An inkjet printhead is disclosed which has a cavity unit. To accomplish this, it is checked if the number of lines transferred to a printer is smaller than a page break reference line count N. An antimicrobial composition is placed in the container and the container is inserted into a drain opening. A quantization parameter for each coding unit is determined from the corresponding statistics. A temperature corrector corrects functions of the processing circuit according to the detection result provided from the temperature change detector.