Questions tagged [raster]
Raster is a data format consisting of regular grids of values, usually stored in an image-like format.
8,551
questions
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1answer
69 views
Clipping all files from multiple subfolders using multiple polygons that have same attribute
I'm new to Python.
I have two dataset folders one with subfolders containing shapefiles and the other with subfolders containing raster.
I'm trying to complete a loop that takes the polygons of the ...
4
votes
1answer
1k views
How to "mosaic" rasters and keep attributes
I have numerous individual 10m Raster files (with both quantitative and qualitative data) for each state and need to combine them into a national dataset.
However, when using a mosaic it seems that ...
0
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0answers
17 views
Proximity map in QGIS
I am using the proximity tool (raster distance) in QGIS to calculate the distance from each pixel to the nearby forest. I created the proximity map using the forest raster as input but the output ...
2
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0answers
99 views
Create shadow mask from DEM using QGIS
How do I create a shadow mask based on a DEM, with the sun conditions (azimuth and altitude) known?
I am using QGIS, and had hoped to use the r.sunmask.position tool for this. The DEM is in UInt16 ...
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0answers
17 views
Stacking multi-dimensional bands in rasterio
I'm trying to stack numpy arrays to write a tif file:
stacked_bands = []
for i in range(1, 37):
stacked_bands.append(np.stack(([get_window(t, x, y, i) for t in tif_files])))
stacked_bands ...
8
votes
1answer
760 views
Raster smoothing
I am an italian student. I'm using ArcMap 10. For my thesis I need to simulate a debris avalanche, but in my elevation raster the avalanche deposit is included so I'd need to take it off to simulate ...
3
votes
1answer
63 views
QGIS iterative rasterize naming
I am working on a PyQGIS script that gives similar behaviour to the GeoCube package. Specifically, I want to create a bunch of rasters from vector data for a selection of fields.
For example, if I ...
1
vote
1answer
47 views
Restarting the count of runs in rasterbrick in R
I got myself a rasterstack with 6300 layers - which represent 70 winterseasons since 1950 till 2019 (70x90 days). Values range from 0.5 to 1.5 and I am looking for amount of runs of at least 5 days ...
2
votes
1answer
27 views
Moran's I statistical significance with spdep mc.moran function
I would like to obtain Moran's I estimation together with its p-value from a raster data layer --which has na value-- including a figure showing the simulation distribution by mean of spdep::mc.moran()...
2
votes
2answers
308 views
Exporting raster with transparency from QGIS
As a follow on from my earlier question on reprojecting raster images - is there a way to export a reprojected PNG file (with transparency) from QGIS, with an associated world file?
I can now ...
0
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1answer
44 views
GDAL translate to COG seems altering the original data image
Trying to compare with gdal info on both images, nothing seems been different but when trying preview images on QGIS with same band settings value, the image seems to be altered.
Command use for that :...
0
votes
1answer
33 views
Raster Merge Tool QGIS 3.16.11
I am performing Raster-> Miscellaneous-> Merge tool using QGIS version 3.16.11 to merge approximately fourteen Landsat8 OLI images. These images are stacked using Bands2-7 and while create the ...
0
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1answer
53 views
Statistical significance of Moran I
I would like to estimate the Moran's I coefficient for raster data together with the statistical significance of the spatial autocorrelation obtained.
I found that the raster package function Moran() ...
0
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0answers
9 views
Why do these MODIS images look so different?
Why do these 3 MODIS NDVI images have such different shades of grey? The middle image has so many dark spots and the last one is also somehow not the same in terms of shade. All of them have been ...
11
votes
1answer
5k views
+50
Fixing Raster layer: Provider is not valid error when loading PostGIS rasters?
I compiled and installed the current QGIS master as usual and I imported some raster data into my postgres 9.3 database with postgis 2.0.2 extension. Whenever I try to import the raster data into qgis ...
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vote
0answers
15 views
TypeError: cannot unpack non-iterable NoneType object when converting raster file to csv file
I want to convert a raster file to csv file. When I use raster2xyz, my code raises TypeError: cannot unpack non-iterable NoneType object error.
from raster2xyz.raster2xyz import Raster2xyz
from ...
2
votes
1answer
48 views
Adding styles for a raster in PostGIS
I have a PostgreSQL/PostGIS database located on a server.
