Patent ID: 8422894

Claim:
An image processing apparatus using a toner cartridge not having a stirring mechanism, comprising: a detecting unit for detecting a toner remaining amount in a first position; an output unit for outputting N pieces (N>1) of a uniform pattern of density onto the first position and a second position other than the first position on an area covering an effective print region in a main scan direction of image formation for detecting a partial toner-low state; an acquiring unit for acquiring read values from N positions on the pattern; a determining unit for determining whether a partial toner-low state occurs in the first position by using a detection result by the detecting unit and determining whether a partial toner-low state occurs in the second position by using a density difference between a read value of the pattern outputted on the first position and a read value of the pattern outputted on the second position; and a control unit for controlling execution of calibration adjusting a reproduction characteristic in outputting an image using the toner, if the determining unit determines a partial toner-low state occurs in the first position or the second position.