Imaging technique embeds data without distortion

Scientists from both the University of Rochester (Rochester, NY; and Xerox Corp. (Webster, NY; have invented a new technique to hide information within an ordinary digital image and then extract it without distorting the original or losing any information.

Scientists from both the University of Rochester (Rochester, NY; and Xerox Corp. (Webster, NY; have invented a new technique to hide information within an ordinary digital image and then extract it without distorting the original or losing any information. Called "reversible data hiding," this technique is expected to solve a severe problem confronted by digital image users, particularly in sensitive military, legal, industrial, and medical applications. Until now, these users have had to choose between an image that's been watermarked to establish its trustworthiness and one that isn't watermarked but preserves all the original information, allowing it to be enlarged or enhanced to show important details. When information is embedded using the newly discovered method, authorized users can do both.

The technique, described in a paper presented at the recent 2002 IEEE International Conference on Image Processing (Rochester, NY), was codeveloped by Mehmet U. Celik and A. Murat Tekalp of the University of Rochester and Gaurav Sharma and Eli Saber of Xerox. Their collaborative research was done in the Center for Electronic Imaging Systems (CEIS; Rochester, NY;, a New York State Office of Science, Technology, and Academic Research designated center for advanced technology. The CEIS is devoted to enhancing the economic development of the greater Rochester region and state of New York by developing and transferring electronic imaging technology to industry for commercialization and educating the next generation of leaders in the field of electronic imaging.

Sharma, an imaging scientist at the Xerox Solutions and Services Technology Center, says, "Commonly used techniques for embedding messages such as digital watermarking irreversibly change the image, resulting in distortions or information loss. While these distortions are often imperceptible or tolerable in normal applications, if the image is enlarged, enhanced, or processed using a computer, the information loss can be unacceptable," he adds. "With our new data-embedding algorithm, authorized recipients can not only extract the embedded message but also can recover the original image intact, identical bit for bit to the image before the data was added," he says. "The technique offers a significantly higher capacity for embedding data and/or a lower distortion than any of the alternatives," explains Sharma.

Tekalp, professor of electrical engineering, says, "The technique will be widely applicable to situations requiring authentication of images with detection of changes, and it also can be used to encode information about the image itself, such as who took the picture, when, or with what camera. The greatest benefit of this technology is in determining if anyone has clandestinely altered an image. These days many commercial software systems can be used to manipulate digital images. By encoding data in this way we can be sure the image has not been tampered with and then remove the data within it without harming the quality of the picture," he adds.

The novel lossless (reversible) data-embedding (hiding) technique provides high embedding capacities, allows complete recovery of the original host signal, and introduces only a small distortion between the host and the image bearing the embedded data. The capacity of the technique depends on the statistics of the host image. For typical images, the technique offers adequate capacity to address most applications. In applications requiring high capacities, the technique can be modified to adjust the embedding level to meet the capacity requirements, therefore trading off intermediate distortion for increased capacity. In such scenarios, the generalized least significant bit (LSB) embedding method proposed results in significant advantages over conventional LSB embedding techniques because it allows finer granularity along the capacity distortion curve.

Although the technique is currently implemented in software, it could be implemented in hardware or firmware in trusted devices where image integrity is critical to the application, the researchers comment. For instance, the technique could be used in a trusted digital camera used to gather forensic evidence to be later used at a trial. If information is embedded in the images captured with the camera using the new algorithms, any subsequent manipulations of the pictures could be detected and the area where they occurred pinpointed.

The University of Rochester has filed a patent application on the methods developed for reversible data hiding. The university and Xerox will share the rights to this invention.

Alliances accelerate

V.J. Electronix (Bohemia, NY; is providing a VJ-1000 x-ray inspection system as part of a strategic alliance with the American Competitiveness Institute (Philadelphia, PA;, a scientific research corporation dedicated to the advancement and integration of leading-edge technologies in electronics manufacturing and related engineering applications. The institute provides resources for the Electronics Manufacturing Productivity Facility (Philadelphia, PA:, a Navy agency that aids the electronics industry in improving the manufacturing processes required in the manufacture of military systems.

Contracts committed

phoenix|x-ray Systems + Services Inc. (Camarillo, CA; has received an order for five OVHM4 (Oblique View at Highest Magnification) x-ray inspection systems from a US-based semiconductor manufacturer. These systems generate multiple-angle real-time x-ray images of the same sample with a dual detector module offering adjustable penetration angles to detect semiconductor failures.

Analogic Corp. (Peabody, MA; has received orders for 245 explosive assessment computed tomography systems from L-3 Communications Security and Detection Systems for US airport installations.

