An apparatus includes a buffer to store n lines of data divided into areas of column units. The apparatus obtains information of a column position corresponding to an end of an image to be printed with respect to a scanning direction of a print head. The apparatus reads data from the areas of the column units including the column position information and reduces the data to generate reduced data. The apparatus compresses the reduced data by using a pattern having n lines of data to generate first compressed data. Then, the apparatus compresses the first compressed data by k-bit units to generate second compressed data.