Extracting binary data with Exiftool

Question

I am doing a steganography challenge. I have a jpeg file, and when I look the metadata of it with Exiftool, I see something interesting.

Red Tone Reproduction Curve     : (Binary data 64 bytes, use -b option to extract)
Green Tone Reproduction Curve   : (Binary data 64 bytes, use -b option to extract)
Blue Tone Reproduction Curve    : (Binary data 64 bytes, use -b option to extract)

So I thought that maybe there is something interesting there, but I am not sure on how to extract that binary data. When I use the following command: exiftool -b -RedTRC nameOfThePicture.jpeg, then I get this message: curv ck?Q!)2;FQw]kpz|i}0. I think that message can be something but I don't how to extract that binary data and which type of file could it be. Any help?

[Related post](https://exiftool.org/forum/index.php?topic=11406.msg61081#msg61081) on the exiftool forums. — StarGeek, Jul 10 '20 at 15:58

score 3 · Accepted Answer · answered Jul 10 '20 at 16:02

3

That "message" is simply the binary data of that tag displayed on the command line. The curv part is the ID value for the TRC (see example code, specifically tagbase.sig = swap((long)0x63757276L); /*’curv’*/).

To extract that data to a file, you just need to redirect the output.
exiftool -b -RedTRC nameOfThePicture.jpeg >RedTRC.dat

answered Jul 10 '20 at 16:02

StarGeek

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So, I suppose that is not something interesting. Thank you ;) @StarGeek – largoWinch Jul 11 '20 at 11:10

Extracting binary data with Exiftool

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