Image forensics Research Papers - Academia.edu (original) (raw)

— Electrical machines are devices that change either mechanical or electrical energy to the other and also can alternate the voltage levels of an alternating current. The need for electrical machines cannot be overemphasized since they... more

— Electrical machines are devices that change either mechanical or electrical energy to the other and also can alternate the voltage levels of an alternating current. The need for electrical machines cannot be overemphasized since they are used in various applications in the world today. Its design is to meet the specifications as stated by the user and this design has to be an economical one. The design therefore revolves around designing the machine to meet the stipulated performance required, the cost available and the lasting life of the machine. This work aims to eliminate the tediousness involved in the manual hand calculations of designing the machines by making use of a graphical user interface and using iterations in situations where the data would have been assumed.

Photographs are considered to be the most powerful and trustworthy media of expression. For a long time, those were accepted as proves of evidences in varied fields such as journalism, forensic investigations, military intelligence,... more

Photographs are considered to be the most powerful and trustworthy media of expression. For a long time, those were accepted as proves of evidences in varied fields such as journalism, forensic investigations, military intelligence, scientific research and publications, crime detection and legal proceedings, investigation of insurance claims, medical imaging etc. Today, digital images have completely replaced the conventional photographs from every sphere of life but unfortunately, they seldom enjoy the credibility of their conventional counterparts, thanks to the rapid advancements in the field of digital image processing. The increasing availability of low cost and sometimes free of cost image editing software such as Photoshop, Corel Paint Shop, Photoscape, PhotoPlus, GIMP and Pixelmator have made the tampering of digital images even more easier and a common practice. Now it has become quite impossible to say whether a photograph is a genuine camera output or a manipulated versio...

Image forensic plays a crucial role in both criminal investigations (e.g., dissemination of fake images to spread racial hate or false narratives about specific ethnicity groups) and civil litigation (e.g., defamation). Increasingly,... more

Image forensic plays a crucial role in both criminal investigations (e.g., dissemination of fake images to spread racial hate or false narratives about specific ethnicity groups) and civil litigation (e.g., defamation). Increasingly, machine learning approaches are also utilized in image forensics. However, there are also a number of limitations and vulnerabilities associated with machine learning-based approaches, for example how to detect adversarial (image) examples, with real-world consequences (e.g., inadmissible evidence, or wrongful conviction). Therefore, with a focus on image forensics, this paper surveys techniques that can be used to enhance the robustness of machine learning-based binary manipulation detectors in various adver-sarial scenarios.

Using image manipulation programs has become easier and more powerful than before. Due to such fact, detection of image forgeries has produced significant interest recently. Falsification of images can initiate dangerous legal concerns.... more

Using image manipulation programs has become easier and more powerful than before. Due to such fact, detection of image forgeries has produced significant interest recently. Falsification of images can initiate dangerous legal concerns. Among the most extensively utilized approaches for image forgeries is copy-move forgery in which a section of the image is copied and duplicated in another location in the same image. A significant part of a digital image can be covered or added using this procedure. In this paper, we propose an accurate algorithm for copy-move forgery detection. A block-based approach is suggested that uses the KD-tree data structure and a simple yet efficient feature vector to detect the possible forgery. The results demonstrated in this work match state of the art methods while providing a significant speedup.

The recursive and non-recursive comb filters are commonly used as decimators for the sigma delta modulators. This paper presents the analysis and design of low power and high speed comb filters. The comparison is made between the... more

The recursive and non-recursive comb filters are commonly used as decimators for the sigma delta modulators. This paper presents the analysis and design of low power and high speed comb filters. The comparison is made between the recursive and the non-recursive comb filters with the focus on high speed and saving power consumption. Design procedures and examples are given by using Matlab and Verilog HDL for both recursive and non-recursive comb filter with emphasis on frequency response, transfer function and register width. The implementation results show that non-recursive comb filter has capability of speeding up the circuit and reducing power compared to recursive one when the decimation ratio and filter order are high. Using Modified Carry Look-ahead Adder for summation and also apply pipelined filter structure makes it more compatible for DSP application.

