Digital Intermediate

The Digital Intermediate ( DI) is a digital intermediate in the post-production of films between ingested and ausbelichtetem film. In a first step for this purpose the received analog to camera negative film is scanned using a film scanner. Alternatively, the digital images a digital cinema camera be used directly. The resulting material is digitally cut and edited ( color correction, CGI, etc.). This produces the so-called DI - Master, which serves both as a template for subsequent digital evaluation (DVD, HD DVD, Blu -ray disc), as well as for the production of copies / master for the analog or digital cinema projection. To create analog film prints, the DI is exposed on negative film and copied the resulting internegative in the lab. Alternatively, a digital master in accordance with DCI is created for digital cinema projection.

Technology

The DI is usually stored in uncompressed frames. The time and memory requirement depends on the chosen resolution and color depth. Typical resolutions for photochemical film prints are 1920 × 1080p, 2K ( horizontal depending on the format from 1860 to 2048 pixels) and 4K ( horizontal depending on the format 3612-4096 pixels). For the digital performance are 1080p and the specification of the Digital Cinema Initiative market- determining.

The number of vertical pixels is dependent on the aspect ratio of the selected frame format and the exposed area of the camera used.

2K and 4K

The classic 35-mm projection reached in an independent test by the International Telecommunication Union, a maximum image resolution of 875 horizontal lines ( light-dark change). The lion's share of all film productions will be processed in 2K. Sometimes it is qualitatively useful to work with 4K resolution and perform.

From 1990 to 2007 hundreds of feature films were mastered in 2K, now almost a dozen in 4K. Even in the digital cinema are thousands 2K screens worldwide so far, compared with only dozens of 4K cinema.

Due to the availability of new digital cinema cameras with 4K resolution as the RED camera, experiencing the 4K production a much more widespread than before.

The market share of 2K editing of feature films since the 90s is constant over 95%. In some cases, higher resolutions are used, especially for visual effects and restoration etc..

Data volume

The costs incurred for DI data volumes and data rates were originally only using specific computer systems conveniently editable, since they are in the range of terabytes.

As image data formats are used:

Instead of RGB color space of the XYZ color space is used in current productions that can represent all the existing colors. The gamma value for gamma encoded signals is 2.6. Audio is generally stored in an uncompressed 24-bit.

The memory requirement for a 3 × 10-bit RGB gamma -encoded production (without compression) with 24 frames per second is:

The amount of data and data rates are computed for the smallest RGB format (3 x 10 bits). At higher color depths (which are sought ), the memory requirements increase. By lossless or nearly lossless compression techniques can be the memory requirements by about a factor of 2 reduction.

The space requirement refers to two hours edited movie. But you have to be aware that, as part of a film production in multiples of this amount is outstanding:

  • The produced video material on the set is usually in the 10 - to 50-fold runtime of the final film.
  • In the editing process created in addition to the final release many intermediate results and alternative interface versions.
  • You also want to be able to access without any effort on source material from other films, that is, one wants to be the total footage of all productions of the studio in a huge pool have ( so-called image library).

History

Meanwhile, the DI method has prevailed. Movies that are copied directly from the negative without digital intermediate step, have become a rarity. Of the world's ten most successful films of the year 2006, the three animated films have been completely digitally created ( in this case results in a DI master without the step of sampling); the remaining seven live-action movies, three of which were partially and fully shot digitally are copied all over the DI master.

Operations and equipment

A working chain of the Digital Intermediate typically consists of three steps:

  • The digitization of the images of a rotated film with a film scanner or alternatively direct digital turning with a digital cinema camera
  • The editing of the film with a digital intermediate system
  • The Ausbelichten the edited film on a film recorder, respectively, the creation of a Digital Masters

Links the supplier of DI systems

There are (as of 10/2007 ) only a dozen suppliers of DI systems. The smaller players have no sales within the EU.

  • Movie light base light
  • IRIDAS SpeedGrade
  • Davinici different devices, also focus restoration
  • Dvs clip art
  • Apple color
  • Discreet luster
  • Chrome matrix
  • Assimilate scratch
  • Nucoda master series
  • SGO Mistika
  • Pogle different devices
Digital movie camera Computer Generated Imagery Digital Cinema Initiatives 4K (resolution) Red Digital Cinema Camera Company Snow White and the Seven Dwarfs (1937 film) Hollywood Spider-Man 2
290488
de