10. A non-transitory computer readable medium that records an image processing program that causes a computer to perform processing comprising: inputting document data of a document; identifying a position of a string in the document; identifying a mark handwritten from a highlighter and is non-textual, the mark being separate from the string, given in the document; detecting an orientation of the mark, wherein the mark is defined by a range from a start position and an end position based on the detected orientation, and extracting a new character string based on the position of the identified string and the identified mark, and the mark identified and defined based on the detected orientation.
10. A non-transitory computer readable medium that records an image processing program that causes a computer to perform processing comprising: inputting document data of a document; identifying a position of a string in the document; identifying a mark handwritten from a highlighter and is non-textual, the mark being separate from the string, given in the document; detecting an orientation of the mark, wherein the mark is defined by a range from a start position and an end position based on the detected orientation, and extracting a new character string based on the position of the identified string and the identified mark, and the mark identified and defined based on the detected orientation. 11. The non-transitory computer readable medium of claim 10 , further comprising: extracting the string based on the identified position and whether the string overlaps the identified mark.