85 results about "Curve smoothing" patented technology

The invention provides a double-taper working roll and a roll shape design method thereof, and belongs to the technical field of plate and strip rolling. The working roll comprises five curves, namely, a middle portion convexity degree control section, curve transition sections and edge portion contour control sections, and the roll shape curves are symmetrically arranged. The middle portion convexity degree control section and the edge portion control sections are smoothly connected through the curves of the transition sections. Special roll shape curves are adopted for the edge portion curvecontrol sections, and effective control over the shape of the edge portions of hot-rolled strip steel is achieved. The quadratic parabola form is adopted for the middle portion convexity degree control section, and the control requirement for the convexity degree of the strip steel can be met. By means of the roll shape curves and roll shape parameters provided by the method, a double-taper rollshape with the strip steel edge portion contour control capacity can be flexibly designed according to requirements of hot rolling field production.

The embodiment of the invention discloses a method and device of obtaining a banknote security thread boundary. By utilizing the characteristic that the gray value of a security thread must be the smallest, according to the characteristics of narrow self width and small searing amount of the security thread, a new banknote security thread integrity detection method is designed. A gray value column projection method is employed to obtain the characteristics of the security thread; the security thread is preliminarily positioned according to the stable and obvious feature that a gray value lowest column must be on the security thread, thereby improving accuracy and eliminating interference. The method and device perform searching from a minimum column to the left and right; the searching at a curve steep portion is not influenced by a curve smooth portion, thereby eliminating the influence of security thread inclination, security thread edge darkening, etc. to integrity detection.

The invention discloses an AR drawing method combined with a physical illumination model, and the method comprises the following steps: S1, enabling an ARkit to capture a current AR scene, enabling the ARkit to be rendered to a texture through an OpenGL, and enabling the texture to serve as a background texture; S2, establishing a Scene scene by using Metal + Scene kit; S3, recording 2D screen track coordinates of the paintbrush, obtaining a current camera V matrix and a current camera P matrix, and sequentially converting the 2D screen track coordinates into 3D space coordinate tracks; S4, generating a uniform and smooth 3D space trajectory coordinate by adopting an interpolation and curve smoothing algorithm; S5, calculating data such as vertex coordinates, normal lines, tangent lines, texture coordinates and RGB (red, green and blue) according to the 3D space trajectory coordinates, deducing and constructing 3D geometric figure nodes with a deformation effect according to an ellipsecalculation formula, and adding the nodes into the Scene scene; S6, adopting a PBR physical illumination model to calculate the illumination effect, carrying out multiple sampling to eliminate sawteeth, rendering a Scene scene through Metal, and rendering a 3D graph to OpenGL and Metal shared textures; and S7, fusing the background texture and the shared texture, and rendering the final pattern to the screen by the OpenGL.