Digital Map Processing and GIS: Unlocking Valuable Information from Historical Maps

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In today’s rapidly evolving world, data is being generated at an astonishing rate. The challenge lies in harnessing this data to gain valuable insights about different locations. This is where Geographic Information Systems (GIS) and digital map processing come into play. Professor Yao-Yi Chiang from the USC Spatial Sciences Institute is an expert in developing algorithms and applications to combine geographic data from various sources. His work focuses on utilizing techniques to extract and integrate information from maps, imagery, social media, and deep web content. With these techniques, users can access rich and detailed information about a specific location, enabling them to track local variations over time and space.

Utilizing Geographic Data

One of the key aspects of Professor Yao-Yi Chiang’s work is the utilization of diverse geographic data sources. These sources include scanned maps, satellite imagery, social media data sets, and deep web content. By integrating these data sources, Chiang’s algorithms enable users to query a single data repository and obtain comprehensive information about a particular place. This approach helps researchers, professionals, and decision-makers understand the intricate details and nuances of a location.

Unlocking Historical Maps

In his previous work, Professor Chiang developed an algorithm to extract information from a 1920 Los Angeles map. This historical map provided essential data for Professor Kurashiki’s research on racism. By unlocking information from archive maps, Chiang’s algorithm proved invaluable in understanding historical memory and conducting detailed analysis. The ability to extract valuable insights from historical maps can shed light on past events, urban development, and social dynamics.

Applying GIS in Contemporary Challenges

Currently, Professor Chiang is collaborating with an insurance company in the UK to extract map labels from historical Ordnance Survey series. The algorithm developed by Chiang consumes map images and converts them into spatial datasets. These datasets contain information about contamination sites in the past, including chemical factories, gasworks, and other query sites. This information becomes crucial in identifying contamination sources and making informed decisions regarding land use. By understanding where contamination exists or has existed, it becomes possible to determine suitable areas for new housing developments or agricultural activities.

Step-by-Step Process

The journey from raw data to valuable insights involves several steps. Professor Yao-Yi Chiang’s algorithm follows a systematic process to unlock information from maps and other geographic data sources. Here is a step-by-step overview:

  1. Data Collection: Gathering data from diverse sources, such as scanned maps, satellite imagery, social media, and deep web content.

  2. Data Integration: Applying techniques to merge and combine the collected data into a single repository.

  3. Querying: Developing user-friendly interfaces that allow users to query this data repository and retrieve relevant information about a specific location.

  4. Algorithm Development: Creating algorithms to extract essential information from maps, imagery, and other data sources.

  5. Spatial Data Conversion: Converting map images into spatial datasets that contain valuable insights about the location, including contamination sites, historical landmarks, and other relevant details.

  6. Analysis and Decision-Making: Analyzing the extracted data to identify patterns, trends, and spatial relationships. This information aids in making informed decisions about urban planning, land use, and resource management.


Professor Yao-Yi Chiang’s expertise in digital map processing and GIS plays a pivotal role in unlocking valuable information from historical maps and other geographic data sources. By integrating and utilizing diverse data sets, Chiang’s algorithms enable researchers and decision-makers to gain rich insights into locations across time and space. Understanding historical memory, identifying contamination sources, and making informed decisions about land use are just a few examples of the value generated by Chiang’s work. The field of GIS continues to expand, and with experts like Chiang, we can expect further advancements in utilizing data for understanding our world.

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