WO2005096615A1 - Watermarking on to color recording media using two color planes - Google Patents
Watermarking on to color recording media using two color planes Download PDFInfo
- Publication number
- WO2005096615A1 WO2005096615A1 PCT/US2005/009243 US2005009243W WO2005096615A1 WO 2005096615 A1 WO2005096615 A1 WO 2005096615A1 US 2005009243 W US2005009243 W US 2005009243W WO 2005096615 A1 WO2005096615 A1 WO 2005096615A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- color
- watermark pattern
- recording medium
- recording
- watermark
- Prior art date
Links
- 238000000034 method Methods 0.000 claims abstract description 103
- 239000003086 colorant Substances 0.000 claims abstract description 55
- 239000000975 dye Substances 0.000 claims description 67
- 239000001043 yellow dye Substances 0.000 claims description 16
- AJDUTMFFZHIJEM-UHFFFAOYSA-N n-(9,10-dioxoanthracen-1-yl)-4-[4-[[4-[4-[(9,10-dioxoanthracen-1-yl)carbamoyl]phenyl]phenyl]diazenyl]phenyl]benzamide Chemical compound O=C1C2=CC=CC=C2C(=O)C2=C1C=CC=C2NC(=O)C(C=C1)=CC=C1C(C=C1)=CC=C1N=NC(C=C1)=CC=C1C(C=C1)=CC=C1C(=O)NC1=CC=CC2=C1C(=O)C1=CC=CC=C1C2=O AJDUTMFFZHIJEM-UHFFFAOYSA-N 0.000 claims description 15
- 238000003384 imaging method Methods 0.000 claims description 12
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 8
- 230000007246 mechanism Effects 0.000 claims description 6
- 230000004044 response Effects 0.000 description 28
- 230000003595 spectral effect Effects 0.000 description 28
- 230000005540 biological transmission Effects 0.000 description 15
- 239000000839 emulsion Substances 0.000 description 15
- 230000035945 sensitivity Effects 0.000 description 14
- 238000013459 approach Methods 0.000 description 11
- 230000008901 benefit Effects 0.000 description 11
- 238000001514 detection method Methods 0.000 description 10
- 230000008569 process Effects 0.000 description 9
- 238000007906 compression Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 238000012545 processing Methods 0.000 description 7
- 230000006835 compression Effects 0.000 description 6
- 238000007639 printing Methods 0.000 description 6
- 230000000996 additive effect Effects 0.000 description 5
- 230000006872 improvement Effects 0.000 description 4
- 230000007935 neutral effect Effects 0.000 description 4
- 230000005236 sound signal Effects 0.000 description 4
- 239000001060 yellow colorant Substances 0.000 description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 238000009472 formulation Methods 0.000 description 2
- 239000000976 ink Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 230000002123 temporal effect Effects 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- VAYOSLLFUXYJDT-RDTXWAMCSA-N Lysergic acid diethylamide Chemical compound C1=CC(C=2[C@H](N(C)C[C@@H](C=2)C(=O)N(CC)CC)C2)=C3C2=CNC3=C1 VAYOSLLFUXYJDT-RDTXWAMCSA-N 0.000 description 1
- 241000860832 Yoda Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000010420 art technique Methods 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000002301 combined effect Effects 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000001143 conditioned effect Effects 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007687 exposure technique Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000007641 inkjet printing Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 229940100890 silver compound Drugs 0.000 description 1
- 150000003379 silver compounds Chemical class 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000001931 thermography Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M3/00—Printing processes to produce particular kinds of printed work, e.g. patterns
- B41M3/10—Watermarks
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M5/00—Duplicating or marking methods; Sheet materials for use therein
- B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C11/00—Auxiliary processes in photography
- G03C11/02—Marking or applying text
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C7/00—Multicolour photographic processes or agents therefor; Regeneration of such processing agents; Photosensitive materials for multicolour processes
- G03C7/22—Subtractive cinematographic processes; Materials therefor; Preparing or processing such materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M2205/00—Printing methods or features related to printing methods; Location or type of the layers
- B41M2205/12—Preparation of material for subsequent imaging, e.g. corona treatment, simultaneous coating, pre-treatments
Definitions
- the invention relates generally to the field of image watermark application onto color recording media and more particularly relates to a watermarking method that records a watermark pattern using some, but not all, colorant layers in a photosensitive medium such as a motion picture film.
