Re: [Qgis-user] Transform vectordata using affine transformation
On Sun, 26 Sept 2021 at 02:49, Bo Victor Thomsen wrote: > > Hi list - > > One of my customers just received a data file, where the coordinates is not > in any projection: Center of map data is (0,0), units in mm. not meter, maybe > some rotation too. However, at least it's a planar coordinate system (I hope). > > Instead of sending the #¤%&! data file back to the "GIS no-good" architect > who send it , I've decided to - once and for all - to find a method to > transform this kind of data to a reasonable CRS using an affine > transformation. > > I'm aware of the Processing algorithm "Affine transform" that can do the > actual transformation once I know the translation, rotation and scale > coefficients of the transformation. > And I know how to find the affine transformation matrix using a set of points > from the data that corresponds with a set of points in the destination CRS. > > However, Is there any plug-in that can: > > Digitize a set of positions from the original data. > Digitize or manually set the corresponding positions in the destination CRS > Create the translation, scale and rotation parameters using data from (2) > Run the "Affine transformation" algorithm to transform the data to the right > position in the chosen CRS > > In short - a Georeferencer for vector data The good news is that this is close...ish. A lot of the groundwork API has been done, and there's an open PR at https://github.com/qgis/QGIS/pull/41386 which adds vector support to the georeferencer. This PR needs some work though, so I'm hoping someone steps up and funds a couple of days development so that I can clean it up and get it merged... Nyall > > A name of a functioning plug-in would be lovely > > A set QGIS classes/methods that could help with establishing the > transformation matrix and other stuff would be really nice > > A "No" to all my wishes would suck. However, In that case, I can start > developing without have the nagging feeling that someone has done this before > > -- > Med venlig hilsen / Kind regards > > Bo Victor Thomsen > > ___ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Transform vectordata using affine transformation
In terms of a functioning plugin for this you can search for the "vector bender" in the qgis plugins On Sat, 25 Sep 2021, 18:49 Bo Victor Thomsen, wrote: > Hi list - > > One of my customers just received a data file, where the coordinates is > not in any projection: Center of map data is (0,0), units in mm. not meter, > maybe some rotation too. However, at least it's a planar coordinate system > (I hope). > > Instead of sending the #¤%&! data file back to the "GIS no-good" architect > who send it , I've decided to - once and for all - to find a method to > transform this kind of data to a reasonable CRS using an affine > transformation. > >- I'm aware of the Processing algorithm "Affine transform" that can do >the actual transformation once I know the translation, rotation and scale >coefficients of the transformation. >- And I know how to find the affine transformation matrix using a set >of points from the data that corresponds with a set of points in the >destination CRS. > > However, Is there any plug-in that can: > >1. Digitize a set of positions from the original data. >2. Digitize or manually set the corresponding positions in the >destination CRS >3. Create the translation, scale and rotation parameters using data >from (2) >4. Run the "Affine transformation" algorithm to transform the data to >the right position in the chosen CRS > > In short - a Georeferencer for vector data > >- A name of a functioning plug-in would be lovely > >- A set QGIS classes/methods that could help with establishing the >transformation matrix and other stuff would be really nice > >- A "No" to all my wishes would suck. However, In that case, I can >start developing without have the nagging feeling that someone has done >this before > > -- > Med venlig hilsen / Kind regards > > Bo Victor Thomsen > > ___ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] Transform vectordata using affine transformation
Hi list - One of my customers just received a data file, where the coordinates is not in any projection: Center of map data is (0,0), units in mm. not meter, maybe some rotation too. However, at least it's a planar coordinate system (I hope). Instead of sending the #¤%&! data file back to the "GIS no-good" architect who send it , I've decided to - once and for all - to find a method to transform this kind of data to a reasonable CRS using an affine transformation. * I'm aware of the Processing algorithm "Affine transform" that can do the actual transformation once I know the translation, rotation and scale coefficients of the transformation. * And I know how to find the affine transformation matrix using a set of points from the data that corresponds with a set of points in the destination CRS. However, Is there any plug-in that can: 1. Digitize a set of positions from the original data. 2. Digitize or manually set the corresponding positions in the destination CRS 3. Create the translation, scale and rotation parameters using data from (2) 4. Run the "Affine transformation" algorithm to transform the data to the right position in the chosen CRS In short - a Georeferencer for vector data * A name of a functioning plug-in would be lovely * A set QGIS classes/methods that could help with establishing the transformation matrix and other stuff would be really nice * A "No" to all my wishes would suck. However, In that case, I can start developing without have the nagging feeling that someone has done this before -- Med venlig hilsen / Kind regards Bo Victor Thomsen ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
