The autopsy and histopathologic examination are traditional and classic approaches in forensic pathology.In recent years,with the tremendous progresses of computer technology and medical imaging technology,the develop...The autopsy and histopathologic examination are traditional and classic approaches in forensic pathology.In recent years,with the tremendous progresses of computer technology and medical imaging technology,the developed post-mortem computer tomography,post-mortem magnetic resonance imaging and other new methods provide non-invasive,intuitive,high-precision examining methods and research tools for the forensic pathology.As a result,the reconstruction of the injury as well as the analysis of injury mechanism has been essentially achieved.Such methods have become popular in the research field of forensic science and related work has also been carried out in China.This paper reviews the development and application of abovementioned post-mortem forensic imaging methods in China based on the relevant literature.展开更多
Clinical forensic imaging encompasses the diverse application of imaging procedures that serve the same purpose:to enable the analysis and investigation of criminal activities and consequences of a crime.All kinds of ...Clinical forensic imaging encompasses the diverse application of imaging procedures that serve the same purpose:to enable the analysis and investigation of criminal activities and consequences of a crime.All kinds of imaging techniques and their corresponding images can be subsumed under“forensigraphy”,a more comprehensive term for forensic imaging created by the Ludwig Boltzmann Institute for Clinical Forensic Imaging in Graz,Austria.As the word forensigraphy suggests,criminal imaging material should be of use in forensic investigations.Ideally,this can lead to new findings that would not have been revealed without the application of imaging techniques and are moreover admissible as evidence in criminal proceedings.However,the admissibility of evidence can only be facilitated through the implementation of clinical forensic imaging techniques into the forensic routine case work,which requires a precise pre-analysis of the corresponding legal framework.Because taking and displaying internal images of a person’s body touches upon various aspects of one’s physical and psychological integrity,imaging methods in general and clinical forensic imaging methods especially have a strong impact on and interfere regularly with the fundamental rights of the concerned person.Particularly with regard to a possible medical context,certain legal regulations have to be taken into account.Therefore,this paper examines forensic imaging in the field of radiological forensigraphy,specifically its in vivo(i.e.clinical)application.It is designed to enlighten readers as to the great significance of legal barriers that emerge from fundamental rights,as laid down in the European Convention on Human Rights(ECHR),when dealing with clinical forensic imaging.As a result,the legal framework of clinical forensic imaging procedures are comprehensively described,the relevant fundamental rights,especially the right to respect for private and family life,the right to data protection and certain procedural guarantees,are concisely presented to further raise awareness regarding the importance of fundamental rights.展开更多
Forensic imaging is a non-invasive examination process during the forensic investigation.It is mainly used in forensic pathology as an adjunct to the traditional autopsy.In the past two decades,forensic imaging has be...Forensic imaging is a non-invasive examination process during the forensic investigation.It is mainly used in forensic pathology as an adjunct to the traditional autopsy.In the past two decades,forensic imaging has been vigorously developed by forensic experts from computed tomography(CT)to multiple augmented techniques through CT and magnetic resonance imaging(MRI).The application field of forensic imaging has also been broadened as its advantages are recognised by more forensic practitioners.In addition to the forensic pathology,this technique has been used in other forensic disciplines,including forensic anthropology,forensic odontology,forensic ballistics and wildlife forensics,etc.This article reviews the development of forensic imaging as the practice and research development in different forensic disciplines based on the relevant literature analysis.展开更多
Background:Postmortem imaging has played an important role in the field of forensic medicine.Objective:To preliminarily explore the application value of cadaver imaging in mechanical injury.Methods:Three cases of mech...Background:Postmortem imaging has played an important role in the field of forensic medicine.Objective:To preliminarily explore the application value of cadaver imaging in mechanical injury.Methods:Three cases of mechanical injury were collected,and the external examination,postmortem computed tomography(PMCT),postmortem computed tomography angiography(PMCTA),and autopsy examination were performed in proper order to compare and analyze the diagnostic ability of postmortem imaging in the exploration of fractures,organ ruptures,and bleeding sources.Conclusion:Postmortem imaging(PMCT and PMCTA)has important application value in the analysis of cause of death,inference of injury objects,wound reconstruction,and search for bleeding sources.The combination of postmortem imaging and traditional anatomy can significantly imp rove the quality of forensic examinations.展开更多
In today’s digital era,the rapid evolution of image editing technologies has brought about a significant simplification of image manipulation.Unfortunately,this progress has also given rise to the misuse of manipulat...In today’s digital era,the rapid evolution of image editing technologies has brought about a significant simplification of image manipulation.Unfortunately,this progress has also given rise to the misuse of manipulated images across various domains.One of the pressing challenges stemming from this advancement is the increasing difficulty in discerning between unaltered and manipulated images.This paper offers a comprehensive survey of existing methodologies for detecting image tampering,shedding light on the diverse approaches employed in the field of contemporary image forensics.The methods used to identify image forgery can be broadly classified into two primary categories:classical machine learning techniques,heavily reliant on manually crafted features,and deep learning methods.Additionally,this paper explores recent developments in image forensics,placing particular emphasis on the detection of counterfeit colorization.Image colorization involves predicting colors for grayscale images,thereby enhancing their visual appeal.The advancements in colorization techniques have reached a level where distinguishing between authentic and forged images with the naked eye has become an exceptionally challenging task.This paper serves as an in-depth exploration of the intricacies of image forensics in the modern age,with a specific focus on the detection of colorization forgery,presenting a comprehensive overview of methodologies in this critical field.展开更多