- Patent 6,239,818 discloses embedding a pattern in a color print and adjusting cyan, magenta, yellow, black (CMYK) values such that the embedded data matches the color of the surround when viewed under a standard illuminant; commonly assigned U.S. Patent 5,752,152 (Gasper et al.) discloses a pattern of microdots, less than 300 ⁇ m in diameter, for marking a photographic print that is subject to copyright. Illegal copying is a particular concern to motion picture studios and distributors, representing a noticeable source of lost revenue. Watermarking of motion picture images would enable the source of an illegal copy to be tracked and would thus provide a deterrent to this activity.
- CMYK cyan, magenta, yellow, black
- Watermarking techniques for still images and prints may not be well-suited to motion picture film media.
- An encoded pattern that might not be easily visible within the single image of a print could become visible and annoying if it appears in a sequence of image frames.
- a motion picture watermark must be detectable from a copy, such as a videotape copy, that is typically captured in a timing sequence that varies from the timing of motion picture frames through projection equipment and with varying image resolution, lighting, and filtering.
- motion picture watermarking requires a special set of techniques beyond those normally applied for still images.
- a number of watermarking methods for motion images have been described in prior art patents and technical literature. Included are methods that apply a spatial-domain or frequency-domain watermark.
- PN pseudo-random noise
- the PN sequence serves as a carrier signal, which is modulated by the original message data, resulting in dispersed message data (that is, the watermark) that is distributed across a number of pixels in the image.
- a secret key (termed a "seed value") is commonly used in generating the PN sequence, and knowledge of this key is required to extract the watermark and the associated original message data.
- Patent 5,901,178 issued May 4, 1999 to Lee et al. entitled “Post-Compression Hidden Data Transport for Video”; and U.S. Patent No. 5,991,426 issued November 23, 1999 to Cox et al. entitled “Field- Based Watermark Insertion and Detection”.
- U.S. Patent No. 6,026,193 issued February 15, 2000 to Rhoads, entitled “Video Steganography”, discloses the basic concept of using multiple watermarked frames from an image sequence to extract the watermark with a higher degree of confidence than would be obtained with only a single frame.
- the method described by Lubin et al. may provide a temporally distributed watermark that is relatively robust.
- this method suffers from a key limitation for temporally distributed watermarking schemes: the requirement for temporal synchronization in order to recover or decode the watermark. That is, some method must be provided that allows indexing of each image frame with a reference frame; a sampling of successive image frames must include this reference in order to allow synchronization of watermarked frames and subsequent decoding.
- the method described by Lubin et al. requires prior knowledge of the image content before application of a watermark is possible. Thus, this method would not be suitable for use as a pre-exposure scheme by a film manufacturer.
- the watermark pattern is exposed using all three color planes (Red, Green, and Blue, referred to as RGB). Stated alternately, the watermark pattern is exposed onto all three colorants, such as dye layers (cyan, magenta, and yellow, referred to as CMY) for a photosensitive medium.
- RGB Red, Green, and Blue
- CMY dye layers
- This approach can provide a watermark with a neutral color that is substantially robust with respect to the various color distortions that can occur during illegal capture and distribution.
- CMY cyan, magenta, and yellow
- This approach can provide a watermark with a neutral color that is substantially robust with respect to the various color distortions that can occur during illegal capture and distribution.
- CMY cyan, magenta, and yellow
- This approach can provide a watermark with a neutral color that is substantially robust with respect to the various color distortions that can occur during illegal capture and distribution.
