For the first class, processing time depends on
frames emission rates per second which can be 25f/s
or 30f/s depending on the standard system used in
each country. Considering this rate equal to 30f/s,
30 frames can be transmitted in one second it means
0.033seconds (33 milliseconds) is allocated for every
frame. Thus, a real time scheme must treat a frame no
more than 33 milliseconds.
In (Lee and Seo, 2013) a real time watermark-
ing based on temporal modulation was proposed. It
operates in spatial domain with an error correcting
code to ameliorate robustness. Other methods are
proposed in transformed domain (Maity and Kundu,
2009), (Wang et al., 2009), (Bhaisare et al., 2013)
as in (Lee and Im, 2012) where authors propose to
embeed signature into compressed domain to mini-
mize the proceeding time. In fact, the video is par-
tially compressed to generate DCT coefficients where
the signature is inserted using the Quantization In-
dex Modulation QIM. This last one consists to select
the nearest byte in the coefficient from the mark to
guarantee a good insertion quality. The proposed per-
ceptual watermarking by (P.Mohanty and Kougianos,
2011) aims to develop an architectural idea which im-
prove the treatment time using the parallel implemen-
tation.
Concerning the collusion attack, it became a ma-
jor threat for video security. In fact, the attacker tries
to predict the original document exploiting the tempo-
ral redundancyin the sequence video. There were two
types of collusion. The first one estimates the embed-
ded mark then eliminates it from the document. This
method is possible when the hacker has a lot of differ-
ent marked images using same signature. For the sec-
ond type of collusion, the attacker must have a large
combination of similar images which are marked dif-
ferently and he averages them to destroy the signa-
ture and obtain the unmarked video. To resolve col-
lusion problem, movement and redundancy must be
reduced (Dorr and Dugelay, 2005). So, the better idea
to obtain robustness against this attack consists to em-
bedding signature into mosaic image generated from
the video. In fact, the mosaic presents an accumula-
tion of dispersed information into the sequence where
the same point repeated along the video will be repre-
sented by a single reference in the panoramic image.
Therefore, all similar pixels are marked with the same
way. Koubaa et al (Koubaa et al., 2012) proposed
to insert the signature with a wavelet watermarking
into the feature regions selected from the mosaic im-
age. Bayoudh et al (Bayoudh et al., 2013) also used
the mosaic image generated from the original video
to embed the signature. The insertion is done using
frequential domain and the Krawtchouk moments to
improve robustness and invisibility of the signature.
Kerbiche et al (Kerbiche et al., 2012) proposed an-
other watermarking based on mosaic image. They se-
lected feature regions where the objects move. First,
the wavelet transform is applied on the selected re-
gion. Then, obtained frequencies are marked using
two different approaches to verify the best compro-
mise invisibility/robustness. These techniques present
a good robustness but they require an important pro-
cessing time allocated to generate the mosaic. So,
they can’t be applied for real time applications.
In this paper, a new video watermarking scheme
is proposed. It aims to resist to almost of attacks
with a higher capacity, imperceptibility and time pro-
cessing reduction. In fact, the new approach is based
on dynamic multisprites generation to guarentee a ro-
bustness against collusion attacks with a processing
time minimization. In more, the signature embedding
is based on spatial domain which allows obtainning
high invisbility and an independency from standard
of compression. Finally, the proposed algorithm is
blind. This last criterion permits to reduce processing
time at detection step. The remaining sections of this
paper are organized as follows. The proposed water-
marking is described in section 2 and the experimen-
tal results are provided in section 3. Finally, section 4
summaries the proposed work and presents the future
work.
2 PROPOSED WATERMARKING
The main idea of the proposed scheme is to embed
signature into mosaic image generated from origi-
nal video to guarantee the robustness against collu-
sion attacks. Different recent techniques are based
on panoramic video image to resist collusion (Koubaa
et al., 2012), (Kerbiche et al., 2012), (Bayoudh et al.,
2013). For all these techniques, the first step consists
to generate mosaic from different images of original
video sequence. Then, the obtained mosaic will be
marked using a spatial or frequential embedding. Ev-
ery technique try to improve robustness against differ-
ent attacks with a high invisibility but the mainly lim-
itation of these techniques is processing time which
is important. In fact, the generation of a panoramic
image from the whole video sequence requires an im-
portant processing time with an eventual distortion of
the reconstructed video sequence. To resolve these
two problems, multi-sprites are proposed in this pa-
per. The use of multi-sprites will offer a reduction of
processing time of mosaic generation and will reduce
the distortion effect due to the video reconstruction
from the mosaic image.
OnLineVideoWatermarking-ANewRobustApproachofVideoWatermarkingbasedonDynamicMulti-sprites
Generation
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