FLIR Systems Inc. (Portland, OR; has been awarded a $3.5 million contract to supply Star Safire II airborne thermal-imaging systems for the Air National Guard HC-130 search and rescue aircraft.

Market vision

According toIn-Stat/MDR (Scottsdale, AZ:, shipments of image sensors in 2001 totaled 109 million for a market of more than $1.2 billion. The market researcher expects that CMOS image-sensor shipments will overtake CCD image-sensor shipments in 2004.

Semiconductor Equipment and Materials International (SEMI; San Jose, CA; reports that the August 2002 sales of worldwide semiconductor-manufacturing equipment totaled $1.12 billion at a book-to-bill ratio of 1.14. This means that manufacturers of semiconductor equipment received $114 of new orders for every $100 of orders shipped. The August 2002 bookings are 5% less than the revised July 2002 bookings of $1.18 billion, but 57% higher than the August 2001 orders of $715 million. August 2002's three-month average of worldwide billings was $981 million, which is 2% above the revised July 2002 level of $969 million, but 14% below the $1.14 billion of August 2001.

Semico Research Corp. (Santa Clara, CA; predicts that the worldwide semiconductor market will grow by only 6% in 2002. However, the company projects a 30% growth in 2003, a strong market in 2004, but a downturn in 2005.

According to theSemiconductor Industry Association (SIA; San Jose, CA;, worldwide sales of semiconductors in August 2002 totaled $11.9 billion, an increase of 2.2% over the July 2002 level of $11.4 billion. On a year-to-year basis, semiconductor sales in August 2002 rose 14% from the $10.45 billion in revenues posted in August 2001, the first double-digit increase from the industry's cyclical low in 2001. Worldwide semiconductor sales are expected to exceed 2001 levels by 3% to $143 billion. The industry is forecasting growth rates exceeding 20% in both 2003 and 2004.

Business Communications Co. (Norwalk, CT;, in its Medical Imaging Report, estimates the US medical imaging market at $8.2 billion in 2002 and expects this market to grow at a 4.0% average annual growth rate to nearly $10 billion by 2007.

Technology trends

TheIBM Corp. Thomas J. Watson Research Center (Yorktown Heights, NY; has developed an electron microscope that can make subangstrom measurements in finer detail using adaptive-optics techniques employed by advanced astronomical telescopes. By controlling 40 magnetic, rather than glass or plastic, lenses to correct for the aberrations of the three lenses normally used in electron microscopes and applying only 120 keV, IBM and collaborator Nion Co. (Kirkland, WA;, a researcher of electron-microscope optics, have focused their microscope's beam down to 0.75 Å. The new technology makes it possible to create three-dimensional images up to 10 nm in depth—the equivalent of as many as 50 layers of atoms.

OmniVision Technologies Inc. (Sunnyvale, CA; is sampling its color OV9630 and black-and-white OV9130 CMOS CameraChips that offer 1280 × 1024-pixel resolution for high-volume imaging applications.

Carl Zeiss MicroImaging Inc. (Thornwood, NY; has unveiled its AxioVision Inside 4D microscopy software for viewing correctly scaled 3-D fluorescence images in time dimension using traditional fluorescence microscopes.

Management moves

Media Cybernetics Inc. (Silver Spring, MD;, a provider of image-analysis software, has acquired all of the intellectual property and related assets of Definitive Imaging Ltd., an image-analysis software provider for metallographic and materials-science quality control.

Primagraphics Ltd. (Litlington, Nr. Royston, Herts, UK;, a supplier of command, control, video, and graphics products, has appointed Bruce W. Carriker to head its technical-support operation for North America (Charlottesville, VA).

JPA Electronics Supply Inc. (Santa Clara, CA;, the North American representative for i-Chips Technology Inc. (Tokyo. Japan;, a supplier of image- and video-processing ICs, has changed its name to Jepico America Inc.

Nikon Instruments Inc. (Melville, NY;, a developer of precision optics manufacturing, has formed two new business divisions: microscopy sales and microscopy product/marketing. The company also established a Nikon Semiconductor Inspection Technology Group (Tempe, AZ).

Cedara Software Corp. (Mississauga, ON, Canada;, a provider of medical-imaging software, has appointed Abe Schwartz chief executive officer. He formerly managed his own software-development company, Schwartz Technologies Inc.

Schott-Fostec LLC (Auburn, NY;, a supplier of fiberoptic and LED illumination devices, has appointed Tony Ruffini director of sales and marketing. He was most recently vice president sales and US general manager at Sagitta Inc.

Roper Industries Inc. (Bogart, GA;, a diversified, high-technology product manufacturer, has acquired QImaging (Vancouver, BC, Canada;, a FireWire camera supplier.

George Kotelly, Editor in Chief

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