Colourisation

Coloursation (colorization) is the process of adding colour to footage which presently contains no colour data.

Footage of this type can fall into two categories, depending on the need to colourise, and the process is radically different:

1. Colour stripping, commonly referred to as Film_colorization is the process where the footage was iriginally recorded in colour, but then certain areas of the colour data was stripped out of the frame in post production to create the effect of a film noir, or monochrome footage with certain items in the frame retaining their colour. This has been used to best effect on films such as Sin City, Kill Bill and Schindlers List and is the common use for colourisation within the media industry at present.

2. Colour addition is the process of adding colour to footage which did not not previously contain any colour data and no colour data was recorded at the time of filming. The monochrome film stock, once digitised has marked out areas which have colour added to them. Examples of this have included Eisenstein's Battleship Potemkin where the flag on the battleship was hand coloured onto the film stock in one shot.

The process of colourisation involves a series of complex area tracks which are performed by computer known as Rotoscoping. This process of following a given masked area as it adjusts its shape across the shot relies on the use of Alpha, luma or colour data within the frame to determine the shape. With colour addition, this process is more complex as pixel tracking by luminance only often leads to haphazard results. Rotoscoping using this method is therefore labour intensive by the post production staff involved.

The technique is compounded further as colour information should match acroos the entire film. This is often difficult to achieve without a pervasive database of colour reference data used.

The interest in colourisation has seen an interest in resaearch roles dedicated to fashion and styles for specific periods in history as colourists attempt to be truthful to the look and feel of the orginal material.

The debate as to the morality is complex and presently is lead by negative views formed by bad colourisation attempts in the 80s and 90s. However, as technology has moved forward, the search for more fluid techniques and better standards continues. An 'Institute for Colourisation' has been created to search for a de facto standard in the technical process which will achieve the most effective results which the media industry can use.

A community of practice is being created on this subject, which is designed to stimulate debate into colourisation techniques and processes. The colourisation wiki - colourisation.net contains a series of related documents, links, research papers and test material to stimulae debate in this growing subject. For this community a Frappr Map is also available.