63fb46d6_bster_US___Patent_applications__Description
[Patent application number] 20140368886 [Published] 12-18-2014 [Description] 
BLACK TRAPPING METHODS, APPARATUS AND SYSTEMS FOR BINARY IMAGES - Provided are black trapping methods, apparatus and systems for binary images. According to one exemplary method, black trapping color image data is performed by incorporating a set of trapping condition logical operations. Specifically, edge checking is based on estimated contone color values and density checking based on a binary bitmap.
Xing Li, Webster US - Patent applications