[OPTICAL REVIEW Vol. 16, No. 3 (2009) 241-246]
© 2009 The Optical Society of Japan

A Thin and Compact Compound-Eye Imaging System Incorporated with an Image Restoration Considering Color Shift, Brightness Variation, and Defocus

Ryoichi HORISAKI*, Yoshizumi NAKAO1, Takashi TOYODA1, Keiichiro KAGAWA, Yasuo MASAKI1, and Jun TANIDA

Department of Information and Physical Sciences, Graduate School of Information Science and Technology, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
1Funai Electric Co., Ltd., 1-3 Kamiyama-cho, Kita-ku, Osaka 530-0026, Japan

(Received January 7, 2009; Accepted February 10, 2009)

A compact system of the thin observation module by bound optics (TOMBO) imager based on compound-eye imaging has been constructed to demonstrate its advantages over single-eye imaging systems such as thinner hardware. To reconstruct a high-resolution image from low resolution images captured by the compound-eye optics, we propose an image restoration scheme based on the iterative back-projection algorithm with depth map estimated from the disparities on the captured image. The scheme includes suppression of unit-by-unit color shift caused by the offset microlenses and the color filters on the commercial image sensors and deblurring of defocus by geometrical optics using the depth map. In the experiment, three-dimensional objects were captured by the TOMBO imager and reconstructed with the scheme. After the processing, the power spectrum of the captured image was improved by up to 19 dB, and the power spectrum of the effect of the color shift was reduced by 7 dB.

Key words: compound-eye camera, TOMBO, super-resolution, depth estimation, image restoration

*E-mail address: r.horisaki@ist.osaka-u.ac.jp