US20090086100A1

US20090086100A1 - Method, Apparatus and System for Providing Reproducible Digital Imagery Products From Digitally Captured Images

Info

Publication number: US20090086100A1
Application number: US12/085,262
Authority: US
Inventors: Joshua Pines; Chris Kutcka
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-12-16
Filing date: 2006-05-25
Publication date: 2009-04-02
Also published as: CA2632678A1; CA2632599C; US20090201367A1; US9699388B2; EP1961213A1; WO2007070088A1; CA2631893A1; CA2632599A1; JP2009520395A; WO2007070087A1; WO2007070089A1; US20100220971A1; US8982409B2; CN101331756A

Abstract

The present invention provides a method, apparatus and system for the transfer of a digital video content captured by a digital motion picture camera (310) to reproducible digital imagery products such as digital dailies. In one embodiment, the present invention provides a log video signal of said digital video content using information regarding the dynamic range of at least one of said digital video content or said digital camera. Said log video signal comprises at least grey scale values of the colors of the original video content for enabling a quantitative assessment of the video content capture information for providing repeatable and reproducible values from which a cinematographer/director of photography could order the color correction or adjustment of the video content in a reproducible manner understood by a color correction specialist or “timer”.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 60/751,021, filed Dec. 16, 2005, which is herein incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention generally relates to digital imagery and, more particularly, to a method, apparatus and system for providing reproducible digital imagery products from digitally captured video content and for providing color correction of the reproducible digital imagery products.

BACKGROUND OF THE INVENTION

Initially in the motion picture industry an original motion picture negative film was exposed during a camera exposure operation, developed into a processed camera negative and subsequently operated upon in one of several ways to produce an imagery product. In such prior art analog systems, film dailies or rushes were conventionally produced as a motion picture was shot. These dailies or rushes were processed and then viewed by the director, the producer, the film editor, etc. working on the production to determine whether the scenes shot were acceptable. Each person on the production team assessed the dailies for different elements relevant to their respective roles in the team. That is, dailies or rushes were printed on film. The cinematographers and directors could see the results of the previous day's work in a format that faithfully “previewed” what the final release could look like. A language developed between cinematographers and the “timer” at a lab where a director of photography (dp) could either literally dictate the lites, and hence the look of the dailies, or, assuming a relationship of trust which existed between the dp and the timer, the timer would choose the lites based on discussions with the dp, and the dp could verify, based on these lites, that the exposure was correct and that enough latitude was present on the negative for future color correction during the answer print process.
More specifically, with the dailies, “Printer Lite” information was provided which assisted the cinematographer/director of photography to determine whether the scenes were shot with a satisfactory exposure. This Printer Light information was determined from the settings of a conventional motion picture film printer required to produce a print with laboratory aim densities. This information was obtained by passing white light from a scene through dichroic filters to split the light into its three components, red, green and blue. The three light components were used to expose a test film strip from which the densities corresponding to the intensities of the red, green and blue components of the light could be measured and compared with standard densities which correspond to an “ideal” exposure. The densities produced by the red, green and blue light components on the test film strip gave an indication of the exposure given to the original film as the scene was recorded. The “Printer Light” information provided repeatable and reproducible values from which a cinematographer/director of photography could order the color correction of the film in a manner understood by a color correction specialist (colorist) or “timer”.
Today, however, there is an increasing move toward the digital filming of content made for theatre programming. As such, color correction as described above, cannot not be performed on such content intended to be viewed in a theatre. With such digital filming systems, a sequence of motion images is captured using a full resolution image sensor system, resulting in a captured sequence of full resolution unprocessed image signals corresponding to the motion images. The full resolution unprocessed image signals are recorded and provided to a post-production process where the images will be subsequently rendered in a post-processing stage to simulate a particular look for producing, for example, video dailies. More specifically, video dailies are replacing the film dailies or rushes and non-linear editing techniques are replacing conventional film editing.
In the world of “digital motion picture cameras” there are several makes and models currently in use, and many more can be expected to be introduced. Although these new cameras promise efficient workflows, there are many technical concerns which have to be addressed. For example, cameras from different manufacturers produce varying output in terms of colour space, bit depth, and tonal range. Dailies still have to be produced from the “raw” image data captured on set, just as dailies had to be produced from film. This same “raw” image data is the basis for the digital intermediate, where final color correction is applied, just as it was to scanned film negative. The resulting final digital intermediate data is recorded to film negative to make release prints for film distribution.
Cinematographers, for example, have expressed a desire to be able to “preview” the captured images and “set a look” right there on the set, however they also want to capture as much dynamic range as possible—as much as the digital camera can capture. The cinematographers want to control the “look” of the images for dailies, but without permanently “baking in” any color correction. This is because the manipulation of the dailies can be destructive, often limiting the dynamic range which can be captured by the camera. Instead it would be preferable to capture and record the full dynamic range, but at the same time “specify” the creative intent in some non-destructive manner.
In addition, a major drawback in all these digital capture applications is that the resulting digital images have to be custom processed for each application. That is, an acceptable scene reproduction is obtained from dailies created on a trial-and-error basis, which is generally time-consuming. In case the cinematographer is not pleased with the scene look on the daily, the whole process is then repeated, starting with new adjustments and ending with another post production process, until the desired look is obtained. Besides being time consuming, this is also a relatively expensive process. Also, the digital post production processing method typically does not offer a quantitative assessment of the digital capture information and does not provide, as in prior art systems, repeatable and reproducible values from which a cinematographer/director of photography could order the color correction of the film in a manner understood by a color correction specialist or “timer”.

