Photoshop图像分析法在不规则瘢痕鉴定中应用

目的 探讨photoshop图像分析方法在不规则瘢痕鉴定中的应用价值.方法 用photoshop图像分析方法和数格法对30种不规则瘢痕进行面积计算,并对其准确性和实用性进行比较.结果 photoshop图像分析方法与数格法所计算出的面积之间无明显差异(P =0.960 7),而在检测时间和过程等方面photoshop图像分析方法明显优于数格法.结论 photoshop图像分析法用于不规则瘢痕的面积计算,具有既准确又节省时间的优点,可以在不规则瘢痕的法医学鉴定中选择使用.     

A measurement of human hair oxidation by Fourier transform infrared spectroscopy

Human scalp hair samples were oxidized to determine the sulfonic acid absorption peak. This peak was monitored at 1044 cm-1 by Fourier transform infrared spectroscopy (FTIR) in hair samples from 135 whites and found to provide a degree of discrimination in treated and untreated hairs. The effects of moisture, laboratory storage, natural hair color, and variation over time were also studied.     

A comparison study of hair examination methodologies

A study was conducted to investigate the accuracy between two methods of hair analysis: PCR-STR DNA analysis and microscopic comparison analysis. Standard sets of pubic hairs were collected from volunteers, and unknown sets were generated from these samples. Three out of five (60%) of the hairs analyzed produced full DNA profiles that were correctly matched to the standard sets. DNA analysis was inconclusive (partial or no DNA profile) for two out of five (40%) of the samples. In contrast, the microscopic comparison analysis correctly matched four out of five (80%) of the samples to the standard sets but mis-identified one out of five (20%) of the samples. These results reinforce the practice of preliminary microscopic hair examination in narrowing down a set of hairs for DNA analysis. Microscopic comparison analysis is sufficiently reliable to remain a rapid and inexpensive method for forensic hair analysis.     

Preliminary study of hair form of Japanese head hairs using image analysis

The use of average curvature measurements for the forensic comparison of curly hairs has been reported, but a method, in which various types of hair form are quantitatively examined and objectively interpreted for hair comparison, has not been reported to date. In the present study, numerical data on hair form from Japanese subjects were obtained by image analysis and a morphological comparison of these head hairs was investigated. Head hairs obtained from eight Japanese males were measured for length (L), distance (D) and area (A) using a Kontron Imaging System KS400. From the three measurements mentioned above, three indexes, L/D, A/D and 2(A/L), were examined. The inter-individual variations for each value were investigated by a t-test and the availability of six values for the forensic comparison of hair form was evaluated by a stepwise linear discrimination analysis. Six values obtained from hair form by an image analysis showed large intra-individual variations. However, these six values were found to be useful for discriminating between two individuals, since the six values showed larger inter-individual variations than intra-individual variations. Discrimination on each comparison using a stepwise linear discrimination analysis was performed for some of the values and the results indicated conspicuous inter-individual variations between the two individuals. On 11 of 28 comparisons, 30 hairs from one individual could be completely distinguished from hairs of another individual, when a two-way comparison was employed. These results confirm that hair form could be quite useful in the forensic comparison of hair morphology, and suggest that numerical data obtained from hair form by image analysis are very important values for constructing a screening procedure for evidential hairs. The use of an objective measure of hair form will be especially useful for Japanese head hairs since they are generally thought to show very limited variation in morphological features.     

Identification of human hair stained with oxidation hair dyes by gas chromatographic-mass spectrometric analysis.

This paper describes the gas chromatographic-mass spectrometric (GCMS) analysis of oxidation hair dyes from human hair. Diamines from the dyes were directly extracted from the hair in basic solution and aminophenols were extracted after neutralization. Both extracts were derivatised with trifluoroacetic anhydride and analysed by GCMS. Five components of oxidation hair dyes namely, p-phenylenediamine, toluene-2,5-diamine, o-aminophenol, m-aminophenol and p-aminophenol were clearly identified, whilst no other compounds originating from the hair dyes were detected. The presence and relative amounts of these dye components from hair extracts may assist in the discrimination of human hair especially in cases involving forensic science.     

