166 research outputs found
Texture representation through overlapped multi-oriented tri-scale local binary pattern
This paper ideates a novel texture descriptor that retains its classification accuracy under varying conditions of image orientation, scale, and illumination. The proposed Overlapped Multi-oriented Tri-scale Local Binary Pattern (OMTLBP) texture descriptor also remains insensitive to additive white Gaussian noise. The wavelet decomposition stage of the OMTLBP provides robustness to photometric variations, while the two subsequent stages – overlapped multi-oriented fusion and multi-scale fusion – provide resilience against geometric transformations within an image. Isolated encoding of constituent pixels along each scale in the joint histogram enables the proposed descriptor to capture both micro and macro structures within the texture. Performance of the OMTLBP is evaluated by classifying a variety of textured images belonging to Outex, KTH-TIPS, Brodatz, CUReT, and UIUC datasets. The experimental results validate the superiority of the proposed method in terms of classification accuracy when compared with the state-of-the-art texture descriptors for noisy images
An investigation into the requirements for an efficient image transmission system over an ATM network
This thesis looks into the problems arising in an image transmission system when
transmitting over an A TM network. Two main areas were investigated: (i) an
alternative coding technique to reduce the bit rate required; and (ii) concealment of
errors due to cell loss, with emphasis on processing in the transform domain of
DCT-based images. [Continues.
Comparative Analysis of Techniques Used to Detect Copy-Move Tampering for Real-World Electronic Images
Evolution of high computational powerful computers, easy availability of several innovative editing software package and high-definition quality-based image capturing tools follows to effortless result in producing image forgery. Though, threats for security and misinterpretation of digital images and scenes have been observed to be happened since a long period and also a lot of research has been established in developing diverse techniques to authenticate the digital images. On the contrary, the research in this region is not limited to checking the validity of digital photos but also to exploring the specific signs of distortion or forgery. This analysis would not require additional prior information of intrinsic content of corresponding digital image or prior embedding of watermarks. In this paper, recent growth in the area of digital image tampering identification have been discussed along with benchmarking study has been shown with qualitative and quantitative results. With variety of methodologies and concepts, different applications of forgery detection have been discussed with corresponding outcomes especially using machine and deep learning methods in order to develop efficient automated forgery detection system. The future applications and development of advanced soft-computing based techniques in digital image forgery tampering has been discussed
Comparative Analysis of Techniques Used to Detect Copy-Move Tampering for Real-World Electronic Images
Evolution of high computational powerful computers, easy availability of several innovative editing software package and high-definition quality-based image capturing tools follows to effortless result in producing image forgery. Though, threats for security and misinterpretation of digital images and scenes have been observed to be happened since a long period and also a lot of research has been established in developing diverse techniques to authenticate the digital images. On the contrary, the research in this region is not limited to checking the validity of digital photos but also to exploring the specific signs of distortion or forgery. This analysis would not require additional prior information of intrinsic content of corresponding digital image or prior embedding of watermarks. In this paper, recent growth in the area of digital image tampering identification have been discussed along with benchmarking study has been shown with qualitative and quantitative results. With variety of methodologies and concepts, different applications of forgery detection have been discussed with corresponding outcomes especially using machine and deep learning methods in order to develop efficient automated forgery detection system. The future applications and development of advanced soft-computing based techniques in digital image forgery tampering has been discussed
Cast shadow modelling and detection
Computer vision applications are often confronted by the need to differentiate between objects and their shadows. A number of shadow detection algorithms have been
proposed in literature, based on physical, geometrical, and other heuristic techniques.
While most of these existing approaches are dependent on the scene environments and
object types, the ones that are not, are classified as superior to others conceptually
and in terms of accuracy. Despite these efforts, the design of a generic, accurate,
simple, and efficient shadow detection algorithm still remains an open problem. In
this thesis, based on a physically-derived hypothesis for shadow identification, novel,
multi-domain shadow detection algorithms are proposed and tested in the spatial and
transform domains.
A novel "Affine Shadow Test Hypothesis" has been proposed, derived, and validated
across multiple environments. Based on that, several new shadow detection algorithms
have been proposed and modelled for short-duration video sequences, where
a background frame is available as a reliable reference, and for long duration video
sequences, where the use of a dedicated background frame is unreliable. Finally, additional
algorithms have been proposed to detect shadows in still images, where the
use of a separate background frame is not possible. In this approach, the author
shows that the proposed algorithms are capable of detecting cast, and self shadows
simultaneously.
All proposed algorithms have been modelled, and tested to detect shadows in the
spatial (pixel) and transform (frequency) domains and are compared against state-of-art approaches, using popular test and novel videos, covering a wide range of
test conditions. It is shown that the proposed algorithms outperform most existing
methods and effectively detect different types of shadows under various lighting and
environmental conditions
Semi-automatic video object segmentation for multimedia applications
A semi-automatic video object segmentation tool is presented for segmenting both still pictures and image sequences. The approach comprises both automatic segmentation algorithms and manual user interaction. The still image segmentation component is comprised of a conventional spatial segmentation algorithm (Recursive Shortest Spanning Tree (RSST)), a hierarchical segmentation representation method (Binary Partition Tree (BPT)), and user interaction. An initial segmentation partition of homogeneous regions is created using RSST. The BPT technique is then used to merge these regions and hierarchically represent the segmentation in a binary tree. The semantic objects are then manually built by selectively clicking on image regions. A video object-tracking component enables image sequence segmentation, and this subsystem is based on motion estimation, spatial segmentation, object projection, region classification, and user interaction. The motion between the previous frame and the current frame is estimated, and the previous object is then projected onto the current partition. A region classification technique is used to determine which regions in the current partition belong to the projected object. User interaction is allowed for object re-initialisation when the segmentation results become inaccurate. The combination of all these components enables offline video sequence segmentation. The results presented on standard test sequences illustrate the potential use of this system for object-based coding and representation of multimedia
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