Fast Fourier transform (FFT) is widely applied in OFDM trance-receiver communications system. Hence Efficient FFT algorithm is always considered. This paper proposed FPGA realization of high resolution high speed low latency floating... more

Fast Fourier transform (FFT) is widely applied in OFDM trance-receiver communications system. Hence Efficient FFT algorithm is always considered. This paper proposed FPGA realization of high resolution high speed low latency floating point adder/subtractor for FFT in OFDM trance-receiver. The design was implemented for 32 bit pipelined adder/subtractor which satisfied IEEE-754 Standard for floating-point Arithmetic. The design was focused on the trade-off between the latency and speed improvement as well as resolution and silicon area for the chip implementation. In order to reduce the critical path and decrease the latency, the novel structure was designed and investigated. Consequently, synthesis report indicated the latency of 4 clock cycles due to each stage operated within just one clock cycle. The unique structure of designed adder well thought out resulted 6691 equivalent gate count and lead us to obtain low area on chip. The synthesis Xilinx ISE software provided results representing the estimated area and delay for design when it is pipelined to various depths. The report shows the minimum delay of 3.592 ns or maximum frequency of 278.42 MHz.

Copy–move forgery is one of the most common types of tampering for digital images. Detection methods generally use block-matching approaches, which first divide the image into overlapping blocks and then extract and compare features to... more

Copy–move forgery is one of the most common types of tampering for digital images. Detection methods
generally use block-matching approaches, which first divide the image into overlapping blocks and then extract and compare features to find similar ones, or point-based approaches, in which relevant keypoints are extracted and matched to each other to find similar areas. In this paper, we present a very novel hybrid approach, which compares triangles rather than blocks, or single points. Interest points are extracted from the image, and objects are modeled as a set of connected triangles built onto these points. Triangles are matched according to their shapes (inner angles), their content (color information), and the local feature vectors extracted onto the vertices of the triangles. Our methods are designed to be robust to geometric
transformations. Results are compared with a state-of-the-art block matching method and a point-based method. Furthermore, our data set is available for use by academic researchers.

The main issue in image forensics is to discover whether an image is authentic or forged and, if forged, to locate which regions have been manipulated. The simple accessibility of image manipulation software have proliferated the... more

The main issue in image forensics is to discover whether an image is authentic or forged and, if forged, to locate which regions have been manipulated. The simple accessibility of image manipulation software have proliferated the possibility of image forgery. Detection of Splicing forgery is targeted in this paper. Noise component of a color image have been utilized to extract features from suspected image. As the consistency of noise between RGB color channel of forged and authentic image are different, so it leaves the clues of forgery. First digit features are extracted using Benfords’ law and provided to the SVM classifier Columbia uncompressed image splicing detection evaluation dataset and CASIA v1.0 dataset are used to test the proposed technique. Our technique outperforms various previous techniques of image splicing detection.

The need for wireless communication has driven the communication systems to high performance. However, the main bottleneck that affects the communication capability is the Fast Fourier Transform (FFT), which is the core of most... more

The need for wireless communication has driven the communication systems to high performance. However, the main bottleneck that affects the communication capability is the Fast Fourier Transform (FFT), which is the core of most modulators. This paper presents FPGA implementation of pipeline digit-slicing multiplier-less radix 2 2 DIF (Decimation In Frequency) SDF (single path delay feedback) butterfly for FFT structure. The approach taken; in order to reduce computation complexity in butterfly multiplier, digit-slicing multiplier-less technique was utilized in the critical path of pipeline Radix-2 2 DIF SDF FFT structure. The proposed design focused on the trade-off between the speed and active silicon area for the chip implementation. The multiplier input data was sliced into four blocks each one with four bits to process at the same time in parallel. The new architecture was investigated and simulated with MATLAB software. The Verilog HDL code in Xilinx ISE environment was derived to describe the FFT Butterfly functionality and was downloaded to Virtex II FPGA board. Consequently, the Virtex-II FG456 Proto board was used to implement and test the design on the real hardware. As a result, from the findings, the synthesis report indicates the maximum clock frequency of 555.75 MHz with the total equivalent gate count of 32,146 is a marked and significant improvement over Radix 2 2 DIF SDF FFT butterfly. In comparison with the conventional butterfly architecture design which can only run at a maximum clock frequency of 200.102 MHz and the conventional multiplier can only run at a maximum clock frequency of 221.140 MHz, the proposed system exhibits better results. It can be concluded that on-chip implementation of pipeline digit-slicing multiplier-less butterfly for FFT structure is an enabler in solving problems that affect communications capability in FFT and possesses huge potentials for future related works and research areas. Key words— Pipelined digit-slicing multiplier-less; Fast Fourier Transform (FFT); Verilog HDL; Xilinx; Radix 22 DIF SDF FFT.