Images and videos play an increasingly vital role in daily life and are widely utilized as key evidentiary sources in judicial investigations and forensic analysis.Simultaneously,advancements in image and video proces...Images and videos play an increasingly vital role in daily life and are widely utilized as key evidentiary sources in judicial investigations and forensic analysis.Simultaneously,advancements in image and video processing technologies have facilitated the widespread availability of powerful editing tools,such as Deepfakes,enabling anyone to easily create manipulated or fake visual content,which poses an enormous threat to social security and public trust.To verify the authenticity and integrity of images and videos,numerous approaches have been proposed,which are primarily based on content analysis and their effectiveness is susceptible to interference from various image or video post-processing operations.Recent research has highlighted the potential of file containers analysis as a promising forensic approach that offers efficient and interpretable results.However,there is still a lack of review articles on this kind of approach.In order to fill this gap,we present a comprehensive review of file containers-based image and video forensics in this paper.Specifically,we categorize the existing methods into two distinct stages,qualitative analysis and quantitative analysis.In addition,an overall framework is proposed to organize the exiting approaches.Then,the advantages and disadvantages of the schemes used across different forensic tasks are provided.Finally,we outline the trends in this research area,aiming to provide valuable insights and technical guidance for future research.展开更多
Modern post-mortem investigations use an increasing number of digital imaging methods,which can be collected under the term“post-mortem imaging”.Most methods of forensic imaging are from the radiology field and are ...Modern post-mortem investigations use an increasing number of digital imaging methods,which can be collected under the term“post-mortem imaging”.Most methods of forensic imaging are from the radiology field and are therefore techniques that show the interior of the body with technologies such as X-ray or magnetic resonance imaging.To digitally image the surface of the body,other techniques are regularly applied,e.g.three-dimensional(3D)surface scanning(3DSS)or photogrammetry.Today’s most frequently used techniques include post-mortem computed tomography(PMCT),post-mortem magnetic resonance imaging(PMMR),post-mortem computed tomographic angiography(PMCTA)and 3DSS or photogrammetry.Each of these methods has specific advantages and limitations.Therefore,the indications for using each method are different.While PMCT gives a rapid overview of the interior of the body and depicts the skeletal system and radiopaque foreign bodies,PMMR allows investigation of soft tissues and parenchymal organs.PMCTA is the method of choice for viewing the vascular system and detecting sources of bleeding.However,none of those radiological methods allow a detailed digital view of the body’s surface,which makes 3DSS the best choice for such a purpose.If 3D surface scanners are not available,photogrammetry is an alternative.This review article gives an overview of different imaging techniques and explains their applications,advantages and limitations.We hope it will improve understanding of the methods.展开更多
As the advent and growing popularity of image rendering software,photorealistic computer graphics are becoming more and more perceptually indistinguishable from photographic images.If the faked images are abused,it ma...As the advent and growing popularity of image rendering software,photorealistic computer graphics are becoming more and more perceptually indistinguishable from photographic images.If the faked images are abused,it may lead to potential social,legal or private consequences.To this end,it is very necessary and also challenging to find effective methods to differentiate between them.In this paper,a novel leading digit law,also called Benford's law,based method to identify computer graphics is proposed.More specifically,statistics of the most significant digits are extracted from image's Discrete Cosine Transform(DCT) coefficients and magnitudes of image's gradient,and then the Support Vector Machine(SVM) based classifiers are built.Results of experiments on the image datasets indicate that the proposed method is comparable to prior works.Besides,it possesses low dimensional features and low computational complexity.展开更多
As a common medium in our daily life,images are important for most people to gather information.There are also people who edit or even tamper images to deliberately deliver false information under different purposes.T...As a common medium in our daily life,images are important for most people to gather information.There are also people who edit or even tamper images to deliberately deliver false information under different purposes.Thus,in digital forensics,it is necessary to understand the manipulating history of images.That requires to verify all possible manipulations applied to images.Among all the image editing manipulations,recoloring is widely used to adjust or repaint the colors in images.The color information is an important visual information that image can deliver.Thus,it is necessary to guarantee the correctness of color in digital forensics.On the other hand,many image retouching or editing applications or software are equipped with recoloring function.This enables ordinary people without expertise of image processing to apply recoloring for images.Hence,in order to secure the color information of images,in this paper,a recoloring detection method is proposed.The method is based on convolutional neural network which is quite popular in recent years.Unlike the traditional linear classifier,the proposed method can be employed for binary classification as well as multiple labels classification.The classification performance of different structure for the proposed architecture is also investigated in this paper.展开更多
The multi-purpose forensics is an important tool for forge image detection.In this paper,we propose a universal feature set for the multi-purpose forensics which is capable of simultaneously identifying several typica...The multi-purpose forensics is an important tool for forge image detection.In this paper,we propose a universal feature set for the multi-purpose forensics which is capable of simultaneously identifying several typical image manipulations,including spatial low-pass Gaussian blurring,median filtering,re-sampling,and JPEG compression.To eliminate the influences caused by diverse image contents on the effectiveness and robustness of the feature,a residual group which contains several high-pass filtered residuals is introduced.The partial correlation coefficient is exploited from the residual group to purely measure neighborhood correlations in a linear way.Besides that,we also combine autoregressive coefficient and transition probability to form the proposed composite feature which is used to measure how manipulations change the neighborhood relationships in both linear and non-linear way.After a series of dimension reductions,the proposed feature set can accelerate the training and testing for the multi-purpose forensics.The proposed feature set is then fed into a multi-classifier to train a multi-purpose detector.Experimental results show that the proposed detector can identify several typical image manipulations,and is superior to the complicated deep CNN-based methods in terms of detection accuracy and time efficiency for JPEG compressed image with low resolution.展开更多