Two-dimensional linear analysis of dynamic bare footprints: A comparison of measurement techniques

In forensic intelligence-gathering, footprints have been shown to be valued evidence found at crime scenes. Forensic podiatrists and footprint examiners use a variety of techniques for measuring footprints for comparison of the crime scene evidence with the exemplar footprints. This study examines three different techniques of obtaining two-dimensional linear measurement data of dynamic bare footprints. Dynamic bare footprints were gathered from 50 students from a podiatric medical school using the Identicator® Inkless Shoe Print Model LE 25P system. After obtaining 100 bilateral footprints from the participants, the quantitative measurement data were collected by using three different measurement techniques: (i) a manual technique using a ruler (direct technique); (ii) an Adobe® Photoshop® technique; and (iii) a GIMP (GNU Image Manipulation Program) technique. The seven Reel linear measurement methodology was used for producing measurements using these three techniques.This study showed that all the mean bare footprint measurements on the right and left feet obtained using the direct technique were larger than those obtained using GIMP and Adobe® Photoshop® images. Differences were also observed in measurements produced using GIMP software and Photoshop images. However, the differences observed in the three techniques used for bare footprint measurements were not found to be statistically significant. The study concludes that there are no significant differences between the three measurement techniques when applied to two-dimensional bare footprints using the Reel method. It further concluded that any of these measurement techniques can be used when employing the Reel methodology for footprint analysis without significant difference.     

Fingerprint pattern restoration by digital image processing techniques

Fingerprint evidence plays an important role in solving criminal problems. However, defective (lacking information needed for completeness) or contaminated (undesirable information included) fingerprint patterns make identifying and recognizing processes difficult. Unfortunately. this is the usual case. In the recognizing process (enhancement of patterns, or elimination of "false alarms" so that a fingerprint pattern can be searched in the Automated Fingerprint Identification System (AFIS)), chemical and physical techniques have been proposed to improve pattern legibility. In the identifying process, a fingerprint examiner can enhance contaminated (but not defective) fingerprint patterns under guidelines provided by the Scientific Working Group on Friction Ridge Analysis, Study and Technology (SWGFAST), the Scientific Working Group on Imaging Technology (SWGIT), and an AFIS working group within the National Institute of Justice. Recently, the image processing techniques have been successfully applied in forensic science. For example, we have applied image enhancement methods to improve the legibility of digital images such as fingerprints and vehicle plate numbers. In this paper, we propose a novel digital image restoration technique based on the AM (amplitude modulation)-FM (frequency modulation) reaction-diffusion method to restore defective or contaminated fingerprint patterns. This method shows its potential application to fingerprint pattern enhancement in the recognizing process (but not for the identifying process). Synthetic and real images are used to show the capability of the proposed method. The results of enhancing fingerprint patterns by the manual process and our method are evaluated and compared.     

Hair-MAP: a prototype automated system for forensic hair comparison and analysis

This paper demonstrates the feasibility of the automation of forensic hair analysis and comparison task using neural network explanation systems (NNESs). Our system takes as input microscopic images of two hairs and produces a classification decision as to whether or not the hairs came from the same person. Hair images were captured using a NEXTDimension video board in a NEXTDimension color turbo computer, connected to a video camera. Image processing was done on an SGI indigo workstation. Each image is segmented into a number of pieces appropriate for classification of different features. A variety of image processing techniques are used to enhance this information. Use of wavelet analysis and the Haralick texture algorithm to pre-process data has allowed us to compress large amounts of data into smaller, yet representative data. Neural networks are then used for feature classification. Finally, statistical tests determine the degree of match between the resulting collection of hair feature vectors. An important issue in automation of any task in criminal investigations is the reliability and understandability of the resulting system. To address this concern, we have developed methods to facilitate explanation of neural network's behavior using a decision tree. The system was able to achieve a performance of 83% hair match accuracy, using 5 of the 21 morphological characteristics used by experts. This shows promise for the usefulness of a fuller scale system. While an automated system would not replace the expert, it would make the task easier by providing a means for pre-processing the large amount of data with which the expert must contend.     

