Method and device for detecting defective liquid ejection

A defective liquid ejection detection device comprising:

• a sensor for reading an image, the image being formed on a medium on the basis of image data by ejecting liquid from a nozzle while relatively moving the nozzle in a direction of relative movement with respect to the medium;
• a specifying section for specifying a maximum pixel among pixels of read data continuously arrayed in rows in a direction intersecting the direction of the relative movement in the data read with the sensor, the maximum pixel having the maximum pixel value among pixels of the read data;
• a selecting section for selecting a selected pixel in the data read with the sensor, the selected pixel being included in a line constituted by a plurality of pixels including the maximum pixel arrayed in line in the direction of the relative movement;
• and
• a detector for detecting defective liquid ejection in the nozzle by comparing the selected pixel with the pixel of the image data corresponding to the selected pixel in the image data.