In re Nuijten

• Decision Date: 20 September 2007
• Docket Number: No. 2006-1371.,Serial No. 09/211,928.,2006-1371.
• Citation: 500 F.3d 1346
• Parties: In re Petrus A.C.M. NUIJTEN.
• Court: U.S. Court of Appeals — Federal Circuit

500 F.3d 1346

In re Petrus A.C.M. NUIJTEN.

No. 2006-1371.

Serial No. 09/211,928.

United States Court of Appeals, Federal Circuit.

September 20, 2007.

Jack E. Haken, Philips Intellectual Property & Standards, of Briarcliff Manor, NY, argued for appellant. Of counsel was Larry Liberchuk.

Raymond T. Chen, Associate Solicitor, United States Patent and Trademark Office, of Arlington, VA, argued for the Director of the United States Patent and Trademark Office. With him on the brief was Thomas W. Krause, Associate Solicitor.

Robert R. McKelvie, Covington and Burling LLP, of Washington, DC, for amicus curiae. With him on the brief was Peter Swanson. Of counsel on the brief were Marc S. Adler and Richard F. Phillips, Intellectual Property Owners Association, of Washington, DC. Of counsel was Herbert C. Wamsley.

Before GAJARSA, LINN, and MOORE, Circuit Judges.

Opinion for the court filed by Circuit Judge GAJARSA. Opinion concurring-in-part and dissenting-in-part filed by Circuit Judge LINN.

GAJARSA, Circuit Judge.

The issue before the court is whether or not a signal is patentable subject matter. Petrus A.C.M. Nuijten appeals the decision of the Board of Patent Appeals and Interferences ("Board") of the United States Patent and Trademark Office ("PTO"), which rejected claims 14, 22, 23, and 24 in his patent application Serial No. 09/211,928 as unpatentable subject matter outside the scope of 35 U.S.C. § 101. The claims seek to patent any "signal" that has been encoded in a particular manner. Because we agree with the Board that the "signal" claims in Nuijten's application are not directed to statutory subject matter, we affirm.

I. BACKGROUND

A. Nuijten's Invention and Patent Application

Nuijten's patent application discloses a technique for reducing distortion induced by the introduction of "watermarks" into signals. In the context of signal processing, watermarking is a technique by which an original signal (such as a digital audio file) is manipulated so as to embed within it additional data. The additional data is preferably imperceptible to someone who views or listens to the signal — for instance, a listener who plays back a watermarked digital audio file would, if the watermark is sufficiently unobtrusive, not be able to distinguish between the watermarked and unwatermarked versions. However, an analysis of the file by software capable of detecting the watermark will reveal the mark's contents. This ability to encode additional data into a signal is useful to publishers of sound and video recordings, who can use watermarks to embed in the media they distribute information intended to protect that media against unauthorized copying. For these publishers and others, watermarking represents a trade-off: the desired additional data is encoded directly into the signal, but like any change to a signal, the watermark introduces some level of distortion. Thus, a key goal of watermarking techniques is to minimize the distortion so that the resulting diminution in signal quality is as minimal as possible.

Nuijten's technique improves existing watermark technology by further modifying the watermarked signal in a way that partially compensates for distortion introduced by the watermark. A helpful illustration is found in the diagrams of Nuijten's application:

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This diagram, Figure 2 of the application, demonstrates a relatively simple form of digital audio encoding called "delta modulation."¹ The smooth line in the upper graph (labeled `x') represents a very small slice of the sound wave to be encoded. The lower graph represents a digital encoding of that signal. It takes on only two values. They are labeled here as `1' and `-1,' rather than the usual labeling of these binary values as one and zero. The sound wave is reconstructed from the digital signal one step at a time, left to right. If the digital signal has value `1,' the reconstructed sound wave's value is increased slightly, and if the digital signal has value `-1,' the sound wave is decreased by the same amount. The recording is therefore represented by the change (or "delta") over a very small increment of time, either `1' for an increase or `-1' for a decrease. Hence, the encoding scheme is known as "delta modulation." The result is a close but imperfect approximation of the original sound wave, illustrated on the upper graph by `x' with a caret above it. The fidelity of the reconstructed sound wave to the original will depend in large part on the "sample rate" — the length of the time interval represented by each discrete value in the digital signal. Representing all of the nuances of the original sound wave in order to produce a rich, clear recording may require tens or hundreds of thousands of samples per second.