Research in virtualization technology has gained significant developments in recent years, which brings not only opportunities to the forensic community, but challenges as well. This paper discusses the potential role...Research in virtualization technology has gained significant developments in recent years, which brings not only opportunities to the forensic community, but challenges as well. This paper discusses the potential roles of virtualization in digital forensics, examines the recent progresses which use the virtualization techniques to support modem computer forensics. The influences on digital forensics caused by virtualization technology are identified. Tools and methods in common digital forensic practices are analyzed, and experiences of our practice and reflections in this field are shared.展开更多
Diseases not only bring troubles to people’s body functions and mind but also influence the appearances and behaviours of human beings.Similarly,we can analyse the diseases from people’s appearances and behaviours a...Diseases not only bring troubles to people’s body functions and mind but also influence the appearances and behaviours of human beings.Similarly,we can analyse the diseases from people’s appearances and behaviours and use the personal medical history for human identification.In this article,medical indicators presented in abnormal changes of human appearances and behaviours caused by physiological or psychological diseases were introduced,and were applied in the field of forensic identification of human images,which we called medical forensic identification of human images(mFIHI).The proposed method analysed the people’s medical signs by studying the appearance and behaviour characteristics depicted in images or videos,and made a comparative examination between the medical indicators of the questioned human images and the corresponding signs or medical history of suspects.Through a conformity and difference analysis on medical indicators and their indicated diseases,it would provide an important information for human identification from images or videos.A case study was carried out to demonstrate and verify the feasibility of the proposed method of mFIHI,and our results showed that it would be important contents and angles for forensic expert manual examination in forensic human image identification.展开更多
In the field of image forensics,image tampering detection is a critical and challenging task.Traditional methods based on manually designed feature extraction typically focus on a specific type of tampering operation,...In the field of image forensics,image tampering detection is a critical and challenging task.Traditional methods based on manually designed feature extraction typically focus on a specific type of tampering operation,which limits their effectiveness in complex scenarios involving multiple forms of tampering.Although deep learningbasedmethods offer the advantage of automatic feature learning,current approaches still require further improvements in terms of detection accuracy and computational efficiency.To address these challenges,this study applies the UNet 3+model to image tampering detection and proposes a hybrid framework,referred to as DDT-Net(Deep Detail Tracking Network),which integrates deep learning with traditional detection techniques.In contrast to traditional additive methods,this approach innovatively applies amultiplicative fusion technique during downsampling,effectively combining the deep learning feature maps at each layer with those generated by the Bayar noise stream.This design enables noise residual features to guide the learning of semantic features more precisely and efficiently,thus facilitating comprehensive feature-level interaction.Furthermore,by leveraging the complementary strengths of deep networks in capturing large-scale semantic manipulations and traditional algorithms’proficiency in detecting fine-grained local traces,the method significantly enhances the accuracy and robustness of tampered region detection.Compared with other approaches,the proposed method achieves an F1 score improvement exceeding 30% on the DEFACTO and DIS25k datasets.In addition,it has been extensively validated on other datasets,including CASIA and DIS25k.Experimental results demonstrate that this method achieves outstanding performance across various types of image tampering detection tasks.展开更多
Targeted post-mortem computed tomography(PMCT)combined with coronary angiography has the potential to play a significant role in the investigation of sudden cardiac death.The authors utilized a targeted PMCT coronary ...Targeted post-mortem computed tomography(PMCT)combined with coronary angiography has the potential to play a significant role in the investigation of sudden cardiac death.The authors utilized a targeted PMCT coronary angiography in a case involving a 53-year-old man who died from acute myocardial ischemia and cardiac decompensation which may result from coronary artery disease(CAD).The victim collapsed suddenly at work and died soon after arrival to hospital.The body was examined using PMCT and targeted PMCT coronary angiography.The left anterior descending coronary artery exhibited 75%-100%stenosis in the middle segment;however,the distal segment could not be clearly visualized.In addition,the left circumflex and right coronary artery exhibited calcification,atherosclerosis and an area of 50% stenosis.Signs of cardiogenic pulmonary oedema were also identified.The imaging results suggested that this individual had coronary atherosclerosis and probably died from CAD.The autopsy and histological examination revealed acute myocardial ischemia and myocardial scarring,confirming the cause of death while excluding other probabilities.In summary,targeted post-mortem computed tomography angiography(PMCTA)can visualize the arteries and estimate the degree of principal pathological changes.This method is a simple,reliable and sensitive technique for identifying the presence of coronary atherosclerosis.It is a valuable post-mortem forensic imaging method and should be recommended in the investigation of suspicious cardiac deaths.展开更多
Three-dimensional surface scanning(3DSS)and multi-detector computed tomography(MDCT)are two techniques that are used in legal medicine for digitalizing objects,a body or body parts such as bones.While these techniques...Three-dimensional surface scanning(3DSS)and multi-detector computed tomography(MDCT)are two techniques that are used in legal medicine for digitalizing objects,a body or body parts such as bones.While these techniques are more and more commonly employed,surprisingly little information is known about the quality rendering of digitalized three-dimensional(3D)models provided by each of them.This paper presents findings related to the measurement precision of 3D models obtained through observation of a study case,where a fractured skull reconstructed by an anthropologist was digitalized using both post-mortem imaging methods.Computed tomography(CT)scans were performed using an 8-row MDCT unit with two different slice thicknesses.The variability of 3D CT models superimposition allowed to assess the reproducibility and robustness of this digitalization technique.Furthermore,two 3D surface scans were done using a professional high resolution 3D digitizer.The comparison of 3D CT-scans with 3D surface scans by superimposition demonstrated several regions with significant differences in topology(average difference between+1.45 and-1.22 mm).When comparing the reproducibility between these two digitalizing techniques,it appeared that MDCT 3D models led in general to greater variability for measurement precision between scanned surfaces.Also,the reproducibility was better achieved with the 3D surface digitizer,showing 3D models with fewer and less pronounced differences(from+0.32 to-0.31 mm).These experiments suggest that MDCT provides less reproducible body models than 3D surface scanning.But further studies must be undertaken in order to corroborate this first impression,and possibly explain the reason for these findings.展开更多
