Questions tagged [affine-transformation]

An affine transformation is a 2-dimension cartesian transformation applied to both vector and raster data, which can rotate, shift, scale (even applying different factors on each axis) and skew geometries.

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15 views

Reading CRS and Affine transformation from a NetCDF with CF conventions

I have a NetCDF with geographical information. I'd like to obtain a GeoTIFF file with rasterio. The problem is how to translate the geographical information from CF standard to something that GeoTIFF ...
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25 views

Width and value problems with rasterstats

I am trying to extract data from a raster with a gpkg file as a vector. The issue is that, the data can't be extracted because the internal Bounding Box is negative. There I am not sure, whether this ...
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42 views

How to use affine transform parameters in a PROJ or WKT2 string

Can anyone show me how I can construct a PROJ or WKT2 string with affine transformation parameters to create a custom CRS in QGIS? I wish to use the following affine transformation parameters to ...
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71 views

Getting geo transforms (affine) without a TIFF reference image

I have a binary mask with buildings' footprints. What I have is a latitude and longitude of the center of my image and I want to georeference each polygon first. And here is what I have done before: ...
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1answer
45 views

Rotation of a cropped portion of a raster map

We create printed maps from a GeoTIFF file projected in LCC, which is a common projection for aviation maps. Part of our process includes customization of the raster image by selecting a region and ...
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2answers
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Renaming multiple layers in the legend from an attribute in each layer in QGIS

I have 72 layers that have been generated via affine transform of a single layer that has 72 categories. But the 72 layers have been given names that are sequential numeric. The original categories ...
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1answer
96 views

Define Affine transform with rasterio

I have transform vector that I have gotten from bbox with sentinelhub: transform=bbox.get_transform_vector(10,10) >>> (-101.7359960059834, 10.0, 0, 20.8312118894487, 0, -10.0) The type of ...
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24 views

rasterio reprojection produces no visible changes

I've been trying to perform translation of a raster using the reproject function from rasterio.warp. I've calculated the translation amount in X and Y from a series of "control points" ...
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106 views

Reproject a NumPy array with affine transform

I have NumPy array with one band and no CRS. I do have the shape of the image and the coordinates of the bbox, in WGS84. I would like to reproject it based on bounding box and the shape. I have ...
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1answer
37 views

Visually correcting systematic shift between two geodatasets using ArcMap

I often have two datasets that are obviously not georeferenced correctly. Most of the time a simple translation (shift by x/y) could fix this. Is there an easy way to do this e.g. by specifying one or ...
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32 views

How can one transform XY and Z coordinates to another coordinate system?

How can we convert X ,Y and Z values from one coordinate system to another coordinate system using node js or any other similar packages or equations without directly using the convertor tools ...
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1answer
50 views

Rotate, Scale, Translate in OpenLayers 4 and MapServer

Sometimes, I get spatial data (usually DGNs but I am not sure the format matters) that in the coordinate control sheet a 'Project Datum Factor' is noted. Say: 1.000073496. If I add them as is in ...
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1answer
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Affine Tranformation Matrix; shapely asks 6 coefficients, but rasterio delivers 9; how to translate

Some lines have been extracted via scikit-image, now tho goal is to vectorize them within the origin coordinate reference system #some geotif opened with rasterio src = rasterio.open(raster_path) ...
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Difference between Affine, Bilinear and Helmert Transformations

I'm georeferencing old arial photos with a commercial GIS. The software offers me 'Affine', 'Bilinear' and 'Helmert transformation' as transformation options. Unfortunately, the support of the GIS can'...
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1answer
84 views

Using “raster.transform” function of “rasterio” in Python

When I execute the "raster.transform" function in Python it returns me a matrix. What I can understand is that it tells me my data has a 10 m pixel resolution, It also tells me that my left ...
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1answer
111 views

How do I mirror a vector layer along a line in QGIS?

