Methods and apparatus for comparing blank forms represented in a digital format to digitized filled-in forms are described. Different errors are attributed different weights when attempting to correlate regions of blank and filled-in forms. Foreground pixels in the blank form which are not found in a corresponding portion of a filled-in form are attributed greater error significance than foreground pixels, e.g., pixels which may correspond to added text, found in the filled-in form which correspond to a background pixel value in the blank form. A virtual filled-in form including content, e.g., pixel values, from the filled-in form is generated from the content of the filled-in form and pixel value location mapping information determined from comparing the blank and filled-in forms. Various analysis is performed on a block basis, but in some embodiments the final pixel mapping to the virtual form is performed on a pixel by pixel rather than a block basis.