This case reports on a 68-year-old man who was found dead in hospital next to his bed.Before this,he had been treated with intravenous antibiotics for pneumonia.The body was found with a peripheral venous catheter con...This case reports on a 68-year-old man who was found dead in hospital next to his bed.Before this,he had been treated with intravenous antibiotics for pneumonia.The body was found with a peripheral venous catheter connected to a nasal cannula delivering oxygen(O_(2))from the wall.Extensive medico-legal examinations were performed,including post-mortem computed tomography(CT),complete conventional autopsy,histological and immunohistochemistry analysis,toxicological analysis and post-mortem chemistry.Additionally,CT-guided gas sampling was performed at multiple sites to collect samples for gas analysis.During the external examination,massive subcutaneous emphysema was visible over the entire surface of the body.The CT scan revealed the presence of gas throughout the vascular system,and in the subcutaneous and muscular tissues.The autopsy confirmed the presence of lobar pneumonia and multiple gas bubbles in the vascular system.The gas analysis results showed a subnormal concentration of oxygen,confirming the suspected pure O_(2) embolism.Moreover,the carbon dioxide(CO_(2))concentration in the gas sample from the heart was elevated to a level similar to those found in scuba diving fatalities.This could come from degassing of dissolved CO_(2) that accumulated and was trapped in the cardiac cavity.Based on the results of the different exams performed,and especially the gas analysis results,it was concluded that the cause of death was O_(2) embolism.展开更多
Virtual autopsy,or virtopsy,is an innovative forensic technique that employs advanced imaging modalities such as computed tomography and magnetic resonance imaging for the examination of cadavers.Compared to the stand...Virtual autopsy,or virtopsy,is an innovative forensic technique that employs advanced imaging modalities such as computed tomography and magnetic resonance imaging for the examination of cadavers.Compared to the standard autopsy,an invasive procedure,virtual autopsy is noninvasive.This article reviews the forensic applications of virtual autopsy,its advantages and disadvantages,and compares it to traditional autopsy techniques.It emphasizes the expanding role of virtual autopsies in contemporary forensic investigations and the technological innovations,ethical implications,and logistical hurdles related to these techniques.展开更多
A blind digital image forensic method for detecting copy-paste forgery between JPEG images was proposed.Two copy-paste tampering scenarios were introduced at first:the tampered image was saved in an uncompressed forma...A blind digital image forensic method for detecting copy-paste forgery between JPEG images was proposed.Two copy-paste tampering scenarios were introduced at first:the tampered image was saved in an uncompressed format or in a JPEG compressed format.Then the proposed detection method was analyzed and simulated for all the cases of the two tampering scenarios.The tampered region is detected by computing the averaged sum of absolute difference(ASAD) images between the examined image and a resaved JPEG compressed image at different quality factors.The experimental results show the advantages of the proposed method:capability of detecting small and/or multiple tampered regions,simple computation,and hence fast speed in processing.展开更多
In this paper,a new approach is proposed to determine whether the content of an image is authentic or modified with a focus on detecting complex image tampering.Detecting image tampering without any prior information ...In this paper,a new approach is proposed to determine whether the content of an image is authentic or modified with a focus on detecting complex image tampering.Detecting image tampering without any prior information of the original image is a challenging problem since unknown diverse manipulations may have different characteristics and so do various formats of images.Our principle is that image processing,no matter how complex,may affect image quality,so image quality metrics can be used to distinguish tampered images.In particular,based on the alteration of image quality in modified blocks,the proposed method can locate the tampered areas.Referring to four types of effective no-reference image quality metrics,we obtain 13 features to present an image.The experimental results show that the proposed method is very promising on detecting image tampering and locating the locally tampered areas especially in realistic scenarios.展开更多
Copy-Move Forgery(CMF) is one of the simple and effective operations to create forged digital images.Recently,techniques based on Scale Invariant Features Transform(SIFT) are widely used to detect CMF.Various approach...Copy-Move Forgery(CMF) is one of the simple and effective operations to create forged digital images.Recently,techniques based on Scale Invariant Features Transform(SIFT) are widely used to detect CMF.Various approaches under the SIFT-based framework are the most acceptable ways to CMF detection due to their robust performance.However,for some CMF images,these approaches cannot produce satisfactory detection results.For instance,the number of the matched keypoints may be too less to prove an image to be a CMF image or to generate an accurate result.Sometimes these approaches may even produce error results.According to our observations,one of the reasons is that detection results produced by the SIFT-based framework depend highly on parameters whose values are often determined with experiences.These values are only applicable to a few images,which limits their application.To solve the problem,a novel approach named as CMF Detection with Particle Swarm Optimization(CMFDPSO) is proposed in this paper.CMFD-PSO integrates the Particle Swarm Optimization(PSO) algorithm into the SIFT-based framework.It utilizes the PSO algorithm to generate customized parameter values for images,which are used for CMF detection under the SIFT-based framework.Experimental results show that CMFD-PSO has good performance.展开更多
基金supported by grants from National Key R&D Program of China[grant number 2016YFC0800702]Sci-ence and Technology Committee of Shanghai Municipality[grant numbers 17DZ2273200 and 16DZ2290900]National Natural Science Foundation of China[grant numbers 81571851 and 81401559].
