Method and apparatus for storing and merging multiple optically scanned images

A method of storing multiple scanned images of a response-marked form document, comprising the steps of:

• (a) scanning a copy of the form document on which no response information has been marked, using a scanning method with a first pixel grayscale range that detects substantially all visual information present on the form document and produces a pixel image thereof;
• (b) storing the pixel image data from step (a) in a computer storage device;
• (c) scanning at least one copy of the form document that has been marked with at least one response mark that absorbs light falling outside the visible spectrum, using a scanning method that detects only the presence of light outside the visible spectrum and produces a pixel image including said at least one response mark but excluding visual information detected in step (a) that does not absorb light falling outside the visible spectrum, said scanning method of step (c) being done at a different pixel grayscale range than the scanning of the document in step (a);
• (d) compressing the pixel image produced in step (c) to reduce the amount of pixel data used to represent areas of the response-marked form document bearing no marks that absorb light falling outside the visible spectrum;
• (e) storing the pixel image data obtained from step (d) in a computer storage device;
• and
• (f) adjusting at least one of the pixel images of step (a) or (c) in a remapping process to resolve the differences between the two pixel grayscale ranges.

A method for storing multiple scanned images of a response-marked form document, comprising the steps of:

• (a) scanning a copy of the form document on which no response information has been marked, using a scanning method that detects substantially all visual information present on the form document and produces a pixel image thereof;
• (b) storing the pixel image data from step (a) in a computer storage device;
• (c) scanning at least one copy of the form document that has been marked with at least one response mark that absorbs light falling outside the visible spectrum, using a scanning method that detects only the presence of light outside the visible spectrum and produces a pixel image including said at least one response mark but excluding visual information detected in step (a) that does not absorb light falling outside the visible spectrum;
• (d) compressing the pixel image produced in step (c) to reduce the amount of pixel data used to represent areas of the response-marked form document bearing no marks that absorb light falling outside the visible spectrum;
• (e) storing the pixel image data obtained from step (d) in a computer storage device;
• and
• (f) in connection with step (b), processing the unmarked form to a predefined grayscale index level to insure that blank information on the unmarked form will prevail in a merge with overlapped blank information in the pixel image from step (c).

A method for storing multiple scanned images of a response-marked form document, comprising the steps of:

• (a) scanning a copy of the form document on which no response information has been marked, using a scanning method that detects substantially all visual information present on the form document and produces a pixel image thereof;
• (b) storing the pixel image data from step (a) in a computer storage device;
• (c) scanning at least one copy of the form document that has been marked with at least one response mark that absorbs light falling outside the visible spectrum, using a scanning method that detects only the presence of light outside the visible spectrum and produces a pixel image including said at least one response mark but excluding visual information detected in step (a) that does not absorb light falling outside the visible spectrum;
• (d) compressing the pixel image produced in step (c) to reduce the amount of pixel data used to represent areas of the response-marked form document bearing no marks that absorb light falling outside the visible spectrum;
• (e) storing the pixel image data obtained from step (d) in a computer storage device;
• (f) processing the pixel images of steps (a) and (c) to correct for optical distortion in the scanning steps (a) or (c), respectively, and for each response-marked copy of the form document for which a reproduction of the document is desired, decompressing the pixel data stored in step (e) to obtain the pixel image of step (c), performing a pixel for pixel merge of the pixel images of steps (a) and (c) to produce a single merged pixel image and;
• and
• (g) outputting the merged pixel image from the computer processing system.

An apparatus for storing multiple scanned images of a response-marked form document in a computer processing system, comprising:

• first means for scanning a copy of the form document on which no response information has been marked using a scanning method that detects substantially all visual information present on the form document and produces a first pixel image thereof;
• second means for scanning at least one copy of the form document that has been marked with at least one response mark that absorbs light falling outside the visible spectrum, using a scanning method that detects only the presence of light outside the visible spectrum and produces a second pixel image including said at least one response mark but excluding visual information detected by said first means that does not absorb light falling outside the visible spectrum;
• means for compressing the second pixel image produced by said second scanning means to reduce the amount of pixel data used to represent areas of the response-marked form document bearing no marks that absorb light falling outside the visible spectrum;
• and
• means for storing the pixel image data obtained from said first and second scanning means in a computer storage device.

A method for storing multiple scanned images of a response-marked form document, comprising the steps of:

• (a) scanning a copy of the form document on which no response information has been marked, using a scanning method that is responsive to light of a first spectral range and produces a pixel image of those portions of the form document that absorb light in such range;
• (b) storing the pixel image data from step (a) in a memory device;
• (c) scanning at least one copy of the form document that has been marked with at least one response mark that absorbs light falling outside said first spectral range, using a scanning method that detects only the presence of light outside the first spectral range and produces a pixel image including said at least one response mark but excluding visual information detected in step (a) that does not absorb light falling outside the first spectral range;
• (d) compressing the pixel image produced in step (c) to reduce the amount of pixel data used to represent areas of the response-marked form document bearing no marks that absorb light falling outside the first spectral range;
• and
• (e) storing the pixel image data obtained from step (d) in a memory device.