Accurate and cost-effective MTF measurement system for lens modules of digital cameras

Gao-Wei Chang, Chia Cheng Liao, Zong-Mu Yeh

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

For many years, the widening use of digital imaging products, e.g., digital cameras, has given rise to much attention in the market of consumer electronics. However, it is important to measure and enhance the imaging performance of the digital ones, compared to that of conventional cameras (with photographic films). For example, the effect of diffraction arising from the miniaturization of the optical modules tends to decrease the image resolution. As a figure of merit, modulation transfer function (MTF) has been broadly employed to estimate the image quality. Therefore, the objective of this paper is to design and implement an accurate and cost-effective MTF measurement system for the digital camera. Once the MTF of the sensor array is provided, that of the optical module can be then obtained. In this approach, a spatial light modulator (SLM) is employed to modulate the spatial frequency of light emitted from the light-source. The modulated light going through the camera under test is consecutively detected by the sensors. The corresponding images formed from the camera are acquired by a computer and then, they are processed by an algorithm for computing the MTF. Finally, through the investigation on the measurement accuracy from various methods, such as from bar-target and spread-function methods, it appears that our approach gives quite satisfactory results.

Original languageEnglish
Title of host publicationProceedings of SPIE-IS and T Electronic Imaging - Image Quality and System Performance IV
Publication statusPublished - 2007 May 25
EventImage Quality and System Performance IV - San Jose, CA, United States
Duration: 2007 Jan 302007 Feb 1

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume6494
ISSN (Print)0277-786X

Other

OtherImage Quality and System Performance IV
CountryUnited States
CitySan Jose, CA
Period07/1/3007/2/1

Keywords

  • Digital camera
  • Image quality
  • Modulation transfer function

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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  • Cite this

    Chang, G-W., Liao, C. C., & Yeh, Z-M. (2007). Accurate and cost-effective MTF measurement system for lens modules of digital cameras. In Proceedings of SPIE-IS and T Electronic Imaging - Image Quality and System Performance IV [64940S] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 6494).