- a three-color watermark exposure may work suitably for many types of color film and print media, there are problems specific to
- the photosensitive emulsions for color printing that are sensitized to Green and Blue light are more sensitive to exposure energy than is the emulsion that is sensitized to Red light. Because of this, depending upon the writing technology that is employed to provide the watermark exposures, it may be difficult to achieve the necessary exposure levels for all three photosensitive emulsions. This problem is particularly pronounced for high-speed fabrication of motion picture print film.
- the primary (additive) RGB colors are formed by imaging onto their complementary (subtractive) cyan, magenta, and yellow (CMTY) colorant dye layers. Parts of the image that are not Red are imaged in the cyan dye layer.
- a curve 30a shows normal D log E response of an unexposed film layer.
- a curve 30b shows this response when a watermark pattern has been pre-exposed on the film layer.
- a third curve 30c shows the sensitometry adjustment needed to compensate for watermark exposure. This adjustment is carried out by changing emulsion response characteristics for the particular dye layer of the print film.
- a preferred approach to compensate for this problem is to reformulate the photosensitive emulsions, correcting for the watermark exposure and response, as shown in the example of Fig. 4, in order to provide the same effective response to image content exposure as if there were no watermark exposure.
- a neutral watermark is produced by exposing all three color planes with a watermark pattern, it is then necessary to re-formulate all three photosensitive emulsions. It must be observed that emulsion re-formulation is a difficult process, requiring careful process adjustments and testing, potentially adding considerable expense to the manufacturing process.
- One solution that has been proposed for other types of color photosensitive medium is to apply a watermark only to a single color plane.
- compression techniques such as MPEG use a luminance/chrominance color representation, discarding at least some portion of the chrominance information, because it is less perceptible to a human observer. Even if a different color plane is used, this single-channel method may not provide satisfactory results. Detection of a watermark pattern encoded in only a single color may be difficult, depending upon scene content. As a result, a single-color watermark exposure may not persist in a copy that is illegally made, thus rendering the watermark useless for the purpose of tracking stolen content.
- Another problem with watermark exposure in the Red color plane relates to the encoding of the audio signal on the film.
- a length of motion picture print film provides not only image content, but also provides accompanying audio soundtracks and synchronization information.
- Fig. 2 there is shown a small segment of 35mm motion picture film having successive image frames 12 plus a number of tracks of encoded audio, and an interframe space 16, is positioned between successive image frames 12.
- An analog sound track 18 is printed between the side edge of frames 12 and perforations 14.
- a DTS (Digital Theater Systems) soundtrack 26 is encoded between frames 12 and analog sound track 18.
- a Dolby digital sound track 22 uses areas interspersed between perforations 14, repeated on both sides.
- Another digital sound track 24, conventionally the standard SDDS (Sony Dynamic Digital Sound) track is encoded along edges of print film 10.
- Digital sound tracks 22 and 24 are redundant, typically appearing on both sides of print film 10 as indicated by digital sound tracks 22' and 24'.
- analog sound track 18 and digital sound tracks 22, 24, and 26 are encoded onto print film 10 using exposure to light, in much the same way as frames 12 are exposed.
- any imperfection in imaging quality of print film 10 may also impact audio quality.
- Film grain, dust, surface imperfections, and other imaging anomalies not only degrade image quality, but may also have an impact on audio quality. Due to the requirements of traditional sensing circuitry using vacuum tubes, the colorant dye layers of early color motion picture films were unable to provide sufficient density for accurately encoding the audio signal.
- Patent Application 2003/0012569 entitled "Pre- Exposure of Emulsion Media with a Steganographic Pattern” by Lowe et al. a latent monochromatic or polychromatic image can be exposed onto the "raw" photosensitive medium itself, at the time of manufacture. Then, when the medium is exposed to form the image, the image frame is effectively overlaid onto the watermark pattern. Such a method is also described in U.S. Patent No. 6,438,231 entitled “Emulsion Film Media Employing Steganography” to Rhoads. The
- Rhoads '231 patent discloses this type of pre-exposure of the watermark onto the film emulsion within the frame area of negative film, for example. It can be appreciated that watermark pre-exposure would have advantages for marking motion picture film at the time of manufacture or prior to exposure with image content. A length of motion picture film could be pre- exposed with unique identifying information, encoded in latent fashion, that could be used for forensic tracking of an illegal copy made from this same length of film.
