Moiré pattern

About: Moiré pattern is a research topic. Over the lifetime, 1917 publications have been published within this topic receiving 27176 citations. The topic is also known as: moiré fringes & moire pattern.

Three-dimensional shape measurement apparatus and method for eliminating2pi ambiguity of moire principle and omitting phase shifting means

Abstract: A three-dimensional (3-D) shape measurement method using a Moire measurement principle and a Stereo vision measurement principle is provided. The method comprises; a first step to detect candidate points and 3D positions of the candidate points in world coordinates which are identical results from typical Moire technique by using a pattern projector, which adjusts a pitch of a fringe pattern and projects the fringe pattern to a measurement object, and a first camera, which detects a modulated fringe pattern caused by shape of shape of the object, by means of obtaining candidate points by comparing a reference fringe pattern to the modulated fringe pattern and calculating 3D positions at an arbitrary point on an image captured from the first camera; a second step to determine a final matching point among the candidate points detected from the first step by using the Stereo vision technique with the first and the second cameras, by means of projecting the 3D positions of the candidate points to an image plane of the second camera based on a camera matrix of the second camera, comparing intensity value of a projected point in the image plane of the second camera to intensity value of given point in the image plane of the first camera, and judging whether the candidate point is matched with an arbitrary point by using the stereo vision criteria; and a third step to measure the depth value of the arbitrary point by using the resultant value of the final matching point, which was determined at the second step. Therefore, the error of 2π ambiguity of the typical Moire principle is eliminated, and thus 3-D shape information can be more rapidly and accurately measured.

Topological defects in moiré fringes with spiral zone plates

Abstract: We present a study of spatial structures created by superposition of spiral zone plates used for generating optical beams with phase singularities. Moire fringes are observed that show topological defects similar to those appearing in interference patterns of optical vortices. A brief theoretical discussion is included that supports the similarities between the two phenomena. Our results may lead to interesting applications to digital information processing by optical means.

Conductive film, display device provided with same, and method for evaluating conductive film

Abstract: A conductive film is such that, when a display unit is one in which subpixel shapes regarding two colors differing from each other are different, subpixel layout pattern cycles of each color are different, or the center of gravity of one subpixel in one pixel exists at a position differing from a line linking the centers of gravity of remaining other subpixels, a wiring pattern is such that, in the frequency and intensity of moire per color respectively calculated from the peak frequency and peak intensity of the two-dimensional Fourier spectrum of each of the transmittance image data of the wiring pattern and the luminosity image data of the subpixel layout pattern of each color, a moire evaluation index calculated from a moire evaluation value obtained by having the visual response characteristic of a human being act, in accordance with an observation distance, upon moire intensity at a frequency of each moire less than or equal to the maximum frequency of moire defined in accordance with the display resolution of the display unit is less than or equal to a prescribed value.

Dot matrix hologram for hiding a moire pattern

Abstract: A moire pattern technology about a dot matrix hologram for hiding a moire pattern is invented. In the moire pattern hidden region of a dot matrix hologram, the moire pattern foreground area and the moire pattern background area are formed identically by interlacing bright lines and dark lines. While position shifting is formed between the lines of the two areas. This position shifting is several times of the size of the grating dots. Thus, a moire pattern hidden in the moire pattern hidden region without being processed specially has a poor hiding ability. Often the above moire pattern can be identified by eyes directly without using a decoding film. Therefore, such kinds of moire patterns have poor hidden effects. However, the moire pattern of the present invention can prevent the aforesaid phenomenon by a well designed pretended pattern. Moreover, the appearance of such a dot matrix hologram can be beautified by the addition of the pretended patern. Furthermore, in the present invention, a technology of one-dimensional moire patterns is upgraded to a technology of two-dimensional moire patterns.

Demoiréing for screen-shot images with multi-channel layer decomposition

Abstract: Moire patterns on screen-shot images are mainly due to the aliasing of the grid of the display and the camera sensor, which heavily degenerated the image quality. This paper proposes an demoireing method for screen-shot images via layer decomposition on polyphase components (LDPC). The layer decomposition model separates the image into a background layer and a moire layer, which are both regularized by a patch-based Gaussian Mixture Model (GMM) prior. To enhance the distinguishability between the image patches and moire patches, the input image is first subsampled into four polyphase components, each of which is decomposed with the GMM-based layer decomposition model. The proposed model is applied on luminance (Y) channel to weaken the intensity of moire patterns, and on red, green, blue channels respectively to further remove moire patterns. Experimental results demonstrate that the proposed method is able to efficiently remove moire artifacts for screen-shot images and outperform several other methods.