ECLAIR Group LABORATOIRES NEYRAC FILMS RD Programme NITROSCAN

ECLAIR Group LABORATOIRES NEYRAC FILMS R&D Programme ! NITROSCAN ! &

LABORATOIRES NEYRAC FILMS HDTV & Digital Cinema The general implementation of HDTV Broadcasting and ECLAIR Group Digital Cinema implies a very high quality films argentic remastering. To address this constraint and consolidate its leadership position in the field of film archives restoration, Laboratoires Neyrac Films (LNF) has launched the following two researches projects. NITROSCAN, subsidised by the French National Centre of Cinematography (CNC), is a plan of building of a specific scanner to digitize film’s archive. Its particularity lies in the fact that it scans directly the original nitrate without having to deal with safety intermediate as it is usually the case today. Improvement of quality (wet scan of the original) and a reduction of the expenses (operations are simplified) are the two main expected benefits of this technology. ! NITROSCAN ! RESONANCES is a project dealing with digital sound restoration. Subsidized by ANR (Agence Nationale pour la Recherche) and led by the University of La Rochelle in partnership with the CMM - Ecole des Mines (Center of Mathematical Morphology of the Paris School of Mines), LNF and CNC. This project has the very specificity to treat the sound – i. e. the “picture” of the sound - graphically. Like Nitroscan, this technology will allow for quality improvement, whilst reducing the improvement cost of digitization thanks to simplified operations. bbbbbb

SHORT HISTORY OF FILM BASIS Nitrate, Acetate and Polyester Cellulose nitrate was the first plastic invented by man. Its excellent mechanical properties and its flexibility allow it to be used in rolls. Since the birth of cinema in 1895 and up until the beginning of the 1950 s, films were made on a nitrate cellulose basis. However, Nitrate based films not only degrades inexorably by depolymerization, but, decomposed cellulose nitrate is also highly exothermic and self combusts with the release of hazardous gas emissions. After 1950, production and use of nitrate film stock were forbidden. Film Archives throughout the world had to safeguard abandoned nitrate films, transferring them onto a safety base for access. After 1950, the film basis shifted from nitrate to acetate, which has the great advantage of a low flammability at 430° C. However, acetate filmstock is also subject to a precocious decomposition, known as the “Vinegar Syndrome”. Since 80 s polyester film is used for prints and intermediates. To restore a film, on first have to make the film basis easy to manipulate. Films going through decomposition are dried in a desiccant containing silica gel which absorbs the water, thus stopping the acid emission through the absence of hydrogen. As for the brittle sticky films, they are humidified and made flexible in a desiccant, a mixture of the three solvents of nitrate and acetate bases.

PHOTOCHEMICAL RESTORATION Repairing Thanks to these repairs the film becomes “printable” and can hence be moved and transported via the pins of a printing machine. Negative Fragile or visible splices are mended or redone. Torn perforations or missing edges are reconstructed. Shrinkage is measured to co-ordinate it with the necessary adjustment on the printing machine. In the worst-case, the frame may be torn and must be repaired.

PHOTOCHEMICAL RESTORATION Printing the interpositive Thanks to these repairs the film becomes “printable” and can hence be moved and transported via the pins of a printing machine. Repairing Negative Grading Once reconstructed and repaired, the original negative is graded, which means that a level of light is determined for each shot of the film. Cleaning The film is then cleaned to eliminate the incrusted dust on its base. Wet and continuous or optical step printing ? The next step is to proceed to its printing by immersion, in order to eliminate the scratches. Depending on the quality of the repaired film basis, frames, will be either transferred on a contact or a step printer for photo-chemical restoration or on a continuous or an alternative scanner for a digital restoration.

PHOTOCHEMICAL RESTORATION Continuous printing In the case of continuous printing by contact, the matt sides of the two films are placed one again the other, driven by a sprocket, and scrolled in front of limelight. Light source Shiny side Original Matt side Print Shiny side Moving

PHOTOCHEMICAL RESTORATION Continuous printing This method is only possible if the print to be transferred does not have too much shrinkage, otherwise the sprocket could harm the film. Whilst this method is rapid, it remains limited to the material with few shrinkage. Sliding and tear

PHOTOCHEMICAL RESTORATION Optical step printing Print Duplicated PICTURE This method can be used if perforations are not too damaged and if the bit of play is not too important to guarantee a good stability. In optical step printing, the shrunk master is projected and enlarged on the new basis, frame by frame. The transport is not longer done by a sprocket, but by a pin, the space being set to the shrink of the original. Lenses Original PICTURE Shutter Light source Setting Original Otherwise, it might be necessary to move each picture manually with the help of an optical collimator.

PHOTOCHEMICAL RESTORATION Consequences of scratches During the printing, the scratches that affect the original diffract the light of printing and provoke a shadow area on the copy. Light SCRATCH Shiny side Original Matt side Print Shiny side Shadow area

PHOTOCHEMICAL RESTORATION Consequences of scratches To eliminate this phenomenon, the printing is done by immersion in a product having the same index of refraction as the film basis. This process allows for the elimination of all scratches on the shiny side of the film basis. It can be equally efficient on the matt side of the basis if the image information is still present. Light Shiny side Original Matt side Print Shiny side Liquid immersion

PHOTOCHEMICAL RESTORATION Printing the interpositive Repairing Negative Grading Cleaning Interpositive Printing Processing After processing the first intermediate film called interpositive is obtained.