I have added shapefiles (with the "PostGIS shapefile import/export manager") and raster (with "raster2pgsql"). It works ...
2
votes
1answer
16 views
Reclassifying raster: operands could not be broadcast together with shapes (3,14452099) (1,3178,9156)
I try to reclassify a DEM file. I never had problem with this code, but with this file (actually with this folder consisting of .adf files) I get the error: 'operands could not be broadcast together ...
2
votes
2answers
33 views
Extracting raster values to points using ArcMap
I am working on a project to determine the coastal vulnerability. I have different variables like elevation, LULC, bathymetry, etc. of the entire study area.
I am stuck in the middle of my analysis.
...
0
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0answers
7 views
Losing raster edges in 3D map
I am using the 3D map viewer in QGIS. When I change from flat terrain to DEM, I'm losing some parts of the DEM tifs.
The image appears like this:
When it should appear like this:
You can see some ...
1
vote
1answer
51 views
Tried to Mosaic Sentinel 2 images but my final image appeared with some overlapping Null data
I'm working on an area that required me to use three sentinel images to fully cover it, I used the "mosaic to new raster" tool in ArcGIS to merge the three images and was surprised to find ...
0
votes
1answer
26 views
Raster math with latitude-specific correction factor for each pixel
I'm working on a problem that requires creating a new raster from a large (~100 GB) global basemap. A different correction factor must be applied for every degree latitude of the basemap, making an ...
1
vote
1answer
18 views
Resize frame to image size problem
I have an image the size of an A4 that I'm trying to place in a layout print in QGIS.
This is the image in an editing software. As you can see it has 210mm in width.
Here is the same image in QGIS ...
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0answers
16 views
How to create nodata area in a multiband raster?
I am running QGIS 3.10.11, and I would like to create a nodata area inside a multiband raster.
What I have done so far is:
Create a polygon on the area that I want to be nodata
Clip with GDAL my ...
1
vote
3answers
58 views
Unable to select a region of a raster
I've been tasked with generating some samples from a larger raster file to use as inputs to a computer model. Since we already have rasters prepared, the hope was that this would just be a matter of ...
2
votes
1answer
23 views
Sum of raster file in QGIS using Python Console
I have 8760 raster file for the precipitation in the netherlands on hourly base, from the first day of the year (01.01.2020) till the last hour of the year (31.12.20). What I have to do with these ...
1
vote
1answer
133 views
Can I access Worldclim 2.1 CMIP6 data in 30-second resolution?
I am trying to access the Worldclim 2.1 CMIP6 future climate data at 30-second resolution. The Worldclim website says 30-second data will be available by then end of March 2020. This is long overdue ...
0
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0answers
19 views
PostGIS WMS raster data - pixel values shifted on different zoom levels
I'm quite new to working with geo data, specifically with PostGIS and currently trying to understand the following phenomenon.
I have some raster data stored in a PostGIS database and use this PgSQL ...
0
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0answers
29 views
Why did the value in raster layer changed after importing it in R
I opened the raster layer in ArcMap where the raster statistics showed the range of the raster value was -1 to 3.
However, when I imported it in R for further analysis, the raster value changed.
>...
1
vote
2answers
177 views
Increase the dimensions of each cell in a raster without any kind of resampling?
I have a DEM interpolated from a TLS point cloud at 1 mm cell resolution. This resolution is too fine for use in a 2D surface inundation model with the required timestep, without the model taking far ...
0
votes
1answer
125 views
Identify raster pixel value using ArcGIS Portal Map Viewer
I have a raster I've published to ArcGIS Image Server 10.5.1. I'm trying to create a web map in 10.7.1 Portal where I can query the pixel value. Ideally the user can click on the raster and a popup ...
7
votes
3answers
733 views
How to resize a raster SUMMING the values of pixels in QGIS?
I would like to be able to resize a raster such that the values of the resized pixels are based on the SUMS of the original raster pixels, rather than the averages. The output should be generated thus:...
2
votes
1answer
30 views
"Eval Error" when selectively rendering raster layers in QGIS Atlas
Using the Atlas feature in the QGIS print composer, it is possible to use rule-based symbology to show/hide components of vector layers as required or defined by the Atlas?
I have multiple pages, ...