A new on-chip implementation of Fast Fourier Transform (FFT) based on Radix 2 is presented. The pipeline and parallel approaches are combined to introduce a new high speed FFT algorithm which increases resolution by using floating point... more

A new on-chip implementation of Fast Fourier Transform (FFT) based on Radix 2 is presented. The pipeline and parallel approaches are combined to introduce a new high speed FFT algorithm which increases resolution by using floating point calculations in its structures. The design has the merits of low complexity and high speed performance. Furthermore, latency reduction is an important issue to implement the high speed FFT on FPGA. The proposed FFT algorithm shows the latency of   11 log 2 2  N N. Moreover, this algorithm has the advantage of low mean squared error (MSE) of 0.0001 which is preferable to Radix 2 FFT.

Copy-move forgery is one of the most common type of tampering in digital images. Copy-moves are parts of the image that are copied and pasted onto another part of the same image. Detection methods in general use block-matching methods,... more

Copy-move forgery is one of the most common type of tampering in digital images. Copy-moves are parts of the image that are copied and pasted onto another part of the same image. Detection methods in general use block-matching methods, which first divide the image into overlapping blocks and then extract features from each block, assuming similar blocks will yield similar features. In this paper we present a block-based approach which exploits texture as feature to be extracted from blocks. Our goal is to study if texture is well suited for the specific application, and to compare performance of several texture descriptors. Tests have
been made on both uncompressed and JPEG compressed images.

Most communications systems tend to achieve bandwidth, power and cost efficiencies to capable to describe modulation scheme. Hence for signal modulation orthogonal frequency division multiplexing (OFDM) transceiver is introduced to cover... more

Most communications systems tend to achieve bandwidth, power and cost efficiencies to capable to describe modulation scheme. Hence for signal modulation orthogonal frequency division multiplexing (OFDM) transceiver is introduced to cover communications demand in four generation. However high performance Fast Fourier Transforms (FFT) as a main heart of OFDM acts beyond the view. In order to achieve capable FFT, design and realization of its efficient internal structure is key issues of this research work. In this paper implementation of high performance butterfly for FFT by applying digit slicing technique is presented. The proposed design focused on the trade-off between the speed and active silicon area for the chip implementation. The new architecture was investigated and simulated with the MATLAB software. The Verilog HDL code in Xilinx ISE environment was derived to describe the FFT Butterfly functionality and was downloaded to Virtex II FPGA board.

Different methods have been experimented for processing and detecting forgery in digital images. Image forgery involves various activities like copy-move forgery, image slicing, retouching, morphing etc. In copy-move forgery a portion... more

Different methods have been experimented for processing and detecting forgery in digital images. Image forgery involves various activities like copy-move forgery, image slicing, retouching, morphing etc. In copy-move forgery a portion within the image is copied and pasted on another part of the same image, generally to conceal or enhance certain portions of the image. This paper proposes a copy-move forgery detection using local fractal dimension and structural similarity indices. The image is classified into different texture regions based on the local fractal dimension. Forgery checking is thus confined to be among the portions within a region. Structural similarity index measure is applied to each block pair in
each region to localize the forged portion. Experimental results prove that this hybrid method can effectively detect such kind of image tampering with minimum false positives.