SUMMARY OF THE INVENTION

The present invention advantageously provides a method, apparatus and system for providing reproducible digital imagery products from digitally captured images/video content.
In one embodiment of the present invention a method for providing a reproducible digital imagery product of digital video content captured by a digital image capture device includes generating a log video signal representation of the digital video content using information regarding a dynamic range of at least one of the digital video content, a broadest range digital video content to be captured, the digital image capture device and a broadest range digital image capture device to be used to capture digital video content. The method of the present invention can further include providing density offsets for each of the color components of the digitally captured video content to color correct the log video signal of the video content. In one embodiment of the present invention, such density offsets are linear offsets and are configured to emulate Printer Light offset values typically between 0 and 50.
In an alternate embodiment of the present invention, a color device includes a processor and a memory configured to generate a respective log video signal representation of received digital video content using information regarding a dynamic range of at least one of the digital video content, a broadest range digital video content to be captured, a respective digital image capture device and a broadest range digital image capture device. The color device of the present invention can further include a user interface configured to enable adjustment of density values of the log video signal representation to color correct the log video signal representation of the digital video content, the log video signal representation of the digital video content having grey scale density values for the colors of the digital video content.
In an alternate embodiment of the present invention, a system for providing a reproducible digital imagery product of digitally captured video content and color correction thereof includes a digital capture device configured to digitally capture the video content, a color device configured to generate a respective log video signal representation of the video content using information regarding a dynamic range of at least one of the video content, a broadest range video content to be captured, the digital capture device and a broadest range digital capture device, and a user interface configured to enable adjustment of density values of the log video signal representation to color correct the log video signal representation of the video content, the log video signal representation of the video content having respective grey scale density values for the colors of the video content.

BRIEF DESCRIPTION OF THE DRAWINGS

The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:

FIG. 1 depicts a high level block diagram of a prior art color correction flow process/system;

FIG. 2 depicts a high level block diagram of a prior art film color correction device suitable for use in the color correction flow process/system of FIG. 1;

FIG. 3 depicts a high level block diagram of a digital color system for the transfer of digitally captured video content to reproducible digital imagery in accordance with an embodiment of the present invention; and

FIG. 4 depicts a high level block diagram of an embodiment of a color device suitable for use in the digital color system of FIG. 3 in accordance with the present invention.

