Figure 1
Tobacco leaves before and after threshing.
(a) Cured tobacco leaves before threshing
(b) Leafy strips
(c) Stems with leaf attached
(d) Fully stripped stems
Table 1
The density of leaves and stems.
| Samples | Apparent density (g/cm3) | Thickness (mm) | Area density (g/cm2) |
|---|---|---|---|
| Leaves | 0 | 0 | 0 |
| Stems (2.38 mm) | 1 | 2 | 0 |
| Stems (1.50 mm) | 1 | 1 | 0 |
Figure 2
Experimental system.
(a) Physical simulation diagram
(b) Schematic illustration of the experimental system
Figure 3
Gray image of tobacco leaves and stems.
Figure 4
Image processing flowchart of stem recognition and quantization algorithm.
Figure 5
Determination of stem diameter by image segmentation.
Figure 6
Comparison of stem images from two kinds of X-ray detectors.
Figure 7
Contrast of stems and leaves on an X-ray image as a function of X-ray intensity.
Table 2
Calculation results of for each image in Figure 5.
| Test No. | Value | Relative deviation (%) |
|---|---|---|
| 1# | 16632 | 0.10 |
| 2# | 16588 | −0.17 |
| 3# | 16613 | −0.02 |
| 4# | 16642 | 0.16 |
| 5# | 16621 | 0.03 |
| 6# | 16600 | −0.10 |
Table 3
The determination result of tobacco stems in pure tobacco leaves by the X-ray identification and determination system.
| Test No. | Actual content of stem (%) | Determination of stem* (%) | Relative error (%) |
|---|---|---|---|
| 1 | 1.0000 | 0.9689 | −3.11 |
| 2 | 1.5000 | 1.4712 | −1.92 |
| 3 | 2.0000 | 2.0552 | 2.76 |
| 4 | 2.5000 | 2.4090 | −3.64 |
| 5 | 3.0000 | 2.9538 | −1.54 |
| 6 | 3.5000 | 3.4926 | −0.21 |
| 7 | 4.0000 | 3.9033 | −0.06 |
| 8 | 4.5000 | 4.4258 | −2.03 |
| 9 | 5.0000 | 4.9108 | −1.78 |
| 10 | 6.0000 | 6.1432 | 2.34 |
Table 4
The comparison of quantitative detection results of two methods.
| Sample | Actual content of stem (%) | ISO method | X-ray method | ||
|---|---|---|---|---|---|
| Detected content (%) | Relative error (%) | Detected content (%) | Relative error (%) | ||
| 3000 g leaves + 30 g stems | 0.9901 | 0.9571 | −3.32 | 1.0105 | 2.07 |
| 3000 g leaves + 60 g stems | 1.9608 | 1.7682 | −9.79 | 2.0003 | 2.06 |
| 3000 g leaves + 90 g stems | 2.9126 | 2.7123 | −6.79 | 2.9376 | 0.95 |
| 3000 g leaves + 120 g stems | 3.8462 | 3.5256 | −8.43 | 3.7995 | −1.31 |