ArcGIS (Map & Pro) has a nifty utility that allows you to mirror a vector layer along a line segment you give it. Before I spend time trying to write something from scratch, I wanted to see if ...
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1answer
70 views

Get geopandas geo or affine transform

Does anyone know how to get the affine transformation from a geopandas dataframe? I need this for rasterising geospatial vector data with rasterio. shapes = ((geom,value) for geom, value in zip(...
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54 views

Transform rectangle from decimal degrees to Cartesian coordinates

I'm trying to achieve the following: Given four coordinates (lat, lng) decimal degrees and a query coordinate within the formed shape, how can I transform these coordinates into Cartesian space where ...
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1answer
232 views

Apply same coordinate system to raster image and GeoJSON with rasterio

I have a dataset containing raster images and corresponding features in geojson files. I would like to use rasterio.features.rasterize to create a footprint image of the features on the raster image, ...
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29 views

QGIS v.transform output extent not lining up with input

I am using the updated Affine tool (v.transform) to rescale my vector layer (containing multiple polygons). I want to shrink each polygon to half of its size. So I enter in 0.5 for both the x and y ...
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107 views

Coordinate transformation for antenna pointing

I may have bitten off more than I can chew with some coordinate transformation math. As a background, I'm working on a project where we need to mechanically point an antenna to a receiving tower. The ...
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25 views

Concatenating numpy arrays based on their relative positions as defined by associated Affine transforms

I have split a raster into 4 numpy arrays to feed into machine learning algorithms. I would now like to join to results of that process back into the full array. For each I have a numpy array, and an ...
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1answer
52 views

Spatial transformation of latitudes and longitudes that preserve distances between points

I have a set of lat,lon points. I would like to apply a spatial transformation (rotate, translate) to place these points somewhere else on the earth surface (for anonymization purposes), but preserve ...
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1answer
210 views

Shapely affine transformations with bounds of GeoDataFrame

I understand that I can use Shapely's affinity.translate to translate a geometry like the below: from shapely import affinity from shapely.geometry import Polygon poly = Polygon([(0, 0), (1, 0), (1, ...
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1answer
331 views

How to calculate affine transformation by Python gdal as same as gdal_translate?

I've made a python script which tries to reproduce what gdal_translate does (given a bounding box BBOX in EPSG:4326 and an UTM32 .jp2 file. Then, translates the BBOX from EPSG:4326 to EPSG:32632 (...
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PyQGIS: Set coordinate transformation for non-referenced raster

I need to add raster layer to a project. Image is PNG and it doesn't have georeferencing. So as far as i know, i need to setCrs (Coordinate Reference System) of the layer, and setup extent of raster. ...
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2answers
114 views

Difference results from QGIS project on fly and gdalwarp for EPSG:4326 of Sentinel 2 UTM zone 32?

I always thought QGIS and gdalwarp should return same result for projecting a 2D Sentinel 2 image (e.g: T32UQD_20200421T102021_TCI_60m.jp2) from UTM 32 to EPSG:4326. What I did was: Open the .jp2 in ...
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2answers
73 views

Multiplying/dividing x/y values of line and polygon layer vertices?

I have several polygon and line layers in shapefile format with no crs so it can't be reprojected. The vertices coordinates need to be divided by 3,600,000 in order for them to match the project crs, ...
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61 views

Raster shapes are not exactly equal after cropping

I clipped multiple rasters to the shape of a polygon shapefile. But, the output rasters do not have exactly the same shapes. I am doing correlation analyses per pixel so I need the array shapes to ...
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1answer
106 views

Creating Affine for 2D Linear Transformation of Fixed Bounding Box

I am currently trying to create an Affine which can transform data from longitude and latitude to a custom CRS that a client is using. Unfortunately the person who originally made this CRS has left ...
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1answer
46 views

Transforming / stretching map or it's part in particular direction

I am trying to model ancient land surfaces we can 'rollback' geological folding and faulting. This is called palinspastic modelling or mapping. So I have an area that due to folding and faulting was ...
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1answer
163 views

Defining rotated CRS with WKT

I am trying to figure out how to display a rotated grid correctly with GeoServer with using the affine transformation in WKT as described here: Defining coordinate reference system with rotation in ...
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1answer
731 views

Defining a coordinate system in WKT or PROJ format that has an Affine transformaiton and bounds

I need to define a local coordinate system via OGC WKT or PROJ form. I know they have implemented Affine transformations in Proj 5 but I am unsure of how to implement it. The base projection is from ...
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1answer
468 views

Which affine format to use in Rasterstats zonal_stats?

