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Questions tagged [raster]

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

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pyqgis change pixel size from raster

how to change pixel size from raster by value using pyqgis or python gdal ? i try to using SAGA GIS tool resampling : ext2 = rasterLyr2.extent() xmin = ext2.xMinimum() xmax = ext2.xMaximum() ymin = ...
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Merge multiple raster .tif in QGIS 3.2?

I'm trying to merge 12 .tif raster layers (raster -> misc -> build virtual raster), but keep getting this error: Loading resulting layers The following layers were not correctly generated./var/...
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Eliminating single raster pixels of flow distance raster in ArcGIS Desktop?

I want to clean up a calculated flow distance raster and need some ideas on how to do it. As you can see in the picture, there are some pixels along streets and rivers (gray) that show connection (...
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How can I create a raster which stores 2 decimal values for each pixel?

I have a raster dataset which is derived from LIDAR. I have created 2 datasets which allow me to read the heights of the first returns and last returns. I would now ideally like to have a raster ...
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Error in compareRaster(rasters) : different extent

I'm preparing independent raster for LR model: the resampled rasters files: Aspect=raster("resampleData/Aspect_re.tif") Curvature=raster("resampleData/Curvature_re.tif") Elevation=raster("...
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ArcMap rendering NoData differently based on zoom level

The gist of the issue is that ArcMap is rendering most of my NoData values as the minimum stretch value color instead of the NoData color. My dataset is for global production of soybeans, so most of ...
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Automatically apply blending mode to raster

Currently using QGIS 2.18.24, but tested this on 2.14.18 as well. I'm trying to load a QML file for a raster with a specific blending mode ('multiply'), however QGIS only applies it until I click '...
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Some edges of raster switch to a value of 0 when clipped and pixels are shifted on QGIS

I am trying to clip trees out of a raster layer using polygon I've traced around them. I've created one polygon that I've copied for each tree so that each clipped raster contains the same width and ...
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Setting extent of raster to only used feature with gdal_rasterize?

Let's say we have a shapefile with only one layer containing multiple features, let's assume they are polygons. Using the command line tool gdal_rasterize, one can burn one of these polygons to a ...
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1answer
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Stack RasterDataset taking into account the dates between images

Good morning, I would like to stack a raster dataset taking into account the number of days between images. Sometimes the number of dates between observations are 8, 16 or 365 days. Is there any ...
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GDAL paint TIF with the shapefile and convert to PNG

Basically, what I want to do is to create a new image that is white where no features exist and black where a feature exists. I am trying another solution, get the pixel coordinates of each feature ...
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1answer
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Extracting a single value to a new raster from a singleband pseudocolor raster image

I have a large raster image depicting land use. It's a singleband pseudocolor image whose values are contained in a text file. There are 5 classes. Following the example of this question I thought I ...
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1answer
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Mann-Kendall test with R

I am trying to do Man-Kendall test over a stack of 620 MODIS images. The code is as follows: library(sp) library(raster) library(Kendall) library(spatialEco) setwd("C:\\NDVI_prueba") rlist=list....
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Updating min and max values with ArcPy on stretched raster symbology in ArcGIS Pro?

I have a map I am making where all I want to do is change the source layer for a raster to a new layer. I would then like to apply the same symbology as the original layer, but change the min and max ...
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1answer
57 views

What algorithm was used for generation of this vector layer?

The second image is a raster layer and in the third image obtained vector layer is so accurate. What algorithm would have been employed? Normal methods doesn't give nearly equal vectorization. I ...
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1answer
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Windowed read of a raster producing wrong projection?

