Perceptually Motivated BRDF Comparison using Single Image
Perceptually Motivated BRDF Comparison using Single Image
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DOI：
10.1111/cgf.12944
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发表时间：
2016-06
影响因子：
2.5
通讯作者：
V. Havran;J. Filip;K. Myszkowski
中科院分区：
文献类型：
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作者：
V. Havran;J. Filip;K. Myszkowski
现在，现实世界材质的表面反射率广泛地由双向反射分布函数(BRDF)以及空间变化的表示(如SVBRDF和双向纹理函数(BTF))来表示。原始表面反射率测量通常是由分析模型压缩或拟合的，这总是会带来一定的精度损失。对于它的评估，我们需要一个参考表面反射率与其近似形式之间的距离函数。虽然过去的一些技术试图反映人类视觉的感知敏感性，但它们既没有优化照明和观察条件，也没有优化表面形状。在本文中，我们提出了一种新的基于图像的方法来比较不同的各向异性BRDF。我们使用优化技术来生成一种新颖的表面，它具有广泛的入射和出射光方向，同时保留了对材料外观判断非常重要的特征和频率。这样的表面的单个渲染图像以及同时优化的照明和观察方向导致通过标准图像差异预测器来计算有意义的BRDF差异。一项心理物理实验表明，我们的表面比计算机图形学中常用的标准表面，如球体或斑点，提供了更丰富的材料属性信息。
Surface reflectance of real‐world materials is now widely represented by the bidirectional reflectance distribution function (BRDF) and also by spatially varying representations such as SVBRDF and the bidirectional texture function (BTF). The raw surface reflectance measurements are typically compressed or fitted by analytical models, that always introduce a certain loss of accuracy. For its evaluation we need a distance function between a reference surface reflectance and its approximate version. Although some of the past techniques tried to reflect the perceptual sensitivity of human vision, they have neither optimized illumination and viewing conditions nor surface shape. In this paper, we suggest a new image‐based methodology for comparing different anisotropic BRDFs. We use optimization techniques to generate a novel surface which has extensive coverage of incoming and outgoing light directions, while preserving its features and frequencies that are important for material appearance judgments. A single rendered image of such a surface along with simultaneously optimized lighting and viewing directions leads to the computation of a meaningful BRDF difference, by means of standard image difference predictors. A psychophysical experiments revealed that our surface provides richer information on material properties than the standard surfaces often used in computer graphics, e.g., sphere or blob.