Tangent Systems, Inc
Power To Solve, Flexibility to Evolve


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MarkDetective® unleashes the power of Tangent's proven mark detection engine for imaging solution providers, OEMs, and in-house IT applications. Detecting various types of constrained and unconstrained marks, MarkDetective is suitable for a variety of applications and markets, including remittance, surveys, ballots, loan applications, health care, insurance, and more.

Proven Technology

MarkDetective is designed for fast, real-time operation, and careful design and years of refining the algorithms have resulted in blazing speed with full functionality. The run-time elements of the Engine and Toolkit packages are coded entirely in ANSI C for portability and efficiency, with an optional .NET wrapper layer.

MarkDetective has been used for real-time control of transports at speeds of up to 600 DPM, where it has processed billions of documents over the past decade. Of course, the Engine can also be used perfectly well for non time-critical operations, where it has also been used to process billions of document images as well.

Key Features

•  Setup Utility - The MarkInspector setup utility is provided with each package except the Engine. This utility loads and displays an image of a representative unmarked document and allows the operator to define the anchors, marks and other detectable objects on that form. The resulting form definition file is used to direct the recognition process for that form type at run time.
•  Anchor mark detection and zone alignment - MarkDetective supports a variety of commonly used anchor symbols including corner marks, crosses, circles, squares, and timing tick marks. The anchors are used to establish a consistent frame of reference providing a significant improvement in accuracy.
•  Automatic skew and speed compensation - Taking further advantage of multiple anchors on a form, MarkDetective can locate zones with extremely high accuracy even in the presence of document skew and transport speed variations. This process is accomplished without the need for time consuming image deskew.
•  Mark detection - MarkDetective supports a wide variety of mark target shapes including square, rectangular, circular, oval, slanted oval and more. No dropout ink is ever required, as the algorithms know the difference between an unmarked black target shape and a marked one. Because of its superior registration capabilities, MarkDetective can read boxes that are very small or tightly grouped with great accuracy.
•  Mark group scoring - MarkDetective employs special algorithms to support the automatic scoring of logical groups of mutually exclusive marks, where only one box out of a certain set or "group" is allowed to be marked.


•  Notation detection - In addition to detecting classical scoring/selection marks, MarkDetective offers sophisticated detection of the presence of handwriting, strike-outs, stamps, or other notations. There are many applications of this capability, including name and address changes on remittance coupons. A variety of tunable algorithms are available to accommodate common form design approaches.

Product Levels

MarkDetective is available in three different packages, each offering different levels of OEM integration and ease of development:

•  Engine -This is essentially the basic Engine that underlies all of the packages, with its detailed API providing direct control of all features. This version is intended for tight integration into an OEM setup utility, as no setup utility is included in the package. This package offers the fastest execution times and the most seamless OEM integration, but at the cost of the most detailed programming. The Engine is written in ANSI C and the API it provides to the calling application is ANSI C compatible.


•  Toolkit - This package is built on the Engine layer, but adds the MarkInspector image-based GUI setup utility and a far simpler programming interface. The Toolkit relies on the MarkInspector setup files to define the elements to be detected, rather than requiring detailed API calls for each element. This package still provides fast execution times and requires far less interface programming, but operationally requires separate form setup.


•  Toolkit .NET - This package offers the same functionality as the Toolkit package, but with a .NET compatible interface layer. The timing inconsistencies of the .NET object oriented environment make this package less amenable to demanding real-time applications. It is recommended for background tasks and for transports without stringent timing requirements.