Using exiftool to create / scale embedded thumbnails?

[clem]

Hello,

I know exiftool can extract embedded thumbnails... but can that be chained within exiftool's Swiss-army-knife of tools to extract and scale / reduce thumbnails to an arbitrary size? i.e. say the size of a 128x128 pix jpg?

thx! 

[Phil Harvey]

ExifTool doesn't do image manipulations.  It will only extract the embedded thumbnails in their original size.

- Phil

[clem]

Thank you for the fast reply! :-)

So...

• can I pipe the extracted jpeg to another process, say the Mac's built in 'scriptable image processing system' to do scaling etc. or will exiftool only generate the file after which I can do something with it with another command?
• how can I get exiftool to extract the largest preview since sometimes there are more than 1 JPEG previews

[Phil Harvey]

1. You can pipe the thumbnail to another application like this:

exiftool -thumnailimage -b FILE | some_other_app

...but the other app must have the ability to read the image from the standard input.

2. The BigImage Composite tag in the example config file gives a way to extract the largest preview image.  (Not including the thumbnail.)

- Phil