• Acta Optica Sinica
  • Vol. 43, Issue 2, 0210001 (2023)
Xinxin Ge1, Haihua Cui1,*, Zhenlong Xu1, Minqi He2, and Xuezhi Han3
Author Affiliations
  • 1College of Mechanical & Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, Jiangsu, China
  • 2Aecc Aviation Power Co., Ltd., Xi'an 710021, Shaanxi, China
  • 3AECC Harbin Dongan Engine Co., Ltd., Harbin 150066, Heilongjiang, China
  • show less
    DOI: 10.3788/AOS221263 Cite this Article Set citation alerts
    Xinxin Ge, Haihua Cui, Zhenlong Xu, Minqi He, Xuezhi Han. Super-Resolution Image Reconstruction Method for Micro Defects of Metal Engine Blades[J]. Acta Optica Sinica, 2023, 43(2): 0210001 Copy Citation Text show less
    Gray images of metal collected from multiple angles of light. (a) From the right; (b) from the bottom; (c) from the left; (d) from the top
    Fig. 1. Gray images of metal collected from multiple angles of light. (a) From the right; (b) from the bottom; (c) from the left; (d) from the top
    Schematic of photometric stereo hardware. (a) Hardware layout diagram; (b) light source vector calibration diagram
    Fig. 2. Schematic of photometric stereo hardware. (a) Hardware layout diagram; (b) light source vector calibration diagram
    Schematic for solving normal vector of highlighted points
    Fig. 3. Schematic for solving normal vector of highlighted points
    Surface normal map reconstructed by photometric stereo method
    Fig. 4. Surface normal map reconstructed by photometric stereo method
    Model network structure with super division ratio of 2
    Fig. 5. Model network structure with super division ratio of 2
    In the process of upsampling on the network, the elements in the four feature layers correspond to the new feature layer graph
    Fig. 6. In the process of upsampling on the network, the elements in the four feature layers correspond to the new feature layer graph
    Flow chart of proposed method
    Fig. 7. Flow chart of proposed method
    Quantitative super-resolution reconstruction test platform. (a) Experiment platform; (b) shooting result
    Fig. 8. Quantitative super-resolution reconstruction test platform. (a) Experiment platform; (b) shooting result
    Imaging detailed display of gray image. (e) Blade gray image; (b)-(e) corresponding local area pictures
    Fig. 9. Imaging detailed display of gray image. (e) Blade gray image; (b)-(e) corresponding local area pictures
    Gray scale images collected from different light source angles
    Fig. 10. Gray scale images collected from different light source angles
    Detailed comparison of quantitative super-resolution reconstruction. (a) Blade normal map; (b)-(e) corresponding local area pictures
    Fig. 11. Detailed comparison of quantitative super-resolution reconstruction. (a) Blade normal map; (b)-(e) corresponding local area pictures
    Comparison of feature boundaries before and after fusion reconstruction. (a) Fig. 9 (b) area; (b) Fig. 11 (b) area
    Fig. 12. Comparison of feature boundaries before and after fusion reconstruction. (a) Fig. 9 (b) area; (b) Fig. 11 (b) area
    Comparison of boundary extraction effects
    Fig. 13. Comparison of boundary extraction effects
    Comparison of high-resolution and low-resolution images in real images. (a) Original image; (b) local high-resolution image; (c) local down sampling low-resolution image
    Fig. 14. Comparison of high-resolution and low-resolution images in real images. (a) Original image; (b) local high-resolution image; (c) local down sampling low-resolution image
    Comparison of the effect of different super dividing networks on the surface image of metal blades. (a) Original picture; (b) local picture; (c)-(g) effects of local area using RDN,SRGAN,EDSR,SRCNN,and proposed method
    Fig. 15. Comparison of the effect of different super dividing networks on the surface image of metal blades. (a) Original picture; (b) local picture; (c)-(g) effects of local area using RDN,SRGAN,EDSR,SRCNN,and proposed method
    Metal blade image and surface defects. (a) Original picture; (b) local picture
    Fig. 16. Metal blade image and surface defects. (a) Original picture; (b) local picture
    Strengthening results of different methods. (a) Method of Ref. [10]; (b) method of Ref. [5]; (c) proposed method
    Fig. 17. Strengthening results of different methods. (a) Method of Ref. [10]; (b) method of Ref. [5]; (c) proposed method
    Defect detection results by different methods. (a) Original detection image; (b) detection result by method of Ref. [10];
    Fig. 18. Defect detection results by different methods. (a) Original detection image; (b) detection result by method of Ref. [10];
    Effect of micro defect boundary extraction after image super-resolution enhancement and reconstruction. (a) Local picture boundary extraction; (b) enhanced reconstruction feature extraction; (c)(d) detail enlarged view
    Fig. 19. Effect of micro defect boundary extraction after image super-resolution enhancement and reconstruction. (a) Local picture boundary extraction; (b) enhanced reconstruction feature extraction; (c)(d) detail enlarged view
    Super-resolution networkSizeCharacteristic
    ESPCN100.0 kBThe model is small in size and fast in training speed,but its super-resolution effect is poor
    SRGAN15.8 MBThe super-resolution effect is good,but the training speed is slow
    SRCNN20.0 kBThe model is small in size and fast in training speed,but its super-resolution effect is poor
    RDN22.1 MBThe super-resolution effect is good,but the training speed is a little slow
    EDSR38.5 MBThe super-resolution effect is good,but the network model is large and the training speed is slow
    Table 1. Comparison of the characteristics of several super-resolution networks
    Hyper parameterValue
    Epoch10
    Batch96
    Iteration300000
    Learning rate0.0001
    Decrease rate of learning rate0.5
    Table 2. Hyper parameters selection in the training process of super-resolution networks
    Ground truthPredicted result
    PositiveNegative
    PositiveTPFN
    NegativeFPTN
    Table 3. Test result confusion matrix
    ModelRDNSRGANEDSRSRCNNOurs
    PSNR41.438.138.140.841.5
    SSIM0.960.930.960.960.96
    Table 4. Comparison of various super-resolution effects of metal blades
    MethodGround truthDetection numberAccuracy /%
    FlawNot flaw
    Origin pictureFlaw27672.9
    Not flaw40
    Method of Ref.[10Flaw28575.7
    Not flaw40
    Method of Ref.[5Flaw30381.1
    Not flaw40
    Proposed methodFlaw32197.2
    Not flaw04
    Table 5. Comparison of extraction effect of blade surface defects by different methods
    Xinxin Ge, Haihua Cui, Zhenlong Xu, Minqi He, Xuezhi Han. Super-Resolution Image Reconstruction Method for Micro Defects of Metal Engine Blades[J]. Acta Optica Sinica, 2023, 43(2): 0210001
    Download Citation