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Re: HIDE: embedding msgs into snd & graphics
- To: [email protected]
- Subject: Re: HIDE: embedding msgs into snd & graphics
- From: Peter & <[email protected]>
- Date: Thu, 11 Mar 1993 22:08:16 -0800
- In-Reply-To: Your message of Thu, 11 Mar 1993 13:22:21 -0800. <[email protected]>
- Phone: (510) 849-2230
- Snail-Address: 2560 Bancroft way #51;Berkeley CA 94704-1700
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>
>The GIF option I mentioned allows a widely disseminated image file to
>contain about 32 KB in just the LSBs of a 512 x 512 x 8-bit gray scale
>image. A color image could easily hold three times more (LSBs in each color
>channel). And some GIFs are much larger than 512 on a side.
IT should be trival to include date into GIFs (or most any other non-lossy
formats) using the ppmplus library.
giftoppm Image.gif | ppmInsertData data.pgp | ppmtogif > Image2.gif
where ppmInsertData is a program that modifies the data stream using
the file data.pgp as the crypt data source
to extract just a command simular to:
ppmExtractData < Image2.gif > data.pgp
for sound file it would just as easy (in fact I am almost tempted to
write some demo code but I have more email to attend to :-)
-Pete
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