## 4 Experimental Evaluation
### Influence of Camera Resolution on the Identification and Detection Processes  
The last series of experiments was focused on verifying the impact of camera resolution on the whole detection process. Here, we wanted to check:  
* The influence of the quality of images obtained from video frames on bee identification process;
* The influence of the quality of video frames (camera resolution) on the varroosis detection;
* The influence of the camera resolution on the time performance of bee identification and the _V. destructor_ detection. For all of the previously described experiments (Section 4.1:Section 4.4), the analyzed (input) images had a resolution of 5 Mpc. In this part, we processed each of the video frames from the 20-element test set to lower the resolution to 1.2 Mpc, 0.3 Mpc, and 0.1 Mpc. For these four resolutions, we performed the bee identification again, checking its effectiveness. The effectiveness was measured in terms of precision, sensitivity, and the F1 score. Figure 9: Time performance for the _V. destructor_ detection. The precision achieved for the bee identification process was almost the same for all used camera resolutions. In most cases, it was close to 1.0. It differed only for image no. 19--we achieved the lowest value of 0.76 for the resolution 0.3 Mpx. The average precision, calculated for all images in particular resolution, is presented in Table 3.  
We noticed much more diversity for sensitivity, which is presented in Figure 10. For camera resolution 0.1 Mpx, the sensitivity was the lowest for most of the analyzed images. Nevertheless, for the other three resolutions, obtained results are close to each other, and differences between them are rather small. The average sensitivity of 0.77 was noted for the two highest resolutions (5 Mpx and 1.2 Mpx), 0.78 for 0.3 Mpx, and 0.68 for the lowest resolution (0.1 Mpx). Figure 11 shows the F1 score measure obtained for particular images in tested resolutions. For some of the processed and analyzed images, the camera resolution does not influence the bee detection process. There are some images for which the camera resolution is important, which is also confirmed by the average value of the F1 score. As it was also visible for the sensitivity, the worst results (with the average F1 score reaching 0.81) were noticed for camera resolution 0.1 Mpx, while for other resolutions, the score reached 0.87. The second part of this experiment covered the analysis of the impact of camera resolution on the _V. destructor_ detection. Again, we used the initial test set with images taken with the 5 Mpx camera, which we processed to lower the resolution. The identified bees (there are usually many bees on each image) were manually labeled as healthy and infected. Then, we performed the detection of the _Varroa destructor_ and calculated the effectiveness based on the confusion matrices obtained for different resolutions (5, 1.2, 0.3, 0.1 Mpx). Results are shown in Table 4. \begin{table}
\begin{tabular}{c c} \hline \hline
**Camera Resolution [Mpx]** & **Avg. Precision** \\ \hline
0.1 & 1 \\ \hline
0.3 & 0.98 \\ \hline
1.2 & 0.99 \\ \hline
5.0 & 0.99 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Average precision for bee identification depending on camera resolution. Figure 10: Sensitivity achieved for the bee identification process for different camera resolutions. Obtained results show that the detection capabilities depend highly on the camera resolution. For lower image resolutions, the classifier categorized most of the bees as infected (which could be observed in confusion matrices). Only for the highest resolution of 5 Mpx, the _V. destructor_ detection was fully successful and reflected the actual state. This proves that, unlike bee identification, the detection of varroosis depends on the quality of the video stream. We expected that better quality images would result in better detection capabilities. However, we wanted to confirm how large the influence is to confirm the camera choice.