Figure 1.
Example of a magnet with a south and north pole. The lines represent the direction of the magnetic induction (B).
Figure 2.
Regula Magmouse Model 4197.
Figure 3.
Two images created with the Magmouse of the word ‘Bob’ printed with a non-magnetic toner (left) and a magnetic toner (right)
Figure 4.
Histogram of magnetic induction of a non-magnetic toner (above) and a magnetic toner (below). The x-axis describes the strength of the magnetic induction in mT and the y-axis describe the number of pixels N (logarithmic scale, 10log(N)).
Figure 5.
Ten different locations in the laboratory.
Figure 6.
Ten different measuring areas on the sensor of the Magmouse.
Figure 7.
Boxplot of the variation in flux.
Figure 8.
The measurement of a sample printed with a HP LaserJet 2200 (red curve) and HP LaserJet 4100 (blue curve). The x-axis describes the strength of the magnetic induction in mT and the y-axis describe the number of pixels N (logarithmic scale, 10log(N)). The squared area is a visualization of the calculated 1-norm distance score (Manhattan distance score).
Figure 9.
Top left shows the within-variation histogram; top right shows the between-variation histogram; Bottom left shows the probability density curves (red within-variation / blue between-variation); Bottom right shows the LR as function of the score.
Figure 10.
LR values plotted on a logarithmic scale.
Figure 11.
Boxplots of the variation in flux of the word “Bob” in three different fonts.
Table A-1
Used printers during this study with corresponding sample numbers.
| Sample ID | PrinterID | Brand | Type |
|---|---|---|---|
| 1 | 1 | Canon | ImageClass MF4770n |
| 2 | 1 | Canon | ImageClass MF4770n |
| 3 | 1 | Canon | ImageClass MF4770n |
| 4 | 1 | Canon | ImageClass MF4770n |
| 5 | 2 | Dell | Laserprinter 1700 |
| 6 | 2 | Dell | Laserprinter 1700 |
| 7 | 2 | Dell | Laserprinter 1700 |
| 8 | 2 | Dell | Laserprinter 1700 |
| 9 | 3 | HP | LaserJet 1018 |
| 10 | 3 | HP | LaserJet 1018 |
| 11 | 3 | HP | LaserJet 1018 |
| 12 | 3 | HP | LaserJet 1018 |
| 13 | 4 | HP | LaserJet 2200 (series PCL 5) |
| 14 | 4 | HP | LaserJet 2200 (series PCL 5) |
| 15 | 4 | HP | LaserJet 2200 (series PCL 5) |
| 16 | 4 | HP | LaserJet 2200 (series PCL 5) |
| 17 | 5 | HP | LaserJet 4100 (series PCL) |
| 18 | 5 | HP | LaserJet 4100 (series PCL) |
| 19 | 5 | HP | LaserJet 4100 (series PCL) |
| 20 | 5 | HP | LaserJet 4100 (series PCL) |
| 21 | 6 | HP | LaserJet 4L |
| 22 | 6 | HP | LaserJet 4L |
| 23 | 6 | HP | LaserJet 4L |
| 24 | 6 | HP | LaserJet 4L |
| 25 | 7 | HP | LaserJet 6L |
| 26 | 7 | HP | LaserJet 6L |
| 27 | 7 | HP | LaserJet 6L |
| 28 | 7 | HP | LaserJet 6L |
| 29 | 8 | HP | LaserJet 5P |
| 30 | 8 | HP | LaserJet 5P |
| 31 | 8 | HP | LaserJet 5P |
| 32 | 8 | HP | LaserJet 5P |
| 33 | 9 | HP | LaserJet 4L |
| 34 | 9 | HP | LaserJet 4L |
| 35 | 9 | HP | LaserJet 4L |
| 36 | 9 | HP | LaserJet 4L |
| 37 | 10 | HP | LaserJet Pro 400 M401dw |
| 38 | 10 | HP | LaserJet Pro 400 M401dw |
| 39 | 10 | HP | LaserJet Pro 400 M401dw |
| 40 | 10 | HP | LaserJet Pro 400 M401dw |
| 41 | 11 | HP | LaserJet 600 M602 |
| 42 | 11 | HP | LaserJet 600 M602 |
| 43 | 11 | HP | LaserJet 600 M602 |
| 44 | 11 | HP | LaserJet 600 M602 |
| 45 | 12 | HP | LaserJet P1006 |
| 46 | 12 | HP | LaserJet P1006 |
| 47 | 12 | HP | LaserJet P1006 |
| 48 | 12 | HP | LaserJet P1006 |
| 49 | 13 | HP | LaserJet 1022nw |
| 50 | 13 | HP | LaserJet 1022nw |
| 51 | 13 | HP | LaserJet 1022nw |
| 52 | 13 | HP | LaserJet 1022nw |
| 53 | 14 | HP | LaserJet P2015dn |
| 54 | 14 | HP | LaserJet P2015dn |
| 55 | 14 | HP | LaserJet P2015dn |
| 56 | 14 | HP | LaserJet P2015dn |
| 57 | 15 | HP | LaserJet P2035 |
| 58 | 15 | HP | LaserJet P2035 |
| 59 | 15 | HP | LaserJet P2035 |
| 60 | 15 | HP | LaserJet P2035 |
| 61 | 16 | HP | LaserJet P2055dn |
| 62 | 16 | HP | LaserJet P2055dn |
| 63 | 16 | HP | LaserJet P2055dn |
| 64 | 17 | HP | LaserJet 4015 |
| 65 | 18 | HP | LaserJet 4250 TN |
| 66 | 18 | HP | LaserJet 4250 TN |
| 67 | 18 | HP | LaserJet 4250 TN |
| 68 | 18 | HP | LaserJet 4250 TN |
| 69 | 19 | HP | LaserJet 4250dtn |
| 70 | 19 | HP | LaserJet 4250dtn |
| 71 | 19 | HP | LaserJet 4250dtn |
| 72 | 19 | HP | LaserJet 4250dtn |
Figure B-1.
