Films are rarely viewed only in the 'film' cinema; many cinemas have already gone digital and many people see films at home via high quality DVD or via digital broadcasting, both SD and increasingly HD.

DI creates an edited and graded digital master from which it is easy to make the highest quality film deliverables as well as the highest quality versions for all other media.

At the same time a well-designed DI system can offer an easy and cost-effective path to create different versions (foreign language, etc.) as well as trailers and promotional requirements for the movie.

Digital Intermediate vs. Digital Film
The term Digital Intermediate describes a process that is nominally one third of the operation termed Digital Film. The other two thirds encompass acquisition [the obtaining of the source material through some form of capture] and presentation [the distribution, projection and/or transmission of the final result - also known as D-Cinema or e-Cinema, although D-Cinema tends to specify high-resolution theatrical imagery (films) and e-Cinema any alternative electronically projected product (concerts, sports events, etc.).

These three processes are all independent of one another, and inclusion of one process in a project doesn't immediately require the involvement of the other two. Therefore, digitally acquired material can just as easily be projected via traditional celluloid means as via a digital projector and equally as likely film originated material may be shown digitally via a digital projector. The Digital Intermediate [DI] process is therefore applicable for traditional film projects [acquired and presented] as well as those classified as 'digital', through the use of digital capture or projection techniques. The DI process is chosen on the benefits it provides for the project in question, not the use of any additional digital technology elsewhere within the project.

Digital Intermediate vs. Traditional Chemical Lab
The traditional chemical film post-production chain accepts original camera negative (OCN) and, after copying, editing, grading, the generation of optical effects, etc. produces a number of internegatives from which the release prints are made.

Traditional Chemical Lab Workflow (simplified)

DI realises a digital form of the chemical lab, producing a timed intermediate from which distribution prints can be generated. The key to realising a Digital Intermediate is to edit, grade and add VFX in the digital domain, requiring the film negative to be scanned once, and thereafter no further manipulation of the negative is required. From this point onwards the DI process is loss less.

Typical DI workflow (simplified)

The DI Process
If we accept that the DI process aims to digitally master a film in its entire form there are a number of parameters any DI system must be able to meet, assuming major compromise is not acceptable.

• Provide controlled input to output calibration, including working with different colour space, bit depth, resolution & format images.
• Hold an entire film [with handles and variants] in full film resolution [2K, with possibility for 4K].
• Autoconform from an offline edl with ability to compare online to offline for verification.
• Playback the entire film project in real-time, with temps/animatics/previews as necessary, at full resolution.
• Display the film images in true ‘film’ colourimetry, contrast, gamma, etc.
• Respond immediately to changes for review and sign-off.
• Perform the basic functions necessary for a DI operation to proceed including editing, opticals, colour correction, vfx work, titles, etc.
• Work with accepted technical image parameters to present a final image quality acceptable as 'film'.
• Be able to output all deliverable formats for a single editorial and grade Master, including film’ D-Cinema, HD video, SD video, DVD, foreign language, director’s cut, the making of, etc.

From this it becomes apparent that the DI process cannot simply be described as a digital equivalent to a traditional chemical Lab. The parameters within which the DI system must be able to operate if it is to function acceptably require more understanding and thought. The steps that must be taken to get material into and out of the lab are, by definition, open to more options. And the entire process needs to be calibrated throughout and provide the necessary tools to perform the required DI functions.

Capabilities - More than just Colour Correction
One of the biggest misconceptions of Digital Intermediate operations is that they are totally focused on colour correction. This view has been sustained, in part, by system manufacturers themselves as many offerings purported to be DI systems are capable only of colour correction.

