Command-line image manipulation

[sect0id]

I currently use this for shrinking image.png to a smaller dimension of 110x120.
convert -resize '110x120!' image.png test2.png

How would I overlay test2.png onto the center of a transparent 128x128 image or increase test2.png's dimensions to 128x128, while keeping its original dimensions and having it centered, with a transparent background?

Not necessary to have this integrated into the command above but would be preferable.

[el_supremo]

This should do it.

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convert image.png -resize "110x120!" -size 128x128 xc:none +swap -gravity center -composite test2.png

Pete

[sect0id]

Aside from having to swap " for ' that works great, thanks

[sect0id]

Does ImageMagick support file piping to/from the convert command? (to eliminate the need for a temp file)

[magick]

Yes, see http://www.imagemagick.org/Usage/.

[anthony]

More specifically the second section on "File Handling" Reading and saving.

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    type:-

will read or write to stdin/stdout an image of the type given. When reading the type can usally be skipped as IM can usally figure it out on the fly.

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   convert .....  miff:- | display - 

is actually quite a common command to display rather than save the results of a command.