It should be understood that the drawings are for purposes of illustrating the concepts of the invention and are not necessarily the only possible configuration for illustrating the invention. To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.

DETAILED DESCRIPTION OF THE INVENTION

The present invention advantageously provides a method, apparatus and system for providing reproducible digital imagery products from digitally captured video content. Although the present invention will be described primarily within the context of a specific digital color correction system for producing digital dailies from digitally capture images/video content, the specific embodiments of the present invention should not be treated as limiting the scope of the invention. It will be appreciated by those skilled in the art and informed by the teachings of the present invention that the concepts of the present invention can be advantageously applied in substantially any system for the transfer of digitally captured images/video content to reproducible digital imagery for many applications such as the color correction of digitally captured images, the re-timing of digital dailies, determining an initial starting point for a final digital intermediate and the like.
FIG. 1 depicts a high level block diagram of a prior art color correction flow process/system. The prior art color correction flow process/system 100 of FIG. 1 illustratively comprises an original film content block 110, a traditional film color correction device 120, a color control device 125 and a resulting film answer print block 130. In the prior art color correction flow process/system of FIG. 1, original film content from the film content block 110 is fed into the film color correction device 130. In the film color correction device 130 white light is passed from a scene through dichroic filters/mirrors to split the light into its three components, red, green and blue. The three light components are used to expose a test film strip from which the densities corresponding to the intensities of the red, green and blue components of the light could be measured and compared with standard densities which correspond to an “ideal” exposure. The densities produced by the red, green and blue light components on the test film strip give an indication of the exposure given to the original film as the scene was recorded. The density information provides values typically between 0 and 50, the neutral values typically being 25, 25, 25 and correspond to the median exposure.
FIG. 2 depicts a high level block diagram of a film color correction device 130 suitable for use in the color correction flow process/system of FIG. 1. The film color correction device 130 of FIG. 2 illustratively comprises six (6) dichroic filters/mirrors 210 ₁-210 ₆and three mechanical light valves 220 ₁-220 ₃. The six (6) dichroic filters/mirrors 210 ₁-210 ₆are implemented to split the light into its three components, red, green and blue. The three light components are then used to expose a film strip. The three mechanical light valves 220 ₁-220 ₃are used to respectively adjust the amount/density of red, green and blue light used to expose a film strip to color correct the specific scene of the film strip being illuminated. That is, a colorist (timer) via the color control device 125 adjusts the three mechanical light valves 220 ₁-220 ₃to vary the densities of the respective red, green and blue lights in a very repeatable manner, which can be recalled by a cinematographer/director of photography or the colorist (timer) to reproduce the desired color information for various scenes. The three mechanical light valves 220 ₁-220 ₃, controlled by the color control device 125, provide density values typically between 0 and 50, for each of the respective red, green and blue lights such that a desired value can be determined and recalled for each of the respective red, green and blue lights to produce a desired, very repeatable color effect for respective scenes of a film strip.
However and as previously mentioned, there is an increasing move toward the digital capture of images for theatre programming and the like such that film is never printed as described above in the prior art color correction systems. As such, color correction as described above, cannot not be performed on such content intended to be viewed in a theatre.
As previously described, digital dailies resulting from the digital capture of images are replacing the film dailies or rushes. As described however, a major drawback in all these digital capture applications is that the resulting digital images have to be custom processed for each application. That is, an acceptable scene reproduction is obtained from dailies created on a trial-and-error basis, which is generally time-consuming. In case the cinematographer is not pleased with the scene look on the daily, the whole process is then repeated, starting with new adjustments and ending with another post production process, until the desired look is obtained. Also, available digital color correction methods typically do not offer a quantitative assessment of the digital capture information and do not provide, as in prior art analog systems, repeatable and reproducible values from which a cinematographer/director of photography could order the color correction in a manner understood by a color correction specialist or “timer”.
To address the deficiencies of the prior art digital capture systems and the digital color correction process and to attempt to recapture the reproducible and repeatable results of the optical color correction systems, such as the color correction system 100 of FIG. 1, the inventors provide a method, apparatus and system for providing reproducible digital imagery products from digitally captured video content/images.
