On the use of discrete Pascal transform in hiding data in images

The Discrete Pascal Transform (DPT) has been proved remarkably useful for edge detection, filter design, discrete-time signal interpolation and data hiding. In the present work a new blind fragile data hiding technique for secretly embedding messages into color images, is proposed. The embedding procedure is based on dividing each color image component into even-sized blocks. Information embedding is determined by monitoring the lower-right corner of the DPT coefficient matrix. This particular coefficient suffers the highest change for small pixel modifications. The embedding affects the coefficient’s sign. In case that the sign is not the desired one, i.e. negative for a message bit value of ‘0’ and positive for a message bit value of ‘1’, it is changed by repeatedly adding to the block or subtracting from the block the identity matrix. This process is based on the DPT properties and on the sensitivity of the lower-right coefficient in even the smallest pixel changes. The em...

• Authors: Eleni E. Varsaki, Vassilis Fotopoulos and Athanassios N. Skodras
• Keywords: Data Hiding, Discrete Pascal Transform, Steganography