The aim of edge detection is to extract object boundaries and perceptually significant edges from natural images, thereby preserving key points of the image and ignoring unexpected details, especially important for various mid-to-high-level vision tasks (such as image segmentation, object detection and recognition, image classification). With the development of technology, the demand for edge detection is getting higher and higher. The required edge information is more abundant and more accurate in the areas of intelligent driving, medical detection, and industrial applications[1].
Over time, edge detection algorithms can be divided into two categories. One is traditional edge detection algorithms, such as Canny, Sober, Laplacian edge detection [2–4]; The second is modern edge detection algorithms, such as SUSAN edge detection algorithm, ant colony optimization, neural network detection algorithm (fast-rcnn), watershed algorithm based on neutrosophic sets, etc [5–8]. There is no balance between detection accuracy and detection speed although the detection accuracy is constantly improved. In addition, images are susceptible to various types of noise during collecting image process. Therefore, it is more important to apply new methods and concepts.
In image processing, traditional fuzzy theory is limited to some applications. For example, fuzzy sets not only fail to effectively process noisy images, but are still sensitive to noise, and have defects in processing spatial uncertainty [9]. Therefore, people found that the edge of image is actually an uncertain information. It is in an uncertain state on both the object and the background. Smarandache proposed the concept of intelligence set (NS), which can effectively solve the problem of uncertainty [10]. In NS, real, uncertain and false information can be independent, and this assumption is important in many applications. Therefore, someone introduced True(T), Uncertain(I) and False(F) subsets into image processing, such as edge detection and image segmentation, and achieved good results [11, 12]. However, there are only a few studies on edge detection based on NS. SudanJha et al. proposed a neutrosophic image segmentation with Dice Coefficients. The neutrosophic sets and Dice Coefficients were fused to ensure correct assessment of missing data uncertainty and image segmentation uncertainty [13]. Ahmed M.Anter et al. proposed a hybrid segmentation method for CT liver tumor based on neutrosophic set, fast fuzzy C-means and adaptive watershed algorithm [14]. Ming Zhang et al. proposed a watershed-based CIMC image segmentation algorithm. The watershed algorithm was used for segmentation based on the neutral set [8]. Furthermore, EserSert proposed a new and improved mid-intelligence set segmentation based on this research [15]. However, there are few researches on edge detection. Therefore, Eser and Derya proposed a maximum entropy-based neutrosophic edge detection algorithm (NMNE) [16]. But there are common problems, the algorithm is complex and sensitive to noise.
Therefore, this paper proposes an edge detection algorithm based on adaptive threshold for neutrosophic set (P_NMNE), which effectively solves the problem of high complexity and sensitivity to noise. The proposed algorithm is compared with NMNE to reveal its effectiveness. Furthermore, the anti-noise performance of the proposed algorithm is compared with Canny edge and Sobel edge detection methods. The experimental results prove that the proposed algorithm has the advantages of low complexity and high anti-noise performance. The work is organized as follows: Following the introduction, Section 2 describes the theory of neutrosophic sets, and based on it, an edge detection algorithm with adaptive threshold is proposed; Section 3 conducts edge detection experiments on images in multiple domains, comparing the P_NMNE algorithm with other algorithms to verify the accuracy and performance improvement of the proposed algorithm. The conclusion is given in Section 4 to end the paper.