A lossless transmission of an error-diffused image by coding a multi-level image generated through inverse halftoning process using soft decision method similar to Viterbi decoding is proposed and studied. Through the study, block-type error diffusion is introduced, and entropy-based method and prediction-error-based method for inverse halftoning are compared. The result shows that the decoded image by proposed methods has about 30-40% less entropy than that of the original multi-level image. Finally it was expected that the entropy of decoded multi-level image will be even less than that of bi-level image in higher resolution case.
Recently, soft proof, which can confirm the color reproduction of printed matter on a monitor is coming into wide use in the field of graphic arts. However, there is a problem that hue of the monitor is different from that of printed matter, even if L*a*b* value of the monitor white point is adjusted to that of paper white. In this paper, we assume that the cause of this phenomenon is bright line spectrums of the monitor and illumination measured by a spectroradiometer are inaccurate. Then, we propose a method to correct this error and report the effect of our method under three kinds of illuminations. Firstly, L*a*b value of the paper was more reddish than that of the monitor in all conditions, even though the color of the monitor was adjusted to that of paper by visual calibration. On the other hand, L*a*b* value calculated by sharpened spectrum of the monitor was almost same as that of the paper.
We have found that amorphous n-type metal oxide semiconductors such as SnO2 placed on conductive films exhibit photo-induced structural change; here, the crystal structure of the metal oxide and the electroconductive layer in contact with the crystal structure play an important role. When irradiated by ultraviolet rays, this film becomes colored, and heating it causes it to return to its original state of transparency. It is also possible to use the element thus formed in applications such as controlling a change in visible light transmittance by using an electric field, which is a more practical method. It is expected that an efficient device can be obtained by applying this element to a reflection-type display device, in particular. Here we describe the principle, characteristics, and applications of the photo-induced structural change in amorphous n-type metal oxide semiconductors.
We studied on the movement of many particles independently to display color image in toner display. Two positively charged black and yellow particles with different amount of charge to mass ratio and two negatively charged white particle and magenta particle were enclosed in the toner display cell. Magenta, yellow, black and white images were displayed by an application of voltage of a saw wave pattern.
By combining the organic field-effect-transistor (OFET) and the organic photoreceptor (organic photoconductor: OPC), an optical-drive type OFET was achieved. In this device, the change of electric potential in the OPC, which incorporated between gate electrode and insulator of OFET, is detected as the channel current (between source and drain electrodes) of the OFET. This device showed the increase in the channel current by the laser irradiation (780 nm) for the OPC under applied the gate voltage. On the other hand, the current did not change by the laser irradiation, when there was no gate voltage. These results indicated that this current increasing by laser irradiation was originates from the drive of the OPC. And, the current hysteresis by the charge storage at the interface between OPC and insulator was confirmed. Furthermore, utilizing the charge injection from electrode to OPC, the increase in the channel current was observed without laser irradiation. These results indicated that this device can be utilized as an organic memory device.
Despite the emergence of digital maps, paper maps retain considerable popularity. In road-design CAD, it is demanded to scan two or more paper maps along a single road and connect the adjacent raster-maps for creating vector maps. However, when adjacent raster-maps are connected, expansion and contraction result in distortions, gaps and overlaps in roads and contour lines. However, when adjacent raster-maps are connected, expansion, contraction and/or curve distortions result in gaps and overlaps in roads and contour lines. These problems present serious obstacles to the automatic creation of usable, linked vector maps. The purpose of this paper is to propose an optimum method for correcting distortions in linked adjacent maps, thereby obtaining precisely connected raster-maps and contributing to the automatic production of high quality vector maps.
The accuracy of the color reproduction is demanded in many fields, and it, therefore, asks the imaging device to acquire accurate color information on objects. In this paper, the still camera that could acquire XYZ tristimulus values was made in our laboratory. In order to synthesize images for acquiring wide dynamic range image, we propose the method of adaptive selection of exposure time ratio at image synthesis. As a result, at using the selected exposure ratio, the synthesized image was very clear at the low brightness parts and natural at synthetic boundaries.