Reply by Nishit Jain June 17, 20052005-06-17
This is normal. This may be because there are several decoders possible for
decoding JPEG2000 encoded image which may vary slightly. Also, there is a
possibility that the commercial tool may have appended its own information to
the image.

--
Nishit Jain
IIT Guwahati "Real success is finding your lifework in the work that you love."
> Message: 1
> Date: Thu, 16 Jun 2005 08:06:16 -0000
> From: "eflame1979" <eflame1979@efla...>
> Subject: Query in Image compression using jpeg 2000
>
> It is normal get a file size smaller than the initial image after jp2
> compression. But using a commercial tool save the jp2 image as a the
> format of the original image increases the final file size of the image
> to be greater than the original image. Is this normal?
>
> eg
> initial file size, format uncompressed tiff: 300kb
> after jp2 compression of 1bit/pixel : 4kb
> after using commercial tool to save the jp2 image back to tiff: 321kb
>
> 300kb -> 321kb??
> why is there an increase in file size? Is it a common phenomenon?
> Can anyone explain?
>
> Thank you.
> -Arvin


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Reply by Juan de Dios Santander Vela June 16, 20052005-06-16
El 16/06/2005, a las 10:06, eflame1979 escribi

> It is normal get a file size smaller than the initial image after jp2
> compression. But using a commercial tool save the jp2 image as a the
> format of the original image increases the final file size of the
> image
> to be greater than the original image. Is this normal?
>
> eg
> initial file size, format uncompressed tiff: 300kb
> after jp2 compression of 1bit/pixel : 4kb
> after using commercial tool to save the jp2 image back to tiff: 321kb
>
> 300kb -> 321kb??
> why is there an increase in file size? Is it a common phenomenon?
> Can anyone explain?
>
> Thank you.
> -Arvin

There could be two causes for this. The first I can think of is just
that a low-res preview has been added, making for those 21KB of
increase.

This can also been compounded with additional tags the commercial
application might have added to the TIFF.

--
Juan de Dios Santander Vela
Diplomado en CC. Ficas, Ingeniero en Electrica
Doctorando en Tecnologs Multimedia
Becario Predoctoral del Instituto de Astrofica de Andaluc

Albert Einstein: No intentes hacerte un hombre de ito, es mejor
intentar ser un hombre de val.