Optical brand recognition (also called optical mark reading and OMR) is the process of capturing human-tagged data from document forms such as surveys and tests. They are used to read questionnaires, multiple choice exam paper in the form of shaded lines or areas. Many traditional OMR devices work with a dedicated scanner device that shines a beam of light onto the forms 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 pre-printed on 'transoptic' paper and measure the amount of light passing through the paper, so a mark on each side of the paper will reduce the amount of light passing through the paper. Unlike the dedicated OMR device, desktop OMR software allows the user to create their own forms in a word processor and print them on a laser printer. The OMR software works with a common desktop image scanner with a document feeder to process the forms once they are filled.
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 requires the image to have high contrast and an easily recognizable or irrelevant form. A field related to OMR and OCR is the recognition of bar codes such as the UPC barcode found on the product packaging.
One of the most well-known applications of optical marker recognition is the use of pencil # 2 (HB in Europe) with optical bubbles in multiple-choice quizzes. Students mark their answers, or other personal information, obscuring marked circles on a preprinted sheet. Subsequently, the sheet is automatically sorted by a scanning machine. In the United States and in most European countries, a horizontal or vertical "tick" in a rectangular "tablet" is the most commonly used OMR type, the best known application being the UK lottery form. Pill brands are a later technology and have the advantage of being easier to mark and easier to erase. The big brands of "bubbles" are technology inherited from the first OMR machines that were so insensitive that a great brand of reliability was required. In most Asian countries, a special marker is used to fill an optical response sheet. Students also mark responses or other information through darkened circles marked on a preprinted sheet. The sheet is then sorted automatically by a scanning machine.
Many of OMR's current applications involve people filling out specialized forms. These forms are optimized for computer scanning, with careful print registration and careful design to minimize ambiguity. Because of its extremely low error rate, low cost and ease of use, OMR is a popular method of counting votes. The OMR tags are also added to the physical mail items so that the folder insertion equipment can be used. Marks are added to each page (usually opposite / odd) of an email document and consist of a sequence of black dashes that the folder insertion equipment scans to determine when mail should be folded and then inserted into an envelope.