Sub-image search is one of the search strategies that I use a lot when trying to find out what an unfamiliar object is. I’ve used it to identify some old farm equipment, to find the origins of some flea market pottery, and to identify types of plants whose names I don’t know. It’s that last example that I share in my course on Search Strategies Students Need to Know. What is sub-image search?
Simply put, sub-image search is the process of cropping an image to focus on just the most important part and then conducting a reverse image search for that cropped image. Cropping the image removes any extraneous information that isn’t helpful in the reverse image process. For example an example of sub-image search, watch this new video that I made. In the video below I provide a demonstration of what happens when I conduct a reverse image search of mushroom surrounded by brown leaves and what happens when I conduct a reverse image search of the cropped version of that same image.

Applications for Education

Sub-image search isn’t a magic pill that instantly give students answers to “what is that?” when they conduct a reverse image search. Sub-image search will, however, give them a better direction for refining their searches. They still need to read the contents of the web pages that host the visually similar images that are revealed through the reverse image search. Sub-image search will, however, give them a better direction for refining their searches.