Export PNG DPI setting interaction with root

Question

Goal
To reliably reproduce pixel dimensions when exporting a vector document to PNG across Inkscape releases.
Background
The Export PNG dialog exposes a DPI field that is supposed to map directly to the pixel size of the output image. However, the documentation notes that the DPI value may be overridden by a non‑zero scale transform applied to the root  element. Prior to Inkscape 1.3, this interaction caused the DPI setting to be ignored, producing a PNG that was smaller than expected. The behavior is only partially described in the user manual, and inconsistencies have been observed when exporting from multi‑page PDF imports.
Unresolved Questions

Does the DPI setting still have no effect when a root  scale transform is present in the latest stable release?
Is there a documented or expected precedence order between the DPI field and the root  transform in the export logic?
What is the recommended workflow to guarantee that the exported PNG size matches the intended DPI regardless of document transforms?

Tasadduq Burney · Answer

Answer
In Inkscape 1.3 and later, the DPI value you set in the Export PNG dialog determines the base pixel size first; any scale transform on the root  element is then applied as a post‑scale. Consequently, the DPI setting is respected regardless of the root transform.
Confirmed facts

Prior to Inkscape 1.3, a non‑zero scale transform on the root  caused the export DPI to be ignored, producing a PNG based on the unscaled SVG dimensions.
Starting with Inkscape 1.3, the export pipeline was refactored so the DPI field sets the base pixel count before the root transform is applied as a post‑scale.

Likely explanation
The change aligns PNG export with PDF/EPS export behavior: the root  transform is treated as a view‑box adjustment that scales the already‑rasterized image, rather than overriding the DPI‑to‑pixel conversion.
Steps to guarantee the intended PNG size

Open the XML editor and verify whether the root  has a transform attribute (e.g., scale(2)).
If a transform is present, decide whether you want to keep it:
    
      To keep the transform, multiply your target DPI by the inverse of the scale factor when entering the DPI field (e.g., for scale(2) and desired 90 dpi effective, enter 45 dpi).
      To ignore the transform, remove or reset the root scale (set it to scale(1) or delete the attribute) before exporting.

Set the document units to match your real‑world size (mm, inches, etc.).
In the Export PNG dialog, enter the DPI value (adjusted as above if keeping the transform) and ensure the export area is set to “Page” or “Drawing” as needed.
Check the preview pixel dimensions shown in the dialog; they should equal (real‑world size in inches) × DPI × scale_factor.
Export the PNG.

Please confirm your Inkscape version to verify that you are using 1.3 or newer, as the behavior differs in older releases.

Export PNG DPI setting interaction with root <svg> scale transform

Goal

Background

Unresolved Questions

1 answer

Answer

Confirmed facts

Likely explanation

Steps to guarantee the intended PNG size

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