A dynamic chaotic lossy compression-encryption scheme for color images in the YCbCr space
INFORMATION SCIENCES, cilt.765, 2027 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 765
- Basım Tarihi: 2027
- Doi Numarası: 10.1016/j.ins.2026.124349
- Dergi Adı: INFORMATION SCIENCES
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, MLA - Modern Language Association Database, zbMATH, MLA International Bibliography
- Ankara Üniversitesi Adresli: Evet
Özet
Secure transmission of digital images over open networks demands efficient image encryption. Traditional RGB-based encryption suffers from heavy computation and poor dynamical complexity allocation. To address this, this study proposes a lossy compression-encryption scheme for color images based on a two-dimensional coupled chaotic system (2D-SCCS). To reduce high-dimensional data redundancy during nonlinear perturbation, the scheme converts RGB images to the YCbCr color space. It adopts 4:2:0 chroma subsampling, DWT low-frequency extraction and quantization to cut data volume while retaining core visual content. A dynamic parameter generator is constructed using a 256-bit master key, a random synchronization parameter and an input image. The luminance (Y) and chrominance (Cb, Cr) channels are separately confused via 2D-SCCS to realize accurate pixel permutation. A position-dependent bidirectional recursive diffusion is further applied to spread pixel changes. Simulations and security tests verify that finite-precision confusion-diffusion sequences have strong statistical randomness; the ciphertext achieves good performance in information entropy, adjacent-pixel correlation and differential attack resistance. Moreover, YCbCr processing lowers computational cost under identical test settings. Overall, the proposed scheme achieves a practical balance among lossy compression efficiency, encryption performance, and reconstruction quality.