The above-illustrated signal has no watermark. Nuijten's application next illustrates in Figure 3 what occurs when the signal is modified to add a watermark:

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The watermark Nuijten posits here is imposed on the signal by altering, if necessary, every hundredth value of the digital signal. A reader seeking to extract the watermark from the digital signal would therefore view only every hundredth value, disregarding the other 99 along the way; by stringing together all such values, the watermarked data may be discerned. Every point where a portion of the watermark is found represents a possibility that the signal may be distorted. If the watermark value designated for a certain position and the original value at that same position happen to coincide, there is no need to modify the original and hence no distortion. About half of the time, though, those values will not coincide and the digital signal will be altered. The result is shown in the diagram: the digital value at the point labeled `21' and illustrated by a vertical dashed line has been changed from `1' in the original to `-1.' The reconstructed signal is thus decreased where it should be increased, and the encoded signal departs from the original in a pronounced manner.

Nuijten's application teaches that this departure may be minimized by making an additional change to the watermarked digital signal, as shown in Figure 4:

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Here, the value preceding the one that was modified by the watermark has also been modified: it was `-1' in the original signal, but is now `1.' The signal is therefore increased, then decreased (where in the original it was decreased, then increased). The resulting encoding has the same watermark as the above example, but as the diagram indicates, it tracks the original sound wave much more accurately. There is still some small loss in encoding quality relative to the unwatermarked original, but the magnitude of that loss has been greatly decreased.

The above-described procedure is most naturally expressed as a series of steps for adding a low-distortion watermark to a signal, and indeed Nuijten has already obtained allowance of ten claims (Claims 1-10) directed to such a process. Claim 1 is the broadest process claim allowed. It reads:

A method of embedding supplemental data in a signal, comprising the steps of: encoding the signal in accordance with an encoding process which includes the step of feeding back the encoded signal to control the encoding; and modifying selected samples of the encoded signal to represent the supplemental data prior to the feedback of the encoded signal and including the modifying of at least one further sample of the encoded signal preceding the selected sample if the further sample modification is found to improve the quality of the encoding process.

Nuijten's Claims 11-13, also allowed by the PTO, are directed to "[a]n arrangement for embedding supplemental data in a signal," including "encoder means for encoding the signal" and other structural features that carry out the above process. Finally, Nuijten's allowed Claim 15 is directed to "[a] storage medium having stored thereon a signal with embedded supplemental data," where the stored signal has essentially the encoding properties described above. Thus, Nuijten has been allowed claims to the process he invented, a device that performs that process, and a storage medium holding the resulting signals. None of these claims is before us on appeal.

B. The Claims on Appeal

The claims whose disallowance Nuijten appeals are not traditional step-by-step process claims, nor are they directed to any apparatus for generating, receiving, processing, or storing the signals. As mentioned above, such claims have been allowed. The claims on appeal seek to cover the resulting encoded signals themselves. Claim 14 of Nuijten's application is the only independent claim of the four rejected by the PTO. It reads:

A signal with embedded supplemental data, the signal being encoded in accordance with a given encoding process and selected samples of the signal representing the supplemental data, and at least one of the samples preceding the selected samples is different from the sample corresponding to the given encoding process.

(emphasis added). Claims 22, 23, and 24 depend on Claim 14, respectively adding requirements that the embedded data be a watermark, that the signal be a video signal, and that the signal be an audio signal.

C. Procedural History

The Examiner rejected a number of claims in Nuijten's application for obviousness-type double patenting, and rejected Claims 14, 15, and 22-24 as directed to nonstatutory subject matter under § 101. On appeal, the Board reversed the double-patenting rejections. As to Claim 15, it found that "[t]he storage medium in claim 15 nominally puts the claim into the statutory category of a `manufacture'" and thus reversed the Examiner's § 101 rejection of that claim. However, it affirmed the Examiner's § 101 rejections of Claims 14 and 22-24 on two...