Accurate Image Generation and Interactive Image Editing with the A‐buffer

Lecture Notes in Computer Science

1995

Abstract. Original z-buer method is a very ecient method for image generation. The limitation is that it introduces aliases into the output image. Although many dierent kinds of methods have been published to address this problem. most of them suer from requiring a large memory space, demanding for high computational power, or having some other limitations. In this paper, we propose a simple anti-aliased method based on the supersampling method. However, instead of supersampling every pixel, we supersample edge pixels only. This method has the advantages of requiring less memory and less processing time than the traditional supersampling method. It is also less problematic than some other rendering methods in handling intersecting surfaces.

Section: Introductionmentioning

confidence: 99%

An adaptive supersampling method

Lecture Notes in Computer Science

1995

“…In [20], a method for computing the subpixel masks is proposed to further improve the quality of the output image through subpixel relocation. Instead of storing the subpixel masks, we earlier proposed a method to store only the positions where a polygon edge crosses a pixel and a method to index the appropriate subpixel mask from a precomputed table given the positions [12]. Although all these methods can significantly reduce memory usage, they suffer from two limitations.…”

Section: A Traditional Approachmentioning

confidence: 99%

An efficient low-cost antialiasing method based on adaptive postfiltering

IEEE Trans. Circuits Syst. Video Technol.

2003

Aliasing in computer-synthesized images not only limits the realism of the images, but also affects the user's concentration. Many antialiasing methods have been proposed to solve this problem, but almost all of them are computation intensive, and some of them are also memory intensive. While these may not be limitations for high-end applications such as medical visualization and architectural design, this kind of antialiasing methods may still be far too costly for the low-cost applications. In this paper, we propose an antialiasing method that operates in the image domain. It is based on fitting curves to the discontinuity edges extracted from the aliased images to reshade those edge pixels. (Note that a curve may be considered as a general form of lines.) To improve the performance and the simplicity of the method, we propose to preprocess all possible edge patterns and fit curves in advance. During runtime, we only need to construct an index to obtain the filtering information from a lookup table. The new method is extremely simple and efficient. It provides a very good compromise between hardware cost and output image quality. In addition, because the new method has a very low computational cost, and hence low power consumption for hardware implementation, it is particularly suitable for low-cost mobile applications such as computer game consoles and palm computers, where low implementation cost and low power consumption are important design factors.

“…The entry and exit positions of the polygon edge at the pixel are combined to form a bitmask index. This bitmask index is then used to access an appropriate bitmask from a precomputed bitmask table [Lau92]. The bitmask is used to set the subpixel coverage.…”

Section: Basic Concept Of Adaptive Supersamplingmentioning

confidence: 99%

“…The VSB methods can be implemented with either a span buffer [Catm78,Naka89,Whit81], with which polygons are divided into horizontal spans, or a pixel buffer [Carp84,Lau92], with which polygons are divided into pixel fragments. These horizontal spans or pixel fragments will then be accumulated in the buffer for hidden surface removal and anti-aliasing.…”

Section: Introductionmentioning

confidence: 99%

Adaptive parallel rendering on multiprocessors and workstation clusters

Lin¹,

IEEE Trans. Parallel Distrib. Syst.

Hwang

et al. 2001

This paper presents the design and performance of a new parallel graphics renderer for 3-D images. This renderer is based on an adaptive supersampling approach that works for time/space-efficient execution on two classes of parallel computers. Our rendering scheme takes sub-pixel supersamples only along polygon edges. This leads to a significant reduction in rendering time and in buffer memory requirement. Furthermore, we offer a balanced rasterization of all transformed polygons. Experimental results prove these advantages on both a shared-memory SGI multiprocessor server and a Unix cluster of Sun workstations. We reveal performance effects of the new rendering scheme on subpixel resolution, polygon number, scene complexity, and memory requirements.The balanced parallel renderer demonstrates scalable performance with respect to increase in graphics complexity and in machine size. Our parallel renderer outperforms Crow's scheme in benchmark experiments performed. The improvements are made in three fronts: (i) reduction in rendering time, (ii) higher efficiency with balanced workload, and (iii) adaptive to available buffer memory size. The balanced renderer can be more cost-effectively imbedded within many 3-D graphics algorithms, such as those for edge smoothing and 3-D visualization. Our parallel renderer is MPI-coded, offering high portability and cross-platform performance. These advantages can greatly improve the QoS in 3-D imaging and in real-time interactive graphics.