Author Topic: IPTC inconsistency  (Read 3429 times)

Offline vAfotoriporter

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IPTC inconsistency
« on: July 03, 2013, 01:21:07 AM »
I fill IPTC information in PM, I upload my JPG images onto my WordPress blog and it shows an older version of the IPTC info. Originally the image had an English caption but I translated it into a different language before upload, but Wordpress shows only the English version not the translated one. This is not true for all the images, some have the translation some don't.

I don't know what might cause this and how can it be corrected or at least prevented to happen in the future.
Working on Mac, OSX, iOS and with some Canons.
Allways shooting RAW.

http://www.volgyiattila.hu

Offline Kirk Baker

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Re: IPTC inconsistency
« Reply #1 on: July 03, 2013, 06:43:05 AM »
Szurkebarat,

I fill IPTC information in PM, I upload my JPG images onto my WordPress blog and it shows an older version of the IPTC info. Originally the image had an English caption but I translated it into a different language before upload, but Wordpress shows only the English version not the translated one. This is not true for all the images, some have the translation some don't.

I don't know what might cause this and how can it be corrected or at least prevented to happen in the future.

WordPress is probably picking up the EXIF Description tag.  PM will only update the EXIF Description tag if the new Caption is shorter than or equal to the current EXIF Description tag.

You can either strip the EXIF data, or try and find a better WordPress plugin that understands and prefers XMP over EXIF for Caption information.

-Kirk

Offline Hayo Baan

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Re: IPTC inconsistency
« Reply #2 on: July 03, 2013, 07:07:29 AM »
You can either strip the EXIF data, or try and find a better WordPress plugin that understands and prefers XMP over EXIF for Caption information.

Another option would be to open the file in Photoshop and than save it anew, this will have Photoshop update the EXIF Description tag. Note that with JPG files this likely degrades the quality somewhat.

Hope this helps,
Hayo
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Web: www.hayobaan.nl

Offline vAfotoriporter

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Re: IPTC inconsistency
« Reply #3 on: July 03, 2013, 11:48:35 AM »
Szurkebarat,

I fill IPTC information in PM, I upload my JPG images onto my WordPress blog and it shows an older version of the IPTC info. Originally the image had an English caption but I translated it into a different language before upload, but Wordpress shows only the English version not the translated one. This is not true for all the images, some have the translation some don't.

I don't know what might cause this and how can it be corrected or at least prevented to happen in the future.

WordPress is probably picking up the EXIF Description tag.  PM will only update the EXIF Description tag if the new Caption is shorter than or equal to the current EXIF Description tag.

You can either strip the EXIF data, or try and find a better WordPress plugin that understands and prefers XMP over EXIF for Caption information.

-Kirk

Thanks for the answer. WP definetly calls it Description so you may be right. This means if the new caption is longer than the EXIF Description tag then PM doesn't update it? Sad and I don't really understand the feature side of it - so this seems to me rather to be a bug.

I guess at first PM does updates the empty EXIF Descreption with the Caption even if it is not shorter or equal with the yet empty field. Why would it be practical later at any time not to update a field that has outdated, probably useless or clearly wrong data - unless the new content would exceed the allowed length of the EXIF Description tag.

Also it would be great to have options in PM to remove only parts of the EXIF data as one may not need GPS coordinates, Description or camera type, but would like to still keep capture time and other details for sorting reasons and the like.
Working on Mac, OSX, iOS and with some Canons.
Allways shooting RAW.

http://www.volgyiattila.hu

Offline Kirk Baker

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Re: IPTC inconsistency
« Reply #4 on: July 03, 2013, 12:24:37 PM »
Szurkebarat,


I fill IPTC information in PM, I upload my JPG images onto my WordPress blog and it shows an older version of the IPTC info. Originally the image had an English caption but I translated it into a different language before upload, but Wordpress shows only the English version not the translated one. This is not true for all the images, some have the translation some don't.

I don't know what might cause this and how can it be corrected or at least prevented to happen in the future.

WordPress is probably picking up the EXIF Description tag.  PM will only update the EXIF Description tag if the new Caption is shorter than or equal to the current EXIF Description tag.

