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- More information is obtained though hyperspectral imaging than though traditional methods of analysis
- Hyperspectral imaging enables examiners to analyze a wider range of evidence
- Hyperspectral imaging provides accurate, reliable, validated, courtroom friendly results
- Data can be obtained in a nondestructive manner
The advantage of hyperspectral imaging lies in the information embedded within the image. Because the images are a series of snapshots collected as a function of wavelength, each pixel within the image has a fully resolved spectrum associated with it. This method of data collection allows for better visualization and discrimination of a wider range of documents. Because the type of information contained in hyperspectral images is easier to interpret for non-scientists, the presentation of data and information to jurors in the courtroom is easy and straightforward.
Shows information from a hyperspectral image revealing the alteration in the year portion of the date, by showing contrast in the visible and NIR image extracts. The contrast exhibited in the images between the different inks and the paper substrate is a result of the inherently dissimilar reflectance properties (and therefore dissimilar formulations) of these materials. The optical image of the sample is shown in Figure 1A. Figure 1B shows a 440 nm visible reflectance hyperspectral image extract while image 1C shows an 865 nm near-infrared reflectance hyperspectral image extract. The underlying spectral differences in the two inks and the paper background can be seen in image 1D.
Shows information from a hyperspectral image of a forged check. Figure 2A shows a digital image and corresponding fluorescence hyperspectral image resulting from two different inks used to generate the number “4” on the check. The horizontal line in the “4” was written using one type of blue ink while the vertical line was drawn using a second type of blue ink. The spectra are shown in Figure 2B. Image pixels correlating with the fluorescence inherent to the ink used to draw the horizontal and vertical lines were colored blue and green, respectively. The “black” pixels in the image show portions of the image that did not correlate with the spectral
properties of the inks. These image regions are associated with the
paper substrate.
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