DETC2005-85314 AN APPROACH TO DRAWING-LIKE VIEW GENERATION FROM 3D MODELS

ABSTRACT In this paper we propose a method to generate 2D drawinglike views from 3D models automatically. The view generation process is conducted in object space and supported by two algorithms: (1) pose determination for 3D models: unifying the space between 2D drawings and 3D models; and (2) 2D drawing-like view generation from 3D models: building the correspondence between 2D drawings and 3D models. The pose determination method for 3D objects is proposed on the basis of a concept called Virtual Contact Area. Meanwhile an efficient occlusion algorithm based regular grid is described to generate orthogonal drawing-like views from 3D models along the pose orientations. To evaluate the validity of the proposed methods, respective experiments are presented. INTRODUCTION As two different ways to express and communicate design ideas, 2D drawings and 3D models are now being widely used in many fields. For designers with special skills, 2D drawings are usually used as the principal way to express ideas; while for most common users, 3D models are more intuitive than 2D drawings from the perspective of information communication. How to seamlessly transit between the two representations is a public problem for many researchers in engineering fields. In spite of the fact that many methods To find the optimal orientations for a 3D model, Park et al. [4] used a pose determination technique to integrate tw

A Comparative Study of Image Restoration Networks for General Backbone Network Design

Despite the significant progress made by deep models in various image restoration tasks, existing image restoration networks still face challenges in terms of task generality. An intuitive manifestation is that networks which excel in certain tasks often fail to deliver satisfactory results in others. To illustrate this point, we select five representative image restoration networks and conduct a comparative study on five classic image restoration tasks. First, we provide a detailed explanation of the characteristics of different image restoration tasks and backbone networks. Following this, we present the benchmark results and analyze the reasons behind the performance disparity of different models across various tasks. Drawing from this comparative study, we propose that a general image restoration backbone network needs to meet the functional requirements of diverse tasks. Based on this principle, we design a new general image restoration backbone network, X-Restormer. Extensive experiments demonstrate that X-Restormer possesses good task generality and achieves state-of-the-art performance across a variety of tasks

An Integrated 2D and 3D Shape-based Search Framework and Applications

ABSTRACT Traditional computer-aided design tools have lead to proliferation of products. In itself CAD systems have become complex to use with many features. In the light of the use of menu driven systems, this article proposes a freehand sketch driven search and reuse of designs, beautification of sketches, and a new interaction paradigm with navigation. We review our prior work in this area in an integrated fashion. The central part of this paper addresses the representation of both 2D sketches and 3D designs in a manner that is tailored for engineering. The interaction of the user with the sketch based search forms a natural interface for interaction with both 2D and 3D models. In addition, the interface is also integrated with a constraint solver for freehand sketches. The system can also suggest to the user the part-class name allowing the probing of the classes and semantics in the database. Besides, users can discover new knowledge by navigating our 2D/3D visualization interface freely based on the preliminary retrieval of classification results. Similarity search can be performed any time during the navigation process. Keywords: Shape Analysis; Supply Chain; Sketch Based Search. INTRODUCTION It is well recognized that engineering design starts with a sketch. Sketch-based part retrieval is a more natural form for searching during early conceptual design than say example-based part retrieval. When a 3D query example is not available, a sketch is especially useful. Therefore, it is necessary to have a fast and effective system for sketch-based engineering part retrieval and interaction. Sketches provide the possibility to record abstract information and are very close to a designer's model of a product. During the design process, the sketch compensates for short-term memory limitations. At the same time the sketch supplements the engineer's cognition by depicting the visual perception in a concrete form [1]. In addition, a sketch can set up a visual dialog between the designer and other group members [2]. Although the freehand sketch allows the designer to explore new ideas with a minimal effort, the interpretation of sketches is still very difficult for computers because sketches are vague and incomplete [3]. Sketches can provide cues for knowledge searching due to the connection between the perception-based actions and design knowledge. It is clear that the knowledge reuse is important in the process of computer-aided design. However, implementing such a system is still difficult. Earlier work has not closely examined how to use sketches for knowledge retrieval and reuse. Methods for transforming the vague knowledge in a sketch to a precise representation, which can further be used for search in 3D models, 2D drawings and other sketches is reviewed. We exploit the advantages of a sketch based user interface to (1) extract the implicit constraints in a user sketch for beautification, (2) search for both 2D and 3D models, (3) obtain suggestions of part classes from the classification in the system, and (3) interact with 2D and 3D models for query modification and/or reuse. Finally the paper concludes by outlining some practical applications of this research

A 3D Model Retrieval Method Using 2D Freehand Sketches,” accepted for

Abstract A method is proposed in this paper to retrieve desired 3D models by measuring the similarity between user’s sketches and 2D orthogonal views generated from 3D models. The proposed method contains three steps: (1) determinate the orientation of 3D model; (2) generate the 2D orthogonal views along the orientations; and (3) measure the similarity between user’s sketches and the 2D views. For these purposes, three respective algorithms are proposed. Users can submit one, two or three views intuitively as a query, which are similar to the three main views in engineering drawing. The weight of each sketch view can be reconfigured by users to emphasize its importance. It is worth to point out that our method only needs three or six views, while 13 views is the minimum set that have been reported by other researchers. A prototype system is developed to evaluate the validity of this proposed method. Key Words: 3D model retrieval, similarity measurement, sketch, user interface

Machine Vision based Micro-crack Inspection in Thin-film Solar Cell Panel

Thin film solar cell consists of various layers so the surface of solar cell shows heterogeneous textures. Because of this property the visual inspection of micro-crack is very difficult. In this paper, we propose the machine vision-based micro-crack detection scheme for thin film solar cell panel. In the proposed method, the crack edge detection is based on the application of diagonal-kernel and cross-kernel in parallel. Experimental results show that the proposed method has better performance of micro-crack detection than conventional anisotropic model based methods on a cross- kernel