# Distance Estimation with a Stereo Camera and Accuracy Determination
## 5 Conclusions  
This paper presents the methodology and measurement stand created to test the distance of objects from a stereo camera. By comparing absolute and relative errors, the accuracy of the system was evaluated and the distance ranges where the measurements are most precise were identified. This was evaluated on the basis of the results obtained from measurements in the range of 20 to 70 cm, where three measurements were taken every 2.5 cm. The conclusions of the study of the precision of a measurement system based on stereo camera technology indicate significant differences in measurement accuracy depending on object size and distance from the camera. Analyzing the results for two different objects--a cup and a LEGO man figurine--it was noted that the system had different levels of precision depending on the object size and distance range. For measurements of the cup, which is a larger object, the system showed very high precision in the distance range of 25 to 60 cm. In this range, absolute errors were generally less than 1 cm, which translated into an average absolute error of 0.4 cm and a relative error of 0.95%. The highest precision, characterized by a minimum absolute error of 0.02 cm (relative error of 0.05%), was achieved at a distance of 50 cm. It is important to note that this is one of the distances at which the cameras were calibrated. It should be noted that an absolute error of less than 0.5 cm occurred in most of the measurements in this range, demonstrating the exceptional precision of the system under these conditions. The largest absolute errors were recorded at a distance of 70 cm, where they were 4.43 cm (relativeerror of 6.32%). This showed that the accuracy of the system decreased at longer distances, which may be due to technological limitations or the specifics of the object itself and its reflective properties. The LEGO figurine, which is a smaller object, had overall larger measurement errors compared to the cup. The largest absolute error was 4.81 cm at a distance of 70 cm, representing a relative error of 6.88%. The lowest absolute error was recorded at a distance of 45 cm and was 0.23 cm (relative error of 0.52%). The separated range of distances from 30 to 47.5 cm had an average absolute error of 0.56 cm and a relative error of 1.46%, suggesting that measurements in this range were more precise compared to measurements at other distances. The highest error in this range was 0.92 cm at a distance of 42.5 cm, which translates into a relative error of 2.17%. These results showed that the system tended to produce better results at closer distances for smaller objects. By comparing the two cases, it can be concluded that the measurement system is more precise for larger objects, which is evident in the lower average absolute and relative errors. The average absolute error for the cup was 0.98 cm and the relative error was 2.42%, which is an acceptable level of precision for many applications. For the LEGO man figurine, the average absolute error was 1.81 cm, and the relative error was 4.07%, suggesting a greater variation in measurement. These results point to the need for further optimization of the system, especially for measuring smaller objects at longer distances. In conclusion, the study has provided valuable data on the capabilities and limitations of the stereo camera-based measurement system. The system's high precision over certain distance ranges and for larger objects shows its potential for precision measurement applications, but higher errors for smaller objects indicate areas that require further research and improvement. These results can serve as a basis for the further optimization of the technology and the adaptation of the system to different applications, which is key to its versatile use in practice. This article focuses on the use of only one neural network, Mask R-CNN, for object detection, allowing a thorough analysis of its capabilities and effectiveness. Nevertheless, the authors are not limited to this method exclusively.