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.

Application of the Digital Moiré Technique with Circular and Radial Gratings in Fracture Analysis of Rubber-like Materials

Abstract: A new digital moire method is proposed to analyze the displacement distributions near the crack tip of rubber-like materials. With circular and radial gratings, the distributions of in-plane displacement are measured directly. The principle of forming digital moire and experimental method are described in detail. An application is carried out to measure the mechanical field of a cracked rubber sheet under plane stress condition using delicate digital moire technique. The radial and circular displacement distributions in the polar coordinate system are obtained. The displacement isolines distributions near the crack tip are discussed. Finally, the distribution rules to mechanical fields near the crack tip are discussed with the sector division method.

Adaptive-hierarchical-filtering technique for high-quality magazine image reproduction

Abstract: This paper proposes a novel adaptive filtering technique to achieve high-quality image enhancement when the image possesses the artifact of moire pattern during the reproduction by different computer peripherals such as color copiers, or scanners plus printers.Commercial magazine images are halftoned images. Unacceptable noises and moire distortion may occur when halftone images are copied (i.e., scanned and printed). In this paper, we analyze the formation of moire patterns in both the frequency and spatial domain. Basically moire noise often appears due to the aliased frequency when a halftone image is scanned. Based on the analysis of the scanned halftone image, we develop an adaptive filter to suppress the moire artifacts and produce the high-quality image reproduction. The adaptive filter consists of modules of anti-aliased filter and image enhance filter: the anti-aliased filter is applied to cancel aliased low frequency components (moire distortion); the image enhance filter is applied to sharpen image edges. It depends on the information provided by an image classification module to decide either the anti-aliased or image enhance module should be applied. The classification module is developed based on a set of pyramid images to determine an edge is either a global true edge (for sharpening enhancement) or a local halftone's micro-structural edge (for moire reduction). Depending on the information from the classification module, the adaptive filter technique then applies the anti-aliased filter to the halftone micro-structured edge or the enhanced filter to the image global edge correctly and efficiently, and therefore both the moire reduction and image enhancement can be achieved simultaneously. Experimental results show the outstanding effectiveness of the presented technique for high-quality magazine image reproduction.

Inspection method and device of pattern, and manufacturing method of electronic device

Abstract: PROBLEM TO BE SOLVED: To provide an inspection method of a pattern and an inspection device of the pattern capable of detecting accurately a defect even when an interference fringe (moire) is generated, and a manufacturing method of an electronic device. SOLUTION: This inspection method of the pattern for inspecting by imaging a pattern on an inspection object has characteristics wherein an imaged image is divided to generate a plurality of inspection images, and a reference image is generated based on periodical information carried by the inspection image, and the phase of the reference image is allowed to agree with the phase of the inspection image, and the amplitude of the reference image whose phase is allowed to agree therewith is allowed to agree with the amplitude of the inspection image, and the reference image whose amplitude is allowed to agree therewith is sampled, to thereby restore the inspection image. COPYRIGHT: (C)2008,JPO&INPIT

Image reduction ratio conversion processing program and image reduction ratio conversion processing device

Abstract: PROBLEM TO BE SOLVED: To suppress generation of moire for performing high quality reduction ratio conversion on image data including an image expressed by halftone dots in digital image processing. SOLUTION: A halftone dot area recognition means 11 detects the halftone dots by a pixel assembly unit from the image data to recognize the halftone dot area with the halftone dots. A halftone dot area mask creation means 12 creates a mask pattern from a distance between the halftone dots. A halftone dot area separation means 13 separates the halftone dot area from other non-halftone dot areas in the mask pattern. A halftone dot area reduction ratio conversion means 14 converts the respective halftone dots in the halftone dot area so that they give an approximately linear symmetric shape by adding/removing pixels. A non-halftone dot area reduction ratio conversion means 15 converts the non-halftone dot area by another technique. A halftone dot area/non-halftone dot area synthesis means 16 synthesizes the converted halftone dot area and non-halftone dot area. COPYRIGHT: (C)2004,JPO&NCIPI

Non-contact solid measurement device

Abstract: PURPOSE:To provide a non-contact solid-measuring device capable of measuring with high accuracy and of facilitating the adjustment work at a low cost. CONSTITUTION:An emission light from a point source array 5 is inputted to a lens 1 via a focusing face 4 and a shading grating 2 and the lens 1 introduces the inputted light to an image-taking face 3. A moire fringes 7 are generated on the image-taking face 3 without adjusting the position strictly. The moire fringes 7 are deformed by a strain of an object to be measured placed on the focusing face 4. The surface strain is measured based on the deformation of the moire fringes.