FIG. 3 depicts a high level block diagram of a digital color system for the transfer of digitally captured images to reproducible digital imagery in accordance with an embodiment of the present invention. The digital color system 300 of FIG. 3 illustratively comprises a digital image capture device (illustratively a digital motion picture camera) 310, a digital color device 320, and a video tape recording device 340. Alternatively, the video tape recording device 340 of the digital color system 300 can further comprise separate storage sections (not shown) for storing a raw log video signal and a color corrected log video signal (described in further detail below). In an alternate embodiment of the present invention, a digital color system of the present invention can comprise a separate storage means for individually storing a raw log video signal and a color corrected log video signal. In addition, although in FIG. 3, the system of the present invention is illustratively depicted as a digital color system 300 including a digital motion picture camera as the capture device, in alternate embodiments of the present invention, other devices and means can be implemented to digitally capture the desired video content.
In the digital color system 300 of FIG. 3, original video content is captured by the digital motion picture camera 310. The digitally captured video content is communicated to the color device 320. The color correction device 320 is implemented to generate a reproducible digital imagery product (e.g., log video signal representation) of the digitally captured video content from the digital motion picture camera 310 and to provide color correction for the generated reproducible digital imagery product. In one embodiment of the present invention the generated, reproducible digital imagery product from the color device 320 is communicated to the video tape recording device 340 both in raw form and in color corrected form. In addition, in the digital color system 300 of FIG. 3, a display conversion can be applied so that the digital imagery product (e.g., log video signal) is able to be viewed onset on a calibrated display device (not shown). The display conversion corrects the digital imagery product such that it can be displayed on a calibrated display device such that the image on the display matches what a final film print would look like if that same color correction would be applied during a final digital intermediate color correction process. That is, the of the on set color correction which produced the desired look on the calibrated display device is later applied to the raw log video signal to produce dailies, editorial, and preview elements which match what was displayed on set. The preliminary color correction can also be used as a starting point for the final digital intermediate color correction.
FIG. 4 depicts a high level block diagram of an embodiment of a color device 320 suitable for use in the digital color system 300 of FIG. 3 in accordance with the present invention. The color device 320 of FIG. 4 comprises a processor 410 as well as a memory 420 for storing control programs, density charts, look-up tables (LUTs) and the like in accordance with the present invention. The processor 410 cooperates with conventional support circuitry 430 such as power supplies, clock circuits, cache memory and the like as well as circuits that assist in executing the software routines stored in the memory 420. As such, it is contemplated that some of the process steps discussed herein as software processes may be implemented within hardware, for example, as circuitry that cooperates with the processor 410 to perform various steps. The color device 320 also contains input-output circuitry 440 that forms an interface between the various functional elements communicating with the color device 320. For example and as depicted in FIG. 3, the color device 320 communicates with the motion picture camera 310 via a first, input path S1 and communicates with the tape recording device 340 via a second, output path O1.
Although the color device 320 of the present invention is depicted as a general purpose computer that is programmed to perform various control and program functions in accordance with the present invention, the invention can be implemented in hardware, for example, as an application specified integrated circuit (ASIC). As such, the process steps described herein are intended to be broadly interpreted as being equivalently performed by software, hardware, or a combination thereof.
Referring back to FIG. 3, the digitally captured video content from the motion picture camera 310 is communicated to the color device 320. In a first embodiment of the present invention, at the color device 320 a log video signal representation of the digitally captured video content is generated using, for example, dynamic range information of the captured video content. For example, a log video signal comprising grey scale density values for the digitally captured video content is generated in the color device 320. More specifically, information regarding the dynamic range of the digitally captured video content is used by the color device 320 of the present invention to map a full range of the grey scale density values of the log video signal to the dynamic range of the specific digital video content captured by the motion picture camera 310. In one embodiment of the present invention, the color device 320 can determine the dynamic range of the digitally capture video content or alternatively, can receive information regarding the dynamic range of the captured video content from the motion picture camera 320. Alternatively, a color device 320 of the present invention can generate a signal to cause a message to be displayed to a user on, for example the motion picture camera 310 or an associated display, which requests required information regarding the dynamic range of the digitally captured video content.
