Digital Image Processing for Evaluating the Characteristics of the Microstructure of a Holographic Plate
Chern-Sheng Lin* and Rong-Seng Chang**

* Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan

** Institute of Optical Sciences, National Central University, Chung-Li, Taiwan

ABSTRACT

A system of evaluating the microstructure of a holographic plate(for example, a light sensitive plate in dichromated gelatin (DCG) or photoresist emulsion) with economical measuring equipment is described. We observe the holographic plate with a microscope and CCD camera with a PC 486 computer. With the information from gray levels of the scanning image we obtain a new concepts of four film quality characteristics to evaluate the quality of the film. We can scan the full size of the plate to obtain the macro- pattern. We also can select other magnification of the local pattern. The apparatus also has particular use in the detection of micro-particles of a microstructure.

Subject terms: DCG; photoresist emulsion; film quality characteristics; micro-particles


1. INTRODUCTION
2. THE FILM QUALITY CHARACTERISTICS
3. EXPERIMENT
4. CONCLUSION and ACKNOWLEDGMENT
References
Figure Legend
Table 1 One example of the measurement results of our system.
Fig.1 Experimental set-up
Fig.2 adjust the parameters in film fabricating process.
Fig.3 (A) The histogram of a unmodified look up table
Fig.3 (B) The histogram of a modified look up table.
Fig.4 The image of a film with micro-particle.
Fig.5 The short-axis and long-axis of the profile of a particle.
Fig.6 The measurement of the photoresist thickness corresponding to the resist hickness
Fig.7 The measurements results which are identified on two types of particle.
   
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