Journal ArticleDOI
The aliasing problem in computer-generated shaded images
TLDR
This paper explains the observed defects in terms of the aliasing phenomenon inherent in sampled signals and discusses prefiltering as a recognized cure.Abstract:
Certain defects, such as jagged edges and disappearing detail, have long been an annoyance in digitally generated shaded images. Although increasing the resolution or defocusing the display can attenuate them, an understanding of these defects leads to more effective methods. This paper explains the observed defects in terms of the aliasing phenomenon inherent in sampled signals and discusses prefiltering as a recognized cure. A method for evaluating filters is presented, the application of prefiltering to hidden-surface algorithms is discussed, and an implementation of a filtering tiler is shown accompanied by examples of its effectiveness.read more
Citations
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Book
An improved illumination model for shaded display
TL;DR: In this article, a tree of "rays" extending from the viewer to the first surface encountered and from there to other surfaces and to the light sources is used to calculate the intensity of the light received by the viewer.
Journal ArticleDOI
An improved illumination model for shaded display
TL;DR: Consideration of all of these factors allows the shader to accurately simulate true reflection, shadows, and refraction, as well as the effects simulated by conventional shaders.
Journal ArticleDOI
Survey of Texture Mapping
TL;DR: The fundamentals of texture mapping are surveyed, which can be spilt into two topics: the geometric mapping that warps a texture onto a surface, and the filtering necessary to avoid aliasing.
Fundamentals of Texture Mapping and Image Warping
TL;DR: This work develops a new theory describing the ideal, space variant intialiazing filter for signals warped and resampled according to an arbitrary mapping of texture mapping and filtering techniques.
Journal ArticleDOI
Reconstruction filters in computer-graphics
TL;DR: It is shown that reconstruction using derivative as well as amplitude values can greatly reduce aliasing, and a new family of piecewise cubic filters are investigated as a practical demonstration.
References
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Journal ArticleDOI
Illumination for computer generated pictures
TL;DR: Human visual perception and the fundamental laws of optics are considered in the development of a shading rule that provides better quality and increased realism in generated images.
Journal ArticleDOI
Computer Processing of Line-Drawing Images
TL;DR: Various forms of line drawing representation are described, different schemes of quantization are compared, and the manner in which a line drawing can be extracted from a tracing or a photographic image is reviewed.
Journal ArticleDOI
A Characterization of Ten Hidden-Surface Algorithms
TL;DR: The paper shows that the order of sorting and the types of sorting used form differences among the existing hidden-surface algorithms.
Proceedings ArticleDOI
High-speed convolution and correlation
TL;DR: A procedure for synthesizing and analyzing Fourier series for discrete periodic complex functions and computation times are proportional to log 2sub 2 as expressed in Eq.
Illumination for computer-generated images.
TL;DR: In this paper, a new model for the shading of computer-generated images of objects in general and polygonally described free-form curved surfaces in particular is described, where the shading function is determined by a linear interpolation of the curvature of the surface.