公开(公告)号：US5831624A

公开(公告)日：1998-11-03

申请号：US640450

申请日：1996-04-30

申请人： Gary Tarolli ,  Scott Sellers ,  James E. Margeson, III

发明人： Gary Tarolli ,  Scott Sellers ,  James E. Margeson, III

IPC分类号： G06T15/04 ,  G06T11/40

CPC分类号： G06T15/04

摘要： A high quality texture filtering technique in a computer hardware system. The texture filtering quality of the present invention is comparable to trilinear filtering. However, the present invention reduces the number of memory accesses by fifty percent in comparison to trilinear filtering. To achieve this result, the present invention determines a pixel value based upon one or more texel values, e.g., four texel values, from only one of two mipmap levels. The mipmap level that is used is based upon the fractional portion of the LOD value and the position of the pixel. For a group of pixels having the same LOD value, the present invention performs a dithering operation that results in some pixel values being determined using texel values from the lower level mipmap and the remaining pixel values being determined using texel values from the higher level mipmap. The percentage of pixel values that are determined using texel values from the higher level mipmap is proportional to the fractional portion of the LOD value.

摘要翻译： 计算机硬件系统中的高质量纹理过滤技术。 本发明的纹理滤波质量与三线性滤波相当。 然而，与三线性滤波相比，本发明将存储器访问次数减少了百分之五十。 为了实现该结果，本发明仅从两个mipmap级别中的一个确定基于一个或多个纹素值（例如，四个纹理值）的像素值。 所使用的mipmap级别基于LOD值的小数部分和像素的位置。 对于具有相同LOD值的一组像素，本发明执行导致使用来自较低级别映像的纹理值确定一些像素值的抖动操作，并且使用来自上级mipmap的纹素值来确定剩余像素值。 使用来自较高级别mipmap的纹素值确定的像素值的百分比与LOD值的小数部分成比例。