This misnomer can be the biggest restriction for DI operations built around this single concept. The reality is that true DI requires many tools and capabilities if it is to be able to perform DI work in a cost effective and viable way, including:

• Full editorial capabilities, including edl autoconforming, manual edit changes, wipes, dissolves and custom transitions, re-order edits, replace shots, etc.
• Compare online to offline via visual comparison – i.e. real-time and simultaneous split screen
• Text capabilities for lower thirds, titles and credits
• Paint and retouch for image repair
• Ability to work with any image format, including high resolution data, HD video, SD video, etc.
• Full colour correction including primary correction, secondary, selective control, tracking based correction, etc.
• Versioning and playout in real-time, including Pan & Scan

Multiple Deliverables

Applications
While to many people the term Digital Intermediate immediately refers to the generation of a full feature film using digital post-production technology this is not an exclusive application, although it is the arena within which DI has initially evolved.

The processes used with the DI 'film' world are just as applicable in the commercial and promo's world where the prospect of enhanced quality and creativity combined with ultimate flexibility is extremely appealing, regardless of the destination format.

Therefore, the DI process can be applied throughout the moving image world, not just for direct 'film' applications, although it is this primary market that the concept of DI has grown up around.

• Feature film post-production and mastering
• Trailer post-production
• Commercials post-production - TV and cinematic
• Music video post-production
• Promo post-production - for cinema and TV
• Feature film restoration
• Multiple release format single mastering - film, D-Cinema, DVD, HD, SD, etc. from the one DI master

Benefits
The digital Intermediate process, in its most basic form, can be considered as a replacement for the opto/chemical film lab environment offering digital neg. cutting from offline edit information, optical transition processes such as wipes and dissolves and film grading aimed at producing the equivalent of a timed intermediate from which distribution print can be generated.

This base level of operation is the heart of a Digital Intermediate Lab and through its ability to provide enhancements throughout the process can be a strong enough reason to be chosen in preference to the traditional chemical lab.

The additional benefits it offers can make its choice yet more compelling, and range from almost unlimited flexibility, with multiple variations available for assessment immediately, without need to process and project film, to a guarantee of quality regardless of the number or complexity of optical process undergone. To be able to sit within a DI environment and see, interactively, changes as they are made, is a film Producer's/Director's/DoP's dream. To be able to try a dissolve between two scenes, followed by an alternate wipe to assess the difference is an impossibility outside of the DI environment for film projects.

Additionally, a DI environment is able to provide all deliverables from the single DI master, including: film internegative master, digital projection master, HD and SD video masters, DVD master, trailers and promo material including high and low resolution requirements such as print media and web content.

In general, the things taken for granted for years within the longform video market have been all but impossible for film based projects, but through the use of DI are now available to all.

And compared to a traditional film grading or timing station, where the operator's screen is about 6" wide, often of indeterminate playback speed with variable colourimetry compared with the final print, requiring ‘interpretation’ by the film timer, a DI environment can offer editorial and grading decision making via a D-Cinema digital projector on a full size theatre screen with real-time 2K playback.

Benefits for the Director
• Ability to see the entire project at an early stage
• Complete flexibility for change, even after the offline is finished
• Review changes instantly on a large screen
• Greatly improved colour enhancement tools without going through the vfx pipeline
• Simultaneous multiple versions including foreign language and the ‘Director’s Cut’

Benefits for the DoP

• Cinematic editorial and grading environment
• Retain compete control over the look and feel throughout post-production
• Sophisticated colour enhancement available on every shot
• Complete colour control over different format deliverables
• Maintain high quality irrespective of the number of ‘opticals’

Benefits for the Producer

• Reduce the time taken for post-production
• Reduce the costs associated with late changes
• Quickly produce multiple versions for audience testing
• Quickly produce all the different format deliverables

Benefits for Production

• Reduce post-production costs and time scales through single mastering for all deliverables
• Easy project tracking and management
• Enhanced quality control for all deliverables
• Improved security capabilities

Benefits for Post-Production

• A new service for its clients generating new revenue
• High level creative work plus multiple deliverable production
• High profile, growth business
• Infrastructure and expertise requirements limit competition

Benefits for Film Laboratories

• Leverage existing relationships and expertise
• Develop current business by adding new services
• Protect revenues by digitalising current services, e.g. HD Dailies
• Position business for the increasingly digital future

A Typical DI Environment

For more in-depth information please review the "Technical Papers" within the links above.

Toys!