- the present invention provides a method for recording a watermark pattern on a color recording medium that forms an image using a number N of colorants, the method comprising the step of forming the watermark pattern using at least two colorants, but fewer than N colorants. It is a feature of the present invention that it takes advantage of a combination of imperfections that are inherent not only to the process of forming an image onto a color recording medium using colorants, but also inherent to the process of sensing the image thus formed using an electronic recording mechanism.
- Figure 1 is a graph showing the relative sensitivity of the three- color planes for a typical photosensitive color medium
- Figure 2 is a prior art plan view showing a typical arrangement of exposed areas on a motion picture print film
- Figure 3 is a plan view showing exposure of only two color planes for a color motion picture film
- Figure 4 is a graph showing the relationship of density to exposure for a sensitized layer in a color photosensitive medium with and without a watermark
- Figure 5 is a schematic diagram showing how film layers provide color images from projected light
- Figures 6a and 6b are graphs showing the ideal and actual transmission response characteristics, respectively, for magenta dye in a typical motion picture print film
- Figure 7 is a graph showing the ideal and actual transmission response characteristics for yellow dye in a typical motion picture print film
- Figure 1 is a graph showing the relative sensitivity of the three- color planes for a typical photosensitive color medium
- Figure 2 is a prior art plan view showing a typical arrangement of exposed areas on a motion picture print film
- Figure 3 is
- the present description is directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art. It must be observed that the method of the present invention is directed to a watermarking scheme that is especially well-suited to photosensitive media used for motion picture imaging and having an encoded analog soundtrack. The detailed description given below focuses on application of the present invention to this type of media in a preferred embodiment. It must be noted, however, that the method of the present invention could be applied more generally to embodiments using any type of color recording medium that forms an image using a set of colorants.
- This invention could be applied, for example, to other types of photosensitive media that are coated with, colorant dye-producing layers that respond to exposure energy at different wavelengths to form a color image, including still imaging films, for example. More broadly, the present invention could be applied to other types of color recording media that employ a set of colorants for forming an image, including media onto which colorant is applied, such as thermal imaging media or substrates used for ink jet printing.
- analog sound track 18 is between perforations 14 and frames 12. It is instructive to note that the position of analog sound track 18 relative to frames 12 is not known at the time of motion picture print film manufacture. That is, with respect to the plane view of Fig.
- the method of the present invention exposes a watermark pattern to some, but not all, of the sensitized color planes of a photosensitive medium.
- watermark encoding is provided only in Green- and Blue-sensitized color planes. These color planes correspond to magenta and yellow dye-producing layers, as is described in the background section above.
- the watermark pattern typically a tiled pattern 20 as represented in Fig. 3, is not applied in the Red-sensitized color plane, that is, not in the cyan dye layer. With this arrangement, a robust watermark pattern is formed, without affecting the sensing requirements of analog sound track 18.
- Blue-sensitized color plane that is, of the yellow dye- producing layer
- markings in this color plane are the least perceptible to the viewer.
- Marks made in the Green color plane have the advantage of being most easily extracted from an unauthorized copy, since this color plane has the most pronounced influence on the luminance signal that is processed by a camcorder.
- Empirical results have shown that a watermark provided only in Blue and Green color planes, without marking the Red color plane, provides sufficient energy for extraction, is below threshold perceptibility levels to a viewer, and is well suited to the motion picture environment.
- Imperfection in Dve Behavior In order to appreciate how the method of the present invention accomplishes this result, it is first instructive to review the process by which colors are projected from a color motion picture print film. Referring to Fig. 5, there is shown a schematic of the color projection process.
- a projection bulb acting as a light source 32, emits white light toward a segment of processed print film 34.
- Processed print film 34 has three component colorants: a cyan dye layer 36c, a magenta dye layer 36m, and a yellow dye layer 36y.
