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STANDARDS PIPELINE |
Vol.32 No.2 May 1998
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PIKS and BIIF ExploredGeorge S.Carson
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This issue’s column is an introduction to the Image Processing and Interchange standards (ISO/IEC 12087) developed by ISO/IEC JTC 1/ SC 24 (Computer Graphics and Image Processing.). First, Bill Pratt of PixelSoft, the Editor of the Programmer's Imaging Kernel System (PIKS) International Standard (ISO/IEC 12087-1:1995), describes PIKS and how it can be applied. Next, I describe the Basic Image Interchange Format (BIIF), ISO/IEC 12087-1:1998, and its applications. |
Overview of the Programmer's Imaging Kernel System (PIKS) Application Program InterfaceWilliam K. Pratt
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IntroductionThe Programmer's Imaging Kernel System (PIKS), is a C language Application Program Interface (API) for image processing. It is part of the International Standard for Image Processing and Interchange (ISO/IEC 12087) developed by the Subcommittee for Computer Graphics and Image Processing (ISO/IEC JTC 1 SC 24) of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). PIKS contains a rich set of operators that perform manipulations of images or of data objects extracted from images in order to enhance, restore or assist in the extraction of information from images. These operators range from primitive operators, such as convolution and histogram generation to complex, higher level operators such as histogram equalization and edge detection. The following sections provide a brief overview of PIKS. References 1 to 4 provide further information. PIKS Imaging ModelFigure 1 describes the PIKS imaging model. The solid lines indicate data flow and the dashed lines indicate control flow. The PIKS application program interface consists of four major parts:
The PIKS data objects include both image and image-related, non-image data objects. The operators, tools and utilities are functional elements that are used to process images or data objects extracted from images. The system mechanisms manage and control the processing. PIKS receives information from the application to invoke its system mechanisms, operators, tools and utilities, and returns certain status and error information to the application. The import and export facility provides the means of accepting images and image-related data objects from an application, and for returning processed images and image-related data objects to the application. PIKS can transmit its internal data objects to an external facility through the ISO-standard Image Interchange Facility (IIF) (ISO/IEC 12087-3) or the Basic Image Interchange Format (BIIF). Also, PIKS can receive data objects in its internal format, which have been supplied by the IIF or the BIIF. PIKS Data ObjectsA PIKS image object is a five-dimensional (5D) collection of pixels whose structure is:
PIKS supports the following pixel data types:
PIKS also supports several image related, non-image data objects. These include:
PIKS OperatorsThe following is a list of PIKS operators categorized by functionality with examples of each class. The numbers in parentheses are the number of operators in each class.
PIKS Conformance ProfilesBecause image processing requirements vary considerably across various applications, PIKS functionality has been subdivided into the following four nested sets of functionality called conformance profiles. They are:
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William K.Pratt is a pioneer in digital image processing. He is responsible for the discovery of the transform image coding concept, which is the basis for the JPEG and MPEG image coding standards. He is the inventor of a facsimile coding system and a means of high-speed image convolution, as well as the document editor of the Programmer’s Imaging Kernel System (PIKS) application program interface standard. Pratt is the author of Laser Communications, Digital Image Processing, PIKS Foundation C Programmer’s Guide and XIL: An Imaging Foundation Library.
