An image processing apparatus, comprising: an edge image generating unit configured to detect edges in an original image and to generate an edge image formed by the detected edges; a connection pixel extracting unit configured to extract connection pixel sets in the edge image; a binary image generating unit configured to classify the connection pixel sets by colors and generate respective character images which are binary images corresponding to the colors, wherein a character image is generated on the basis of connection pixel sets except for a connection pixel set which does not correspond to a character; a background image generating unit configured to generate a background image of the original image on the basis of the character images; and an image compressing unit configured to compress image data of the character images and image data of the background image using respective different compressing methods; wherein the binary image generating unit is further configured (a) to identify which of a density reversed character, an ordinary character and non character each one of the connection pixel sets is, on the basis of luminance values of the original image on pixels at four corners of a rectangle circumscribed to the connection pixel set, and (b) to generate the character image of the density reversed character and the character image of the ordinary character a connection pixel combining unit configured to detect the connection pixel sets to which the circumscribed rectangles are close to each other and to group the detected connection pixel sets as one connection pixel set; wherein, if two connection pixel sets are grouped then they are managed as one connection pixel set; the binary image generating unit configured to classify the groups of connection pixel sets by colors of the group of connection pixel sets and to generate character images corresponding to the colors. an edge image generating unit configured to detect edges in an original image and to generate an edge image formed by the detected edges; a connection pixel extracting unit configured to extract connection pixel sets in the edge image; a binary image generating unit configured to classify the connection pixel sets by colors and generate respective character images which are binary images corresponding to the colors, wherein a character image is generated on the basis of connection pixel sets except for a connection pixel set which does not correspond to a character; a background image generating unit configured to generate a background image of the original image on the basis of the character images; and an image compressing unit configured to compress image data of the character images and image data of the background image using respective different compressing methods; wherein the binary image generating unit is further configured (a) to identify which of a density reversed character, an ordinary character and non character each one of the connection pixel sets is, on the basis of luminance values of the original image on pixels at four corners of a rectangle circumscribed to the connection pixel set, and (b) to generate the character image of the density reversed character and the character image of the ordinary character a connection pixel combining unit configured to detect the connection pixel sets to which the circumscribed rectangles are close to each other and to group the detected connection pixel sets as one connection pixel set; wherein, if two connection pixel sets are grouped then they are managed as one connection pixel set; the binary image generating unit configured to classify the groups of connection pixel sets by colors of the group of connection pixel sets and to generate character images corresponding to the colors.