that can reclassify the pixel values with a defined area (eg. smaller than 10 m2) into the value of the pixels that are neighboring?
Something like Sieve (...
1
vote
0answers
24 views
Ranking water basins by canopy cover? [closed]
I have a river raster that is composed of a range of canopy cover percentages by pixel. I want to rank which water basin's have the river with the best canopy cover. How do I do this?
0
votes
0answers
18 views
Selecting grid squares (polygons) that intersect with a raster
I have a raster dataset that I have exported a subset from using attribute values (so the extract has areas where there are no pixels). I also have a fishnet grid (polygons) and I want to select the ...
0
votes
0answers
20 views
Elevation Map from Slope and Aspect Rasters
I am trying to create an elevation map (e.g., recreate a DEM) from the following input data:
Slope Raster
Aspect Raster
ASCII file containing XYZ data points (Easting, Northing, and Elevation for ...
0
votes
0answers
9 views
Modeled quickflow data per pixel
community! I'm running a hydrological model called Seasonal Water Yield from InVEST, based on monthly precipitation rasters, monthly ET rasters, a land use raster and watershed shapefile. One of the ...
1
vote
1answer
26 views
Doing pairwise or pixel wise raster comparison using PyQGIS & Processing Scripts?
Do you know how to do a pairwise o pixel wise raster comparison using PyQGIS or Processing Scripts?
Pairwise or pixel wise comparisons are made between two raster datasets pixel by pixel. That means ...
0
votes
0answers
24 views
Convert a raster to a polygon with gdal in command line
I want to convert a raster (agric.tif) to a polygon layer (agric.shp). I want to use gdal in command line since the QGIS (raster to polygon) seems to takes for ever (still running over an hour).
I am ...
0
votes
0answers
20 views
Georeference ortho images
How I can georeference ortho images from
exterior orientation parameters (px, py, pz in [meter] omega,phi,kappa in [grd] )
2
votes
1answer
38 views
Query land use (Raster calculator)
I have a land use raster file and am trying to use the raster calculator to query the file for surface water.
The saga formula (11 = surface water band):
(a, 11)
This does not work.
Can anyone ...
1
vote
0answers
22 views
Model binary rasters over time against non-spatial variable (e.g., inundation over time vs. gage height)
I have a time series of raster images for a study area that have been processed to a binary classification (inundated/not inundated). Each image in the series is time-stamped and can be associated ...
1
vote
1answer
16 views
Printing/displaying coordinate system of several raster files using ArcPy? [closed]
How can I extract the Coordinate System of many raster files (GeoTIFF) so the information is displayed, and I can ascertain that all of them are correctly settled in the same projection, using ArcPy?
...
0
votes
0answers
27 views
Raster data projection without spatial reference
I have hundred raster data without spatial reference on it. (Spatial Reference is undefined and xY coordinate system is unknown)
The original raster data was Subdataset so I used 'Data Management ...
4
votes
1answer
48 views
Adding up several rasters to show the change
I want to add several images such that their change is shown in different colors. Such as the following in which I simply added two images in their grayscale. But I would like to have a colored ...
2
votes
1answer
51 views
Zonal statistics basic output
I have been using the zonal statistics tool to quantify the variability of slopes around archaeological sites.
I have noticed in some experiments that there are differences between the mean and the ...
0
votes
1answer
46 views
Weighted mean of raster by polygons in R?
I have two rasters, raster_a and raster_b, and a shapefile, world_shapefile. Both rasters are of the world extent and overlay each other.
What I want to do is to create a weighted average of raster_a,...
1
vote
1answer
47 views
How to use a regression equation to create a map in QGIS?
I have been working on creating an exposure map based on measures taken at fixed points. I want to extrapolate the results to a grid to get an exposure map (air pollution data) for a region based on ...
0
votes
1answer
48 views
Setting origin raster to resample using R?
I need to resample a raster from nrow= 467, ncol=805, res=0.0416667 degree to nrow=2335, ncol=4025, res=0.00833333 degree. Basically make the pixel size smaller, because I have too many small polygons ...
2
votes
1answer
43 views
Moving a set of rasters in QGIS
After running a GRASS watershed algorithm I've got nine new layers:
Each one is in its own folder with a long hex name under a processing folder with a long hex name:
/tmp/...
2
votes
1answer
67 views
Changing min max of Stretched Raster with ArcPy?
I have two rasters r1 & r2:
Maximum cell value of r1: 0.9
Maximum cell value of r2: 0.3
Minimum value for both is 0
I am using a color gradient: white - yellow - green - blue - red - black
...
0
votes
1answer
14 views
Statistical downscale of raster with sum function
Usually raster dowscaling methods exploit interpolation techniques. However, I am not sure how to proceed (in R, QGIS, GEE, or Python) if a raster needs to be downscaled (=i.e. its resolution ...
2
votes
1answer
70 views
Error in batch process converting raster from .img to .tif in QGIS 3.4.8
I'm a long time GIS user but new to QGIS. I can convert single raster files in .img format to .tif files in QGIS 3.4.8 without any issues. However, I cannot batch process the same files. The Python ...
