With the rapid development of image processing technology, it is getting easier to tamper with digital images without leaving any obvious visual trace. Today, seeing does no longer believe [1]. Image forgery, like any other illegal and pernicious activity, could cause serious harm to society.
Digital image forensics is a new emerging field. The aim of image forensics is to detect whether an image has been tampered with. With the widespread usage of high-resolution digital cameras and highly advanced photo editing software, image tampering has become more commonplace, it may be often required to re-sample (resize/rotate/stretch) the image to make it look natural.
Therefore, verifying the authenticity of digital images has become a very important issue. JPEG is one of the most commonly used compression schemes in many practical applications. Therefore JPEG image forensics has attracted increasing attention recently. Typically, there are two significant properties available for forensic analysis. The first and the most obvious property are the blocking artifacts in the spatial domain. Due to the block-based processing in the lossy JPEG compression, the discontinuous pixels usually occur in the boundary between two adjacent 8 × 8 blocks.
Such a blocking signature can served as an evidence of JPEG compression [2], and some tampering operations [3]. Another important property is the quantization artifacts in the DCT frequency domain. During JPEG compression, each DCT frequency component in the 8 × 8 block is quantized by a quantization step. It will lead to a specific shape of the corresponding DCT histogram.
That is, those dequantized coefficients will just cluster in the multiples of the quantization step. Combined with the Laplac...
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...ting the disparity map was based on belief propagation and mean shift segmentation [19]. The disparity map and the reference image (JI_L) are segmented into some objects. The objects and the average disparity of these objects are denoted by O_(JI_L)^i & d_(JI_L)^i, respectively, i = 1,2,…,m. If d_(JI_L)^i is in [D_b,D_f ], O_(JI_L)^i is regarded as the main content, O_(JI_L)^i∈O_maipart.If d_(JI_L)^iis not in [D_b,D_f ], O_(JI_L)^i is regarded as the background, O_(JI_L)^i∈O_background. That is,
O_(JI_L)^i∈{█(O_mainpart d_(JI_L)^i∈[D_b,D_f ] @O_background d_(JI_L)^i∉[D_b,D_f ] )→(1)┤
A seam is an optimal eight-connected path of pixels on a single JPEG image from top to bottom (vertical) and consisted of one and only one pixel in each row, which guarantees that the JPEG image keeps a rectangle when the seams are removed. In [20], an energy function defines the
Forensics investigations that require the analyzation and processing of digital evidence can be influenced both positively and negatively by a number of outside sources. In this paper, we will explore how physical security plays a role in forensics investigations activities. We will start by examining how physical and environmental security might impact the forensics investigation process. Next, we will discuss the role that physical and logical security zones play in supporting effective forensics activities. We will illustrate how centralized and decentralized physical and environmental security affects the forensics professional’s approach toward the investigation. Lastly, we will evaluate some potential areas of risk related to the physical security of our case study organization, Widget Factory, identified in Attachment 1.
In photospreads, there are numerous ways that one picture can be subtly different: lighting, color tone, brightness, sharpness, viewing angle, background or location of face in the frame (Green, 2013)”. According to Green these few factors alone cause eyewitness testimony to be 90 percent incorrect. However, digging a little deeper into the eyewitness testimony and police proceeding coming to eye witnesses (Green,
the mean value and the standard deviation, to represent the global characteristics of the image, and the image bitmap is used to represent the local characteristics of the image for increasing the accuracy of the retrieval system. Aptoula et al. [8] presen...
There is a wide range of Linux forensic software available. There are single tools like file carvers, or there are comprehensive collections of tools. In the following, some of the most popular Linux forensic tools are described. The focus is put on The Sleuth Kit because it is organized according to the different filesystem layers. This provides an interesting insight on how forensics is done on filesystems.
A common characteristic of most of the images is that the neighboring pixels are highly correlated and therefore contain superfluous information. I...
There are many private companies or public spaces still using CCTV (analogue) at low resolution formats for surveillance purposes. Analogue CCTV has great disadvantage in resolution compared to megapixels or high resolution CCTV (Cavoukian, 2001). According to Ratcliffe (2006) analogue resolution is enough for general su...
