purpose : to offer a semi-automatic algorithm to determine the area of angiographic hyperfluorescence methods : the proposed algorithm included wavelet filter, histogram equalization and modified otsu thresholding. hyperfluorescent area of 30 angiographic images obtained from patients with leaking choroidal neovascularization (cnv) and diabetic retinopathy were evaluated and the results were co...

In this paper a novel edge detection method has been proposed which outperform Otsu method [1]. The proposed detection algorithm has been devised using the concept of genetic algorithm in spatial domain. The key of edge detection is the choice of threshold; which determines the results of edge detection. GA has been used to determine an optimal threshold over the image. Results are compared wit...

Image segmentation of pulmonary parenchyma can be detected from multisliced CT images using image segmentation. It can be modeled as a nonlinear multimodal global optimization problem. The traditional 2D Otsu algorithm, though effective, is quite time consuming for determining the optimum threshold values. In this paper we propose a combination of 2D Otsu method with modified ABC algorithm (cal...

Aiming at the issues of complex calculation and low accuracy two-dimensional (2D) Otsu segmentation images, an image threshold means 2D ground on a modified sparrow search algorithm is proposed. Firstly, in initialization stage, tent chaos mapping added to enhance multiformity population, population elite strategy introduced quality initial solution. Secondly, local reverse learning applied ren...

The Otsu s method has been proven as an efficient method in image segmentation for bi-level thresholding. However, this method is computationally intensive when extended to multi-level thresholding. In this paper, we present a hybrid optimization scheme for multiple thresholding by the criteria of (1) Otsu s minimum within-group variance and (2) Gaussian function fitting. Four example images ar...

In the face of the problem of high complexity of two-dimensional Otsu adaptive threshold algorithm, a new fast and effective Otsu image segmentation algorithm is proposed based on genetic algorithm. This algorithm replaces the segmentation threshold of the traditional two dimensional Otsu method by finding the threshold of two one-dimensional Otsu methods it reduces the computational complexity...

We summarize the results on the differential geometric structure of Alexandrov spaces developed in [Otsu and Shioya 1994; Otsu 1995; Otsu and Tanoue a]. We discuss Riemannian and second differentiable structure and Jacobi fields on Alexandrov spaces of curvature bounded below or above.

The multilevel thresholding problem is a challenge task due to the fact that the computation is usually very time-consuming for obtaining the optimal multilevel thresholds. Though the state-of-the-art multilevel thresholding algorithms applied various meta-heuristic techniques or acceleration strategies, they still directly searched the optimal thresholds in the whole histogram only for the fix...

Overlapping of cervical cells and poor contrast of cell cytoplasm are the major issues in accurate detection and segmentation of cervical cells. An unsupervised cell segmentation approach is presented here. Cell clump segmentation was carried out using the extended depth of field (EDF) image created from the images of different focal planes. A modified Otsu method with prior class weights is pr...