Defects in an image forming system may give rise to visible streaks, or
one-dimensional defects in an image that run parallel to the process
direction. One known method for compensating for streaks introduces a
separate tone reproduction curve for each pixel column in the process
direction. A compensation pattern according to this invention has
alignment marks before and after a halftone compensation region. The
alignment marks provide alignment between the printer pixel grid and a
scanning pixel grid. The line width of each alignment mark and the gray
level in each pixel column of each gray level portion is measured and
analyzed to produce a local tone reproduction curve for each pixel column
and associated line width. The line widths of the alignment marks can be
remeasured to adjust the local tone reproduction curves to compensate for
the streak defect when printing.