I have a Shapefile file with more than 2,000 elements, with its extensive table of attributes, and I have made a model file, through the Atlas, where a map appears with a zoom of each element and a set of attributes that change, as that each of the elements is represented.


1 - How to reduce the size of the output pdf? For each element, your pdf weighs about 10 MB, since each element is represented on an orthophoto, but I would like to reduce the output quality.

2 - I would like to generate a single output pdf with a specific set of elements, that is, for example, a single pdf with the files that go between 30 and 50. I interpret that it should be done by code in the Atlas section / Output / Output expression file / in the epsilon, in the expression section, there I imagine it can be automated but I don't know how.

  • 2
    Please translate your question to English, since that is the official language of this site (and not everybody understands Spanish). Also, it seems to me you are asking two questions at the same time, please reduce this to one and ask the other separately, thank you. – Erik Jul 6 at 8:04
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Your questions:

  1. You can reduce the size of the output PDF with for instance Ghostscript (gs) after the Atlas has been generated. You can also reduce the Export resolution (the default is 300 dpi) to for instance 100 dpi in the Layout-> Export settings.

    I don't know if there are other "compression" settings available for layouts.

    Update: The recent https://github.com/qgis/QGIS/commit/b2cef7377cfcae3ccb70b89921f456b0d2403ce9 (QGIS 3.14) exposes image compression methods when exporting layouts to PDF.

  2. The easiest way generate an output with a specific set of elements is to use Query Builder in the Provider Feature Filter in the Source tab of the Layer Properties of your Atlas coverage layer.

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