imagemagick users.. better thumbnails?

[Brujah]

what options do you use with imagemagick to crank out better thumbnails? i'd like to brighten and maybe sharpen up some dull looking thumbnails with imagemagick.

do you have a preference on thumb sizes, when you create yours?
do you go with perfect landscape or portrait thumbs and auto crop center?

[digifan]

Imagemagick filters can do better thumbs than photoshop... and smaller in size, I recommend it.

[CamsLord]

imagemagick works great along agsql

[woj]

-quality -sharpen etc, just look in the man page

[tenderobject]

imagemagick works great along agsql

what the scammer said!

[Tempest]

I haven't quite figured out all the things one could do with imagemagick, but a couple things I use are
-filter Lanczos - I "think" this gets you better quality on resizing but not sure)
-gamma # - like brightening but in some cases a bit better
-sharpen # - to sharpen it up

-quality is just the compression quality for saving to jpg

I've been using "composite" to build thumbs with text on them in bulk and it may be possible to do some other things.. for example, make a copy of the thumb, blur it out and then layer it on top with an opacity. Haven't investigated that yet though

haven't played with these yet
-contrast
-level
-modulate

[everestcash]

I tried many but prefer the following filter for thumbnail postprocessing
-unsharp 1.0x1.0+0.5 -unsharp 1.0x1.0+0.5 -quality 95
if you are worried about traffic reduce quality to 80
usually 120*160 thumbs are about 8-9kb with this command line

[Brujah]

I've got something like this so far.. I'm cropping so all thumbs are the exact same size. I haven't settled on 135x180 yet.

Images where width is equal or larger than height:

convert original.jpg \
-size 720x720 -thumbnail x360 -resize '360x<' -resize 50% \
-gravity center -crop 135x180+0+0 +repage \
-antialias -unsharp 1x1+.05 \
-normalize -contrast -gamma 1.4 -quality 95 \
thumbnail.jpg

Images where height is equal or larger than width:

convert original.jpg \
-size 720x720 -thumbnail x360 -resize '360x>' -resize 50% \
-gravity center -crop 135x180+0+0 +repage \
-antialias -unsharp 1x1+.05 \
-normalize -contrast -gamma 1.4 -quality 95 \
thumbnail.jpg