Abstract: Disclosed is a color image processing apparatus, for converting source data into bit map data of each primary color, used for a color image outputting mechanism for expressing secondary colors by superposing a plurality of primary colors. This color image processing apparatus includes bit map memory having a plurality of planes, provided corresponding to the plurality of primary colors, for storing bit map data of the respective primary colors. A write control circuit is formed with a control area, within an address, for designating the plane on which source data should be written. A data converting circuit for writing the source data is provided in the plane of the bit map memory that is designated by data of this address control area. The write plane is designated within the address, and hence the writing on the plurality of planes can be performed at one time, thereby attaining a high-speed writing process.

Abstract: An image forming apparatus for continuously feeding sheets and transferring images thereon, includes an endless type rotatable image forming body, an image forming unit for forming an image on the image forming body, a transfer unit for transferring the image on the image forming body onto a sheet being fed, a feeding unit for feeding the sheet, a first position detector for detecting the sheet being fed at a first predetermined position in a feeding path of the sheet, and a second position detector, located on a side of the transfer unit at a second predetermined position, for detecting the sheet being fed. A control unit is provided for controlling a feeding speed of the feeding unit to compensate for a transfer position of the sheet, in accordance with a measured feeding time from the first predetermined position to the second predetermined position based on outputs of the first and second position detectors.