Abstract: A method for object detection includes: extracting a plurality of identification features from a plurality of reference images that are related to a target object; selecting a plurality of selected identification features respectively from the identification features so as to obtain a first feature dataset, and storing the first feature dataset, a quantity of selected identification features being smaller than a quantity of the identification features; in response to receipt of a to-be-detected image, performing a feature extraction operation on the to-be-detected image to obtain a second feature dataset; performing a similarity determination operation with respect to the to-be-detected image based on the first feature dataset and the second feature dataset, and calculating a quantity of instances of the target object in the to-be-detected image.