yccstego
Copyright 2026 Yukinoshita-lin

This product includes software developed by Yukinoshita-lin.

Licensed under the Apache License, Version 2.0 (the "License"); you may not
use this file except in compliance with the License. You may obtain a copy
of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
License for the specific language governing permissions and limitations
under the License.

================================================================================
Third-Party Software Notices and Attributions
================================================================================

This project depends on the following third-party software, which are
licensed under their respective open-source licenses. The full license
texts are available in the upstream project repositories.

--------------------------------------------------------------------------------

1. NumPy
   - Version: >= 1.20
   - License: BSD-3-Clause
   - URL:    https://numpy.org
   - Used for: array operations, DCT/IDCT, quantization tables,
              byte-stream assembly, and JPEG Huffman coding/decoding.

2. Pillow (PIL Fork)
   - Version: >= 9.0
   - License: HPND (Historical Permission Notice and Disclaimer)
   - URL:    https://python-pillow.org
   - Used for: JPEG file I/O (open/save), YCbCr<->RGB conversion,
              and verification of decoded cover images.

================================================================================
Reference Implementations and Algorithms
================================================================================

The algorithms implemented in this project are based on the following
public-domain academic references and the published JPEG / Huffman /
DCT specifications. No source code was copied; only the published
specifications were followed.

  - Independent JPEG Group, "JPEG Standard (JPEG ISO/IEC 10918-1)",
    ITU-T T.81, 1992.
  - J. Fridrich, T. Pevný, J. Kodovský, "Statistically undetectable
    JPEG steganography: dead ends, challenges, and possible alternatives",
    Information Hiding Workshop (IH), 2007.
  - J. Fridrich, "Steganography in Digital Media: Principles, Algorithms,
    and Applications", Cambridge University Press, 2009.
  - J. Fridrich, M. Goljan, "On steganographic embedding capacity
    (and why it matters)", Security, Steganography, and Watermarking
    of Multimedia Contents X, SPIE, 2008.

================================================================================
Bundled Sub-Projects
================================================================================

This package is shipped alongside its parent project:

  nsf5stego — spatial-domain nsF5 steganography with blind steganalysis
              and a GUI, located at the parent directory of this package.
    Copyright 2026 Yushitayuri <dev@example.com>
    License: Apache-2.0
    License file: ../LICENSE
    NOTICE file:    ../NOTICE

The two packages are independent: each has its own LICENSE and NOTICE.
They are co-developed and co-distributed for convenience.

================================================================================
Trademark Notice
================================================================================

"Apache" is a registered trademark of the Apache Software Foundation.
The Apache License, Version 2.0 is published by the Apache Software
Foundation; this project is NOT affiliated with or endorsed by the
Apache Software Foundation.