Furthermore, the color device 320 of the present invention can separate the received digital video content into color components such as red, green and blue components. As such, mapping can be performed to provide respective grey scale densities for the separated colors. In accordance with the present invention, the range of the grey scale density values of the log video signal generated by the color device 320 is projected across the dynamic range of the video content captured by the digital motion picture camera 310. Using the known densities between the colors, the color device 320 can provide digital color correction by providing density offsets for at least one or each of the separated colors as will be described in greater detail below.
In an alternate embodiment of the present invention, at the color device 320 a log video signal representation of the digitally captured video content is generated using, for example, dynamic range information of the motion picture camera 310. For example, a log video signal comprising grey scale density values for the digitally captured video content is generated at the color device 320. More specifically, information regarding the dynamic range of the motion picture camera 310 is used by the color device 320 of the present invention to map a full range of the grey scale density values of the log video signal to the dynamic range of the specific motion picture camera 310 used to digitally capture the video content. In one embodiment of the present invention, the motion picture camera 310 can have stored information regarding its dynamic range from, for example, previously performed tests.
For example, a series of exposure tests can be run on a specific camera before its use in production. The exposure tests can be shot over a wide range of exposures to insure the full dynamic range of the camera is characterized. A physical chart currently used is a backlit transmissive glass plate with 13 discreet patches at increments of 1 f-stop. Such a chart is exposed over the range of f-stops on the camera lens—typically at least 6 f-stops. From the resulting frames, a mapping from camera output digital code values to “relative scene intensity” is derived. In one embodiment of the present invention, this mapping is concatenated with a “relative scene intensity” to “canonical log code value” table which corresponds to a what a perfectly scanned idealized camera original film negative would have produced if it had photographed the same chart. As such, the output of any digital camera can be characterized as if a scene had been captured with a “canonical” negative film stock and then that negative scanned.
Alternatively, a color device 320 of the present invention can generate a signal to cause a message to be displayed to a user on, for example the motion picture camera 310 or an associated display, which requests required information regarding the dynamic range of the motion picture camera 310. In such embodiments, the information regarding the dynamic range of the motion picture camera 310 can be communicated to the color device 320 of the present invention such that the color device 320 is able to assign corresponding grey scale density values to the full dynamic range of colors of the motion picture camera 310 to generate a respective log video signal representation of the digitally capture video content. Alternatively, a color device 320 in accordance with the present invention can have information stored regarding the dynamic range of various digital capture devices, including the motion picture camera 310.
In accordance with the embodiment of the present invention described directly above, in the color device 320, the range of the grey scale density values of the log video signal is projected across the dynamic range of an image capture device (e.g., the motion picture camera 310). As such, subsequent images captured by the same image capture device will be respectively represented by the log video signal and as such by the grey scale density values. With such an arrangement, similar color values in different captured images will have corresponding grey scale density values which will be consistent throughout the dynamic range of a specific image capture device (e.g., the motion picture camera 310 of FIG. 3). As previously described above, the color device 320 of the present invention can separate the received digital video content into color components such as red, green and blue components. As such, mapping can be performed to provide respective grey scale densities for the separated colors. Using the known densities between the colors, the color device 320 can provide digital color correction by providing density offsets for any or each of the separated colors as will be described in greater detail below.
In accordance with the concepts of the present invention, substantially any image capture device can be calibrated using information regarding its dynamic range such that subsequent images captured by the same image capture device will be respectively represented by a log video signal of the present invention and as such by the grey scale density values of the log video signal.
In accordance with an alternate embodiment of the present invention, at the color device 320 log video signal representations of digitally captured video content are generated using fixed grey density values for specific colors, however, taking into account the dynamic range information of either a broadest range video content to be captured or a broadest range image capture device or both. More specifically, information regarding the dynamic range of a broadest range image capture device (e.g., motion picture camera) or a broadest range video content to be captured (e.g., motion picture) is used by the color device 320 of the present invention to map a full range of the grey scale density values of the log video signal to specific colors such that the full range of the grey scale density values encompass a broadest dynamic range required for all applications and combinations of a broadest range image capture device and a broadest range video content to be captured (i.e., grey scale density values available for any color able to be captured by any image capture device or for any color in any digitally captured video content).
