I have talked about EXIFTOOL before. A free command-line utililty that aloows you to read all the EXIF data in an image. And there’s a lot. A LOT!
But for those of you who use it, a little gem here: extracting the built-in preview images from a RAW file. You do it like this:
exiftool -a -b -W %d%f_%t%-c.%s -preview:all /Users/Michael/1DX_9187.CR2
This causes it to generate a file for each built-in preview (in this case, it creates thumbnail and “large” images:
So now you know how to extract the preview images from a RAW file. Just in case you ever want to do that!