Yuki Naka ¹ Yuzuko Utsumi ^2* Masakazu Iwamura ¹ Hirokazu Tsukaya ³ Koichi Kise ¹

• ¹ Graduate School of Informatics, Osaka Metropolitan University, Sakai, Ōsaka, Japan
• ² Osaka Metropolitan University, Osaka, Japan
• ³ The University of Tokyo, Bunkyo, Tōkyō, Japan

Manual segmentation of the petals of flower computed tomography (CT) images is timeconsuming and labor-intensive because the flower has many petals. In this study, we aim to obtain a three-dimensional (3D) structure of Camellia japonica flowers and propose a petal segmentation method using computer vision techniques. Petal segmentation on the slice images fails by simply applying the segmentation methods because the shape of the petals in CT images differs from that of the objects targeted by the latest instance segmentation methods. To overcome these challenges, we crop two-dimensional (2D) long rectangles from each slice image and apply the segmentation method to segment the petals on the images. Thanks to cropping, it is easier to segment the shape of the petals in the cropped images using the segmentation methods. We can also use the latest segmentation method for the task because the number of images used for training is augmented by cropping. Subsequently, the results are integrated into 3D to obtain 3D segmentation volume data. The experimental results show that the proposed method can segment petals on slice images with higher accuracy than the method without cropping. The 3D segmentation results were also obtained and visualized successfully.