In existing picture search techniques, users typically input a search word in the search box and submit it to the search engine of a website. The search engine then searches among a large number of pictures obtained by a web crawler, for the searched keywords in the text associated with the pictures, such as the word in the filename or the subordinate field of the pictures. Further, the server returns to the users the pictures for which the filename or the subordinate field of the file attributes matches the keywords.
This type of picture search is essentially a text-content-based search. Pictures searched in this way are often not those really desired by the users. For example, among the picture search results that correspond to the searched keyword, users tend to desire pictures of a certain shape, for which the prior art picture search technologies do not account. Therefore, a picture search that takes the shape of the desired pictures into account may be advantageous.