In one embodiment of the present invention, available motion picture cameras can have stored information regarding respective dynamic ranges from, for example, previously performed tests. Alternatively, the color device 320 of the present invention can generate a signal to cause a message to be displayed to a user on, for example the motion picture cameras or an associated display, which requests required information regarding the dynamic range of a broadest range motion picture camera and/or a broadest range video content to be captured. In such embodiments, the information regarding the dynamic range of a broadest range motion picture camera or broadest range video content can be communicated to the color device 320 of the present invention. Alternatively, a color device 320 in accordance with the present invention can have information stored regarding the dynamic range of various capture devices, including the motion picture camera 310 and information regarding the dynamic range of video content to be captured. In addition, in an alternate embodiment of the present invention, the color device 320 can determine the dynamic range of a broadest range digitally captured video content or alternatively, can receive information regarding the dynamic range of the broadest range captured video content from the motion picture camera 320.
The color device 320 of the present invention can also separate received digital video content into color components such as red, green and blue components. As such, mapping can be performed to provide respective grey scale densities for any or each of the separated colors. Using the known densities between the colors, the color device 320 can provide digital color correction by providing density offsets for any or each of the separated colors as will be described in greater detail below.
In accordance with the embodiment of the present invention described directly above, in the color device 320, grey scale density values of the log video signal are to specific colors regardless of which image capture device is being used or what video content is being captured. As such, all video content captured by substantially any image capture device will be respectively represented by the log video signal and as such by the grey scale density values. With such an arrangement, similar color values in different captured images as captured by substantially any image capture device will have corresponding grey scale density values.
As described above, using the known densities between the colors of a received digital video content, the color device 320 can provide digital color correction by providing density offsets for the grey scale density values of, for example, any or each of the separated colors of the received digital video content. Such offsets can be linear offsets and can be configured to emulate the Printer Light correction of prior art analog color correction devices. For example, in one embodiment of the present invention, the linear density offsets can be configured to provide values typically between 0 and 50 to emulate the prior art analog Printer Light offset values.
In various embodiments of the present invention, specific grey scale density values of the log video signal representation of the present invention can be associated with colors of the digitally captured video content via a look-up-table (LUT). That is, in various embodiments of the present invention, (a) 3D LUT(s) can be provided in, for example, the memory 420 of the color device 320 for mapping the grey density values of the log video signal representation to respective colors of received video content. The look-up-table (LUT) which is applied to the raw digital camera data converts raw digital camera data to, in one embodiment of the present invention, canonical log.
As described above, a display conversion can be applied to the output of the color device 320 so that the digital imagery product (e.g., log video signal) is able to be viewed onset on a calibrated display device. The display conversion corrects the digital imagery product such that it can be displayed on a calibrated display device such that the image on the display matches what a final film print would look like if that same color correction would be applied during a final digital intermediate color correction process. That is, the of the on set color correction which produced the desired look on the calibrated display device is later applied to the raw log video signal to produce dailies, editorial, and preview elements which match what was displayed on set. The preliminary color correction can also be used as a starting point for the final digital intermediate color correction.
Furthermore, in accordance with the present invention, the output of the color device 320 can be used as a pipeline (transport device) for an intrinsically log video signal. That is, the color device 320 of the present invention outputs a log video signal that contains grey scale values of the received digital video content on, for example, a scene by scene basis. The log video signal provided by the color device 320 is a real-time log video signal. The log video signal provided by the color device 320 is communicated to the video tape recording device 340 for recording. As described above, the video tape recording device 340 can comprise separate storage sections (not shown) for storing a raw log video signal and a color corrected log video signal. The log video signal provided by the color device 320 comprises a low resolution and low compression signal, which is acceptable for producing digital dailies on, for example, the video tape recording device 340.
