Abstract
Image thresholding is a widely used technology for a lot of computer vision applications, and among various global thresholding algorithms, Otsu‐based approaches are very popular due to their simplicity and effectiveness. While the usage of Otsu‐based thresholding methods is well discussed, the performance analyses of these methods are rather limited. In this paper, we first review nine Otsu‐based approaches and categorize them based on their objective functions, preprocessing, and postprocessing strategies. Second, we conduct several experiments to analyze the model characteristics using different scene parameters both on synthetic images and real‐world cell images. We put more attention to examine the variance of foreground object and the effect of the distance between mean values of foreground and background. Third, we explore the robustness of algorithms by introducing two typical kinds of noises under different intensities and compare the running time of each method. Experimental results show that NVE, WOV, and Xing’s methods are more robust to the distance of mean values of foreground and background. The large foreground variance will cause a larger threshold value. Experiments on cell images show that foreground miss detection becomes serious when the intensities of foreground pixels change drastically. We conclude that almost all algorithms are significantly affected by Salt&Pepper and Gaussian noises. Interestingly, we find that ME increases almost linearly with the intensity of Salt&Pepper noise. In terms of algorithms’ time cost, methods with no preprocessing and postprocessing steps have more advantages. All these findings can serve as a guideline for image thresholding when using Otsu‐based thresholding approaches.
Highlights
Image segmentation which extracts objects of interest from background is a fundamental technology for various image processing tasks
While we can choose more than one threshold values for multilevel segmentation, in this paper, we only focus on a single threshold segmentation which separates the whole image into two parts, and each corresponds to the background and foreground
The main contributions of the paper are as follows: (1) We propose a categorization method for different improved Otsu-based algorithms based on their objective functions, preprocessing, and postprocessing strategies
Summary
Image segmentation which extracts objects of interest from background is a fundamental technology for various image processing tasks. (1) We propose a categorization method for different improved Otsu-based algorithms based on their objective functions, preprocessing, and postprocessing strategies (2) The characteristics of each Otsu-based method are analyzed in-depth. The effect of variance and distance between mean values of foreground and background, the ratio of foreground object in the whole image are discussed using a Monte Carlo-based image synthetic method (3) The robustness of each Otsu-based method to two typical kinds of corruptions is studied on a real-world cell image dataset, and the performance of each algorithm corresponding to different noise intensities is analyzed (4) We compare the time cost of all test algorithms and find that preprocessing or postprocessing steps may significantly increase algorithm’s consuming time when implementing by Matlab if the preprocessing or postprocessing does not meet the language characteristics.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.