This paper presents an efficient method for high payload reversible data-hiding in H.264/AVC intra bitstream with a minimal drift, which is controllable and proportional to the payload. In contrast to previously presented open-loop reversible data hiding techniques for H.264/AVC bitstream, which mainly perform drift-compensation, we propose a new reversible data hiding technique for H.264/AVC intra bitstream which avoids drift . The major design goals of this novel H.264/AVC reversible data hiding algorithm have been runtime-efficiency, high perceptual quality with a minimal effect on bit-rate. The data is efficiently embedded in the compressed domain in an open-loop fashion, <i>i.e</i>., all prediction results are reused. Nevertheless intra-drift is avoided, as only specific solution patterns are added, which are solutions of a system of linear equations that guarantee the preservation of the block’s edge pixel values.
This paper presents a novel method for the real-time protection of new emerging High Efficiency Video Coding (HEVC)
standard. Structure preserving selective encryption is being performed in CABAC entropy coding module of HEVC, which
is significantly different from CABAC entropy coding of H.264/AVC. In CABAC of HEVC, exponential Golomb coding
is replaced by truncated Rice (TR) up to a specific value for binarization of transform coefficients. Selective encryption
is performed using AES cipher in cipher feedback mode on a plaintext of <i>binstrings </i>in a context aware manner. The
encrypted bitstream has exactly the same bit-rate and is format complaint. Experimental evaluation and security analysis
of the proposed algorithm is performed on several benchmark video sequences containing different combinations of motion,
texture and objects.
Next generation image compression system should be optimized the way human vision system (HVS) works. HVS
has been evolved over millions of years for the images which exist in our environment. This idea is reinforced by
the fact that sparse codes extracted from natural images resemble the primary visual cortex of HVS. We have
introduced a novel technique in which basis functions trained by Independent Component Analysis (ICA) have
been used to transform the image. ICA has been used to extract the independent features (basis functions) which
are localized, bandlimited and oriented like HVS and resemble wavelet and Gabor bases. A greedy algorithm
named matching pursuit (MP) has been used to transform the image in the ICA domain which is followed by
quantization and multistage entropy coding. We have compared our codec with JPEG from the DCT family
and JPEG2000 from the wavelets family. For fingerprint images, results are also compared with wavelet scalar
quantization (WSQ) codec which has been especially tailored for this type of images. Our codec outperforms
JPEG and WSQ and also performs comparable to JPEG2000 with lower complexity than the latter.
This paper develops a new adaptive scanning methodology for intra frame scalable coding framework based on a
subband/wavelet(DWTSB) coding approach for MPEG-4 AVC/H.264 scalable video coding (SVC). It attempts
to take advantage of the prior knowledge of the frequencies which are present in different higher frequency
subbands. We propose dyadic intra frame coding method with adaptive scan (DWTSB-AS) for each subband
as traditional zigzag scan is not suitable for high frequency subbands. Thus, by just modification of the scan
order of the intra frame scalable coding framework of H.264, we can get better compression. The proposed
algorithm has been theoretically justified and is thoroughly evaluated against the current SVC test model JSVM
and DWTSB through extensive coding experiments for scalable coding of intra frame. The simulation results
show the proposed scanning algorithm consistently outperforms JSVM and DWTSB in PSNR performance.
This results in extra compression for intra frames, along with spatial scalability. Thus Image and video coding
applications, traditionally serviced by separate coders, can be efficiently provided by an integrated coding system.