In one embodiment of the present invention, the color correction device 320 of the present invention comprises a user interface 325 for providing a user with a means for providing density offsets for each of the separated colors to accomplish color correction or adjustments. The user interface 325 of the color correction device 320 can comprise wireless remote controls, pointing devices, such as a mouse or a trackball, voice recognition systems, touch screens, on screen menus, buttons, knobs and the like. In addition, the user interface 325 can be provided directly on the color correction device 320 or on a remote panel or device. As such, digital color correction or adjustments can be made to the individual color components of the digitally captured video content via the provided user interface 325. Such offsets can be linear offsets and can be configured to emulate the Printer Light correction of prior art analog color correction devices. For example, in one embodiment of the present invention, the linear density offsets can be configured to provide values typically between 0 and 50 to emulate the prior art analog Printer Light offset values. As such, and because the log video output of the color device 320 of the present invention comprises at least grey scale values and information of the digitally captured video content on, for example a scene by scene basis, the digital color system of the present invention is able to provide reproducible digital imagery products which offer a quantitative assessment of the color components of the digitally captured video content and provide, as in prior art systems, repeatable and reproducible values from which a cinematographer/director of photography could order the color correction of the video content in a manner understood by a color correction specialist or “timer”. Furthermore, because in several embodiments of the present invention, the color corrected log video signal (e.g., digital dailies) are recorded on tape, the recorded video can be replayed again for further color correction or adjustment and such a process eliminates the need for the originally captured video content to be processed again to adjust a previously determined color correction or to determine an entirely new color correction.
In addition to providing log video signals for the purposes of creating digital dailies recorded by the video tape recording device 340, the digital color system 300 of the present invention can be used to determine an initial starting point for a final digital intermediate. That is, for the concepts of the present invention to be used directly for color correction, the “full range” calibration which was used during the dailies process must match the “full range” calibration used for calibrating the log video signal and grey scale density values for the digital intermediate. The physical dailies are not used as source material for the digital intermediate because the physical dailies media has the look of the dailies already preserved (e.g., “baked in”). The original uncorrupted source acquisition material (raw log video signal representation) must be used as the starting point for the digital intermediate.
More specifically, the digital color system 300 of the present invention can be used to color correct an entire original video content for final versions. Unlike in previous digital devices used for color correction where a video signal resulting from a correction process has to be custom processed for each application, the information used in the color correction of a digital color system of the present invention, specifically the grey scale values in the log video signal of the present invention used to create, for example, the digital dailies, can be used as a starting point or a reference point for a final color correction or adjustment of the entire original video content. That is, in accordance with the present invention, if the full range video signal (e.g., the raw log video signal representation before any initial color correction had been applied) is captured on, for example, a video tape (i.e., a separate recording section of the video tape recording device 340) during the dailies process as described above, then additional “creative” color corrections could be applied to this “raw full-range” capture without having to re-calibrate and process the original video content. This provides the creative types (e.g., the director and/or cinematographer) with additional opportunities during post-production stages to re-visit and modify the “look” of each shot, no longer being locked in and limited by the initial look imposed during the dailies process.
Even further, there are many low-budget productions and independent films which, for financial reasons, perform final color correction via a “video” workflow. If in accordance with the present invention, the video content is calibrated in “full range log” video as described above, then the entire latitude of the video content would be available for further creative modification during the color correction process.
In various embodiments of the present invention the printer lite emulation of the present invention is calibrated to a specific lab, so calling a particular set of lites matches calling the same lites at a specific lab. However, there is nothing to prevent a system in accordance with the present invention to be calibrated with any other specific laboratory's printer lites.
Having described various embodiments for a method, apparatus and system for providing reproducible digital imagery products of digitally captured video content (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments of the invention disclosed which are within the scope and spirit of the invention as outlined by the appended claims. While the forgoing is directed to various embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof.

