Method of scoring a printed form having targets to be marked
AssigneeScan-0ptics LLC
InventorEdward F. Scanlon
Life of this patent
Estimating the term…
Abstract
A digital form scoring system that does not require that the targets on the marked form be digitally captured with a drop-out scanner. This is accomplished by locating each target, and in the mark interpretation logic, sensing an area within the outline of the target, then digitally removing all or most of thin lines of print that form a symbol or character within the outline, and removing the shading in the background, before applying the logic that determines whether a region of dark gray scale values in the sensing area should be considered a valid mark entered by the subject.
Claims13
A method of scoring a printed form having a plurality of preprinted reference marks at known locations and spatial relationships and a preprinted group of bubble targets, each target having a known size and shape at known nominal locations, the bubble targets representing possible responses to a question associated with the form, each target of the target group to be marked or left blank by the subject for the purpose of recording said response, comprising:
- with a non-dropout scanner, producing a digital virtual form file from the preprinted form, which virtual form defines a virtual layout of the printed form on a virtual coordinate system;
- non-dropout scanning the marked form to produce a marked form file of gray scale darkness values;
- comparing the marked form file and the virtual form file to determine the locations and spatial relationships of the reference marks in the marked form file according to the virtual coordinate system;
- based on the locations and spatial relationships of the reference marks according to the virtual coordinate system, establishing the nominal virtual coordinate location of each target in the marked form file;
- sampling the gray scale darkness values at each nominal target location and producing an interpreted mark darkness value for each target of the marked form file;
- interpreting whether the darkness value of the interpreted mark is to be deemed an intentional response;
- and
- producing as an output, a scored form file containing a scored value for each target group or target on the marked form page;
- wherein said production of an interpreted mark darkness value for each target is preceded by filtering out the gray scale contributions of the printed targets at each target location.
A method of scoring a printed form having a plurality of preprinted reference marks of known size and shape at known nominal locations and a preprinted group of bubble targets, each target having a known size and shape at known nominal locations and printed on a background of one of at least two background gray scale shading values, the bubble targets representing possible responses to a question associated with the form, each target of the target group to be marked or left blank by the subject for the purpose of recording said response, comprising:
- producing a digital virtual form file from the preprinted form, which digital form defines a virtual layout of the printed form by sets of coordinates on a virtual form coordinate system;
- digitally scanning the marked form to produce a marked form file of gray scale darkness values;
- assigning each pixel of the marked form file, to a coordinate of the virtual form coordinate system;
- processing the marked form file to determine the locations and spatial relationships of the reference marks according to virtual form coordinate system;
- comparing the locations and spatial relationships of the reference marks of the marked form file to the locations and spatial relationships of the reference marks in the virtual form file, and adjusting the nominal location of each target in the virtual form file according to this comparison;
- applying search criteria for sampling the darkness values of the pixels in a search zone at each adjusted nominal location and producing an interpreted mark darkness value for each target;
- applying read criteria for interpreting whether the darkness value of the interpreted mark is to be deemed an intentional response;
- applying logic criteria for permitted relationships between plural targets in a given target group;
- and
- producing as an output, a scored form file containing a scored value for each target group or target on the marked form page of said subject;
- wherein said production of an interpreted mark darkness value for each target includes applying a first filter to remove the contribution of the gray scale values of the printed target in the search zone and applying another filter to remove the contribution of gray scale values of the background shading in the search zone.
Dependencies are inferred from the claim text.