I'm using rasterio to read in a .tif file and converting it to vectors using the rasterio.features module. For a particularly large .tif file, I thought I'd use the windowed read option, but for some ...
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1answer
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Converting lat, long and values to raster doesn't project correctly

I have a some data like so: x <- c(59.06321, 59.22318, 59.38157, 59.53835, 59.69351, 59.84704, 59.99891, 60.14911, 60.29761, 60.44440, 60.58946, 60.73278, 60.87433, 61.01410, 61.15207, 61.28822, ...
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Viewshed Analysis Raster layer turns black? [on hold]

Whenever I try and create a viewshed analysis the new raster layer is just one black square. Trying to create using a raster terrain layer and targets of 9m. What am I doing wrong?
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1answer
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Use of consistent symbology across multiple stretched rasters in ArcGIS Pro

I have multiple rasters that represent the same thing (NDVI) at different times. Each of the rasters has a different range of values. I want to symbolise them using the same range of values (e.g. from ...
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40 views

Avoiding artefacts by pixel filtering in a raster

I have a DEM with a spatial resolution of 2 meters with a lot of areas with no data. I want to fill those gaps in order to use the whole DEM. I used the 'close gaps' tool in QGIS (it's a SAGA tool) ...
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Reading backscatter value of each pixel of Sentinel-1A images in Java? [on hold]

I am new to working with Sentinel-1A images but have better knowledge of Java. I want to get backscatter value of each pixel of Sentinel-1A image, store it and then get the frequency of each value. ...
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Plot scatterplot of raster stacks in R with ggplot2 [on hold]

I have two raster stacks with 12 layers each (exactly the same extent and pixel size) and I would like to make their scatterplots (a panel of twelve scatterplots) in ggplot2, but ggplot does not seem ...
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Mosaic To New Raster (ArcMap 10.5) one raster is missing in new Raster

I have several Raster Datasets (DGM). They all have different columns and rows. They have the same bands, pixel size, type and depth and the same coordinate system. When I choose the Tool Mosaic to ...
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Query PostGIS raster table in QGIS

I would like to know if it is possible to query a PostGIS raster directly in QGIS in the same way one can use the query builder to filter a vector layer? I have successfully built database views of ...
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1answer
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Clipping Raster Object with Polygon Object in ArcPy?

I have about 400 rasters that I want to clip each of them based on a polygon object. The code I tried to use is the following: import arcpy, os origpath = ur'd:\test' jpgs = [f for f in os.listdir(...
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1answer
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Circle turns into ellipse after converting it into raster in ArcGIS Pro?

I have a polygon layer that contains a circle and an irregular polygon and I want to convert it into a raster in ArcGIS Pro. When I do that, the result is a raster containing the irregular polygon and ...
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2answers
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Define projection on raster problem

I have a raster map that needs to be defined in 2 different coordinate systems. I added control points to my unprojected map and rectified it. It's OK for the first coordinate system. (European datum ...
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Geologica data UDM(unusable data mask) have 8 bits per pixel

UNUSABLE DATA MASK FILE(UDM) The unusable data mask file provides information on areas of unusable data within an image (e.g. cloud and non-imaged areas). The pixel size after orthorectification ...
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rt_raster_from_two_rasters: The two rasters provided do not have the same alignment

I have a set of geometries in my database which I used to create a set of rasters (each raster has a unique color). Now I would like to merge all of these rasters into one but get an error such as : ...
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QGIS crashes when trying to build virtual raster

Currently trying to create a new virtual raster with images from Earth Explorer. I am inputting as the separate bands (B2,B3,B4) by selecting those individual bands as input then selecting separate, ...
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Change No Data Value Geotif File with Qgis or Gdal

I have a little question for Change No Data Value Geotiff File with Qgis or Gdal by another value. Usually one imports or exports a file with no data value -9999, but sometimes we need to change that ...
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batch saving 10m DTM layers using python console

I am attempting to batch save 300 10m DTM tiles all in the same Raster type 'Float 32-bit' for using to create a VRT. At present I cannot create a VRT using the original Raster layers as some of the ...
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3answers
39 views

Working with 2 rasters, having different extents but same resolution, in ArcGIS raster calculator?

