Optical Mark Recognition

I.Technical Background

OMR is a system that gathers information by using a hardware device that detects a reflection or an absence of reflection from a card or piece of paper. OMR enables the processing of hundreds or thousands of documents every hour automatically.

OMR processing is popular for tests, where students receive a special card containing several empty circles and a packet that contains the questions and possible answers to each of the questions. The student must complete the test by using a pencil to fill in each blank circle with what he or she believes is the correct answer.

II.Company Profile

The first mark sense scanner was the IBM 805 Test Scoring Machine; this read marks by sensing the electrical conductivity of graphite pencil lead using pairs of wire brushes that scanned the page. In the 1930s, Richard Warren at IBM experimented with optical mark sense systems for test scoring, as documented in US Patents 2,150,256 (filed in 1932, granted in 1939) and 2,010,653 (filed in 1933, granted in 1935). The first successful optical mark-sense scanner was developed by Everett Franklin Lindquist as documented in US Patent 3,050,248 (filed in 1955, granted in 1962). Lindquist had developed numerous standardized educational tests, and needed a better test scoring machine than the then-standard IBM 805. The rights to Lindquist’s patents were held by the Measurement Research Center until 1968, when the University of Iowa sold the operation to Westinghouse Corporation.

During the same period, IBM also developed a successful optical mark-sense test-scoring machine, as documented in US Patent 2,944,734 (filed in 1957, granted in 1960). IBM commercialized this as the IBM 1230 Optical mark scoring reader in 1962. This and a variety of related machines allowed IBM to migrate a wide variety of applications developed for its mark sense machines to the new optical technology. These applications included a variety of inventory management and trouble reporting forms, most of which had the dimensions of a standard punched card.

While the other players in the educational testing arena focused on selling scanning services, Scantron Corporation, founded in 1972, had a different model; it would distribute inexpensive scanners to schools and make profits from selling the test forms. As a result, many people came to think of all mark-sense forms (whether optically sensed or not) as scantron forms. Scantron operates as a subsidiary of M&F Worldwide(MFW) and provides testing and assessment systems and services and data collection and analysis services to educational institutions, businesses and government.

In 1983, Westinghouse Learning Corporation was acquired by National Computer Systems (NCS). In 2000, NCS was acquired by Pearson Education, where the OMR technology formed the core of Pearson’s Data Management group. In February 2008, M&F Worldwide purchased the Data Management group from Pearson; the group is now part of the Scantron brand.

OMR has been used in many situations as mentioned below. The use of OMR in inventory systems was a transition between punch cards and bar codes and is not used as much for this purpose. OMR is still used extensively for surveys and testing though.

III.Significance and Purpose

The significance and purpose of optical mark reader software is primarily used when documents have fully structured format. These documents are normally called structured forms and they are usually questionnaires and surveys where data always is present in a fixed location in a particular type of form. When optical mark reader software is used to capture data present on such forms the software is usually trained with a template to look for data in specific locations and to ignore all else.

IV.Conceptual Development and Implementation

OMR devices use forms which are preprinted onto ‘transoptic’ paper and measure the amount of light which passes through the paper, thus a mark on either side of the paper will reduce the amount of light passing through the paper.

In contrast to the dedicated OMR device, desktop OMR software allows a user to create their own forms in a word processor and print them on a laser printer. The OMR software then works with a common desktop image scanner with a document feeder to process the forms once filled out.

V.Quality Attributes

Reliability

The large ‘bubble’ marks are legacy technology from the very early OMR machines that were so insensitive a large mark was required for reliability. In most Asian countries, a special marker is used to fill in an optical answer sheet. Students, likewise mark answers or other information via darkening circles marked on a pre-printed sheet. Then the sheet is automatically graded by a scanning machine.

Performance

In today’s fast-paced information-driven society, the need for accurate, timely, and cost-effective data collection is very critical. Optical mark reader (OMR) systems can be used to achieve these aspects. This paper describes the development of a low-cost and high-speed OMR system prototype for marking multiple-choice questions. The novelty of this approach is the implementation of the complete system into a single low-cost Field Programmable Gate Array (FPGA) to achieve the high processing speed. Effective mark detection and verification algorithms have been developed and implemented to achieve real-time performance at low computational cost. The OMR is capable of processing a high-resolution CCD linear sensor with 3456pixels at 5000frame/s at the effective maximum clock rate of the sensor of 20MHz (4x5MHz). The performance of the prototype system is tested for different marker colours and marking methods. At the end of the paper the proposed OMR system is compared with commercially available systems and the pro and cons are discussed.

Security

VI.Possible Problems

This method can cause problems when a user changes his mind, and so some products started to use grayscale to better identify the intent of the marker—internally scantron and NCS scanners used grayscale.

OMR software is also used for adding OMR marks to mail documents so they can be scanned by folder inserter equipment. An example of OMR software is Mail Markup from UK developer Funasset Limited. This software allows the user to configure and select an OMR sequence then apply the OMR marks to mail documents prior to printing.

VII. Design Specification