1
vote
1answer
16 views
Quantile of a polygon over a raster stack in R
I'm working with RasterStack of 300 simulations sims_trend. and I also have a SpatialPolygonsDataFrame limits. I'm trying to calculate quantiles for each polygon through the raster stack.
I know that ...
-1
votes
0answers
10 views
Compressing timeseries of raster data for use in Geoserver
I have many sets of raster time series data, i.e. raster maps that change over time. I now store them as individual GeoTIFF files. The changes from one year to the next are small, so these maps would ...
1
vote
1answer
69 views
Binning of satellite Level 2 data
I can see that for the Aqua instruments (AIRS, MODIS, CERES etc), the Level 2 data are binned into Level 3 data providing average values for (say) a 1° x 1° cells grid.
Let's say that I would like to ...
0
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0answers
7 views
Merging ALOS-PALSAR Raster Tiles in Delta Region
I am trying to merge a set of ALOS-PALSAR tiles in delta region. The purpose of the work is to extract stream networks. But upon merging, the landscape gets darker and loses the fine details as can be ...
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0answers
21 views
Importing and updating raster table in GeoPackage using gdal-translate
Based on answered script from a previous question I continued studying GeoPackage documentation but I didn't found a solution to overwrite the table in GeoPackage when the original file (in '...
0
votes
0answers
28 views
Average of elevation values not for the entire raster but for created tiles in the raster
I have a raster representing the elevation of an entire city (1-meter resolution LiDAR DSM) and I would like to calculate the average height of the features in the city for 200mx200m squares. I am ...
0
votes
1answer
17 views
Raster calculator - negative exponential transformation gives single-value output
I'm trying to apply a negative exponential transformation to a raster with values ranging from 0 to 1.
In the literature, the function to do so is
R = 100 - 99 * ((1 - exp(- c * H)) / (1 - exp(-c))) ...
0
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0answers
25 views
Changing raster pixel values outside of polygon box using rioxarray
How do I change all raster pixel values outside of a polygon (keep the original values inside polygon) into a certain value?
I have passed through rioxarray clip() like below from this link:
...
3
votes
2answers
78 views
Changing raster source using QGIS
I am using QGIS 1.8.0.
I have two raster image files that I want to see interchangeably, so I duplicated the first layer that's already been georeferenced properly to ensure that all the location data ...
1
vote
1answer
132 views
Rotating raster using Python [closed]
I am trying to rotate a DEM raster (NetCDF file) using Python language, but there is still no progress. I have tried GDAL Python but not so much information in the document about rotation. Do you know ...
0
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0answers
13 views
How to multiply lines layer by raster layer?
I am trying to take my lines layer with unique values for each segment, and multiply it by a raster layer. This seemed easy and straightforward at first, but after thinking about it, now it seems ...
2
votes
1answer
286 views
Convert Esri ASCII grid raster to WKT polygons efficiently
I need to transform a large number of Esri ASCII grid files to polygonized WKT format, e.g. as CSV. Currently, I use GeoTools with the ArcGrid reader and a polygon extraction process. For parallelism ...
1
vote
1answer
137 views
Temporal rolling mean in stars
I need to find temporal rolling means (or other stats - max, min, etc.) in stars spatial obects. For stars raster cubes, this would be directly analogous to the calc(rasterBrick, function(x) movingFun(...
0
votes
1answer
40 views
Importing landuse (raster) to polygon using ArcGIS Pro
I have a raster file (Landuse classes) and a polygon file (administrative units).
How can I import the raster landuse classes to the administrative limits so I can find what landuse classes are in ...
0
votes
1answer
17 views
Calculate raster mean within polygon limit using R
I have a rasterlayer MeanMap and I would like to do some calculations of the raster values contained within a determinate polygon fregs. How can I calculate the mean and the median of the raster for ...
0
votes
1answer
268 views
Export raster in pieces to stitch together afterwards or other way to print a big map?
I used QGIS to put together an OSM XYZ Tile-layer and some WMS-layers. Now I want to make a print map out of it. When I try to export it from the print layout editor to PNG or PDF in the desired ...
1
vote
1answer
71 views
Calculating area of pixles for certain Aspect value per specific area?
I am using ArcGIS 10.6. I have the aspect (raster file) for the roof of buildings at the city scale. Now I want to calculate the area of each aspect group per building. I tied zonal statistics, zonal ...