文摘The autopsy and histopathologic examination are traditional and classic approaches in forensic pathology.In recent years,with the tremendous progresses of computer technology and medical imaging technology,the developed post-mortem computer tomography,post-mortem magnetic resonance imaging and other new methods provide non-invasive,intuitive,high-precision examining methods and research tools for the forensic pathology.As a result,the reconstruction of the injury as well as the analysis of injury mechanism has been essentially achieved.Such methods have become popular in the research field of forensic science and related work has also been carried out in China.This paper reviews the development and application of abovementioned post-mortem forensic imaging methods in China based on the relevant literature.
文摘Clinical forensic imaging encompasses the diverse application of imaging procedures that serve the same purpose:to enable the analysis and investigation of criminal activities and consequences of a crime.All kinds of imaging techniques and their corresponding images can be subsumed under“forensigraphy”,a more comprehensive term for forensic imaging created by the Ludwig Boltzmann Institute for Clinical Forensic Imaging in Graz,Austria.As the word forensigraphy suggests,criminal imaging material should be of use in forensic investigations.Ideally,this can lead to new findings that would not have been revealed without the application of imaging techniques and are moreover admissible as evidence in criminal proceedings.However,the admissibility of evidence can only be facilitated through the implementation of clinical forensic imaging techniques into the forensic routine case work,which requires a precise pre-analysis of the corresponding legal framework.Because taking and displaying internal images of a person’s body touches upon various aspects of one’s physical and psychological integrity,imaging methods in general and clinical forensic imaging methods especially have a strong impact on and interfere regularly with the fundamental rights of the concerned person.Particularly with regard to a possible medical context,certain legal regulations have to be taken into account.Therefore,this paper examines forensic imaging in the field of radiological forensigraphy,specifically its in vivo(i.e.clinical)application.It is designed to enlighten readers as to the great significance of legal barriers that emerge from fundamental rights,as laid down in the European Convention on Human Rights(ECHR),when dealing with clinical forensic imaging.As a result,the legal framework of clinical forensic imaging procedures are comprehensively described,the relevant fundamental rights,especially the right to respect for private and family life,the right to data protection and certain procedural guarantees,are concisely presented to further raise awareness regarding the importance of fundamental rights.
文摘Forensic imaging is a non-invasive examination process during the forensic investigation.It is mainly used in forensic pathology as an adjunct to the traditional autopsy.In the past two decades,forensic imaging has been vigorously developed by forensic experts from computed tomography(CT)to multiple augmented techniques through CT and magnetic resonance imaging(MRI).The application field of forensic imaging has also been broadened as its advantages are recognised by more forensic practitioners.In addition to the forensic pathology,this technique has been used in other forensic disciplines,including forensic anthropology,forensic odontology,forensic ballistics and wildlife forensics,etc.This article reviews the development of forensic imaging as the practice and research development in different forensic disciplines based on the relevant literature analysis.
基金supported by the 2023 National Key R and D Program Project(2023YFC3303901)the 2022 Ministry of Public Security Technical Research Program(2022JSYJC10).
文摘Background:Postmortem imaging has played an important role in the field of forensic medicine.Objective:To preliminarily explore the application value of cadaver imaging in mechanical injury.Methods:Three cases of mechanical injury were collected,and the external examination,postmortem computed tomography(PMCT),postmortem computed tomography angiography(PMCTA),and autopsy examination were performed in proper order to compare and analyze the diagnostic ability of postmortem imaging in the exploration of fractures,organ ruptures,and bleeding sources.Conclusion:Postmortem imaging(PMCT and PMCTA)has important application value in the analysis of cause of death,inference of injury objects,wound reconstruction,and search for bleeding sources.The combination of postmortem imaging and traditional anatomy can significantly imp rove the quality of forensic examinations.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2021R1I1A3049788).
文摘In today’s digital era,the rapid evolution of image editing technologies has brought about a significant simplification of image manipulation.Unfortunately,this progress has also given rise to the misuse of manipulated images across various domains.One of the pressing challenges stemming from this advancement is the increasing difficulty in discerning between unaltered and manipulated images.This paper offers a comprehensive survey of existing methodologies for detecting image tampering,shedding light on the diverse approaches employed in the field of contemporary image forensics.The methods used to identify image forgery can be broadly classified into two primary categories:classical machine learning techniques,heavily reliant on manually crafted features,and deep learning methods.Additionally,this paper explores recent developments in image forensics,placing particular emphasis on the detection of counterfeit colorization.Image colorization involves predicting colors for grayscale images,thereby enhancing their visual appeal.The advancements in colorization techniques have reached a level where distinguishing between authentic and forged images with the naked eye has become an exceptionally challenging task.This paper serves as an in-depth exploration of the intricacies of image forensics in the modern age,with a specific focus on the detection of colorization forgery,presenting a comprehensive overview of methodologies in this critical field.
