Fig. 1. Pilot/Chenguang thermosensitive erasable pen writingbefore erasing (a), (d), after erasing (b), (e), and fluorescent effect (c), (f)
Fig. 2. Fluorescence excitation spectra (a, monitoring wavelength: 716 nm) and 716 nm peak intensities (b, excitating wavelength: 365 nm) of erasable pens
Fig. 3. The micromorphology of erasing part of the bottom half handwrite (a), and the micromorphology of the erased handwriting (b), at 350× magnification
Fig. 4. Angcai handwriting (a), fluorescence of Angcai handwriting (b); handwriting of lemon juice (c), fluorescence of lemon juice (d)
Fig. 5. Fluorescence exitation and emission spectra of Angcai pen and white paper with a monitoring wavelength of 447 nm and a excitating wavelength of 365 nm
Fig. 6. Reflectance spectra of white paper and lemon juice (a), original appearance of lemon juice handwriting (b) and appearance of lemon juice handwriting irradiated by 365 nm beam (c)
Fig. 7. Original appearance of the chenguong handwriting (a), being covered by Pilot (b), the infrared 850 nm appearance (c)
Fig. 8. Microscope image of covered handwriting at 350× magnification
Fig. 9. Transmissivity curves of different brand pen ink on glass (a), reflectivity curves of different brand pen ink on paper (b)
Fig. 10. LCTF imaging spectrometer (a), spectral curves of different kinds of handwriting (b)
Fig. 11. Chenguang erasable pen erasing handwriting, Angcai steganography pen handwriting, lemon juice handwriting (a), and classification result based on hyperspectral image (b)
擦除字迹 | 密写字迹 | 掩盖字迹 |
---|
晨光热敏可擦笔 AKP61115 | 昂彩隐形 荧光笔AS9 | 晨光中性笔 AGP13608 | 百乐热敏可擦笔 LFBK-23EF-B | 柠檬汁 | 百乐走珠笔V5 |
|
Table 1. List of three kinds of invisible writing samples
| 昂彩 | 柠檬汁 | 碳素笔 | 白纸 |
---|
晨光 | 1.999 95 | 1.995 94 | 2.000 00 | 1.812 44 | 昂彩 | - | 1.972 96 | 2.000 00 | 1.999 38 | 柠檬汁 | - | - | 2.000 00 | 1.920 65 | 碳素笔 | - | - | - | 2.000 00 |
|
Table 2. Separation degree of pair component
| 真实类别 | 晨光 | 昂彩 | 柠檬汁 | 碳素笔 | 白纸 | 合计 | 用户精度/% |
---|
分 类 类 别 | 晨光 | 1 858 | 0 | 1 | 0 | 310 | 2 169 | 85.66 | 昂彩 | 0 | 5 116 | 18 | 0 | 0 | 5 134 | 99.65 | 柠檬汁 | 0 | 78 | 2 608 | 0 | 50 | 2 736 | 95.32 | 碳素笔 | 0 | 0 | 0 | 643 | 0 | 643 | 100.00 | 白纸 | 178 | 0 | 183 | 0 | 103 263 | 103 624 | 99.65 | 合计 | 2 036 | 5 194 | 2 810 | 643 | 103 623 | 114 306 | | 生产者精度 | 91.26% | 98.50% | 92.81% | 100.00% | 99.65% | | | | 总精度: 99.284 4% | Kappa系数: 0.959 1 | |
|
Table 3. Accuracy evaluation