I am working with the Rasterstats package to run zonal statistics on two raster datasets. The documentation calls for the following: import rasterio from rasterstats import zonal_stats with rasterio....
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292 views

Reprojection problem with Rasterio

I have already processed so far NDSI map by using Rrasterio, NumPy, os and matplotlib.pyplot for plotting the data. Now, I would like to eliminate permanent ice from NDSI map. I am facing one major ...
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1answer
65 views

Controling affine transform of raster in ArcGIS Pro

I have a png file which I created from a field equation. I need to plot that on my map. I am plotting it on a map with Coordinate System being GCS WGS 1984 (EPSG: 4326). Since it is not georeferenced,...
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2answers
105 views

is there a way to manually stretch a polygon?

I have this polygon that I want to manually fit and resize(without entering affine numbers, just resizing it with my mouse). Is there a way to do it?
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2answers
1k views

Performing Vector Affine Transformation using QGIS?

Due to an incorrect datum coordinates, I need to move a large number of elements in shapefiles by a specific distance. In 2.8 I would have used the Affine Transformation tool, but this does not appear ...
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88 views

Calculate transform from oblique raster, shape and CRS

Given a simple jpg of an oblique aerial photography, the geometry and a CRS I am trying to determine its affine transform so I can convert it into a GeoTIFF. import rasterio, rasterio.crs raster = ...
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1answer
113 views

Converting coordinates from a local coordinate reference system

I am trying to define a local CRS in R based on the information in the screenshot image below My R code is as follows: I define the local CRS from the screenshot image I apply it to my dummy ...
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0answers
182 views

Non-Earth System in QGIS?

What I need is a function for Non Earth Coordinates in QGIS (both projects and layers). They should be mappable to any projected coordinate system (like SWEREF99TM). Why: In the Mining industry we ...
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1answer
252 views

How to transform a shapefile with a MN03 (LV03) coordinate system into a shapefile with a MN95 (LV95) coordinate system?

Switzerland is currently introducing new coordinates: by the end of 2016, all federal and cantonal reference data (e.g. the Swiss cadastral system) sould be transformed to the new highly-accurate LV95 ...
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1answer
2k views

Transform coordinates from custom projection to lat long PyProj

I am trying to convert a pair of coordinates specified in US survey feet on a custom transverse mercator projection to lat/long using PyProj. I must be doing something wrong because I cannot get the ...
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2answers
793 views

How to create proj4 definition of local coordinatesystem

i have to generate a proj4 definition string from affine transformation parameters (A-F). For example: I have a local coordinatesystem based on EPSG:31466 The affine parameter are: A = 0....
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2answers
2k views

Using shapely.affinity and affine_transform?

I have shapely.geometry Point: from shapely.geometry import Point point1 = Point(0, 100, 200) and I want to swap coordinates Y and Z: from shapely.affinity import affine_transform matrix = [1,0,0, ...
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1answer
422 views

Local coordinate system to EPSG via affine transformation

I have a raster file with a local coordinate system. It is based on EPSG:31466 but with a specific rotation and offset. gdalinfo output is this: I need to transform this gtiff back to 31466, but how?...
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259 views

Why can't I transpose a raster across the pole with rasterio or gdal, and how could it be done?

I have a raster in e.g epsg:4326, it covers all world, from 180E to 180W, from 90S to 90N. I want to re-project a part of it to epsg:3031 and also change the grid size and resolution. Here is a ...
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0answers
145 views

Spatial Adjustment of shapefile not possible

I am trying to spatially adjust a shapefile containing several polygons to another shapefiles where spatial data is correct. Both should share exactly the same extent. However, when I am using spatial ...
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0answers
74 views

Reprojecting trouble: shapes saved in one EPSG load as another EPSG in QGIS and are 200m off?

I'm in a mixed working environment with some ESRI licenses and several people working with QGIS. For a project, we created data and received data in EPSG 31468 (Gauß-Krüger Zone 4). We now need to ...
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548 views

Import Illustrator/Inkscape svg into qgis

I tried to import lines from svg into qgis 3.x by using dxf format. The problem is that the scale of dxf is of course not the right one (a few centimeters whereas my map is kilometers long). I tried ...