基金supported in part by Natural Science Foundation of Hubei Province of China under Grant 2023AFB016the 2022 Opening Fund for Hubei Key Laboratory of Intelligent Vision Based Monitoring for Hydroelectric Engineering under Grant 2022SDSJ02the Construction Fund for Hubei Key Laboratory of Intelligent Vision Based Monitoring for Hydroelectric Engineering under Grant 2019ZYYD007.
文摘Images and videos play an increasingly vital role in daily life and are widely utilized as key evidentiary sources in judicial investigations and forensic analysis.Simultaneously,advancements in image and video processing technologies have facilitated the widespread availability of powerful editing tools,such as Deepfakes,enabling anyone to easily create manipulated or fake visual content,which poses an enormous threat to social security and public trust.To verify the authenticity and integrity of images and videos,numerous approaches have been proposed,which are primarily based on content analysis and their effectiveness is susceptible to interference from various image or video post-processing operations.Recent research has highlighted the potential of file containers analysis as a promising forensic approach that offers efficient and interpretable results.However,there is still a lack of review articles on this kind of approach.In order to fill this gap,we present a comprehensive review of file containers-based image and video forensics in this paper.Specifically,we categorize the existing methods into two distinct stages,qualitative analysis and quantitative analysis.In addition,an overall framework is proposed to organize the exiting approaches.Then,the advantages and disadvantages of the schemes used across different forensic tasks are provided.Finally,we outline the trends in this research area,aiming to provide valuable insights and technical guidance for future research.
文摘Modern post-mortem investigations use an increasing number of digital imaging methods,which can be collected under the term“post-mortem imaging”.Most methods of forensic imaging are from the radiology field and are therefore techniques that show the interior of the body with technologies such as X-ray or magnetic resonance imaging.To digitally image the surface of the body,other techniques are regularly applied,e.g.three-dimensional(3D)surface scanning(3DSS)or photogrammetry.Today’s most frequently used techniques include post-mortem computed tomography(PMCT),post-mortem magnetic resonance imaging(PMMR),post-mortem computed tomographic angiography(PMCTA)and 3DSS or photogrammetry.Each of these methods has specific advantages and limitations.Therefore,the indications for using each method are different.While PMCT gives a rapid overview of the interior of the body and depicts the skeletal system and radiopaque foreign bodies,PMMR allows investigation of soft tissues and parenchymal organs.PMCTA is the method of choice for viewing the vascular system and detecting sources of bleeding.However,none of those radiological methods allow a detailed digital view of the body’s surface,which makes 3DSS the best choice for such a purpose.If 3D surface scanners are not available,photogrammetry is an alternative.This review article gives an overview of different imaging techniques and explains their applications,advantages and limitations.We hope it will improve understanding of the methods.
文摘As the advent and growing popularity of image rendering software,photorealistic computer graphics are becoming more and more perceptually indistinguishable from photographic images.If the faked images are abused,it may lead to potential social,legal or private consequences.To this end,it is very necessary and also challenging to find effective methods to differentiate between them.In this paper,a novel leading digit law,also called Benford's law,based method to identify computer graphics is proposed.More specifically,statistics of the most significant digits are extracted from image's Discrete Cosine Transform(DCT) coefficients and magnitudes of image's gradient,and then the Support Vector Machine(SVM) based classifiers are built.Results of experiments on the image datasets indicate that the proposed method is comparable to prior works.Besides,it possesses low dimensional features and low computational complexity.
文摘As a common medium in our daily life,images are important for most people to gather information.There are also people who edit or even tamper images to deliberately deliver false information under different purposes.Thus,in digital forensics,it is necessary to understand the manipulating history of images.That requires to verify all possible manipulations applied to images.Among all the image editing manipulations,recoloring is widely used to adjust or repaint the colors in images.The color information is an important visual information that image can deliver.Thus,it is necessary to guarantee the correctness of color in digital forensics.On the other hand,many image retouching or editing applications or software are equipped with recoloring function.This enables ordinary people without expertise of image processing to apply recoloring for images.Hence,in order to secure the color information of images,in this paper,a recoloring detection method is proposed.The method is based on convolutional neural network which is quite popular in recent years.Unlike the traditional linear classifier,the proposed method can be employed for binary classification as well as multiple labels classification.The classification performance of different structure for the proposed architecture is also investigated in this paper.
基金supported by NSFC(No.61702429)Sichuan Science and Technology Program(No.19yyjc1656).
文摘The multi-purpose forensics is an important tool for forge image detection.In this paper,we propose a universal feature set for the multi-purpose forensics which is capable of simultaneously identifying several typical image manipulations,including spatial low-pass Gaussian blurring,median filtering,re-sampling,and JPEG compression.To eliminate the influences caused by diverse image contents on the effectiveness and robustness of the feature,a residual group which contains several high-pass filtered residuals is introduced.The partial correlation coefficient is exploited from the residual group to purely measure neighborhood correlations in a linear way.Besides that,we also combine autoregressive coefficient and transition probability to form the proposed composite feature which is used to measure how manipulations change the neighborhood relationships in both linear and non-linear way.After a series of dimension reductions,the proposed feature set can accelerate the training and testing for the multi-purpose forensics.The proposed feature set is then fed into a multi-classifier to train a multi-purpose detector.Experimental results show that the proposed detector can identify several typical image manipulations,and is superior to the complicated deep CNN-based methods in terms of detection accuracy and time efficiency for JPEG compressed image with low resolution.
