page_title: Optical mark recognition
section_title: OMR background
hierarchical_section_title: Optical mark recognition / OMR background
caption_attribution_description: English: OMR test form, with registration marks and drop-out colors, designed to be scanned by dedicated OMR device.
context_page_description: Optical mark recognition is the process of capturing human-marked data from document forms such as surveys and tests. They are used to read questionnaires, multiple choice examination paper in the form of lines or shaded areas.
context_section_description: Many traditional OMR devices work with a dedicated scanner device that shines a beam of light onto the form paper. The contrasting reflectivity at predetermined positions on a page is then used to detect these marked areas because they reflect less light than the blank areas of the paper.
  Some OMR devices use forms that 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.
  OMR is generally distinguished from optical character recognition (OCR) by the fact that a complicated pattern recognition engine is not required. That is, the marks are constructed in such a way that there is little chance of not reading the marks correctly. This does require the image to have high contrast and an easily recognizable or irrelevant shape. A related field to OMR and OCR is the recognition of barcodes, such as the UPC bar code found on product packaging.
  One of the most familiar applications of optical mark recognition is the use of #2 pencil (HB in Europe) bubble optical answer sheets in multiple choice question examinations.  Students mark their answers, or other personal information, by darkening circles marked on a pre-printed sheet.  Afterwards the sheet is automatically graded by a scanning machine.  In the United States and most European countries, a horizontal or vertical "tick" in a rectangular "lozenge" is the most commonly used type of OMR form; the most familiar application in the United Kingdom is the UK National lottery form.  Lozenge marks are a later technology and have the advantage of being easier to mark and easier to erase.  The large "bubble" marks are legacy technology from 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 by darkening circles marked on a pre-printed sheet.  Then the sheet is automatically graded by a scanning machine.
  Many of today's OMR applications involve people filling in specialized forms. These forms are optimized for computer scanning, with careful registration in the printing, and careful design so that ambiguity is reduced to the minimum possible. Due to its extremely low error rate, low cost and ease-of-use, OMR is a popular method of tallying votes.
  OMR marks are also added to items of physical mail so folder inserter equipment can be used. The marks are added to each (normally facing/odd) page of a mail document and consist of a sequence of black dashes that folder inserter equipment scans in order to determine when the mail should be folded then inserted in an envelope.
caption: OMR test form, with registration marks and drop-out colors, designed to be scanned by dedicated OMR device
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