PURPOSE: To inexpensively realize an efficient data conversion circuit rotating and inclining raster data and reduced in a processing time.

CONSTITUTION: A data conversion circuit is equipped with a data latching circuit 1 receiving raster data, a shift register 2 shifting the raster data in a bit unit, singleline buffers 5 storing the data in a line unit, a line changeover circuit 3 controlling a line and adder and subtractor circuits 7 determining the address of the one line buffers 5 and, by arbitrarily setting the quantity of inclination of address adding and subtracting data when the data is read from the singleline buffer 5, the outputs of the adder and subtractor circuits 7 are changed to incline the data at every lines to arbitrary values.