文摘Research in virtualization technology has gained significant developments in recent years, which brings not only opportunities to the forensic community, but challenges as well. This paper discusses the potential roles of virtualization in digital forensics, examines the recent progresses which use the virtualization techniques to support modem computer forensics. The influences on digital forensics caused by virtualization technology are identified. Tools and methods in common digital forensic practices are analyzed, and experiences of our practice and reflections in this field are shared.
基金This work is supported by Shanghai Sailing Program[grant number 17YF1420000]Ministry of Finance of the People's Republic of China[grant numbers GY2018G-6 and GY2020G-8].
文摘Diseases not only bring troubles to people’s body functions and mind but also influence the appearances and behaviours of human beings.Similarly,we can analyse the diseases from people’s appearances and behaviours and use the personal medical history for human identification.In this article,medical indicators presented in abnormal changes of human appearances and behaviours caused by physiological or psychological diseases were introduced,and were applied in the field of forensic identification of human images,which we called medical forensic identification of human images(mFIHI).The proposed method analysed the people’s medical signs by studying the appearance and behaviour characteristics depicted in images or videos,and made a comparative examination between the medical indicators of the questioned human images and the corresponding signs or medical history of suspects.Through a conformity and difference analysis on medical indicators and their indicated diseases,it would provide an important information for human identification from images or videos.A case study was carried out to demonstrate and verify the feasibility of the proposed method of mFIHI,and our results showed that it would be important contents and angles for forensic expert manual examination in forensic human image identification.
基金supported by National Natural Science Foundation of China(No.61502274).
文摘In the field of image forensics,image tampering detection is a critical and challenging task.Traditional methods based on manually designed feature extraction typically focus on a specific type of tampering operation,which limits their effectiveness in complex scenarios involving multiple forms of tampering.Although deep learningbasedmethods offer the advantage of automatic feature learning,current approaches still require further improvements in terms of detection accuracy and computational efficiency.To address these challenges,this study applies the UNet 3+model to image tampering detection and proposes a hybrid framework,referred to as DDT-Net(Deep Detail Tracking Network),which integrates deep learning with traditional detection techniques.In contrast to traditional additive methods,this approach innovatively applies amultiplicative fusion technique during downsampling,effectively combining the deep learning feature maps at each layer with those generated by the Bayar noise stream.This design enables noise residual features to guide the learning of semantic features more precisely and efficiently,thus facilitating comprehensive feature-level interaction.Furthermore,by leveraging the complementary strengths of deep networks in capturing large-scale semantic manipulations and traditional algorithms’proficiency in detecting fine-grained local traces,the method significantly enhances the accuracy and robustness of tampered region detection.Compared with other approaches,the proposed method achieves an F1 score improvement exceeding 30% on the DEFACTO and DIS25k datasets.In addition,it has been extensively validated on other datasets,including CASIA and DIS25k.Experimental results demonstrate that this method achieves outstanding performance across various types of image tampering detection tasks.
基金supported by grants from National Key R&D Program of China[grant number 2016YFC0800702]National Natural Science Foundation of China[grant num-bers 81571851 and 81401559]Science and Technology Committee of Shanghai Municipality[grant numbers 17DZ2273200 and 16DZ2290900].
文摘Targeted post-mortem computed tomography(PMCT)combined with coronary angiography has the potential to play a significant role in the investigation of sudden cardiac death.The authors utilized a targeted PMCT coronary angiography in a case involving a 53-year-old man who died from acute myocardial ischemia and cardiac decompensation which may result from coronary artery disease(CAD).The victim collapsed suddenly at work and died soon after arrival to hospital.The body was examined using PMCT and targeted PMCT coronary angiography.The left anterior descending coronary artery exhibited 75%-100%stenosis in the middle segment;however,the distal segment could not be clearly visualized.In addition,the left circumflex and right coronary artery exhibited calcification,atherosclerosis and an area of 50% stenosis.Signs of cardiogenic pulmonary oedema were also identified.The imaging results suggested that this individual had coronary atherosclerosis and probably died from CAD.The autopsy and histological examination revealed acute myocardial ischemia and myocardial scarring,confirming the cause of death while excluding other probabilities.In summary,targeted post-mortem computed tomography angiography(PMCTA)can visualize the arteries and estimate the degree of principal pathological changes.This method is a simple,reliable and sensitive technique for identifying the presence of coronary atherosclerosis.It is a valuable post-mortem forensic imaging method and should be recommended in the investigation of suspicious cardiac deaths.
文摘Three-dimensional surface scanning(3DSS)and multi-detector computed tomography(MDCT)are two techniques that are used in legal medicine for digitalizing objects,a body or body parts such as bones.While these techniques are more and more commonly employed,surprisingly little information is known about the quality rendering of digitalized three-dimensional(3D)models provided by each of them.This paper presents findings related to the measurement precision of 3D models obtained through observation of a study case,where a fractured skull reconstructed by an anthropologist was digitalized using both post-mortem imaging methods.Computed tomography(CT)scans were performed using an 8-row MDCT unit with two different slice thicknesses.The variability of 3D CT models superimposition allowed to assess the reproducibility and robustness of this digitalization technique.Furthermore,two 3D surface scans were done using a professional high resolution 3D digitizer.The comparison of 3D CT-scans with 3D surface scans by superimposition demonstrated several regions with significant differences in topology(average difference between+1.45 and-1.22 mm).When comparing the reproducibility between these two digitalizing techniques,it appeared that MDCT 3D models led in general to greater variability for measurement precision between scanned surfaces.Also,the reproducibility was better achieved with the 3D surface digitizer,showing 3D models with fewer and less pronounced differences(from+0.32 to-0.31 mm).These experiments suggest that MDCT provides less reproducible body models than 3D surface scanning.But further studies must be undertaken in order to corroborate this first impression,and possibly explain the reason for these findings.
