# An Algorithm for Obtaining 3D Egg Models from Visual Images
## 5 Conclusions  
Methods and tools for analyzing and evaluating bird eggs have been developed based on the analysis of the digital image format of their elements, which create three-dimensional models and descriptions of the shape of the egg elements corresponding to their basic shapes. Approaches have been adapted to recognize the basic elements of eggs by their color digital images based on extracted features that create three-dimensional models of eggs. A method for the formation of three-dimensional models of egg elements is proposed, which describes the nature of the change in the surface of the elements by taking into account the relative lengths and growths of intersecting lines perpendicular to the symmeters and evenly distributed along their length. Based on the descriptions thus obtained, three-dimensional egg-shaped models corresponding to their basic shapes have been defined. Methods and tools for recognizing eggs based on morphological features and the shape of their elements have been developed, represented by three-dimensional descriptions of the surface, based on the basic geometric parameters of the elements and a set of ratios between them. A comparative study was performed to evaluate the effect of the methods used to represent the surface of eggs on recognition accuracy. The use of the method for describing the three-dimensional shape of eggs by geometric and morphological characteristics has been found. Software tools have been developed to implement the proposed digital image analysis methods and procedures, with the purpose of constructing descriptions of the three-dimensional shape of eggs, their classification into major groups based on their shape, and the classification accuracy for recognizing different egg species. The values of the correction factor '\(c\)' have been determined by which the basic three-dimensional shapes of the eggs can be described with sufficient accuracy. The advantage of the algorithms and procedures proposed here over the existing ones is that all the basic parameters involved in the calculations are automatically determined. The deviation from the horizontal axis of the egg in the image \(\pm 10\%\) has been found to produce an error in determining the egg parameters up to \(5\%\). The egg shapes studied were for sparrow, mallard, and wild quails. This is because they are the most studied in Bulgaria. For the future work, a study including species with more extreme egg shapes is needed. The proposed functional solution of the algorithm allows modification of the recognition procedure and its use in the creation of methods and tools for analysis of basic external characteristics, as well as technical equipment for collecting, cleaning, sorting, packaging, transport, and storage of eggs, for both wild birds and domestic poultry. The proposed methods and tools for three-dimensional transformation of egg images would be applicable not only for the needs of poultry farming, but also in ornithological research when working with different-shaped varieties of eggs. Experimental results show that the proposed algorithm has sufficient accuracy. In our work, a comparative analysis of the effectiveness of the algorithm for obtaining 3D egg shapes was proposed, in terms of its error rates. Additional research is needed in the operation of the selected algorithm in its operation on single-board microcomputers, for example, Arduino or Raspberry Pi. Such an analysis would show the working speed of this algorithm and the possibilities for its direct implementation in real recognition systems, applicable directly to portable devices or sorting machines. Conceptualization, Z.Z. and H.L. ; methodology, H.L. ; software, Z.Z. and M.G.-N.; validation, H.L. ; formal analysis, Z.Z. ; investigation, Z.Z., H.L. and M.G.-N.; resources, Z.Z. ; data curation, H.L. ; writing--original draft preparation, Z.Z. and M.G.-N.; writing--review and editing, Z.Z. and H.L. ; visualization, Z.Z. ; supervision, H.L. All authors have read and agreed to the published version of the manuscript.