Lossless Image Data Embedding in Plain Areas

This letter presents a lossless data hiding scheme for digital images which uses an edge detector to locate plain areas for embedding. The proposed method takes advantage of the well-known gradient adjacent prediction utilized in image coding. In the suggested scheme, prediction errors and edge values are first computed and then, excluding the edge pixels, prediction error values are slightly modified through shifting the prediction errors to embed data. The aim of proposed scheme is to decrease the amount of modified pixels to improve transparency by keeping edge pixel values of the image. The experimental results have demonstrated that the proposed method is capable of hiding more secret data than the known techniques at the same PSNR, thus proving that using edge detector to locate plain areas for lossless data embedding can enhance the performance in terms of data embedding rate versus the PSNR of marked images with respect to original image.

Secure logarithmic audio watermarking scheme based on the human auditory system

Peer-reviewed

Tresors amagats per a molts. Els secrets del clàssics.

La paraula «clàssic» sol espantar perquè se sol associar a «difícil», avorrit», «d'altres temps», fins i tot a «lectura obligada». Aquest adjectiu sempre té un regust amarg, però un «clàssic» és precisament tot el contrari: és el segell de garantia d'una creació. Si un llibre és «clàssic» és que ha aconseguit sobreviure al pas del temps i és una autèntica joia. Joanot Martorell va començar a escriure el seu Tirant lo Blanc un 2 de gener de 1460, com diu, i si avui la seva obra segueix entusiasmant uns pocs privilegiats és perquè amaga tresors que ells sols han pogut veure. Per què no en gaudim tots, d'aquesta riquesa? Si els nens, que són el nostre futur, poguessin divertir-se amb el que diu, ells mateixos, de grans, revelarien aquest «secret» als seus fills, i així aquesta novel·la meravellosa deixaria de ser un paradís per a uns pocs, i al mateix temps aquest tros essencial de la cultura seria patrimoni de tots.

Z2Z4-Additive Perdect Codes in Steganography

Steganography is an information hiding application which aims tohide secret data imperceptibly into a cover object. In this paper, we describe anovel coding method based on Z2Z4-additive codes in which data is embeddedby distorting each cover symbol by one unit at most (+-1-steganography). Thismethod is optimal and solves the problem encountered by the most e cientmethods known today, concerning the treatment of boundary values. Theperformance of this new technique is compared with that of the mentionedmethods and with the well-known rate-distortion upper bound to conclude thata higher payload can be obtained for a given distortion by using the proposedmethod.