Determination of chronic methamphetamine abuse by hair analysis

A 30-year-old male truck driver, known to be asthmatic, was found dead at the roadside lying near his car. A nebulizer bottle of Berotec (fenoterol hydrobromide) was found near his hand. The anatomic cause of death was suspected to be asthma. Toxicological screening of urine using Triage demonstrated the presence of methamphetamine. The blood concentration of methamphetamine was 0.4 microg/ml, and fenoterol was not detected. Hair analysis clearly indicated chronic methamphetamine abuse and medium dependency during the 2 months before death. We conclude that death might have been induced by the interaction of fenoterol and methamphetamine.     

Human identification by comparison if skull roentgen image

Comparison of X-rays was found to provide information just as accurate as dactyloscopy for person identification, which is attributable to the high variability of the skeletal system. Reported in this paper is the case of an unknown dead female whose body was found in a condition of advanced decay. That is why conventional methods of criminological identification were not practicable. Only inadequate results were obtained from a muscular sample, while no findings at all were obtainable from DNA analysis of two molars. Identification was achievable only after six months had passed from discovery of the corpse, when two X-rays of the presumed person's skull were retrieved. This case of successful identification has once again provided evidence to the fact that even in our era of DNA research X-ray comparison has retained a firm position in forensic diagnostics.     

Simple determination of carboxyhemoglobin by double wavelength spectrophotometry of absorbance difference and the comparison with gas chromatographic method

This paper describes the spectrophotometric determination of carboxyhemoglobin (CO-Hb) in blood on the basis of double wavelength spectrophotometry of absorbance difference. Absorbance measurements are made in the 500–600 nm region at a blood dilution of 100–200-fold. Blood is diluted with a solution containing Na₂S₂O₄ to provide two components of CO-Hb and deoxyhemoglobin (deoxy-Hb). Absorbance difference at the two wavelengths at which deoxy-Hb has the same absorbance reflects only the CO-Hb component because the opposite component is nulled out of the mixture. After measurement of the absorbance difference, the measuring solution is saturated with CO gas to make all Hb derivative CO-Hb and remeasured at the same wavelengths. The percent of CO-Hb is considered the absorbance difference ratio. Results obtained by the present method was in satisfactory agreement with gas chromatographic data in blood not containing methemoglobin (Met-Hb). Comparative experiments using the gas chromatographic method and the present method were performed with samples containing Met-Hb. However, while there is a deficiency in the gas chromatographic method when the samples contain Met-Hb, the results of the present method were in close agreement with theoretical values when samples are mixed with CO-Hb, O₂-Hb and Met-Hb. Advantages of this method are that it is simple and accurate, standard curve or equation for calculation and accurate dilution are not necessary.     

Potential problems with the interpretation of hair analysis results

Due to differences in hair growth rate depending on anatomical region, age, gender, ethnicity and interindividual variability, interpretation of parent drug or/and metabolite concentrations in hair is not easy. Furthermore, as drug incorporation mechanisms into hair matrix is not yet fully understood, it is rather difficult to extrapolate details on time and dose from hair segment analysis. If incorporation sources other than from bloodstream (skin secretions and/or external/environmental contamination) are considered, interpretation becomes even more complicated. For evaluating possible passive contamination, it is essential to consider specific identification of metabolites, use of metabolite-to-parent drug ratios, assays of decontamination washes and analysis of specimens collected from other body parts. Cosmetic hair treatment, natural and artificial hair colour, differences in hair structure and specificity of analytical methodology may represent other bias sources affecting concentrations of drugs in hair. A suitable cut-off level related to the LOD will allow correct identification of drugs or metabolites in hair. Regarding the performance of different hair testing laboratories, little information is available at this time to what extent test results are comparable and their interpretation is consistent. Frequency of drug consumption and time intervals between multiple consumption or lag time between consumption and appearance in the hair has not been fully investigated and needs further research.     

