How to specify optimization level for lossless PNG compression?

[stamminator]

The documentation for the -q, --quality <quality> argument states "sets output file quality between [0-100], 0 for optimization". It's not clear to me how the optimization level for PNG compression can be specified.

For example, what would be the arguments needed for the following 4 scenarios?

1. Lossy compress img.png using quality level 0
2. Lossy compress img.png using quality level 100
3. Losslessly compress img.png using optimization level 0
4. Losslessly compress img.png using optimization level 6

[Lymphatus]

Not possible at the moment. I should add an option like --png-optimization-level= to be able to pass it from the command line. Thanks for the suggestion!

[stamminator]

@Lymphatus Roger that, thanks. In the meantime, does -q 0 use lossless compression at some default optimization level?

[Lymphatus]

Defaults to 3, on a scale from 0 to 7. Internally sets the optimization preset of oxipng, which is algorithm used. More info here if interested.

[Lymphatus]

Released version 0.21.0 with the --png-opt-level to specify the level.

[stamminator]

Works like a charm, thanks!