Image forgery detection is currently one of the interested research fields of image processing. Copy-Move (CM) forgery is one of the most commonly techniques. In this paper, we propose an efficient methodology for fast CM forgery... more

Image forgery detection is currently one of the interested research fields of image processing. Copy-Move (CM) forgery is one of the most commonly techniques. In this paper, we propose an efficient methodology for fast CM forgery detection. The proposed method accelerates blocking matching strategy. Firstly, the image is divided into fixed-size overlapping blocks then Discrete Cosine Transform (DCT) is applied to each block to represent its features, which are used to indirectly compare the blocks. After sorting the
blocks based on DCT coefficients, a distance is measured between nearby blocks to denote their similarity. The proposed Fan Search (FS) algorithm starts once a duplicated block is detected. Instead of exhaustive search for all blocks,
the nearby blocks of the detected block are examined first in a spiral order. The experimental results demonstrate that the proposed method can detect the duplicated regions efficiently, and reduce processing time up to 75% less than
other previous works.

The need for wireless communication has driven the communication systems to high performance. However, the main bottleneck that affects the communication capability is the Fast Fourier Transform (FFT), which is the core of most... more

The need for wireless communication has driven the communication systems to high performance. However, the main bottleneck that affects the communication capability is the Fast Fourier Transform (FFT), which is the core of most modulators. This study presents on-chip implementation of pipeline digit-slicing multiplier-less butterfly for FFT structure. The approach taken; in order to reduce computation complexity in butterfly, digit-slicing multiplier-less single constant technique was utilized in the critical path of Radix-2 Decimation In Time (DIT) FFT structure. The proposed design focused on the trade-off between the speed and active silicon area for the chip implementation. The new architecture was investigated and simulated with MATLAB software. The Verilog HDL code in Xilinx ISE environment was derived to describe the FFT Butterfly functionality and was downloaded to Virtex II FPGA board. Consequently, the Virtex-II FG456 Proto board was used to implement and test the design on the real hardware. As a result, from the findings, the synthesis report indicates the maximum clock frequency of 549.75 MHz with the total equivalent gate count of 31,159 is a marked and significant improvement over Radix 2 FFT butterfly. In comparison with the conventional butterfly architecture, design that can only run at a maximum clock frequency of 198.987 MHz and the conventional multiplier can only run at a maximum clock frequency of 220.160 MHz, the proposed system exhibits better results. The resulting maximum clock frequency increases by about 276.28% for the FFT butterfly and about 277.06% for the multiplier. It can be concluded that on-chip implementation of pipeline digit-slicing multiplier-less butterfly for FFT structure is an enabler in solving problems that affect communications capability in FFT and possesses huge potentials for future related works and research areas.

Copy-move forgeries are parts of the image that are duplicated elsewhere into the same image, often after being modified by geometrical transformations. In this paper we present a method to detect these image alterations, using a... more

Copy-move forgeries are parts of the image that are duplicated elsewhere into the same image, often after being modified by geometrical transformations. In this paper we present a method to detect these image alterations, using a SIFT-based approach. First we describe a state of the art SIFT-point matching method, which inspired our algorithm, then we compare it with our SIFT-based approach, which consists of three parts: keypoint clustering, cluster matching, and texture analysis. The goal is to find copies of the same object, i.e. clusters of points, rather than points that match. Cluster matching proves to give better results than single point matching, since it returns a complete and coherent comparison between copied objects. At last, textures of matching areas are analyzed and compared to validate results and to eliminate false positives.

This paper presents on-chip implementation of high speed low latency floating point adder /subtractor with high accuracy performance for FFT in OFDM transceiver. However due to high performance and high resolution, the floating point... more

This paper presents on-chip implementation of high speed low latency floating point adder /subtractor with high accuracy performance for FFT in OFDM transceiver. However due to high performance and high resolution, the floating point adder is matched with power network applications as well. The design was implemented for 32-bit pipelined adder/subtractor which satisfied IEEE-754 Standard for floating –point Arithmetic. The design is focused on the trade-off between the latency and speed improvement as well as resolution and silicon area for the chip implementation. In order to reduce the critical path and decrease the latency, the novel structure was designed and investigated. Consequently, synthesis report indicating the latency of 4 clock cycles due to each stage operate within just one clock cycle. The unique structure of designed adder well thought out. The synthesis software provides results representing the estimated area and delay for design when it is pipelined to various depths.

