0

I am trying to extract and georeference the orange polygons/lines from this PDF file of the city of São Paulo, in Brazil.

To do so, I am mostly trying to follow what was discussed in another question, but none of the proposed solutions are working for me.

I tried using Adobe Illustrator to extract those and export to a DXF archive, but the QGIS step is curbing my advances. I am working in EPSG 32723. My first attempt was to use the affine transformation, but the imported shapefile could not pass through: all polygons had invalid geometries.

The attempt to use JOSM also failed. I cannot process the output from downloading São Paulo's data.

Is there another path to extract those vector objects?

Improve this question
5
  • Why did you try JOSM? Is the data in OpenStreetMap?
    – Spacedman
    Jun 30, 2022 at 18:35
  • 2
    I've loaded the PDF into Inkscape which lets me inspect the vector data under the orange areas, and its a real mess. Each orange polygon can be made of several parts, often overlapping, drawn in a very thick line, and sometimes not joining up as a polygon loop. I think it would be very difficult to extract useful vector data from this.
    – Spacedman
    Jun 30, 2022 at 18:46
  • @Spacedman Thank you. I am unsure about how to use JOSM for this particular task. An alternative file from the same set is prefeitura.sp.gov.br/cidade/secretarias/upload/urbanismo/…
    – catatau
    Jun 30, 2022 at 20:08
  • 2
    An alternative I am considering is to extract the orange polygons using Illustrator, forcing a conversion to raster, georreferencing, and then rebuilding the vectors.
    – catatau
    Jun 30, 2022 at 20:14
  • Using QGIS 3.26, I could load your pdf as raster layer in the georeferencer, but not as a vector layer.
    – Babel
    Jun 30, 2022 at 20:35

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Browse other questions tagged or ask your own question.