So, how does film preservation & restoration work?
Film Restoration & Preservation
This is the physical preparation of celluloid film prior to scanning and takes place in a film laboratory. It involves visual inspection, physical repair (when necessary), and chemical and / or ultrasonic cleaning.
This phase is the most important part of the preservation process as old film material can be volatile and extremely fragile – failure to do this could lead to irreparable damage to the material.
Once completed, the “clean” film goes for scanning.
This is where the film is transferred from film into a digital image sequence using either a telecine or scanner. The audio and picture are separated in this process.
Digital Picture Restoration
Once in a digital state, the picture is digitally repaired. This is both a manual and automated (to a degree) process using specialized film restoration software. Each frame of the film is restored, scratches and dust removed, the image is stabilized and so on.
Whilst the picture is being restored, the audio also goes through a similar process, which results in audio clean up, re-syncing and often replacing missing audio.
In most cases, closed caption sub-titles are required. Transcripts are created, and subtitles are laid down.
Once picture restoration is complete, the film goes through a colouring whereby colours are enhanced and the picture is given a general “facelift” before being mastered out.
The final step involves marrying the audio to the picture and creating the new master file from which any broadcast deliverables will be created. This master is then stored in cloud based asset archiving system.
 This gives the viewer the ability to turn sub-titles on or off.
Some sample work below: