better quality thumbnails from imagemagick?

anyone want to share their tips/tricks?

[amznVibe]

I am trying various imagemagick options to attempt to create better, sharper thumbnails.

The images are mostly photos of people though occasionally it will be line art.

I've tried using -thumbnail and -resize but I am not quite clear on the filters, which ones are best and how to do it right in one pass.

I'm not too worried about cpu time, quality is the critical component.

Thanks for any tips!

[Birdman]

Have you tried the -quality flag? It defaults to 75 I think. 100 is the highest quality value.

mogrify -quality 100 -resize 100x100 pic.jpg

[amznVibe]

That just increases the jpeg compression ratio (actually decreases)

So far I have settled on

-antialias -thumbnail WxH\! -unsharp 1x2+1+.10

which seems to make far better looking thumbnails.