Automatic method of generating thematic summaries from a document image without performing character recognition

A processor implemented method of generating a thematic summary of a document image without performing character recognition using a processor, the document including a first multiplicity of sentences and a second multiplicity of word occurrences, the processor implementing the method by executing instructions stored electronically in a memory coupled to the processor, the processor implemented method comprising the steps of:

• a) analyzing the document image to identify sentence boundaries of the first multiplicity of sentences;
• b) analyzing the document image to identify a plurality of word image equivalence classes, each word image equivalence class including at least one word occurrence of the second multiplicity of word occurrences, each word image equivalence class having a bounding box, each bounding box having a width;
• c) determining a number of times each word image equivalence class occurs in the document;
• d) identifying drop words within the word image equivalence classes based upon their bounding box width and the number of times each word image equivalence class occurs in the document;
• e) generating a list of content words by eliminating the drop words from the word image equivalence classes;
• f) selecting as thematic word images a first number of the word equivalence classes from the list of content words based upon the number of times each content word occurs in the document;
• g) scoring each sentence of the first multiplicity of sentences that includes a thematic word image based upon occurrences of thematic word images within each sentence;
• and
• h) selecting as thematic sentences a second number of the first multiplicity of sentences based upon the sentence scores.

An article of manufacture comprising:

• a) a memory;
• and
• b) instructions stored in the memory for a method of generating a thematic summary of a document image without performing character recognition using a processor coupled to the memory, the document including a first multiplicity of sentences and a second multiplicity of word occurrences, the method comprising the steps of:
• 1) analyzing the document image to identify sentence boundaries;
• 2) analyzing the document image to identify word image equivalence classes, each word image equivalence class including at least one word occurrence of the second multiplicity of word occurrences;
• 3) selecting as thematic word images a first number of word image equivalence classes, the first number of thematic word images being less than a second number of thematic sentences to be extracted;
• 4) scoring each sentence of the first multiplicity of sentences based upon occurrence of thematic word images in each sentence;
• and
• 5) selecting the second number of thematic sentences from the first multiplicity of sentences based upon the score of each sentence.

A system for generating a thematic summary from a document image without performing character recognition, the system comprising:

• a) a scanner for generating an electronic representation of the document image;
• b) a processor coupled to the scanner;
• c) a memory coupled to the processor for storing instructions for generating a thematic summary from the electronic representation of the document image, the instructions representing the steps of:
• 1) analyzing the document image to identify sentence boundaries;
• 2) analyzing the document image to identify a plurality of word image equivalence classes, each word image equivalence class including at least one word occurrence of the second multiplicity of word occurrences within the document;
• 3) selecting as thematic word images a first number of word image equivalence classes, the first number being less than a second number of thematic sentences to be extracted;
• 4) scoring each sentence of the first multiplicity of sentences based upon occurrence of thematic word images in each sentence;
• and
• 5) selecting the second number of thematic sentences from the first multiplicity of sentences based upon the score of each sentence.