A method is disclosed for correcting errors introduced by optical distortions or aberrations in the measured values of coordinates of targets of an array of targets, like for example structures on a wafer or a photolithography mask. The apparatus includes a memory and a processor in communication with the memory. A method for preserving copy protection is also presented, where the input video signal is first examined to determine if copy protection has been included in the input video signal. The photoactive monomer having the formula, wherein X is H or CH3\u2014; G is \u2014O\u2014C\u2014, \u2014C\u2014O\u2014, a phenyl group, substituted or un-substituted, or \u2014NR\u2014C\u2014, NR being linked to L and R is H or a C1-C10 alkyl group; L is a spacer group; CR is a photoisomerable chromophore. The resultant plasticized fluff pulp may have one or more of the following: reduced Kamas energy, Mullen strength, and fiber knot and nit contents, when compared to the base cellulosic fluff pulp fiber that is not plasticized. The ACLS methods can also be applied to alternating least squares models.