Machine vision based on the concept of contrast sensitivity of the human eye

The OLED defects generated in the manufacturing process restrict the development of OLED industry, machine vision based automatic OLED-inspection equipment can rapidly detect these defects and help to improve the OLED manufacturing process. The OLED images have the features of repeating texture background, uneven overall brightness of the image and the defects without obvious edge. In addition, an uncertain change in light and position of the inspection system increases the difficulty of the detection. Therefore, we propose the method to detect defects which take advance of the human eye characteristics of the Gabor filter and the unsupervised and fast segmentation features of the Fuzzy C-Means FCM algorithm. Through the combined 2-step segmentation, most OLED defects can be detected. The experimental tests are performed to validate the effectiveness of the proposed method. The result of the experiment shows that this method works well which can meet the requirements of robustness, automation of the fast and reliable of an online inspection system.

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Formula for the contrast sensitivity of the human eye

10.1117/12.537476 ◽

2003 ◽

Cited By ~ 56

Author(s):

Peter G. J. Barten

Keyword(s):

Contrast Sensitivity ◽

Human Eye

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Study on New Measurement Method for Visual Contrast Sensitivity

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.433-435.877 ◽

2013 ◽

Vol 433-435 ◽

pp. 877-881

Author(s):

Ji Yan Zhang ◽

Bao Yu Hong ◽

Wen Li Liu ◽

Tao Geng Zhou

Keyword(s):

Contrast Sensitivity ◽

Measurement Method ◽

Research Result ◽

Optical Path ◽

Integrating Sphere ◽

Real Time Control ◽

Measuring Device ◽

Human Eye ◽

Time Control ◽

Visual Contrast

Contrast sensitivity measurement is widely used in clinical ophthalmology to evaluate visual function of the human eye, and of great significance for early diagnosis and identification of ophthalmic diseases. On the basis of contrast sensitivity definition, current measurement method was analyzed. By analyzing the existing principles and shortcomings of the human eye contrast sensitivity methods, a new method for generating observation targets of contrast sensitivity was proposed. By using double optical path design idea with integrating sphere and self-developed brightness adjustment systems, two beams of uniform light with specific luminance could be produced. With subsequent reuse of the optical path, accurate measurement of eye contrast sensitivity could be achieved, and calibration of contrast sensitivity tester widely used in clinical practice could be solved by developing assistant transfer tools. Moreover, output parameters of this method could be precisely adjusted according to the need as a result it ccould achieve real-time control and calibration. The research result has set the foundation for future establishment of visual threshold measuring device which is especially suitable for scientific and experimental research in clinical ophthalmology and metrology.

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