7. A method for optimizing the description of contents in a layout document, the method comprising: parsing the content of an original layout document to obtain text graphic unit data; identifying text properties of each character of the text graphic unit data, and classifying characters of the text graphic unit data according to the text properties, to save characters with the same text properties to the same text node along with the same text properties; for characters saved in each text node, saving characters on the same line or column, coordinates of an initial character on the same line or column, average character spacing of the same line or column to a text content node to obtain optimized contents in the layout document, wherein the text content node is a text content node under the text node and corresponding to the same line or column.
7. A method for optimizing the description of contents in a layout document, the method comprising: parsing the content of an original layout document to obtain text graphic unit data; identifying text properties of each character of the text graphic unit data, and classifying characters of the text graphic unit data according to the text properties, to save characters with the same text properties to the same text node along with the same text properties; for characters saved in each text node, saving characters on the same line or column, coordinates of an initial character on the same line or column, average character spacing of the same line or column to a text content node to obtain optimized contents in the layout document, wherein the text content node is a text content node under the text node and corresponding to the same line or column. 12. The method of claim 7 wherein when displaying optimized contents in the layout document, determining a display location as well as text properties to be displayed for each character of the contents in the layout document, based on the text properties of the text node, and average character spacing and coordinates of an initial character of a line or column in each text content node under the text node.