Image of sample page. Original sample page was A4 size.
Figure C-1.
Six measurements of magnetic induction on two samples. On each sample the word “Bob” is measured on three different fonts.
Table C-1.
Measurement data (magnetic induction) and calculated distance scores for two samples (LaserJet 2200 and LaserJet 4100) and three fonts (Times New Roman, Arial and Calibri)
| Induction | LJ 2200 (TNR) | LJ 2200 (Arial) | LJ 2200 (Calibri) | LJ 4100 (TNR) | LJ 4100 (Arial) | LJ 4100 (Calibri) | | xi - yi | (TNR) | | xi - yi | (Arial) | | xi - yi | (Calibri) |
|---|---|---|---|---|---|---|---|---|---|
| -2.8 | 0 | 0 | 1.3 | 0 | 0 | 0 | 0 | 0 | 1,3 |
| -2.7 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |
| -2.6 | 1.6 | 0 | 1.7 | 0 | 0 | 0 | 1,6 | 0 | 1,7 |
| -2.5 | 1.9 | 1.3 | 2.1 | 0 | 0 | 0 | 1,9 | 1,3 | 2,1 |
| -2.4 | 2.5 | 1.7 | 2.5 | 0 | 0 | 0 | 2,5 | 1,7 | 2,5 |
| -2.2 | 2.6 | 2.3 | 2.9 | 0 | 0 | 0 | 2,6 | 2,3 | 2,9 |
| -2 | 3 | 2.7 | 3.3 | 1.3 | 0 | 0 | 1,7 | 2,7 | 3,3 |
| -1.7 | 3.5 | 3.4 | 3.5 | 1.8 | 1.3 | 0 | 1,7 | 2,1 | 3,5 |
| -1.4 | 3.6 | 3.5 | 3.8 | 2.4 | 2.5 | 2.4 | 1,2 | 1 | 1,4 |
| -1.1 | 3.8 | 3.8 | 3.9 | 3.4 | 3.3 | 3 | 0,4 | 0,5 | 0,9 |
| -0.9 | 4.2 | 4 | 4.2 | 3.7 | 3.8 | 3.5 | 0,5 | 0,2 | 0,7 |
| -0.7 | 4.1 | 4.2 | 4.2 | 4.1 | 4.1 | 4 | 0 | 0,1 | 0,2 |
| -0.5 | 4.3 | 4.4 | 4.4 | 4.3 | 4.4 | 4.3 | 0 | 0 | 0,1 |
| -0.3 | 4.5 | 4.6 | 4.5 | 4.5 | 4.6 | 4.5 | 0 | 0 | 0 |
| -0.15 | 4.6 | 4.7 | 4.6 | 4.6 | 4.7 | 4.7 | 0 | 0 | 0,1 |
| -0.1 | 4.5 | 4.5 | 4.5 | 4.4 | 4.5 | 4.5 | 0,1 | 0 | 0 |
| 0 | 5.8 | 5.8 | 5.8 | 5.8 | 5.8 | 5.8 | 0 | 0 | 0 |
| 0.1 | 5.4 | 5.4 | 5.4 | 5.4 | 5.4 | 5.4 | 0 | 0 | 0 |
| 0.15 | 4.9 | 4.9 | 4.9 | 5 | 5 | 5 | 0,1 | 0,1 | 0,1 |
| 0.3 | 4.6 | 4.6 | 4.6 | 4.7 | 4.7 | 4.7 | 0,1 | 0,1 | 0,1 |
| 0.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.4 | 4.5 | 0 | 0,1 | 0 |
| 0.7 | 4.4 | 4.3 | 4.4 | 4.2 | 4.3 | 4.2 | 0,2 | 0 | 0,2 |
| 0.9 | 4.2 | 4.1 | 4.2 | 3.9 | 4.1 | 3.9 | 0,3 | 0 | 0,3 |
| 1.1 | 4 | 4 | 4.1 | 3.5 | 3.8 | 3.3 | 0,5 | 0,2 | 0,8 |
| 1.4 | 3.8 | 3.9 | 3.9 | 3.1 | 3.6 | 2.9 | 0,7 | 0,3 | 1 |
| 1.7 | 3.6 | 3.7 | 3.7 | 2.3 | 3 | 2.4 | 1,3 | 0,7 | 1,3 |
| 2 | 3.2 | 3.4 | 3.2 | 1.6 | 2.2 | 1 | 1,6 | 1,2 | 2,2 |
| 2.2 | 2.9 | 3.2 | 3.1 | 0 | 0 | 1 | 2,9 | 3,2 | 2,1 |
| 2.4 | 2.5 | 2.8 | 2.5 | 0 | 0 | 0 | 2,5 | 2,8 | 2,5 |
| 2.5 | 2.1 | 2.2 | 2.5 | 0 | 0 | 0 | 2,1 | 2,2 | 2,5 |
| 2.6 | 1.6 | 1.5 | 2.3 | 0 | 0 | 0 | 1,6 | 1,5 | 2,3 |
| 2.7 | 1 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 1 |
| 2.8 | 1.3 | 0 | 1 | 0 | 0 | 0 | 1,3 | 0 | 1 |
| P1 = ∑ = | 30,4 | 24,3 | 39,1 |