200 to a local area network lan 224 the network i f 211 is used for transmitting and receiving data to and from the lan 224 the lan 224 can be implemented by an ethernet network for example the management unit i f 212 is a function unit for connecting between the mfp 200 and a managing apparatus 225 the management unit i f 212 sends control commands to the managing apparatus 225 and receives enable signals from the managing apparatus 225 the scanner i f 213 has the function of transferring image data read by the scanner unit 214 to the high speed image bus 222 the scanner i f 213 also has the function of subjecting image data read by the scanner unit 214 to binarization processing optimal for processes to be executed afterward and serial parallel conversion dependent on the bus width of the high speed image bus 222 further when image data read by the scanner unit 214 is color data the scanner i f 213 is capable of converting the data of three primary colors r g and b into color data of c m y b and k the scanner unit 214 is an image reading apparatus equipped with an automatic original feeder the scanner unit 214 includes a three line rgb ccd color sensor or a single line monochrome ccd sensor the printer i f 215 transfers the image data sent from the high speed image bus 222 to the printer unit 216 the printer i f 215 has a bus width conversion function for converting the bus width of the high speed image bus 222 to a buss width suitable for the range of levels of halftone of the printer.