- the white light from light source 32 has Red, Green, and Blue spectral components, labeled R, G, and B in Fig. 5.
- the color of the light that passes through the processed print film 34, over an arbitrary area, is conditioned by the dye patches 38 in that area.
- Fig. 5 shows the result of light passing through various dye patches 38 and combinations of dye patches 38.
- cyan dye patch 38 allows transmission of Green and Blue light, blocking the Red light component, based on the relative density of dye patch 38. More accurately stated, to a first approximation, cyan dye patch 38 modulates Red, passing Green and Blue without modulation. Table 1 summarizes the ideal behavior of individual dye patches 38.
- magenta dye patch 38 by wavelength, corresponding to the information in Table 1. That is, the magenta dye ideally has 100% transmission of Red light (nominally 580-700 nm wavelength) and 100% transmission of Blue light (nominally 400-490 nm wavelength). For Green light (nominally 490-580 nm), the Magenta dye modulates the light based on density, with typical density levels shown. Once again, however, it must be emphasized that this is a first approximation, with perfect (100%) transmission of Red and Blue light and with modulation only of Green light.
- magenta dye at density of about 1.0 deviates significantly from this ideal behavior, as is shown by an actual transmission curve 40m in Fig. 6b. That is, while transmission is high for Red and Blue light, it is not perfect but is, rather, somewhat less than 100%. Nor is modulation of Green light perfect, as illustrated in Fig. 6a and represented by a phantom waveform in Fig. 6b. Similarly, the actual response of yellow dye is also imperfect. Referring to Fig. 7, an actual transmission curve 40y for yellow dye at density 1.0 is shown and is compared with its ideal behavior, likewise represented in phantom in Fig. 7. Thus, as Figs.
- the actual spectral range of video-camera color sensing is typically different from the spectral range of projected color film.
- the peak sensitivity of video camera sensing components for the Red channel is nearest the short wavelength edge of the Red channel, typically about 580 - 590 nm.
- camcorder sensitivity in the Red channel is heightened somewhat for the Red- orange region.
- both yellow and magenta dye layers 36y and 36m actually perform some attenuation of Red wavelengths in the 580-590 nm region.
- Tables 2a and 2b illustrate the behavior of magenta and yellow colorant dye layers 36m and 36y relative to the signal sensed by a video camera. Ideal behavior of dye absorption and video camera spectral sensitivities is shown in the example of Table 2a. That is, Table 2a assumes perfect dye response (as was indicated in the theoretical graph of Fig. 6a) and well-matched spectral sensitivities of a video camera. The more realistic behavior that is characteristic of actual dyes and an actual video camera is summarized in Table 2b. As the magenta entry shows, there is some unintended, but significant, modulation of the Red color channel by magenta dye layer 36m. Similarly, there is some unintended modulation of the Green channel by yellow dye layer 36y.
- spectral response curves 42r for Red, 42g for Green, and 42b for Blue peak at particular wavelengths then decay within each color region, even allowing some overlap between ⁇ adjacent spectral regions.
- This overlap means that, in practice, some amount of energy applied to the magenta dye layer 36m has impact in the Red channel.
- This imperfection in spectral response range of a video-camera effectively contributes additional energy to the Red color channel, particularly in combination with dye imperfections (1, above) and spectral peak differences (2, above).
- Figs. 9a and 9b spectral response curves 42r, 42g, and 42b are plotted relative to the transmission curves 40m and 40y for magenta and yellow dyes, respectively.
- Video-camera Color Filter Arrangement and Compression A fourth factor of primary importance for adding energy to the Red channel without modulation of cyan dye layer 36c relates to the nature of image sensing by the video-camera and standardized compression algorithms that are conventionally used by this type of recording device.
- the color filter array (CFA) of the video-camera is conventionally arranged in accordance with the color space modeling that is based on the luminance/chrominance paradigm familiar to those skilled in the color reproduction arts. For the purposes of this discussion, it is enough to observe that the luminance characteristic is highly correlated with the Green color channel.
