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exif data lost #176

Closed GoogleCodeExporter closed 8 years ago

GoogleCodeExporter commented 8 years ago 
What steps will reproduce the problem?
1. exiv2 image.jpg
2. cwebp -metadata all image.jpg -o image.webp
3. rm image.jpg
4. dwebp image.webp -o image.jpg
5. exiv2 image.jpg # not the same as 1.

What is the expected output? What do you see instead?

exif output as original

What version of the product are you using? On what operating system?

Archlinux 0.3.1-30.3.1-3

Please provide any additional information below.

http://sprunge.us/JXUh

Original issue reported on code.google.com by kai.hen...@gmail.com on 27 Oct 2013 at 2:08

Attachments:

GoogleCodeExporter commented 8 years ago 
do you have the original 'image.jpg' file?
What version are you using?

(latest release addressed some of the metadata issues already)

Original comment by pascal.m...@gmail.com on 29 Jan 2014 at 9:23

GoogleCodeExporter commented 8 years ago 
The issue here is dwebp doesn't write any metadata. This is reproducible with 
any jpeg that has exif/xmp/icc.

Original comment by jz...@google.com on 29 Jan 2014 at 10:39

GoogleCodeExporter commented 8 years ago 
you can't do:
  dwebp image.webp -o image.jpg

the image.jpg will be an png file!!

dwebp don't write jpg files.

Original comment by marcomsousa on 8 May 2014 at 10:32

GoogleCodeExporter commented 8 years ago 
PNG does not embed EXIF info. It allows, however, to store metadata ("Chunks") 
which include some EXIF data (physical dimension and timestamp), and also 
permits arbitrary textual data as key=value pairs. So, you could in principle 
store any EXIF information... but in your own custom format. Some attempts to 
standarize have not caught up, apparently.

Original comment by marcomsousa on 8 May 2014 at 10:34

GoogleCodeExporter commented 8 years ago 
I would like to convert my JPEG collections to WebP to save space. But it looks 
like it will loose precious metadata. So WebP is more like a temporary Web 
facing format I guess. Nonetheless, quite a bit of a mess.

Original comment by kai.hen...@gmail.com on 9 May 2014 at 2:01

GoogleCodeExporter commented 8 years ago 
As a workaround, since exiftool-9.40 [1] exif can be extracted from webp files:
$ exiftool -tagsFromFile src.webp -exif:all dst.jpg

[1] http://www.sno.phy.queensu.ca/~phil/exiftool/history.html

Original comment by jz...@google.com on 9 May 2014 at 6:42

GoogleCodeExporter commented 8 years ago 
#6 as workaround work's fine

Original comment by marcomsousa on 12 May 2014 at 2:45

GoogleCodeExporter commented 8 years ago

Original comment by pascal.m...@gmail.com on 19 Aug 2014 at 1:09

GoogleCodeExporter commented 8 years ago 
What's the procedure for adding/embedding additional tags/metadata to the WebP? 
Convert to JPEG, add tags, convert back to WEBP?

Original comment by kai.hen...@gmail.com on 19 Aug 2014 at 1:13

GoogleCodeExporter commented 8 years ago 
> What's the procedure for adding/embedding additional tags/metadata to the 
WebP? Convert to JPEG, add tags, convert back to WEBP?

That wouldn't be ideal from the quality side of things. webpmux can be used to 
add raw metadata to existing webp files as discussed [1].

[1] 
https://groups.google.com/a/webmproject.org/d/msg/webp-discuss/7KNCSYz_Tw0/f9wJ0
_q6g1sJ

Original comment by jz...@google.com on 19 Aug 2014 at 6:33