This is a steganography utility for generating stego images in halftone format and extracting payloads from such generated images. Detailed information about steganography, halftoning, and binary images can be accessed from the following Wikipedia pages:
The utility is designed to work with both color and grayscale images, serving as cover media. During the halftoning procedure, the utility embeds the desired plaintext payload within these images. The embedding process generates multiple output copies for enhanced security, each carrying a distinct set of payload bits. This strategy prevents unauthorized extraction attempts from succeeding without the need to gather all the created images. This security measure also brings an added benefit: the extraction algorithm relies only on the stego images, in contrast to specific other steganography methods where the original image is required during the extraction process.
The sample images provided in the "cover_imgs" directory are obtained from the "UC Merced Land Use Dataset" [1]. The text files in the "payloads" directory are generated randomly using Lorem Ipsum generator [2]. The error diffusion kernels in the "kernels" directory belong to Floyd-Steinberg [3], Jarvis-Judice-Ninke [4], and Stucki [5] algorithms. The files presented in these directories are for demonstration purposes only.
To execute, the numpy, scikit-image, and scipy packages must be installed:
pip install numpy scikit-image scipy
or
pip install -r requirements.txt
Available options for htstego.py:
-h, --help show this help message and exit
-v, --version show program's version number and exit
--gui switch to graphical user interface
Required Options:
--htmethod {errdiff,ordered,pattern} halftoning method
--cover COVER input image
--payload PAYLOAD input payload
--nshares NSHARES number of output shares to generate
Error Diffusion Options:
--kernel {stucki,floyd,jajuni} error diffusion kernel (from kernels directory)
Ordered Dithering Options:
--bayer-size {2,4,8} Bayer matrix size
Output Options:
--no-output-files do not produce output images
--generate-regular-output generate nonstego output image
--output-color {binary,color} output color
--output-format {csv,json,xml} output format
--silent do not display output on screen
--compress-payload compress payload before embedding
cd src
./htstego.py --cover cover_imgs/airplane80.tif --payload payloads/payload128.txt --nshares 4 --htmethod errdiff --kernel floyd
When executed as above, the following output will be displayed:
{"status": "ok", "halftoning_method": "errdiff", "errdiff_kernel": "floyd", "bayer_size": "N/A", "output_color": "binary", "number_of_shares": 4, "cover_file": "cover_imgs/airplane80.tif", "payload_file": "payloads/payload128.txt", "payload_compression": false, "avg_snr": 21.8918, "avg_psnr": 24.0863, "avg_ssim": 0.9916}
and the following files will be created in a timestamped subdirectory under the output directory:
airplane80_hterrdiffbin_stego_msg128_1of4_floyd.png
airplane80_hterrdiffbin_stego_msg128_2of4_floyd.png
airplane80_hterrdiffbin_stego_msg128_3of4_floyd.png
airplane80_hterrdiffbin_stego_msg128_4of4_floyd.png
where each file is a stego image carrying different portions of the payload.
Available options for htstego-extract.py:
-h, --help show this help message and exit
-v, --version show program's version number and exit
--gui switch to graphical user interface
--extract-from EXTRACT_FROM extract from images in this directory
--htmethod {errdiff,ordered,pattern} halftoning method
The directory specified with the --extract-from argument must contain only and only a single set of carrier images (e.g., the timestamped subdirectories under the output directory). --htmethod option must be used to specify which extraction method will be used.
cd src
./htstego-extract.py --htmethod errdiff --extract-from output/2024-03-05-14-06-40-0/
Assuming the specified directory contains the whole set of images generated with the error diffusion method, the following output will be produced:
Result: Donec ut mauris sit amet ...
Both utilities can also be used via a simple graphical user interface (htstego-gui.py and htstego-extract-gui.py). For GNU/Linux distributions such as Debian or Ubuntu, python3-tk package (and its dependencies) must be installed. For other distributions, please refer to the distribution documentation.
HtStego has been featured in the following paper:
Çiftci, E., Sümer, E. (2024). HtStego: A halftone steganography utility. SoftwareX, 27, 101780. https://doi.org/10.1016/j.softx.2024.101780
The steganography and extraction algorithm used by HtStego has been introduced in the following paper:
Çiftci, E., Sümer, E. (2022). A novel steganography method for binary and color halftone images. PeerJ Computer Science, 8, e1062. https://doi.org/10.7717/peerj-cs.1062
@article{cciftci2024htstego,
title={HtStego: A halftone steganography utility},
author={{\c{C}}iftci, Efe and S{\"u}mer, Emre},
journal={SoftwareX},
volume={27},
pages={101780},
year={2024},
publisher={Elsevier}
}
@article{cciftci2022novel,
title={A novel steganography method for binary and color halftone images},
author={{\c{C}}iftci, Efe and S{\"u}mer, Emre},
journal={PeerJ Computer Science},
volume={8},
pages={e1062},
year={2022},
publisher={PeerJ Inc.}
}
Please cite these papers if you use HtStego in your research.
[1] Yi Yang and Shawn Newsam, "Bag-Of-Visual-Words and Spatial Extensions for Land-Use Classification," ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (ACM GIS), 2010.
[2] Lorem Ipsum generator. https://www.lipsum.com/
[3] R.W. Floyd, L. Steinberg, An adaptive algorithm for spatial grey scale. Proceedings of the Society of Information Display 17, 75–77 (1976)
[4] J. F. Jarvis, C. N. Judice and W. H. Ninke, A Survey of Techniques for the Display of Continuous Tone Pictures on Bi-level Displays. Computer Graphics and Image Processing, 5 13–40, 1976.
[5] P. Stucki, MECCA - a multiple error correcting computation algorithm for bi-level image hard copy reproduction. Research report RZ1060, IBM Research Laboratory, Zurich, Switzerland, 1981.