- a conventional arrangement of the video-camera CFA uses a matrix of color filters that are heavily weighted toward detection of Green light. Referring now to Fig.
- color filter array 44 there is shown, as a plan view representation, a portion of a color filter array 44 that is conventionally used, by color, resembling the familiar Bayer pattern known to those skilled in the image recording arts.
- color filter array 44 there are twice as many Green detector components than are used for either Red or Blue light.
- a standard luminance equation also shows the preponderant weighting given to the Green color channel, as follows:
- Y represents luminance.
- the luminance signal is preserved with the highest fidelity when images are compressed using standard algorithms.
- At least some portion of the chrominance information is subsampled and discarded by compression algorithms. Then, in order to reproduce the full RGB color signal for display, interpolation of the chrominance information is necessary for the transformation that converts from this luminance/chrominance representation to RGB representation.
- any type of transform between color models and interpolation within a color space requires some compromises and results in some amount of channel crosstalk.
- One advantage of the method of the present invention relates to the need to adapt the response characteristics of the photosensitive medium for accepting a watermark.
- Curve 30c shows the affect achieved by reformulation. Because the method of the present invention uses only two dye- producing layers, this method requires re-formulation only for those layers. The sensitometric characteristics of the unaffected Red-sensitive layer (that is, of cyan dye layer 36c) need not be modified.
- the method of the present invention could be applied to other types of photosensitive media, such as those used for still imaging, as was noted above.
- other types of photosensitive media such as those used for still imaging, as was noted above.
- the subset chosen is a non-empty proper subset (a subset which has at least one element but is not the entire set) having at least two component colorants, since the full set of available colorants is not used.
- This method could be broadly applied to photosensitive media having more than three color planes. For example, where a fourth visible dye layer is used in a photosensitive medium, it may be advantageous to apply a watermark to only two or three dye layers to achieve a similar effect. While the embodiments described hereinabove are directed to marking photosensitive recording media that employ dye colorant layers, the method of the present invention could be more broadly applied to any class of color recording medium that employs a set of colorants to provide a color image.
- the method of the present invention could be applied for colorants other than dyes, such as inks or pigments, for example.
- the set of component colorants may be contained within the color recording medium, such as with film, or may be applied onto the recording medium, such as from a donor or intermediate substrate or from an ink jet nozzle.
- the set of colorants used could be other than cyan, magenta, and yellow.
- the method of the present invention could also be applied where an applied exposure energy is visible or non- visible light and could also be used where heat or electromagnetic energy serves to expose image content, for example.
- the method of the present invention applies a watermark encoding to a number from 2 to (N-l) colorant materials.
- the colorant materials specified would be chosen based on their response characteristics, using information about attenuation of adjacent color channels and combined effects, as has been described in the present application.
- a film manufacturer could apply the watermarking method of the present invention as a pre-exposure technique, prior to packaging the photosensitive medium for shipment.
- pre-exposure could alternately be performed by a studio before the negative film is exposed or by a lab, prior to printing a print film.
- the method of the present invention need not be constrained to pre-exposure.
- a watermark pattern could be exposed onto a print film during or even after exposure to the image content of a frame.
- the method of the present invention could be carried out by any of a number of types of recording apparatus, at any of several points in the overall image processing chain.
- some portion of the watermarking pattern could be exposed at the camera itself.
- a motion picture camera 50 could even be provided with an exposure mechanism 54 for encoding a watermark pattern to a negative film 52 in specific color planes during a film shoot.
- exposure mechanism 54 may employ an LED array, an LCD spatial light modulator, or other image-forming component for marking negative film 52 before or after image exposure.
- the non-empty proper subset of colorant layers that are employed for encoding must be based on the type of medium and its application.
- the invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
- the method of the present invention could be used in conjunction with any number of prior art techniques that apply a watermark pattern to motion picture content.
- the watermark pattern, encoded message, or message carrier could be changed over a length of motion picture film, using techniques " tmown to those skilled in the art.
