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Samar-

macrumors newbie
Original poster
Nov 3, 2012
4
0
I'm developing a steganography app where the user can hide a "secret message" within an image. One way to do that is by manipulating the DCT coefficients of jpeg images which can be done using the LibJPEG (http://www.ijg.org/) library. I now that I access the DCT coefficients in libjpeg using the jpeg_read_coefficients function.
My problem is that I don't know how to compile/use LibJPEG within my xCode project. I read that I need to compile LibJPEG for two architectures: ARM, for iOS, and x86, for the simulator but I don't know how to do that. I have tried a few different approaches, but being a bit naive, nothing seems to work!

Can anyone link me to a tutorial or give me a push in the right direction?
If anyone successfully installed and used jpeg library please help..

I'm working on Mountain Lion OS X 10.8 and using xCode v4.5.
 
Did it worked out for you?

Hi,

I am using Mountain Lion & XCode 4.6.2. I want to use libjpeg library for image manipulation. If you were able to successfully compile and use libjpeg library in XCode, please let me know how you did it.

-Senthil Ganesh
 
I'm developing a steganography app where the user can hide a "secret message" within an image.

Not to detract you, but couldn't you do something with a bitmap image internally?
At least then you could save the result as a lossless png.

The internal bitmap has an alpha channel, so that would be one place to start,
then at least the resulting png can be saved to the photo album,
unlike jpg, which would be converted to png when saved from an app,
only to lose some of the information you might be playing with.

I did a bitmap block cipher earlier this year:
http://www.youtube.com/watch?v=HUx9w4gyQ5c

I needed to add a simple stream cipher in addition to this in order to
mask parts of any image that have a large area of the same colour pixels.
I gave up on it because of the whole encryption hassle with US distribution.
Good luck with that.
 
I'm developing a steganography app where the user can hide a "secret message" within an image. One way to do that is by manipulating the DCT coefficients of jpeg images which can be done using the LibJPEG (http://www.ijg.org/) library. I now that I access the DCT coefficients in libjpeg using the jpeg_read_coefficients function.
My problem is that I don't know how to compile/use LibJPEG within my xCode project. I read that I need to compile LibJPEG for two architectures: ARM, for iOS, and x86, for the simulator but I don't know how to do that. I have tried a few different approaches, but being a bit naive, nothing seems to work!

Can anyone link me to a tutorial or give me a push in the right direction?
If anyone successfully installed and used jpeg library please help..

I'm working on Mountain Lion OS X 10.8 and using xCode v4.5.

Do you know how to compile a static C/C++ library using XCode?
As that is probably what you need to do.

Or, are you saying you know how to compile a static library, but don't know how to compile this
particular library, as in getting compliation/linker errors?
 
Last edited:
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