You can either strip the EXIF data, or try and find a better WordPress plugin that understands and prefers XMP over EXIF for Caption information.

Thanks for the answer. WP definetly calls it Description so you may be right. This means if the new caption is longer than the EXIF Description tag then PM doesn't update it? Sad and I don't really understand the feature side of it - so this seems to me rather to be a bug.

I guess at first PM does updates the empty EXIF Descreption with the Caption even if it is not shorter or equal with the yet empty field. Why would it be practical later at any time not to update a field that has outdated, probably useless or clearly wrong data - unless the new content would exceed the allowed length of the EXIF Description tag.

Also it would be great to have options in PM to remove only parts of the EXIF data as one may not need GPS coordinates, Description or camera type, but would like to still keep capture time and other details for sorting reasons and the like.

It is difficult to resize EXIF data because of the way it is formed.  If PM was completely rewriting the file (like in a Save As) then it could make the Description tag the same as the Caption field.  Since you did your translation on an already captioned file, PM couldn't resize your EXIF data in place and was forced to skip updating it.  It is not a bug but I suppose it would be called a shortcoming.

The EXIF Description tag is obsolete.  There is no way to describe EXIF text encoding so it can't reliably contain text with accented characters since no apps can tell how to interpret the text.  It was earlier defined as only allowing 7-bit ASCII.  The Metadata Working Group now suggests that the text in EXIF be interpreted as UTF-8 encoding which isn't guaranteed to produce valid UTF-8 text.  This is a problem without a good solution.

Like I said earlier, try and find a plugin for WordPress that uses XMP instead of EXIF for your Captions.  XMP is always Unicode and is not subject to interpretation.

-Kirk

Offline vAfotoriporter

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Re: IPTC inconsistency
« Reply #5 on: July 03, 2013, 12:39:48 PM »
Szurkebarat,


I fill IPTC information in PM, I upload my JPG images onto my WordPress blog and it shows an older version of the IPTC info. Originally the image had an English caption but I translated it into a different language before upload, but Wordpress shows only the English version not the translated one. This is not true for all the images, some have the translation some don't.

I don't know what might cause this and how can it be corrected or at least prevented to happen in the future.

WordPress is probably picking up the EXIF Description tag.  PM will only update the EXIF Description tag if the new Caption is shorter than or equal to the current EXIF Description tag.

You can either strip the EXIF data, or try and find a better WordPress plugin that understands and prefers XMP over EXIF for Caption information.

Thanks for the answer. WP definetly calls it Description so you may be right. This means if the new caption is longer than the EXIF Description tag then PM doesn't update it? Sad and I don't really understand the feature side of it - so this seems to me rather to be a bug.

I guess at first PM does updates the empty EXIF Descreption with the Caption even if it is not shorter or equal with the yet empty field. Why would it be practical later at any time not to update a field that has outdated, probably useless or clearly wrong data - unless the new content would exceed the allowed length of the EXIF Description tag.

Also it would be great to have options in PM to remove only parts of the EXIF data as one may not need GPS coordinates, Description or camera type, but would like to still keep capture time and other details for sorting reasons and the like.

It is difficult to resize EXIF data because of the way it is formed.  If PM was completely rewriting the file (like in a Save As) then it could make the Description tag the same as the Caption field.  Since you did your translation on an already captioned file, PM couldn't resize your EXIF data in place and was forced to skip updating it.  It is not a bug but I suppose it would be called a shortcoming.

The EXIF Description tag is obsolete.  There is no way to describe EXIF text encoding so it can't reliably contain text with accented characters since no apps can tell how to interpret the text.  It was earlier defined as only allowing 7-bit ASCII.  The Metadata Working Group now suggests that the text in EXIF be interpreted as UTF-8 encoding which isn't guaranteed to produce valid UTF-8 text.  This is a problem without a good solution.

Like I said earlier, try and find a plugin for WordPress that uses XMP instead of EXIF for your Captions.  XMP is always Unicode and is not subject to interpretation.

-Kirk

Thanks for the clarification. Now I understand the why too.

I hope to find a solution to it.
Working on Mac, OSX, iOS and with some Canons.
Allways shooting RAW.

http://www.volgyiattila.hu