Creating hi-res sprites

What’s the best way of creating 180dpi (ex0, ey0) sprites with an optimised 256-colour palette?

I usually use ArtWorks to create graphics, which can be exported as bitmaps with optimised palettes to save space. However, the bitmap export seems limited to 90dpi resolution – fine for !Sprites22, but not for !Sprites11. Paint can create 180dpi sprites, but I can’t find a way to optimise the palette or import palettes without getting an error. I’ve not come across a converter that offers conversion into the higher resolutions – if ChangeFSI does it, then I’ve not been able to locate the switch in the documentation.

I’m not aware of an easy, automated way. However, the way I do it is first to get the finished sprite as I want it (with optimised palette), but as a regular 90dpi sprite. As the final step, load the sprite into David Pilling’s Scanning Software and simply edit its dpi values by hand. They appear as editable values in the tool pane at the bottom of the window; just change the 90s to 180s and resave the sprite. It’s a bit tedious to have to do this for every sprite, but it works, and it’s the way I generated the Sprites11 icons for all icons in RISC OS 5 and related third party applications.

They appear as editable values in the tool pane at the bottom of the window; just change the 90s to 180s and resave the sprite. It’s a bit tedious to have to do this for every sprite, but it works,

Would it not be possible to examine a before and after sprite, then put together a little BASIC program to do the grunt work?