Method and device for positioning table in PDF document

An electronic device for positioning a table in a PDF document, comprising:

• one or more processors;
• memory coupled to the one or more processors;
• and
• a plurality of computer instructions stored in the memory, wherein the computer instructions, when executed by the one or more processors, cause the electronic device to perform operations including:
• receiving, by the electronic device, the PDF document containing the table;
• extracting, by the electronic device, character information and line information from vector stream information of the PDF document;
• and
• positioning, by the electronic device, a table area in the PDF document according to the extracted character information and line information,
• wherein the PDF document inputted into the electronic device comprises at least one of a quasi full-line table and a quasi non-line table, wherein in the quasi full-line table, each cell is surrounded by at least three table lines, and in the quasi non-line table, one or more cells are surrounded by fewer than three table lines,
• wherein the quasi non-line table is positioned by:
• clustering adjacent characters into a text block according to character stream sequence and character interval, and clustering the text blocks belonging to the same row into a text row;
• and
• using the text rows or a combination of the text rows and the lines in the PDF document as an initial set of elements for the quasi non-line table positioning, and performing the quasi non-line table positioning based on the initial set of elements and in accordance with the alignment information of the text blocks in the text rows, and/or the line information around the text rows, so as to obtain one or more quasi non-line table areas;
• and
• the quasi full-line table is positioned by:
• combining all lines in the PDF document to obtain one or more sets of lines according to a strategy of combining intersecting or not intersecting but adjoining lines into a set of lines, and using the maximum outer bounding rectangle of each set of lines as a quasi full-line table area.

A non-transitory computer readable storage medium comprising computer readable instructions that, when executed by a processor of an electronic device, cause the electronic device to perform operations including:

• receiving, by the electronic device, the PDF document containing the table;
• extracting, by the electronic device, character information and line information from vector stream information of the PDF document;
• and
• positioning, by the electronic device, a table area in the PDF document according to the extracted character information and line information,
• wherein the PDF document inputted into the electronic device comprises at least one of a quasi full-line table and a quasi non-line table, wherein in the quasi full-line table, each cell is surrounded by at least three table lines, and in the quasi non-line table, one or more cells are surrounded by fewer than three table lines,
• wherein the quasi non-line table is positioned by:
• clustering adjacent characters into a text block according to character stream sequence and character interval, and clustering the text blocks belonging to the same row into a text row;
• and
• using the text rows or a combination of the text rows and the lines in the PDF document as an initial set of elements for the quasi non-line table positioning, and performing the quasi non-line table positioning based on the initial set of elements and in accordance with the alignment information of the text blocks in the text rows, and/or the line information around the text rows, so as to obtain one or more quasi non-line table areas;
• and
• the quasi full-line table is positioned by:
• combining all lines in the PDF document to obtain one or more sets of lines according to a strategy of combining intersecting or not intersecting but adjoining lines into a set of lines, and using the maximum outer bounding rectangle of each set of lines as a quasi full-line table area.