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From Christopher Blunck <>
Subject Re: Copying IPTC/EXIF data from one file to another...
Date Wed, 06 Aug 2008 22:35:52 GMT
Hi Charles.  Isn't the xmp metadata stored in app13?  I thought that  
xmp and the other photoshop format were two ways to represent the same  
thing (iptc metadata) stored in app13.  Maybe I don't understand...

Sent from my iPhone

On Aug 6, 2008, at 4:29 PM, "Charles Matthew Chen" < 
 > wrote:

> Hi Christopher,
>   This is an interesting question.
>   Sanselan cannot read or write image data from JPEG files, so it
> can't be used to resize the images.  However, it can be used to read
> and write metadata from existing JPEGs.  It can currently write EXIF
> metadata, including copying EXIF data from one jpg to another (ie. the
> resized image file).  It can also do this with XMP metadata.  The
> ability to do something similar with IPTC metadata is under active
> development and should be ready soon.
>   For an example of the EXIF update feature, see the
> changeExifMetadata() example in this file, which should be easily
> adapted to your needs:
> Charles
> On Tue, Aug 5, 2008 at 11:43 PM, Christopher Blunck
> <> wrote:
>> Hello,
>> I have JFIF files that are rich in IPTC and EXIF metadata.  I  
>> currently use
>> JAI to resize those images to smaller sizes suitable for publishing  
>> on the
>> web.  Unfortunately when I perform that resizing in JAI I lose all  
>> of my
>> APP0-APP13 metadata.
>> Can Sanselan help me?
>> Can I resize images in Sanselan and preserve the original IPTC/EXIF
>> metadata?
>> Alternatively can I read the IPTC/EXIF metadata contained in the APP
>> sections from my original files and merge it into the images that JAI
>> produces?
>> I'm really stuck and I've been working on some prototype python  
>> code to
>> merge in JPEG sections at the byte[] level but it's not working.   
>> I've
>> reviewed a lot of material online and am familiar with some of the  
>> format
>> rules for JPEG/JFIF files.  I've even written code that can harvest  
>> the 0xFF
>> 0xED (APP13 section) metadata and drop it into another file that  
>> does not
>> contain 0xFF 0xED.  Unfortunately I just did it at the top of the  
>> file
>> (immediately after 0xFF 0xD8) and I believe that 0xFF 0xE0 is always
>> supposed to immediately follow the SOS.  I parsed out the length of  
>> the 0xFF
>> 0xE0 section and tried inserting my APP13 section AFTER the 0xFF 0xE0
>> section but that didn't work.
>> Any pointers or directions would really be appreciated.
>> -c

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