Morphological properties of buildings and open spaces are important aspect for evaluating the ventilation potential in urban space. Current techniques for calculating frontal area density, road orientation consistency and space openness are mostly based on vector objects, which inherently limits its accuracy and location specifity due to non-negligible size of each object relative to the phenomenon in question. Also, reliance on geometric calculations can be time-consuming when facing large data volumes. In light of this, we developed a series of workflows that exploit features and techniques such as orthogonal indexing, sliding-window filtering and mathematical morphology. Using these techniques: (1) time and memory consumption for FAD calculations can be reduced by over 60%; (2) road orientation windward consistency can be calculated locally rather than for each road segment, ruling out inaccuracy on curving roads without significant increase in cost. (3) semi-enclosed open space can be accurately detected and described when designated with an opening width threshold, either in isotropic or anisotropic way. These workflows either improves the calculation of existing indicators or provide new indicators that are closely related to the mechanisms of near-surface wind flow, which could be utilized in the construction of surrogate ventilation models.