How to set DPI in the minimal example

[topochico-one]

Is it possible to set dpi for the output png file in the minimal example?

Adding opt.dpi = 300.0; on line 12 did not seem to affect the output.

I am sorry for such a basic question. I am completely new to resvg and image processing in general.

[RazrFalcon]

I should improve Options::dpi docs... What result do you expect from this setting? This option doesn't "scale" the image (you should use --zoom instead). This option doesn't affect DPI of the produced PNG.
All it does, is affects how relative units (cm, in, etc.) would be converted into pixels. That's it.

[topochico-one]

Thank you for explaining! I would like to increase the DPI of the produced PNGs. Right now, the minimal example outputs PNGs with DPI of 72 pixels/inch. Is it possible to increase it?

[RazrFalcon]

It's not possible and doesn't really makes sense. Why would you want this?

[topochico-one]

I am sorry -- I know very little about these things. I just want to generate sharper PNGs. For example, when I export my artwork in Adobe Illustrator, I can set image resolution by specifying PPI. I want to be able to do the same for the artwork I generate programmatically in Rust.

[RazrFalcon]

PNG is a raster format, it has a fixed "resolution". I'm not sure how Illustrator loads PNGs and if it cares about the DPI property, but you can try rendering your SVG at higher resolution. Like --zoom 4 via CLI or usvg::FitTo::Zoom(4.0) via code.

While PNG indeed has a "resolution"/DPI property, it has nothing to do with SVG DPI and cannot be written at the moment anyway, because the png crate doesn't support it.

[topochico-one]

I see -- thank you so much for explaining!