街道景观视觉评价量化指标及其有效性分析

为建立有效的街道景观视觉评价指标,基于图像处理的思想,提出了6个反映街道景观客观视觉属性的量化指标视觉熵、色彩丰富指数、街道宽度、沿街建筑高度、天际线变化指数和天空开阔指数,并以10条步行街道的实景数字图像为例验证了其有效性.通过主客观指标之间的数学分析发现:街道宽高比、街道宽度、天空开阔指数、视觉熵和色彩丰富指数均能有效反映街道景观的客观视觉属性(相关系数大于0.633,显著性小于0.05);视觉复杂性在评价结论中所占比重最大(22.6%),是最重要的影响因素. 

Quantitative Indices of Streetscape Visual Evaluation and Their Validity Analyses

In order to establish an effective index system of streetscape visual evaluation, 6 quantitative indices were proposed to reflect the objective visual attributes of streetscape based on the idea of image processing, and their validity was verified by digital images of 10 walking streets. The mathematical analyses of subjective and objective indices show that street width-to-height ratio, street width, sky openness index, visual entropy, and color complexity can reflect the streetscape's objective visual attributes effectively (correlation coefficient is above 0.633, significance is smaller than 0.05); the complexity of sight is the most important factor in the streetscape visual evaluation because of its high weight of 22.6%.