ExifTool Forum

ExifTool => Newbies => Topic started by: anddrrw on December 08, 2016, 03:22:07 PM

Title: Tips for Writing the Preview Image
Post by: anddrrw on December 08, 2016, 03:22:07 PM
Hi,
When writing the preview into a jpg image with the following command:

exiftool "-PreviewImage<=preview.jpg" image.jpg

It doesn't seem to work very reliably. It works for images from some camera models, for others it'll give me:

0 image files updated
1 image files unchanged


with no other info.

I've read this page (http://www.exiftool.org/writing.html) and it gives some helpful guidance, but before I dig my way into the specific bytes of the jpg format myself, I just want to be sure there's not something else I'm missing in the exiftool doc (like some kind of force-write), a workflow that might work, or any other simple solutions.

Thanks!
Title: Re: Tips for Writing the Preview Image
Post by: Phil Harvey on December 08, 2016, 03:38:54 PM
ExifTool will update some existing preview images but won't add new ones.  The whole preview image situation is a real mess, and there are very many ways that they are stored in JPEG images.  Personally I would recommend avoiding the whole situation.

- Phil
Title: Re: Tips for Writing the Preview Image
Post by: anddrrw on December 08, 2016, 04:10:13 PM
Haha, good suggestion Phil. Thanks.