| 主权项 |
1. A method for calibrating a printhead in a printer comprising:
operating a printhead with a controller to eject a plurality of ink drops from an inkjet in a printhead to form a plurality of marks on an image receiving surface of a print medium moving past the printhead in a process direction, each mark extending in the process direction on the image receiving surface; generating with an optical sensor image data of a predetermined portion of the image receiving surface that includes the plurality of marks, the image data including a two-dimensional arrangement of pixels with a plurality of pixel rows extending in a cross-process direction and a plurality of pixel columns extending in the process direction; identifying with the controller a plurality of amplitudes, each amplitude being identified for a portion of each pixel column in the image data of the predetermined portion of the image receiving surface, the portion of each pixel column including expected locations for a portion of the plurality of printed marks in the process direction; identifying with the controller a pixel column corresponding to one of the plurality of identified amplitudes having an absolute value that is a local maximum within the image data for the predetermined portion of the image receiving surface; identifying with the controller a cross-process direction location of the inkjet that ejected the ink drops in the identified pixel column with reference to the identified pixel column; and storing with the controller the identified cross-process direction location of the inkjet in a memory for use in printhead registration. |