A preliminary study of skin electrical injury with computerized image analysis

This paper reports the application of computerized image analysis to a quantitative study of skin electrical injury in order to provide an objective and quantitative standard for identifying the electrical mark. The differences between antemortem and postmortem electrical injuries were also studied. In normal and electrically-injured human skin, the long/short axes ratio of nuclei were measured. The mean of epithelial basal cells was 1.4344 and 5.9325, respectively, the mean of hair follicle cells was 1.6193 and 4.5988, respectively, and the mean of capillary endothelial cells was 4.0229 and 4.3593, respectively. In rat specimens, the long/short axes ratio of nuclei of normal skin, at 15 and 5 min ante-mortem and at 5 min postmortem injury, the mean epithelial basal cells was 1.4124, 4.5417, 5.2282 and 5.0447, respectively. The mean of hair follicle cells was 1.4140, 4.4863, 4.1146 and 4.4522, respectively, while the mean of capillary endothelial cells was 2.8398, 3.7514, 3.6159 and 3.6977, respectively. The results indicate that the differences between electrical injuries and normal skin with respect to the ratios of long/short axes of the epithelial basal cell nuclei and hair follicle cell nuclei are of remarkable significance. On the other hand, no significant difference could be found between antemortem and postmortem injuries, nor between electrical injury and normal skin, concerning the long/short axes ratios of capillary endothelial cell nuclei. This result provides a preliminary objective standard for the changes of electrical skin injury.     

Time-resolved hair analysis of MDMA enantiomers by GC/MS-NCI

The aim of the study was to determine the enantioselective disposition of 3,4-methylenedioxymethamphetamine (MDMA) and other amphetamine-type stimulants (ATS) in segmented hair specimens of self-declared ecstasy abusers, who took part in a double-blind placebo-controlled six-way crossover study during approximately 7 weeks, during which they received a 75 and a 100 mg dose of racemic MDMA twice. Hair specimens were washed and cut into pieces of 2 cm length. After digestion and solid phase extraction, the enantiomers were derivatized with a chiral agent (2S,4R)-N-heptafluorobutyryl-4-heptafluorobutoyloxy-prolyl chloride, developed at the authors laboratory and quantified by gas chromatography coupled to mass spectrometry operating in the negative chemical ionization mode. Most of the hair specimens that were tested positive for MDMA showed a predominance of the (R)-enantiomer. The R/S ratios of MDMA varied between 1.02 and 2.75 and total concentrations ranged from 0.1 to 20.1 ng/mg. The enantiomers of its metabolite 3,4-methylenedioxyamphetamine (MDA) were also quantified in most hair segments. The R/S ratios of MDA varied between 0.60 and 1.60, while the concentrations of the enantiomers ranged from 10 to 160 pg/mg hair. When segmental analysis was performed on single hair specimens, no inversion of the R versus S ratios of MDMA and MDA was observed. The predominance of (R)-MDMA in hair was in accordance with those already published for other matrices. Furthermore, both enantiomers of amphetamine (AM) were also detected in hair segments of four volunteers and the R/S ratios ranged from 1.00 to 1.47.     

Impact of image super-resolution technology on comparison of personal image

Objective Through coalescence into deep learning, image super-resolution technology is being paid of attention for forensic personal imaging. Thus, a trial was here to carry out about the impact of image super-resolution technology on comparison of personal photographs from cases or events. Methods With 94 sets of sampling personal photographs collected from real cases, grouping was made on their respective quality-different image so that two image super-resolution algorithms were adopted to enhance the image of personal photograph. Such resultant image was compared against its original photograph image at 1 ∶ 1 (or N) contraposition under different preset conditions, hence having brought forth the intrinsic alternation of causation. Results Comparison results showed that the image super-resolution technology is not universal for improvement of image, demonstrating that it is not so good to improve the low and medium quality images as the sharpening processing, leaving the high quality image being improved significantly yet less practical applicability. Nevertheless, the image super-resolution technology is able to render a good improvement into an individual image. Conclusions From this analysis, the image super-resolution technology is referential for forensic personal image to utilize practically, yet not be over-relied on. © 2021, Editorial Office of Forensic Science and Technology. All rights reserved.     

Alternative light source (polilight) illumination with digital image analysis does not assist in determining the age of bruises

The age of a bruise may be of interest to forensic investigators. Previous research has demonstrated that an alternative light source may assist in the visualisation of faint or non-visible bruises. This project aimed to determine if an alternative light source could be utilised to assist investigators estimate the age of a bruise. Forty braises, sustained from blunt force trauma, were examined from 30 healthy subjects. The age of the bruises ranged from 2 to 231 h (mean = 74.6, median = 69.0). Alternative light source (polilight) illumination at 415 and 450 nm was used. The black and white photographs obtained were assessed using densitometry. A statistical analysis indicated that there was no correlation between time and the mean densitometry values. The alternative light source used in this study was unable to assist in determining the age of a bruise.