We are being hired as a consultant to help respond to a small medical office in which they learned that 10 of their employees have been victims of identity theft. The office has 55 total employees amongst two office locations. They have one workstation per employee and different kinds of computer operating systems in use. There is a mixture of Windows 7, Vista, and XP operating systems. The servers being used are Windows 2003 and 2008 versions. This is used for the billing system which hasn’t been updated to cloud services. As a consultant, I will try to help the business by looking at how their information was being received by the attacker, to prevent further attacks, and to check
...ction for the tampering decision. Texture- and edge-based features are extracted from illuminant estimators which are then provided to a machine-learning approach for automatic decision-making. SVM is used for classification and detection rates of 86% on a dataset consisting of 200 images and 83% on 50 images collected from the Internet was achieved. Another detection scheme based on blur as a clue is proposed in [77]. This method expose the presence of splicing by evaluating inconsistencies in motion blur even under space-variant blurring situations.
First, we should establish that image manipulations are a common occurrence, and always have been. In an article on Fstoppers, Alex Cooke points out that “anything, anything at all, that modifies a capture
The book gives a general overview of the field of forensic science. The sections of the book include “The Scene of the Crime; Working the Scene--The Evidence; Working the Scene of the Body Human; Working the Scene--Different Stages; and Working the Scene--Different Skills (Genge vii-viii). Included are instructions on what professionals should do upon arriving at a crime scene, what items to bring with them, how to protect the crime scene, and how to protect the evidence from contamination. In addition to writing about the subject of forensic science, the author also included several appendixes and suggested readings to help the reader learn even more information about the subject. In addition, the author included a list of colleges that offer programs in the field of forensic science.
The word steganography comes from the Greek name “steganos” which means hidden or secret, and the word graphy, which means writing or drawing. Put them together, and it literally translates to mean “hidden writing” (Richer, 2010). According to Dictionary.com, steganography is “the art of writing in cipher, or in characters, which are not intelligible except to persons who have the key; cryptography.” In the modern use of the word, steganography means the practice of hiding messages within larger messages so that others cannot detect what the message contains, or even that the message is there. It replaces redundant bits in images or other media with secret information from the hidden message. The redundant bits are used because they can be changed without making a noticeable change in the image or sound file.
We do have known what forensics is. Forensics that we know is an application of various sciences to answer questions that are important to legal system in which it may be related to a crime. Forensics generallu covering something or methods of a scientific nature and also the rules established from the facts of the event, to do an introduction to physical evidence. This is just a usual forensics. Nowadays, forensics is not just like that, digital devices are everywhere today, helping people to communicate with other people globally, not just between town. We can use that to do some forensics thing too, and find the evidence. It is called Digital Forensics.
Forensic Science, recognized as Forensics, is the solicitation of science to law to understand evidences for crime investigation. Forensic scientists are investigators that collect evidences at the crime scene and analyse it uses technology to reveal scientific evidence in a range of fields. Physical evidence are included things that can be seen, whether with the naked eye or through the use of magnification or other analytical tools. Some of this evidence is categorized as impression evidence2.In this report I’ll determine the areas of forensic science that are relevant to particular investigation and setting out in what method the forensic science procedures I have recognized that would be useful for the particular crime scene.
The transitional growth in the forensic science sector has not been without challenges. Though the world has experienced increased capabilities and scientific knowledge, which has led to faster investigations and results, many forensic experts have argued that forensic laboratory testing, in the light of 21st century technological advancements, is yet to meet the expected rate in quick available testing and analysis (Mennell & Shaw, 2006). This is with respect to the growing rate of crime and the high demand of quick crime scene testing and analysis. In the science of crime scene, analysis and interpretation of evidence is majorly dependent on forensic science, highlighting the change in the role of forensic sciences (Tjin-A-Tsoi, 2013). In the business of forensic science, time is beginning to play important role in the evidence testing and analysis which is becoming crucial in reducing ...
The ability to alter images can open creative outlets for photographers and In turn, produce better quality work. Any photog...