An Improved U-Net Image Segmentation Method and Its Application for Metallic Grain Size Statistics

Grain size is one of the most important parameters for metallographic microstructure analysis, which can partly determine the material performance. The measurement of grain size is based on accurate image segmentation methods, which include traditional image processing methods and emerging machine-l...

Full description

Bibliographic Details
Main Authors: Peng Shi, Mengmeng Duan, Lifang Yang, Wei Feng, Lianhong Ding, Liwu Jiang
Format: Article
Language:English
Published: MDPI AG 2022-06-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/15/13/4417
_version_ 1797442970533756928
author Peng Shi
Mengmeng Duan
Lifang Yang
Wei Feng
Lianhong Ding
Liwu Jiang
author_facet Peng Shi
Mengmeng Duan
Lifang Yang
Wei Feng
Lianhong Ding
Liwu Jiang
author_sort Peng Shi
collection DOAJ
description Grain size is one of the most important parameters for metallographic microstructure analysis, which can partly determine the material performance. The measurement of grain size is based on accurate image segmentation methods, which include traditional image processing methods and emerging machine-learning-based methods. Unfortunately, traditional image processing methods can hardly segment grains correctly from metallographic images with low contrast and blurry boundaries. Moreover, the proposed machine-learning-based methods need a large dataset to train the model and can hardly deal with the segmentation challenge of complex images with fuzzy boundaries and complex structure. In this paper, an improved U-Net model is proposed to automatically accomplish image segmentation of complex metallographic images with only a small training set. The experiments on metallographic images show the significant advantage of the method, especially for the metallographic images with low contrast, a fuzzy boundary and complex structure. Compared with other deep learning methods, the improved U-Net scored higher in ACC, MIoU, Precision, and F1 indexes, among which ACC was 0.97, MIoU was 0.752, Precision was 0.98, and F1 was 0.96. The grain size was calculated based on the segmentation according to the American Society for Testing Material (ASTM) standards, producing a satisfactory result.
first_indexed 2024-03-09T12:49:21Z
format Article
id doaj.art-baf1e647f4b4415b8cf6afe0f162591d
institution Directory Open Access Journal
issn 1996-1944
language English
last_indexed 2024-03-09T12:49:21Z
publishDate 2022-06-01
publisher MDPI AG
record_format Article
series Materials
spelling doaj.art-baf1e647f4b4415b8cf6afe0f162591d2023-11-30T22:08:39ZengMDPI AGMaterials1996-19442022-06-011513441710.3390/ma15134417An Improved U-Net Image Segmentation Method and Its Application for Metallic Grain Size StatisticsPeng Shi0Mengmeng Duan1Lifang Yang2Wei Feng3Lianhong Ding4Liwu Jiang5National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083, ChinaNational Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083, ChinaNational Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Automation, Nanjing University of Science and Technology, Nanjing 211103, ChinaSchool of Information, Beijing Wuzi University, Beijing 101149, ChinaNational Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083, ChinaGrain size is one of the most important parameters for metallographic microstructure analysis, which can partly determine the material performance. The measurement of grain size is based on accurate image segmentation methods, which include traditional image processing methods and emerging machine-learning-based methods. Unfortunately, traditional image processing methods can hardly segment grains correctly from metallographic images with low contrast and blurry boundaries. Moreover, the proposed machine-learning-based methods need a large dataset to train the model and can hardly deal with the segmentation challenge of complex images with fuzzy boundaries and complex structure. In this paper, an improved U-Net model is proposed to automatically accomplish image segmentation of complex metallographic images with only a small training set. The experiments on metallographic images show the significant advantage of the method, especially for the metallographic images with low contrast, a fuzzy boundary and complex structure. Compared with other deep learning methods, the improved U-Net scored higher in ACC, MIoU, Precision, and F1 indexes, among which ACC was 0.97, MIoU was 0.752, Precision was 0.98, and F1 was 0.96. The grain size was calculated based on the segmentation according to the American Society for Testing Material (ASTM) standards, producing a satisfactory result.https://www.mdpi.com/1996-1944/15/13/4417complex imagegrain sizeimage segmentationimproved U-Netmetallographic microstructure analysis
spellingShingle Peng Shi
Mengmeng Duan
Lifang Yang
Wei Feng
Lianhong Ding
Liwu Jiang
An Improved U-Net Image Segmentation Method and Its Application for Metallic Grain Size Statistics
Materials
complex image
grain size
image segmentation
improved U-Net
metallographic microstructure analysis
title An Improved U-Net Image Segmentation Method and Its Application for Metallic Grain Size Statistics
title_full An Improved U-Net Image Segmentation Method and Its Application for Metallic Grain Size Statistics
title_fullStr An Improved U-Net Image Segmentation Method and Its Application for Metallic Grain Size Statistics
title_full_unstemmed An Improved U-Net Image Segmentation Method and Its Application for Metallic Grain Size Statistics
title_short An Improved U-Net Image Segmentation Method and Its Application for Metallic Grain Size Statistics
title_sort improved u net image segmentation method and its application for metallic grain size statistics
topic complex image
grain size
image segmentation
improved U-Net
metallographic microstructure analysis
url https://www.mdpi.com/1996-1944/15/13/4417
work_keys_str_mv AT pengshi animprovedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT mengmengduan animprovedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT lifangyang animprovedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT weifeng animprovedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT lianhongding animprovedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT liwujiang animprovedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT pengshi improvedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT mengmengduan improvedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT lifangyang improvedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT weifeng improvedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT lianhongding improvedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics
AT liwujiang improvedunetimagesegmentationmethodanditsapplicationformetallicgrainsizestatistics