Photographs are taken as valid evidences in various scenarios of our day to day life. Because of the developments in the field of Image Processing, altering images according to ones need is not a difficult task. Techniques of Image... more

Photographs are taken as valid evidences in various scenarios of our day to day life. Because of the developments in the field of Image Processing, altering images according to ones need is not a difficult task. Techniques of Image Forensics play its crucial role at this juncture. One of the mostly found types of image tampering is Copy-Move forgery. A copy-move forgery is performed by copying a region in an image and pasting it on another region in the same image, mostly after some form of post-processing like rotation, scaling, blurring, noise addition, JPEG compression etc. Two types of copy-move forgery detection techniques exist in literature. They are the Block based methods and Key-point based methods. Both the methods have their own advantages and limitations. This paper presents a survey on the recent developments in block based methods.

Abstract: Digital images are extensively used as communication medium. Forgeries in digital image have grown to be a severe concern, owing to easy and liberated accessibility of puissant image processing tools. The literature addresses... more

Abstract: Digital images are extensively used as communication medium. Forgeries in digital image have
grown to be a severe concern, owing to easy and liberated accessibility of puissant image processing tools. The
literature addresses the stated issue extensively and presents solutions to them. The proposed elucidations have
some commonalities in their methodologies. Nearly all of them are at variance either in feature extraction or in
similarity measure used for forgery detection. A tool is missing in the literature that is capable to detect forgery
on the choice of feature or similarity measure (the other steps of forgery detection remains same as these are
extracted commonalities), and even perform the comparisons. In this paper, a GUI tool is proposed and
designed to detect the Copy-Move forgery in digital images. This tool localizes image areas that are identical or
extremely similar. Firstly, the tool decomposes the input image into number of overlapping chunks. It is
followed by desired feature extraction. Further, duplicated regions are identified using the chosen similarity
criterion. This approach allows the flexibility in selection of feature and similarity measure.
Keywords: Image processing, digital image forensics, digital tampering, feature extraction, similarity measure

The photovoltaic system uses the photovoltaic array as a source of electrical power for the direct conversion of the sun's radiation to direct current without any environmental hazards. The main purpose of this research is to design of a... more

The photovoltaic system uses the photovoltaic array as a source of electrical power for the direct conversion of the sun's radiation to direct current without any environmental hazards. The main purpose of this research is to design of a converter with Maximum Power Point Tracker (MPPT) algorithm for any typical application of soil humidity control. Using this setup the major energy from the solar panel is used for the control of soil humidity. The design of the converter with MPPT together with the soil humidity control logic is presented in this paper. Experimental testing of the design controller is implemented and evaluated for performance under laboratory environment.

With the advent of powerful image editing tools, manipulating images and changing their content is becoming a trivial task. It is now possible to add, modify, or remove important features from an image without leaving any perceptual... more

With the advent of powerful image editing tools, manipulating images and changing their content is becoming a trivial task. It is now possible to add, modify, or remove important features from an image without leaving any perceptual traces of tampering. With more than several million pictures uploaded daily to the net, and the introduction of e-Government services, it is becoming important to develop robust detection methods to identify image tampering operations. To this end, image forensics techniques aim at restoring trust and acceptance in digital media by uncovering tampering methods. Such detection techniques are the focus of this paper. In particular, we provide a survey of different forging detection techniques with a focus on copy and move approaches.

In today’s era role of digital image is eloquent. With its escalating importance and usage it becomes necessary to assess if the content is realistic or has been manipulated to trick the observer. Image forensics answers all these... more

In today’s era role of digital image is eloquent. With its escalating importance and usage it becomes necessary to assess if the content is realistic or has been manipulated to trick the observer. Image forensics answers all these questions. Adding some useful features or eliminating awkward information is the extensively used tampering technique. The image forgery caused using this technique refers to cloning or copy-move attack. This paper elaborates the manifold techniques to detect cloned image forgery.