Quality Assessment of 3D Printed Surfaces Using Combined Metrics Based on Mutual Structural Similarity Approach Correlated with Subjective Aesthetic Evaluation

Krzysztof Okarma,Vladimir Lukin,Piotr Lech,Jarosław Fastowicz

doi:10.3390/app10186248

Abstract

Quality assessment of the 3D printed surfaces is one of the crucial issues related to fast prototyping and manufacturing of individual parts and objects using the fused deposition modeling, especially in small series production. As some corrections of minor defects may be conducted during the printing process or just after the manufacturing, an automatic quality assessment of object’s surfaces is highly demanded, preferably well correlated with subjective quality perception, considering aesthetic aspects. On the other hand, the presence of some greater and more dense distortions may indicate a reduced mechanical strength. In such cases, the manufacturing process should be interrupted to save time, energy, and the filament. This paper focuses on the possibility of using some general-purpose full-reference image quality assessment methods for the quality assessment of the 3D printed surfaces. As the direct application of an individual (elementary) metric does not provide high correlation with the subjective perception of surface quality, some modifications of similarity-based methods have been proposed utilizing the calculation of the average mutual similarity, making it possible to use full-reference metrics without the perfect quality reference images, as well as the combination of individual metrics, leading to a significant increase of correlation with subjective scores calculated for a specially prepared dataset.

Highlights

Additive manufacturing, referred to as the 3D printing, is one of the key technologies which revolutionizes the small series production in the Industry 4.0 era
Analyzing the results, obtained by the unconstrained nonlinear optimization od exponent weights using the MATLAB R fminsearch function, which utilizes the simplex search method, verified using gradient-based methods, it may be noticed that the application of an individual elementary metric leads to PLCC and Spearman Rank Order Correlation Coefficient (SROCC) values not exceeding 0.7 for the best metric (FSIM)
Presented results confirm the usefulness of the combined IQA metrics for the quality evaluation of the 3D printed surfaces, leading to a high correlation with subjective opinions of the surface aesthetics

Summary

Introduction

Referred to as the 3D printing, is one of the key technologies which revolutionizes the small series production in the Industry 4.0 era. The use of the 3D printers makes it possible to create some original 3D objects for entertaining purposes and to launch an individual production of some unique parts of machines and other devices used to replace some damaged older elements. Some other areas of applications of additive manufacturing technology, utilizing plastic filaments usually based on polyactic acid (PLA) or acrylonitrile butadiene styrene (ABS), may be related to biomedical engineering (e.g., individual prosthesis), aerospace and automotive solutions, civil engineering and architecture (e.g., concrete 3D printing), reverse engineering in industry or even the protection of cultural heritage.

Results

Discussion

Conclusion