A method of processing an image of a document having at least one image and at least one text area, the method comprising: scanning a document; detecting a text area and an image area included in the image of the document; converting the image of the document to output one of the detected text and image areas as color data and the other of the detected text and image areas as monochrome data; and outputting the converted document, wherein the image of the document is converted to set a color value of the detected text area to a preset color value so as to output the detected text area as monochrome data or to set a color value of the detected image area to a preset color value so as to output the detected image area as monochrome data; characterized in that: if the scanned document is converted to output the detected text area as monochrome data, and the detected text area comprises a color text, the color text is converted to have a different display state from a monochrome text of the text area such that: the color text is displayed in one of bold or underlined in the different display state; and the monochrome text is not displayed in one of bold or underlined; whereby outputting the text areas or the image areas as monochrome data is decided according to a setting of a printing mode by user. scanning a document; detecting a text area and an image area included in the image of the document; converting the image of the document to output one of the detected text and image areas as color data and the other of the detected text and image areas as monochrome data; and outputting the converted document, wherein the image of the document is converted to set a color value of the detected text area to a preset color value so as to output the detected text area as monochrome data or to set a color value of the detected image area to a preset color value so as to output the detected image area as monochrome data; characterized in that: if the scanned document is converted to output the detected text area as monochrome data, and the detected text area comprises a color text, the color text is converted to have a different display state from a monochrome text of the text area such that: the color text is displayed in one of bold or underlined in the different display state; and the monochrome text is not displayed in one of bold or underlined; whereby outputting the text areas or the image areas as monochrome data is decided according to a setting of a printing mode by user. if the scanned document is converted to output the detected text area as monochrome data, and the detected text area comprises a color text, the color text is converted to have a different display state from a monochrome text of the text area such that: the color text is displayed in one of bold or underlined in the different display state; and the monochrome text is not displayed in one of bold or underlined; whereby outputting the text areas or the image areas as monochrome data is decided according to a setting of a printing mode by user. the color text is displayed in one of bold or underlined in the different display state; and the monochrome text is not displayed in one of bold or underlined; whereby outputting the text areas or the image areas as monochrome data is decided according to a setting of a printing mode by user.