Image Quality and Texture-Based Features for Reliable Textured Contact Lens Detection

2018 ◽  
Author(s):  
Hareesh Mandalapu ◽  
Raghavendra Ramachandra ◽  
Christoph Busch
Keyword(s):  
Image Quality ◽  
Contact Lens ◽  
Contact Lens Detection

scholarly journals Swept Source Optical Coherence Tomography Angiography for Contact Lens-Related Corneal Vascularization

2016 ◽  
Vol 2016 ◽  
pp. 1-3 ◽  
Author(s):  
Marcus Ang ◽  
Yijun Cai ◽  
Anna C. S. Tan
Keyword(s):  
Optical Coherence Tomography ◽  
Image Quality ◽  
Contact Lens ◽  
Optical Coherence Tomography Angiography ◽  
Quality Score ◽  
Image Quality Score ◽  
Optical Coherence ◽  
Swept Source ◽  
Corneal Vascularization ◽  
Significant Difference

Purpose. To describe a novel technique of adapting a swept-source optical coherence tomography angiography (OCTA) to image corneal vascularization.Methods. In this pilot cross-sectional study, we obtained 3 × 3 mm scans, where 100,000 A-scans are acquired per second with optical axial resolution of 8 μm and lateral resolution of 20 μm. This was performed with manual “XYZ” focus without the anterior segment lens, until the focus of the corneoscleral surface was clearly seen and the vessels of interest were in focus on the corresponding red-free image. En face scans were evaluated based on image quality score and repeatability.Results. We analyzed scans from 10 eyes (10 patients) with corneal vascularization secondary to contact lens use in 4 quadrants, with substantial repeatability of scans in all quadrants (mean image quality score 2.7 ± 0.7;κ=0.75). There was no significant difference in image quality scores comparing quadrants (superior temporal: 2.9 ± 0.6, superior nasal: 2.8 ± 0.4, inferior temporal: 2.5 ± 0.9, and inferior nasal: 2.4 ± 1.0;P=0.276) and able to differentiate deep and superficial corneal vascularization.Conclusion. This early clinical study suggests that the swept-source OCTA used may be useful for examining corneal vascularization, which may have potential for clinical applications such as detecting early limbal stem cell damage.

scholarly journals Impact of contact lens zone geometry and ocular optics on bifocal retinal image quality

2014 ◽  
Vol 34 (3) ◽  
pp. 331-345 ◽  
Author(s):  
Arthur Bradley ◽  
Jayoung Nam ◽  
Renfeng Xu ◽  
Leslie Harman ◽  
Larry Thibos
Keyword(s):  
Image Quality ◽  
Contact Lens ◽  
Retinal Image

Contact lens detection for iris spoofing countermeasure

2017 ◽  
Vol 9 (3) ◽  
pp. 243
Author(s):  
Edward Tan ◽  
Anto Satriyo Nugroho ◽  
Maulahikmah Galinium
Keyword(s):  
Contact Lens ◽  
Contact Lens Detection
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