William K.Pratt PixelSoft, Inc. 101 First Street, Suite 429 Los Altos, CA 94022 The copyright of articles and images printed remains with the author unless otherwise indicated. |
PIKS StatusThe PIKS Functional Specification was published in 1994, and in the following year the C language binding was published. The first commercial implementation of the PIKS Foundation profile was released by PixelSoft in early 1995. The National Institute of Standards and Technology (NIST) has undertaken the development of a conformance test suite for private and commercial implementations. The United States National Imagery and Mapping Agency (NIMA) (formerly Central Imagery Office) has endorsed PIKS for imagery applications. References
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Overview of the Basic Image Interchange Format (BIIF)George S.Carson
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The Subcommittee for Computer Graphics and Image Processing (ISO/IEC JTC 1 SC 24) has recently completed a new addition to the International Standard for Image Processing and Interchange (ISO/IEC 12087). International Standard 12087-5, Basic Image Interchange Format (BIIF), provides a proven foundation for interoperability in the interchange of imagery and imagery-related data among computer imaging applications. Development work on this standard started in October 1995 in Vienna, Austria with the preparation of the first Working Draft (WD). The standard was finalized in February 1998 in Annapolis, MD, U.S.A., with the resolution of the comments on the Draft International Standard (DIS) ballot and agreement on the final text of the International Standard. The basis from which BIIF was developed was a U.S. government specification called the National Imagery Transmission Format Standards (NITFS) [2]. NITFS was proven by application to the activities of several departments within the U.S. government in support of military, intelligence, drug interdiction, law enforcement, treaty enforcement, geospatial positioning and other applications. (Note: There is a suite of military standards that make up the “NITF Standard.” They address specific guidance for the application of JPEG compression, bi-level compression, vector quantization and CGM. More information can be found at the web site). The BIIF:
Figure 2 illustrates the structure of a BIIF file that includes images, symbols, labels, text and extensions. Image CompressionThe BIIF supports the application of standard digital imagery compression techniques, both lossless and lossy. For example, it supports the use of the Joint Photographic Experts Group (JPEG) compression algorithms specified by ISO/IEC 10918, Digital compression and coding of continuous-tone still images. It also allows for the use ITU-T T.4 Standardization of Group 3 Facsimile Apparatus to support compression of bi-tonal imagery. Additionally, BIIF anticipates the use and application of future digital imagery compression methodologies forthcoming from such activities as JPEG 2000. Non-destructive OverlaysThe BIIF allows for imagery presentation consisting of images with overlays of image, symbolic and textual annotations in a manner wherein the underlying data is not lost. Overlays are such that the data content of each image, symbol and textual component in the composite presentation is preserved rather than lost through the “burned-in” approach used in some other digital imagery formats. Figure 3 illustrates how BIIF uses common coordinates to combine different types of information in a system of “non-destructive” overlays. Symbolic and Textual AnnotationGraphical symbol and textual annotation of the imagery is supported through the use of ISO/IEC 8632, Computer Graphics Metafile (CGM) for the storage and transfer of picture description information. Textual AdjunctsThe BIIF provides the means to include textual information about the image product contained in the BIIF file. The BIIF supports multi-lingual text content in accordance with ISO/IEC 10646 Universal Multiple-Octet Coded Character Set (USC) and its associated transforms (e.g. ISO/IEC 10646 Amendment 2, UCS Transformation 8). Image Related Extension DataThe BIIF supports the optional inclusion of image related extension data. The inclusion of extension data provides the ability to add data/information about the imagery (metadata) that is not contained in the minimum basic format structure of the BIIF. The use of extension data is often domain specific to the community of interest using a specific profile of BIIF. Exemplary uses of extension data include:
Current Products and ApplicationsThe BIIF is based on an approach that has been used over that past several years in a fielded operational environment. It is supported by at least a dozen commercial providers of imagery application software products that are readily available “off-the-shelf.” The list includes:
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George S.(Steve) Carson is President of GSC Associates of Las Cruces, NM, a systems engineering consulting firm specializing in real-time signal and information processing systems. He is the Chairman of ISO/IEC JTC I/SC 24 (Computer Graphics and Image Processing) and has been involved in ANSI and ISO standards development for 20 years.
George S.Carson GSC Associates, Inc. 5272 Redman Road Las Cruces, NM 88011 Tel: +1-505-521-7399 The copyright of articles and images printed remains with the author unless otherwise indicated. |
The format is now being adopted for the exchange of digital imagery products among nations of the North Atlantic Treaty Organization (NATO). It is the specified digital imagery interchange format for use among nations subscribing to “Standardization of Formats for the Exchange of Digital Data among States Party to the Open Skies Treaty” (27 nation members). The United States Federal Geographic Data Committee (FGDC) is in the process of including BIIF as a means for exchanging raster data in its Spatial Data Transfer Standard (SDTS). The FGDC is comprised of representation from the Departments of Agriculture, Commerce, Defense, Energy, Housing and Urban Development, Interior, State and Transportation; the Environmental Protection Agency; the Federal Emergency Management Agency; the Library of Congress; the National Aeronautics and Space Administration; the National Archives and Records Administration; and the Tennessee Valley Authority. Conformance Test Criteria and Test ServicesConformance test criteria and conformance test services have been established for the use of BIIF within the US Department of Defense. Over 40 defense system applications have been tested to date for conformance with the military use of BIIF. The Department of Defense has made these same test services available to commercial concerns for use on a cost-reimbursable basis. References
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