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We propose and analyze experimentally a blind steganography method based on specific attributes of two dimensional discrete wavelet transform set by Haar mother wavelet. Steganography is the science that deals with hiding a secret message in unsuspicious cover media. The most recent steganographic techniques tend to hide a secret message in digital images. The blind steganography methods do not require...
With the arrival of High Definition Television (HDTV), the TV technology is heading towards 3DTV. Evolution of 3DTV requires the facility of capturing and analyzing the multi-view images and compressing and transmitting massive volume of data through the communication channel. The most sever issue in 3D shape extraction is the roughness of the surfaces. Image focusing is a dominant method of reconstructing...
Visual secret sharing scheme (for short the VSS scheme) with access structure based on graph \cite{ABSS96} has been proposed and this can be considered as an extension of $(2, n) $-threshold VSS scheme. Ateniese et al. showed a decomposition method that we decompose star graphs from a given graph which edges are specified by qualified sets. Namely, two participants (vertices in a given graph) has...
The 3D reconstruction for freehand 3D ultrasound remains a hard problem because that the recorded B-scans are not only sparse, but also non-parallel (actually they may intersect each other). Conventional volume reconstruction methods can't reconstruct sparse data efficiently while not introducing geometrical artifacts, and conventional surface reconstruction methods can't reconstruct surfaces from...
Compression artifacts are the results of an aggressive data compression scheme applied to an image that discards some data which is determined by an algorithm to be of lesser importance to the overall contents but which is nonetheless discernible and objectionable to the user. In this paper we present a post-processing algorithm that focuses on restoring the clarity of important image features and...
Adaptive Optics (AO) refers to (servo-control) methods used in astronomical imaging to compensate in real time for the loss of spatial resolution power of the instrument caused by the earth's upper atmosphere turbulence, which produces inhomogeneties of air refractive index and hence modifies in a chaotic manner the optical phase of incoming light from space. In this paper we present the first results...
For future applications like 3DTV and free view point TV, the video data format is likely to comprise of multiple views plus pre-estimated geometric information such as a depth map corresponding to each view. By using multi-view video plus depth (MVD), it is possible to efficiently render virtual views in decoder site. However, the error and packet loss during the transmission will result in the distortion...
Ship detection involves two correlated tasks — ship target detection and ship wake detection. This paper proposes a method for automatic ship wake detection from SAR image. A localized Radon transform is processed around the ship target to detect linear features after ship target detection. It can smooth the speckle noise and improve the SNR in Radon transform space. So the false alarms can be reduced...
The work presented in this paper addresses the increasing demand of visual signal delivery to terminals with arbitrary resolutions (like in mobile multimedia communication and cloud computing) for universal access and presentation, without extra computational burden to the receiving end. Scalable image compression and transmission are essential, and to be effective and meaningful, it has to be content-based...
Theft of a template is theft of identity Fingerprint identification is used by forensic department in identifying criminals because of its uniqueness. Biometrics is the science of verifying and establishing the identity of an individual through physiological features or behavioral traits. Fingerprint identification is commonly employed in Forensic science to support criminal investigations and in...
The designed circular holographic display system produces ghost-like 3D optical reconstructions of a computer generated 3D model. System uses six phase-only reflective-type spatial light modulators (SLMs) that are configured circularly. Alignment of the SLMs are successful and gap problem is solved by using half-mirrors. The total number of pixels of the resultant display is 11520 × 1080. Reconstructions...
We implement a viewing angle enhanced integral imaging system by the use of more than one lenslet arrays placed in a curve-like manner. The curve effect providing widened viewing angle is achieved, from the nature that we approximate a curved lenslet array using three flat lenslet arrays. To confirm the feasibility of pickup in real time, a digital reconstruction is carried out. It is revealed that...
By learning the various character image samples, the automatic and synchronistic generation of new Chinese calligraphy styles is a key problem in the computer artistic simulating. A curve analogy method based on FSVM is proposed which can generate new calligraphy styles with the user's constraining styles'parameters. Firstly, the input character image samples are transferred into a hierarchical stroke...
A novel hardware implementation of an omnidirectional image sensor is presented which is capable of acquiring and processing 3D image sequences in real time. The system consists of a hemispherical arrangement of a large number of CMOS imagers, connecting to a layered arrangement of a high-end FPGA platform that is responsible data framing and image processing. The hardware platform in charge of real-time...
A novel method named digitized holography is proposed for 3D display systems. This is the technique replacing the whole process of classical holography with digital processing of optical wave-fields. The digitized holography allows us to edit holograms and reconstruct spatial 3D images including real-existent objects and CG-modeled virtual objects.
An optimized iterative algorithm for generalized phase-shifting interferometry is proposed. Using 1/4 plate as phase-shifter, we derive the phase distribution with the initial phase shift of π/2, then a more accurate phase shift can be obtained with the obtained phase distribution. The whole iteration includes the above two steps. The exact phase shift is near π/2, so fewer iterative steps are needed...
Phase-shifted sinusoids are commonly used as projection patterns in structured light systems consisting of projectors and cameras. They require few image captures per 3D reconstruction and have low decoding complexity. Recently, structured light systems with a projector and a pair of stereo cameras have been used in order to overcome the traditional phase discontinuity problem and allow for the reconstruction...
Patch cloud based multi-view stereo methods have proven to be an accurate and scalable approach for scene reconstruction. Their applicability, however, is limited due to the semi-dense nature of their reconstruction. We propose a method to generate a dense depth map from a patch cloud by assuming a planar surface model for non-reconstructed areas. We use local evidence to estimate the best fitting...
An efficient depth map generation method is presented for static scenes with moving objects. Firstly, static background scene is reconstructed. Depth map of the reconstructed static background scene is extracted by linear perspective. Then, moving objects are segmented precisely. Depth values are assigned to the segmented moving objects according to their positions in the static scene. Finally, the...
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