Claims

1. A method for providing a reproducible digital imagery product of digital video content captured by a digital image capture device, comprising:

generating a log video signal representation of said digital video content using information regarding a dynamic range of at least one of said digital video content, a broadest range digital video content to be captured, said digital image capture device and a broadest range digital image capture device to be used to capture digital video content.

2. The method of claim 1, further comprising mapping a full range of said log video signal representation to said dynamic range of said digital image capture device.

3. The method of claim 1, further comprising mapping a full range of said log video signal representation to said dynamic range of said digital video content.

4. The method of claim 1, further comprising mapping a full range of said log video signal representation to said dynamic range of said broadest range digital image capture device.

5. The method of claim 1, wherein said log video signal representation comprises respective grey scale density values for color components of said digital video content.

6. The method of claim 5, further comprising providing respective density offsets for said grey scale density values to color correct said log video signal representation of said digital video content.

7. The method of claim 6, wherein said density offsets comprise linear offsets.

8. The method of claim 6, wherein said density offsets are configured to provide values between 0 and 50 to emulate analog printer light offset values.

9. The method of claim 6, wherein said log video signal representation is color corrected for a specific display environment.

10. The method of claim 5, wherein said log video signal representation provides grey scale values for the colors of said digital video content on a scene by scene basis.

11. The method of claim 1, wherein said log video signal representation is used to create dailies.

12. The method of claim 1 wherein said log video signal representation comprises a low resolution and low compression signal, which is acceptable for producing dailies.

13. The method of claim 1, wherein said log video signal representation is stored on a video storage device.

14. The method of claim 1, wherein said log video signal representation is stored on a scene by scene basis.

15. The method of claim 14, wherein said stored log video signal representation is used as a starting point for a digital intermediate.

16. The method of claim 1, further comprising applying a display conversion to said log video signal representation.

17. The method of claim 16, wherein said log video signal representation is able to be viewed on a calibrated display device such that the image on the display matches a final film print look.

18. A color device, comprising:

a processor and a memory configured to generate a respective log video signal representation of received digital video content using information regarding a dynamic range of at least one of said digital video content, a broadest range digital video content to be captured, a respective digital image capture device and a broadest range digital image capture device.

19. The color device of claim 18, further comprising:

a user interface configured to enable adjustment of density values of said log video signal representation to color correct said log video signal representation of said digital video content, said log video signal representation of said digital video content comprising grey scale density values for the colors of said digital video content.

20. The color device of claim 19, wherein said user interface comprises at least one of a wireless remote control, a pointing device, such as a mouse or a trackball, a voice recognition system, a touch screen, on screen menus, buttons, and knobs.

21. A system for providing a reproducible digital imagery product of digitally captured video content and color correction thereof, comprising:

a digital capture device configured to digitally capture said video content;

a color device configured to generate a respective log video signal representation of said video content using information regarding a dynamic range of at least one of said video content, a broadest range video content to be captured, said digital capture device and a broadest range digital capture device; and

a user interface configured to enable adjustment of density values of said log video signal representation to color correct said log video signal representation of said video content, said log video signal representation of said video content comprising respective grey scale density values for the colors of said video content.

22. The system of claim 21, further comprising a storage means for storing a color corrected log video signal representation.

23. The system of claim 21, further comprising a storage means for storing said log video signal representation from said scanning device before said color correction.

24. The system of claim 21, further comprising a display for displaying a converted log video signal representation such that the image on the display matches a final film print look.