Patent ID: 11933614
Assignee: BOE TECHNOLOGY GROUP CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G  B | IPC B  G

Claim 4:
5. The positioning method according to claim 4, wherein determining a matching key frame comprises:
performing a feature extraction on the current image and obtaining corresponding visual words;
searching a candidate matching frame in key frames of the visual sub-map to be matched, wherein a matching score between at least one visual word of the candidate matching frame and visual words of the current image is greater than a first threshold;
counting an amount of visual words of each candidate matching frame, wherein a matching score between the visual words and the visual words of the current image is greater than a second threshold, and selecting a candidate matching frame with an amount greater than a third threshold as a common-view frame;
making each common-view frame and a preset number of key frames before or after the common-view frame into a group, and calculating an accumulative score of matching degree between visual words of all key frames in each group and the visual words of the current image; and
referring a key frame with the highest matching score in a group with the accumulative score of matching degree greater than a fourth threshold as the matching key frame.