On 08/01/2011 07:25 AM jcup...@gmail.com wrote:
> On 1 August 2011 11:41, ken <geb...@mousecar.com> wrote:
>> The jpg image comes directly from my camera. I want to insert a comment
>> into that image, nothing else. I don't want to change the image at all.
>> I want to leave the image from the camera just as it is.
>
> IM will always decompress on read and recompress on write. The IM
> compressor will not be using exactly the same parameters as the
> compressor on your camera (since the jpeg standard does not define
> these parameters exactly), so the files will be different.
>
> If you want to do "lossless" changes to jpeg images, you could try
> using the IJG jpeg tools directly. They include programs which will do
> things like a 90 degree rotate without decompressing and recompressing
> the image. They might have something to let you change comments.
>
> There are also various programs which will let you manipulate the EXIF
> data in a jpeg, you could try those too. I usually use libexif from
> habit, but I'm told exiv2 is very good.
>
> http://www.ijg.org
> http://www.exiv2.org
>
> John
Thanks, John. Makes sense. exiv2 is lots faster too.
--
"When a society comes together and makes decisions in harmony,
when it respects its most noble traditions, cares for its most
vulnerable members, treats its forests and lands with respect,
then it will prosper and not decline."
--Buddha, Mahaparinirvana Sutra
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