# Networking for Cloud Robotics: The DewROS Platform and Its Application
## 6 Experimental Evaluation
### Analysis of Labels Detected
The labels related to each video, together with the confidence level of the frames, were extracted. Then, an Empirical Cumulative Distribution Function (ECDF) of these values was calculated. The plots in Figure 7 depict the distributions of the confidence levels obtained for a specific video at the four considered resolutions with CVI. For video B, a clear separation between the HD and SD pairs of distributions can be observed, until a confidence level of 0.85 is reached. Before that value, the observations  
Figure 6: Comparison of labels at 240p and 1080p resolutions for the video C: differing ones in italic, solid border, and non pertinent in italics, dashed borders. from the SD distributions show confidence values which are slightly higher than the ones from the HD pair. Indeed, 70% of the observations from the SD distributions exhibit confidence values higher than 0.68 versus the 0.58 of the HD ones. As mentioned before, more irrelevant labels from low-resolution videos, often with high confidence values, were obtained. For instance, labels referring to general elements, such as \"extreme sports\" or \"ecosystem\", appear in many frames of the video with high confidence values, which fill the upper part of the distribution. This explains the trend observed in the A and B videos, where the HD distributions show lower confidence values than the SD ones. This trend seems to be reverted in video C, because several erroneous labels with confidence values in the 0.40 \(\rightarrow\) 0.60 interval were detected, which disappear at the maximum resolution. Those values fill the lower part of the SD distributions, causing an upward shift in the corresponding ECDF curve. The shape of the curves at different resolutions is similar in all three videos, except for B, where it is possible to observe more pronounced differences between HD and SD than in the other cases. In conclusion, there is a balance between the proper labels, whose confidence level tends to increase with the resolution, and the erroneous labels, whose confidence values decrease with increasing resolution. Moreover, more irrelevant labels were obtained in the low-resolution videos. However, clear improvements were not observed in the confidence level of the proper labels with increasing resolution. The same analysis was performed on the same three videos with AR to evaluate the impact of the video resolution on the quality and quantity of labels and obtain a comparison between the two services. The number of labels obtained is much higher than CVI because, in this case, the entire label hierarchy for each object detected is returned. The video resolution does not affect the number of labels received because it is not possible to identify a specific trend, as shown in Figure 8.  
We then examined how the video resolution influences the level of confidence of the labels, with the same procedure used in the CVI case. Figure 9 shows the empirical cumulative distribution function of the level of confidence associated with each label, obtained at different video resolutions, using AR. The CDF curves obtained for different resolutions show similar shapes. The largest difference can be observed in video B, where the CDFs show a significant slope change from the confidence level of 0.55. Therefore, 50% of observations have a confidence level included in the from 0.40 to 0.55 range and lower dispersion. For confidence values larger than 0.55, the distributions are almost flat, which implies a higher dispersion. In this area, the differences between the four distributions are more pronounced. For instance, 30% of observations have confidence values larger than 0.9 at the resolution of 1080p, and then 0.75 at 240p. Generally, higher values of confidence with increasing resolution were observed with AR with respect to CVI. On the other side, the confidence values of CVI are higher than the ones obtained from AR. For example, considering the video B, the median values from AR and CVI are, respectively, 0.55 and 0.75 ca for the SD resolutions.