Description:
Key Words:
Urban safety,Machine vision,Machine learning,Data analytics
Required Skills:
No specific skill needed, basic coding skill will be an added advantage
Required Software:
Rhino + Grasshopper, Google Colab account, Photoshop
Required Hardware:
Personal PC or laptop
Maximum number of participating students:
30
Urban safety perception has long been studied from the perspective of active measures such as patrolling, adequate lighting at night, and fast grievance addressal systems. The use of machine vision allows designers to interrogate how urban fabric affects safety perception, and consequently design interventions that may increase perceived safety. This 2-day workshop is designed to be an introduction (for the uninitiated) to the use of machine vision and machine learning in addressing the age-old question of “How to quantify subjective spatial experience?”
Participants will be introduced to the theories of machine vision and different machine learning techniques. As part of the exercise, machine vision algorithms such as semantic segmentation and object detection will be used to extract and quantify urban features (e.g., road, people, trees, vehicles, sky, building, etc.) from geo-located photographs of urban scenes. Subsequently, using an appropriate data-collecting method, participants will be asked to rate the photographs on a Likert scale of ‘very safe’ to ‘very unsafe’. On the other hand, keyword(s)-driven subjective reviews of the geo-locations of the photographs will be scraped from the web using pre-written code. The corresponding information of the urban features and safety scores of the photographs will be analysed to extract urban design principles. Finally, using the same dataset, different machine learning algorithms (non-linear regression, random forest regression, and regression neural network) will be trained to predict the safety perception of new (designed or speculative) urban scenes.
The use of machine vision and machine learning opens the possibility of statistical assessment of multivariate urban spatial information. Additionally, using crowd-sourced data marks a departure from the top-down evaluative guidelines published by experts to a more inclusive bottom-up evaluation by end-users. The methodology can be later used by the participants to assess other subjective criteria, e.g., urban beauty.