文摘This case reports on a 68-year-old man who was found dead in hospital next to his bed.Before this,he had been treated with intravenous antibiotics for pneumonia.The body was found with a peripheral venous catheter connected to a nasal cannula delivering oxygen(O_(2))from the wall.Extensive medico-legal examinations were performed,including post-mortem computed tomography(CT),complete conventional autopsy,histological and immunohistochemistry analysis,toxicological analysis and post-mortem chemistry.Additionally,CT-guided gas sampling was performed at multiple sites to collect samples for gas analysis.During the external examination,massive subcutaneous emphysema was visible over the entire surface of the body.The CT scan revealed the presence of gas throughout the vascular system,and in the subcutaneous and muscular tissues.The autopsy confirmed the presence of lobar pneumonia and multiple gas bubbles in the vascular system.The gas analysis results showed a subnormal concentration of oxygen,confirming the suspected pure O_(2) embolism.Moreover,the carbon dioxide(CO_(2))concentration in the gas sample from the heart was elevated to a level similar to those found in scuba diving fatalities.This could come from degassing of dissolved CO_(2) that accumulated and was trapped in the cardiac cavity.Based on the results of the different exams performed,and especially the gas analysis results,it was concluded that the cause of death was O_(2) embolism.
文摘Virtual autopsy,or virtopsy,is an innovative forensic technique that employs advanced imaging modalities such as computed tomography and magnetic resonance imaging for the examination of cadavers.Compared to the standard autopsy,an invasive procedure,virtual autopsy is noninvasive.This article reviews the forensic applications of virtual autopsy,its advantages and disadvantages,and compares it to traditional autopsy techniques.It emphasizes the expanding role of virtual autopsies in contemporary forensic investigations and the technological innovations,ethical implications,and logistical hurdles related to these techniques.
基金Project(61172184) supported by the National Natural Science Foundation of ChinaProject(200902482) supported by China Postdoctoral Science Foundation Specially Funded ProjectProject(12JJ6062) supported by the Natural Science Foundation of Hunan Province,China
文摘A blind digital image forensic method for detecting copy-paste forgery between JPEG images was proposed.Two copy-paste tampering scenarios were introduced at first:the tampered image was saved in an uncompressed format or in a JPEG compressed format.Then the proposed detection method was analyzed and simulated for all the cases of the two tampering scenarios.The tampered region is detected by computing the averaged sum of absolute difference(ASAD) images between the examined image and a resaved JPEG compressed image at different quality factors.The experimental results show the advantages of the proposed method:capability of detecting small and/or multiple tampered regions,simple computation,and hence fast speed in processing.
基金Sponsored by the National Natural Science Foundation of China(Grant No.60971095 and No.61172109)Artificial Intelligence Key Laboratory of Sichuan Province(Grant No.2012RZJ01)the Fundamental Research Funds for the Central Universities(Grant No.DUT13RC201)
文摘In this paper,a new approach is proposed to determine whether the content of an image is authentic or modified with a focus on detecting complex image tampering.Detecting image tampering without any prior information of the original image is a challenging problem since unknown diverse manipulations may have different characteristics and so do various formats of images.Our principle is that image processing,no matter how complex,may affect image quality,so image quality metrics can be used to distinguish tampered images.In particular,based on the alteration of image quality in modified blocks,the proposed method can locate the tampered areas.Referring to four types of effective no-reference image quality metrics,we obtain 13 features to present an image.The experimental results show that the proposed method is very promising on detecting image tampering and locating the locally tampered areas especially in realistic scenarios.
基金supported in part by the National Natural Science Foundation of China under grant No.(61472429,61070192,91018008,61303074,61170240)Beijing Natural Science Foundation under grant No.4122041+1 种基金National High-Tech Research Development Program of China under grant No.2007AA01Z414National Science and Technology Major Project of China under grant No.2012ZX01039-004
文摘Copy-Move Forgery(CMF) is one of the simple and effective operations to create forged digital images.Recently,techniques based on Scale Invariant Features Transform(SIFT) are widely used to detect CMF.Various approaches under the SIFT-based framework are the most acceptable ways to CMF detection due to their robust performance.However,for some CMF images,these approaches cannot produce satisfactory detection results.For instance,the number of the matched keypoints may be too less to prove an image to be a CMF image or to generate an accurate result.Sometimes these approaches may even produce error results.According to our observations,one of the reasons is that detection results produced by the SIFT-based framework depend highly on parameters whose values are often determined with experiences.These values are only applicable to a few images,which limits their application.To solve the problem,a novel approach named as CMF Detection with Particle Swarm Optimization(CMFDPSO) is proposed in this paper.CMFD-PSO integrates the Particle Swarm Optimization(PSO) algorithm into the SIFT-based framework.It utilizes the PSO algorithm to generate customized parameter values for images,which are used for CMF detection under the SIFT-based framework.Experimental results show that CMFD-PSO has good performance.
