Reversible watermarking scheme with image-independent embedding capacity

Permanent distortion is one of the main drawbacks of all the irreversible watermarking schemes. Attempts to recover the original signal after the signal passing the authentication process are being made starting just a few years ago. Some common problems, such as salt-and-pepper artefacts owing to intensity wraparound and low embedding capacity, can now be resolved. However, some significant problems remain unsolved. First, the embedding capacity is signal-dependent, i.e., capacity varies significantly depending on the nature of the host signal. The direct impact of this is compromised security for signals with low capacity. Some signals may be even non-embeddable. Secondly, while seriously tackled in irreversible watermarking schemes, the well-known problem of block-wise dependence, which opens a security gap for the vector quantisation attack and transplantation attack, are not addressed by researchers of the reversible schemes. This work proposes a reversible watermarking scheme with near-constant signal-independent embedding capacity and immunity to the vector quantisation attack and transplantation attack

Transportation Risk ANalysis tool for hazardous Substances (TRANS): a user-friendly, semi-quantitative multi-mode hazmat transport route safety risk estimation methodology for Flanders

A

Helicobacter pylori and non-steroidal anti-flammatory drugs in patients with rheumatic diseases

Lems, W.F. [Promotor]Dijkmans, B.A.C. [Promotor]Boers, M. [Promotor

Video coding and decoding devices and methods preserving PPG relevant information

The present invention relates to a video encoding device (10, 10', 10") and method for encoding video data and to a corresponding video decoding device (60, 60') and method. To preserve PPG relevant information after encoding without requiring a large amount of additional data for the video encoder output stream, the proposed video encoding device comprises a selection unit (20, 20') for selecting in input video data (100) skin areas as one or more regions of interest (101), that can be used to provide a strong PPG signal, based on one or more predetermined selection criteria including the spatial size, temporal stability, illumination stability and/or color stability or based on the quality and/or content of PPG signals extracted from skin areas potentially usable as region of interest,, a first encoding unit (30,30') for encoding said one or more regions of interest (101) of said input video data (100) according to a predetermined encoding scheme with a first setting of the encoding to preserve PPG-relevant information in the encoded one or more regions of interest, wherein said first encoding unit (30) is adapted for encoding only the chrominance components (101a) of said one or more regions of interest (101) or for encoding said one or more regions of interest (101) by intra-block coding,, a second encoding unit (40, 40') for encoding remaining parts (103) of said input video data (100) according to said predetermined encoding scheme with a second setting of the encoding, and an encoder combination unit (50) for combining the encoded one or more regions of interest (102) and the encoded remaining parts (104) of said input video data into an encoder output video stream (105).</p

Video coding and decoding devices and methods preserving ppg relevant information

The present invention relates to a video encoding device (10) for encoding video data and a corresponding video decoding device, wherein during decoding PPG relevant information shall be preserved. For this purpose the video coding device (10) comprises a first encoder (20) for encoding input video data (100) according to a first encoding scheme and outputting first coded video data (120) having a lower quality than the input video data, and a second encoder (30) for encoding input video data (100) according to a second encoding scheme preserving PPG-relevant information and outputting second coded video data (130)