We propose an information embedding technique to a real object by projecting a checkered-pattern carrier-screen image as an illumination. The carrier-screen image is an information hiding technique, which can decode a secret image physically by superimposing a periodic pattern. As a kind of carrier-screen images, we have developed the checkered-pattern carrier-screen images, which can be physically decoded by superimposing a sheet of checkered pattern. The secret information is also visualized by image sampling with certain interval. As an example of decoding by image sampling, we proposed a decoding method with a compact digital camera. The encoded carrier-screen image has an almost uniform pattern, because modulating a checkered pattern generates it. It is also easy to display on a liquid-crystal display, because it is represented on a square pixel structure. Experimental optical embedding and decoding with a digital camera results show effectiveness of the proposed system. Since the embedded information can be decoded by using an ordinary digital camera, our system expected to use not only steganographic purpose also prevention techniques on taking photos.
A DNA memory is a storage system utilizing inherent features of DNA, which is promising as a fundamental
technology of nanoscale computing. Realizing a practical DNA memory requires establishment of a method
for accessing to and controlling certain DNA strands among a lot of strands in a solution with high accuracy
and selectivity. For addressing this issue, we have proposed a DNA memory using photonic techniques: the
photonic DNA memory. Manipulation of information by using DNAs on a nanoscale and light on a microscale is
effective in achieving a high capacity and flexible memory. This paper reports on experimental results of photonic
translation of DNAs containing data between microscopic beads and a substrate. The technique is expected to
be useful in writing, transferring, and reading necessary information in a photonic DNA memory effectively. In
the experiments, we prepared a glass substrate coated with titanylphthalocyanine for light absorption and gold
for DNA attachment. Data container DNA strands, which were labeled by fluorescence-dye for observation,
were attached on the substrate by hybridization with their complementary strands immobilized on the substrate;
then a solution containing 6-micrometer-diameter beads on which DNA strands including the complementary
sequence of the data container DNA was placed on the substrate. After a bead was irradiated with a laser
beam and translated on the substrate, the fluorescence intensity of the substrate decreased and that of the bead
increased. The result indicates that the data container DNA was moved from the substrate to the bead owing
to change of the temperature of the solution at the irradiated area.
Based on compound-eye imaging, a compact image capturing system called TOMBO (Thin Observation Module by Bound Optics) is developed. The TOMBO system consists of a microlens array, a signal separator, and an image sensor. The captured compound image is a set of low-resolution unit images, which is processed to retrieve information of the target object. Owing to flexibility in configuration of the compound imaging system, the TOMBO system can be used for versatile applications. Possible configurations of the TOMBO system are summarized. As examples of the applications, multispectral imaging, 3-D data acquisition, short range imaging, gonio-imaging, and 3-D image interface are presented.
This paper demonstrates, for the first time, TOMBO color imaging system that employs color-splitting filters on each
lens. A red, green, or blue color filter is allocated to each microlens instead of each pixel in conventional single-sensor
color imaging system. Thus the microlens array here also makes up a color filter array of Bayer geometry. For the
imaging device, a CMOS image sensor with 1040 x 960 pixels whose size is 6.25 um square was used. 8 x 8 microlens
array with 750 um pitch was employed as a taking lens. Excellent color images were obtained by rearrangement,
interpolation, and postdigital processing.
A very thin image capturing system called TOMBO (Thin Observation Module by Bound Optics)was developed with compound-eye imaging and post digital processing. With the prototype system, some excellent results have been obtained. In this paper, we focus on a multispectral imaging system as an application of the TOMBO.
In the system, it is possible to observe specific points on the target by multiple photodetectors with a special arrangement of the system. A filter array is inserted in front of the image sensor to observe the spectral distribution of the target. A captured compound image is reconstructed by an extended version of the pixel rearrange method. The pixels of the captured image are geometrically rearranged onto a multi-channel virtual image plane. Experimental results of the image reconstruction show effectiveness of the proposed algorithm.