Template for watermark decoder synchronization

A computer-readable medium having stored thereon a program of instructions executable by a processor to perform a method of producing a watermarked image, the method comprising:

• generating a sign template from a predetermined band shape;
• generating a magnitude template from the image;
• generating a synchronization template from the sign template and the magnitude template;
• and
• generating a template encoded image from the image and the synchronization template.

A computer-readable medium having stored thereon a program of instructions executable by a processor to perform a method for determining a shift value and a scaling value of an image having an embedded grid, the method comprising:

• synchronizing the grid with the image by
• determining positions of bands in the grid from the image, the band shape, band separation, and separation offsets, yielding a band template;
• determining row and column sums from the image, the sums having local maxima and local minima;
• enhancing the local maxima and local minima of the row and column sums;
• determining a local maxima template from enhanced row and column sums;
• and
• determining the scale value and the shift value from the local maxima template and the band template.

A computer-readable medium having stored thereon a program of instructions executable by a processor to perform a method for determining a shift value and a scaling value of an image having an embedded grid, the method comprising:

• synchronizing the grid with the image by
• determining positions of bands in the grid from the image, the band shape, band separation and separation offsets, yielding a band template, by generating a plurality of sign bands from information comprising a predetermined starting position and a plurality of predetermined separation distances, and wherein the band template has substantially same dimensions as the image;
• determining row and column sums from the image, the sums having local maxima and local minima;
• enhancing the local maxima and local minima of the row and column sums;
• determining a local maxima template from enhanced row and column sums;
• and
• determining the scale value and the shift value from the local maxima template and the band template.