- a watermarking arrangement can be obtained that is well suited for a range of media types, including motion picture media as well as other types of still imaging filin and paper.
- a watermark according to the present invention can be applied as a pre- exposure marking or applied during or after exposure to image content. Xhus, what is provided is a method for marking a watermark pattern onto a color recording media, such as a motion picture film, by recording the pattern onto only a non-empty proper subset of the available color planes.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP05725955A EP1738576B1 (en) | 2004-03-23 | 2005-03-21 | Watermarking on to color recording media using two color planes |
JP2007505036A JP2007531401A (en) | 2004-03-23 | 2005-03-21 | Method of watermarking a color recording medium using two color planes |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/807,491 US7227671B2 (en) | 2004-03-23 | 2004-03-23 | Motion picture watermarking using two color planes |
US10/807,491 | 2004-03-23 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2005096615A1 true WO2005096615A1 (en) | 2005-10-13 |
Family
ID=34963140
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2005/009243 WO2005096615A1 (en) | 2004-03-23 | 2005-03-21 | Watermarking on to color recording media using two color planes |
Country Status (5)
Country | Link |
---|---|
US (1) | US7227671B2 (en) |
EP (1) | EP1738576B1 (en) |
JP (1) | JP2007531401A (en) |
ES (1) | ES2293559T3 (en) |
WO (1) | WO2005096615A1 (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6728390B2 (en) * | 1995-05-08 | 2004-04-27 | Digimarc Corporation | Methods and systems using multiple watermarks |
US7681040B2 (en) * | 2004-06-02 | 2010-03-16 | Margit Elisabeth Elo | Method for embedding security codes into film during printing |
AU2007254661A1 (en) * | 2007-12-24 | 2009-07-09 | Canon Kabushiki Kaisha | Printing and authentication of a security document on a substrate |
US8477990B2 (en) | 2010-03-05 | 2013-07-02 | Digimarc Corporation | Reducing watermark perceptibility and extending detection distortion tolerances |
US8971567B2 (en) | 2010-03-05 | 2015-03-03 | Digimarc Corporation | Reducing watermark perceptibility and extending detection distortion tolerances |
US10664940B2 (en) | 2010-03-05 | 2020-05-26 | Digimarc Corporation | Signal encoding to reduce perceptibility of changes over time |
CN103873871B (en) * | 2014-03-17 | 2017-02-15 | 北京航空航天大学 | Geometric-attack-resistant robust video watermark method based on timeline spread spectrum |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5752152A (en) * | 1996-02-08 | 1998-05-12 | Eastman Kodak Company | Copy restrictive system |
WO2001035323A1 (en) * | 1999-11-05 | 2001-05-17 | Digimarc Corporation | Watermarking an image in color plane separations and detecting such watermarks |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5118526A (en) * | 1991-03-11 | 1992-06-02 | Regal Press, Incorporated | Method of producing a simulated watermark |
US5291243A (en) * | 1993-02-05 | 1994-03-01 | Xerox Corporation | System for electronically printing plural-color tamper-resistant documents |
US5822436A (en) | 1996-04-25 | 1998-10-13 | Digimarc Corporation | Photographic products and methods employing embedded information |
US6983051B1 (en) | 1993-11-18 | 2006-01-03 | Digimarc Corporation | Methods for audio watermarking and decoding |
US5748763A (en) | 1993-11-18 | 1998-05-05 | Digimarc Corporation | Image steganography system featuring perceptually adaptive and globally scalable signal embedding |
US5901178A (en) | 1996-02-26 | 1999-05-04 | Solana Technology Development Corporation | Post-compression hidden data transport for video |
US5809139A (en) | 1996-09-13 | 1998-09-15 | Vivo Software, Inc. | Watermarking method and apparatus for compressed digital video |
US6239818B1 (en) | 1998-08-28 | 2001-05-29 | Fuji Photo Film Co., Ltd. | Printing method and apparatus |
US5991426A (en) | 1998-12-18 | 1999-11-23 | Signafy, Inc. | Field-based watermark insertion and detection |
