# Oral and Dental Spectral Image Database--ODSI-DB
## 3 Results and Discussion
### Annotations  
The annotation labels are categorized as either _technical issues, hard tissue and augmentations, hard tissue issues, soft tissue, soft tissue issues_, or _miscellaneous_. The labels themselves are listed in Table 1, including the pixel counts (number of spectra) for each annotation label. Since the spatial resolution of Specim IQ spectral camera is approximately 1/4 of Nuance EX spectral camera, the pixel counts per label per image are lower in Specim IQ acquired spectral images. \begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{2}{c}{(**a**) Technical} \\ \hline
**Annotation Class** & **Pixel Counts** \\ \hline Out of focus area & 260,579 \\  & 8,193,912 \\ Shadow/Noise & 306,251 \\  & 425,958 \\ Specular reflection & 1,486,065 \\  & 445,780 \\ \hline \multicolumn{2}{c}{(**b**) Miscellaneous} \\ \hline
**Annotation Class** & **Pixel Count** \\ \hline Hair & 1,009,626 \\  & 374,344 \\ Makeup & 0 \\  & 406 \\ Mole & 2288 \\  & 503 \\ Pigmentation & 43,144 \\  & 0 \\ \hline \multicolumn{2}{c}{(**c**) Hard tissue and augmentations} \\ \hline
**Annotation Class** & **Pixel Counts** \\ \hline Enamel & 3,929,055 \\  & 984,750 \\ Metal & 132,780 \\  & 63,902 \\ Plastic & 211,588 \\  & 43,429 \\ Prosthetics & 667,618 \\  & 87,936 \\ Root & 9991 \\  & 3971 \\ \hline \multicolumn{2}{c}{(**d**) Soft tissue} \\ \hline
**Annotation Class** & **Pixel Count** \\ \hline Attached gingiva & 1,580,681 \\  & 341,864 \\ Blood vessel & 1723 \\  & 1944 \\ Hard palate & 1,292,117 \\  & 1,083,881 \\ Lip & 2,678,629 \\  & 1,241,971 \\ Marginal gingiva & 618,379 \\  & 186,014 \\ Oral mucosa & 6,482,161 \\  & 1,435,382 \\ Skin & 14,625,290 \\  & 4,368,396 \\ Soft palate & 1,013,292 \\  & 385,302 \\ Tongue & 3,177,170 \\  & 904,519 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Annotation labels and separate pixel counts for spectral data acquired with Nuance EX (top value) and Specim IQ (bottom value) spectral cameras per label. The technical annotation labels mark areas that should be excluded from data analysis. For example, specular reflections do not contain any meaningful information, the spectra on these areas may be oversaturated and these areas should be masked off of any other mask. Shadow/noise label is mainly used to denote areas that are either poorly lit or fall outside of the sample area (originally, the manual image segmentation was intended to apply a label on all pixels in an image; this was later found to be overly rigorous). The Specim IQ spectral camera has a fairly short depth of field, the overly blurry areas are thus labeled as out-of-focus areas (see Figure 6). A pixel in the blurry out-of-focus area may be experiencing strong spectral mixing with the nearby pixels depending on the level of the blur. The miscellaneous-category (Table 1b) contains labels that did not seem to fit other categories. Label _hair_ is another exclusion label like the technical annotations. This label is used to mark hairy areas -- not individual strands of hair--so that shadows in the hairy bushes and any possibly visible skin underneath are thus also labeled as hair. Makeup, when clearly present, is annotated as such. _Mole_ and _pigmentation_ labels accurately mark features of interest and can be used in analysis as is. In the the hard-tissue and augmentations -category (Table 1c) the meanings of the labels _enamel_, and _root_ are self-evident, but the distinction between _prosthetics_ and the materials _metal_ and _plastic_ may be less so (Figure 7). The former is used to mark artificial structures, and the latter two to mark repaired parts of a tooth, and in case of _metal_, also dental braces. In the hard-tissue issue -category (Table 1e) labels _attrtition/erosion_ and _microfracture_ mark the site of the find and some surrounding _enamel_.