I am working with 2 rasters, having different extents but same coordinate system and resolution, in Arcgis 10.5. The larger raster has 0 and smaller raster has 1 values. I want to make a new raster ...
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1answer
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PostGIS ST_RECLASS using Lookup Table not working properly

Link to question/answer similar to what I am trying to do I am trying to run ST_RECLASS on a raster to retain certain pixel values while setting others to NoData(0). I have a function that creates a ...
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1answer
37 views

Merge tool QGIS producing black box

I have been using the merge tool in QGIS frequently and it had been working fine until today when the results started producing a black box around the bounding box area for where the raster tiles do ...
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Clipped raster layer has more contrast than original in QGIS?

I am trying to clip a raster layer to the size of a polygon I have created as a shapefile. When I use Raster>Extraction>Clipper and select the file to clip with the mask layer being my polygon, the ...
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Selecting all areas downhill of point using raster ground data in QGIS?

I'm fairly new to QGIS after using ArcGIS Desktop for years, and I'm trying to build a simple tool to help develop my understanding. Does anyone know of a way I can create a tool that will ...
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Editing Specific Raster Cells Via CSV Values using GDAL?

I have a raster grid that I would like to modify. I am trying to manually edit specific raster cells' values via vales in a CSV file. My CSV contains three columns: VAL,LAT,LON 91.0,31.04250,-86....
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Intersection of raster and polygon in ArcGIS Pro?

I have a layer of block group and a raster. I would like to know which block group is covered by the raster. The output I want is a table of only the block groups covered by the raster.
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Calculating block statistics from land cover raster using R?

I have a raster (5 x 5 m resolution) representing land cover. Each cell contains a integer value (from 1 to 10) representing a total of ten land cover classes (e.g. 1-forest; 2-agricultural areas; 3-...
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2answers
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Merge RasterLayers (raster package)

i want to change the resolution of elevation data for several countries and them merge those in one rasterlayer. I use getData function from raster package. I tried this one: library(raster) library(...
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Can QGIS 3.0 identify tool give labels as well as band values for selected raster pixels

I'm using QGIS 3.0 for comparison of several landcover grids. These have a set style with 72 categories of landuse. The Style menu allows you to give a text label for each value within a band. The ...
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Error when masking raster with vector (GPKG)

I am having issues when trying to mask a raster with a vector layer. First, a little summary. I´ve been trying to classify tree canopy in a map. In order to do so I've used a DSM and DTM substraction, ...
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2answers
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Calculating continuous raster representing land cover proportion from categorical raster using QGIS?

I have a raster (5 x 5 m resolution) representing land cover. Each cell contains a integer value (from 1 to 10) representing a total of ten land cover classes (e.g. 1-forest; 2-agricultural areas; 3-...
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1answer
40 views

Setting one class in raster symbology using QGIS?

Is it possible in QGIS to exclude some values from the symbology and define only 1 class with 1 color for all the other values? I have hard time to find how to do it with the Singleband pseudocolor ...
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1answer
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Assign country names to long and lat in R

I have gridded data on temperature, from which I want to extract data for specific countries. Put it in another way, I want to kind of assign country names to the coordinates (long and lat). The way I ...
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0answers
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Could not allocate required memory for image

I'm trying to export a 24k image (export set to 1650DPI) using the "export as image" function but I keep getting the "Could not allocate required memory for image" warning. I don't understand why ...
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2answers
54 views

“Zonal” Statistics Using Line Features

I would like to find the minimum, maximum and (weighted?) average value of the raster cells intersected by a line (vector) layer. This is similar to what common "Zonal Statistics" tools do, but they ...
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1answer
27 views

Troubleshooting batch reprojection script that fails some of the time without error but works other times?

This script, up until now, has successfully batch reprojected datasets of rasters to designated projections. The results of running my script on my new dataset is that the script successfully ...
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1answer
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Rasterizing z values from vector grid points as centroid of cells?

I have read some Q&As related to this: Creating raster or vector raster from DEM point file?, Does a value in srtm dem file refer to the center or corner of a cell? However, none specifically ...