Patent Document ID: 8843493
Application ID: 13622316

Base Claim:
1. A method for comparing documents, comprising: extracting, by a computer processor, a plurality of extracted elements from a first formatted document, wherein each of the plurality of extracted elements corresponds to a text element of the first formatted document, wherein the plurality of extracted elements comprises at least one selected from a group consisting of a plurality of words and a plurality of word lengths; extracting, by the computer processor, a first plurality of text fingerprints from a sequence of the plurality of extracted elements to form a first text feature of the first formatted document, wherein the first plurality of text fingerprints comprises at least one selected from a group consisting of a plurality of word n-grams and a plurality of word length n-grams, wherein the first text feature comprises at least one selected from a group consisting of a first text content feature based on the plurality of word n-grams and a first text geometric feature based on the plurality of word length n-grams; comparing, by the computer processor, the first text feature and a second text feature of a second formatted document to generate a comparison result, wherein the second text feature comprises at least one selected from a group consisting of a second text content feature and a second text geometric feature, wherein the comparison result comprises at least one selected from a group consisting of a text content match rate between the first and second text content features and a text geometric match rate between the first and second text geometric features; and determining, in response to the comparison result meeting a pre-determined criterion, that each of the first formatted document and the second formatted document contains common text content, wherein the comparison result meeting the pre-determined criterion is based on at least one selected from a group consisting of the text content match rate and the text geometric match rate exceeding a pre-determined threshold.

---

Claim 3:
3. The method of claim 1 , further comprising: extracting a second plurality of text fingerprints from the second formatted document to form the second text feature of the second formatted document; and generating, based at least on the second text feature, an inverted index data structure for a document library comprising the second formatted document, wherein the inverted index data structure comprises a tally of at least one of the second plurality of text fingerprints occurring in the second formatted document, and wherein the comparison result is generated using the inverted index data structure.