US20030012569A1 (en) | 2001-04-16 | 2003-01-16 | Lowe Brian D. | Pre-exposure of emulsion media with a steganographic pattern |
AU2002355398A1 (en) * | 2001-08-02 | 2003-02-24 | Thomas M. Wicker | Security documents and a authenticating such documents |
US7460278B2 (en) * | 2004-01-29 | 2008-12-02 | Seiko Epson Corporation | 3-Dimensional dot code for paper storage |
US6980226B2 (en) * | 2004-02-13 | 2005-12-27 | Eastman Kodak Company | Watermarking method for motion picture image sequence |
-
2004
- 2004-03-23 US US10/807,491 patent/US7227671B2/en not_active Expired - Fee Related
-
2005
- 2005-03-21 ES ES05725955T patent/ES2293559T3/en active Active
- 2005-03-21 WO PCT/US2005/009243 patent/WO2005096615A1/en active IP Right Grant
- 2005-03-21 JP JP2007505036A patent/JP2007531401A/en active Pending
- 2005-03-21 EP EP05725955A patent/EP1738576B1/en not_active Expired - Fee Related
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5752152A (en) * | 1996-02-08 | 1998-05-12 | Eastman Kodak Company | Copy restrictive system |
WO2001035323A1 (en) * | 1999-11-05 | 2001-05-17 | Digimarc Corporation | Watermarking an image in color plane separations and detecting such watermarks |
Also Published As
Publication number | Publication date |
---|---|
US20050215293A1 (en) | 2005-09-29 |
JP2007531401A (en) | 2007-11-01 |
EP1738576B1 (en) | 2007-11-21 |
ES2293559T3 (en) | 2008-03-16 |
EP1738576A1 (en) | 2007-01-03 |
US7227671B2 (en) | 2007-06-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7068297B2 (en) | Watermarking method for motion picture image sequence | |
EP1738576B1 (en) | Watermarking on to color recording media using two color planes | |
US7747015B2 (en) | Techniques of imperceptibly altering the spectrum of a displayed image in a manner that discourages copying | |
US4788116A (en) | Full color images using multiple diffraction gratings and masking techniques | |
US6045881A (en) | Copy restrictive documents | |
US20020126871A1 (en) | Watermarking a carrier on which an image will be placed or projected | |
US20040109016A1 (en) | Motion picture anti-piracy coding | |
US6628826B1 (en) | Color reproduction of images from color films | |
US5574659A (en) | Dye transfer prints utilizing digital technology | |
AU2003287014B8 (en) | Motion picture anti-piracy coding | |
US7777859B2 (en) | Two-stage exposure device for watermarking film | |
US7403708B2 (en) | Tracking an image-recording medium using an identifying mark and film encodement | |
JP3771178B2 (en) | Camera, image information reproduction method, and image information calibration method | |
US3857709A (en) | Method of enhancing the information legibility of multi-color graphic material | |
US6917758B1 (en) | Method of image compensation for watermarked film | |
US4708448A (en) | Color picture reproduction with cut-off blue spectrum | |
Miller | Masking: A technique for improving the quality of color reproductions | |
US4065309A (en) | Method of enhancing the information legibility of multi-color graphic material | |
US20030003409A1 (en) | Color film restoration process | |
JP2001053931A (en) | Photograph recording element reading and image forming device | |
US4281049A (en) | Color separation transparency and process for the preparation thereof | |
JP2001249380A (en) | Digital color image forming method, and camera for photographing and image forming device used therefor | |
JP2007272077A (en) | Image exposure method and exposure device | |
JPH07239537A (en) | Color film, and recording method, recording device and reproducing device therefor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2005725955 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2007505036 Country of ref document: JP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWW | Wipo information: withdrawn in national office |
Country of ref document: DE |
|
WWP | Wipo information: published in national office |
Ref document number: 2005725955 Country of ref document: EP |
|
WWG | Wipo information: grant in national office |
Ref document number: 2005725955 Country of ref document: EP |