Journal of Film Preservation - FIAF

the faded color image. Take the ferrocyanide anion as an example. It
reacts with the color developer paraphenyline diamine as follows:
In this reaction, the developer paraphenyline diamine is oxidized into
the equinone-diimine cation. In alkaline an developing bath, the coupler
gains an electron from the hydroxyl radical and forms a coupler anion,
as follows:
The quinone-diimine cation combines with the coupler anion to form
coupling developed dye, and the lost color has thus been restored.
2. Oxidation-development dual-bath chemical color-restoration
process
From these assumption, we began in 1976 to study the chemical
restoration of faded images with faded film copies on Agfa, ORWO, Geva
and color films stocks from the former Soviet Union of the type
identified as water-soluble color positive cine-film. First, the faded film
print is immersed in a solution of potassium ferrocyanide and other
compounds to effect the oxidation treatment, following which the film is
subjected to a color-developing bath. The results of experiments on
scores of films demonstrate that all of the prints subjected to this
treatment have show that almost all have been successful.
From table 1 and photograph 1, one can easily observe the
distinguishing features of the oxydation-development process:
(1) Through this treatment, density of the yellow, cyan and magenta
layers is substantially increased, by increments of 83.3%, 58.85%,
and 53.13% respectively.
(2) The densities of the three color layers in the image can be increased
or decreased to attain color balance through this treatment. For
example, the film Kim ok-hi, which manifest serious fading, showed
an increased of 53.8 % in cyan, 53.13% in magenta, and 32.47% in
yellow. Buddhist monk Ji-gone holds a cricket fight manifested slight
cyan fading as well as magenta fog. After the oxidation-development
color restoration treatment, cyan density was increased by 13.42%,
while yellow decreased by 2.85% and magenta decreased by 4.78%;
overall color balance was restored and the magenta fog disappeared.
(3) Following treatment, image sharpness is increased, color balance is
restored, and saturation is also increased.
41 Journal of Film Preservation / 58/59 / 1999
Color image restored with the oxidationdevelopment
dual-bath technlogy (comparison
before and after restoration) (cine film
“Blessing”)