PHOTOCHEMICAL RESTORATION Printing the internegative The dupe-positive is cleaned in order to eliminate dust … Cleaning Negative Printing Processing Interpositive Internegative Then it is printed … … and processed. This is how the second intermediate film, called internegative is obtained.

PHOTOCHEMICAL RESTORATION Printing the restored print The internegative is in turn graded in order to refine the photographic quality of each film shots… Grading Negative Cleaning … then after cleaning … Printing Interpositive Processing Internegative Print … the internegative is printed … … then developed to obtain the first restored positive print.

NITROSCAN The digital way Negative NITROSCAN Interpositive Internegative Print Photochemical Way The classical photochemical process described above implies a successive making of an interpositive, an internegative and a positive print. In the digital way, the restored negative is no longer printed but scanned to be converted into digital. For that LNF developed a special scanner adapted to film archive characteristics. Thanks to NITROSCAN even the most fragile films can be scanned by immersion, including all formats from 16 mm to 70 mm without even being dependent on the use ofperforations. It is hence no longer necessary to repair the damaged perforations before scanning a film !

NITROSCAN The « Five » archive films characteristics criteria As the printers machines, two kinds of scanners machines are existing, continuous and optical step. But often these scanners are not particularly adapted to the specific problems of old films. On the contrary, Nitroscan is designed on the five major film archive characteristics. 1. Deeply scratched elements 2. Shrunken or warped elements 3. Various or none perforations 4. Fragile or brittle elements 5. Substandard formats

NITROSCAN 1. Deeply scratched elements To get rid of dust Dust detection The digital treatment of scratches is very difficult. In fact, digital restoration automatically uses as references the frame immediately before and after the frame to be restored. Dust detection for instance will be confirmed if the preceding and following frames do not show a similar object in form and density in the same area. The system is very efficient.

NITROSCAN 1. Deeply scratched elements To get rid of scratches Scratch detection On the other hand, detection of scratches with their vertical specificity is very delicate since in most cases these can also be found on neighboring frames. This is even worse when the photographic composition of images carries numerous vertical lines which are difficult to differentiate from scratches. If automatic detection is tricky, restoration is even more so as the information which constitutes the image no longer exists on neighboring frames. The scratches which are part of the picture must be recreated through interpolation. Whilst a scratch even bothersome is tolerated in a cinema screening, a badly digital corrected scratch is really disrupting. To reduce considerably subsequent digital restoration, the scanner must be equipped with an efficient system for removing scratches. Telecinemas and scanners used nowadays are equipped with integration sphere lighting. Diffused light is unfortunately not adequate for the deep scratches frequently met in old movies.

NITROSCAN 1. Deeply scratched elements The only efficient way known today to eliminate scratches is to use a total immersion system as already used in photochemical treatment when making copies. Perchlo extraction Perchlo detection Immersion tank

NITROSCAN 2. Shrunken and warped elements Glass pressers The perfectly linear transport of a warped film during the acquisition is risky, so we choose to scan frame by frame. Consequently, a glass plates system flattens the film during the time the film is exposed to a matrix captor.

NITROSCAN 3. Various or none perforations Because of the damaged or nonexisting perforations and the various kinds of formats existing for old films, LNF designed a driving system independent of pins and sprockets. The film driving system works through a capstan, coupled with image processing with a shape finder to get the final target position frame by frame. Capstan driver

NITROSCAN 3. Various or none perforations The operator choose the reference algorithm which will be used : a frame spacing, a perforation or a detail in the picture. Once the point of reference has been located, the advance of the film is managed for a theoretical image height of a given frame. Recognition of forms: frame spacing

NITROSCAN 4. Fragile or brittle elements The driving system has been devised to scan damaged films to avoid complex and long preliminary film repairs. As these unrepaired films can be extremely brittle and as their processing must be very supple, the rotation of the capstan uses a gradual speed. To limit stresses, supply and take -up reels are not equipped with tension arm or dancing rollers. The angular speeds are measured with encoder on the shafts of the feed, take up and capstan. This allows adjusting the torque depending on the reels diameter and the limitation imposed by the mechanic stress on the film. Angular speed measurement

NITROSCAN 5. Substandard formats Adaptable holders NITROSCAN is designed to scan all gauges between 16 mm and 70 mm. Unwinding and winding film systems are adjustable on the level of the platters and guiding rollers.

DIGITAL RESTORATION Processing Negative Storage Negative NITROSCAN Interpositive Internegative Print Photochemical Way The files obtained by the scan are transferred on a server. From this storage, the data are available on workstations equipped with specialised restoration Processing software.

DIGITAL RESTORATION Processing Visible splices Dust Decomposition Tears Scratches Colorimetric correction …and stabilisation and flickering

DIGITAL RESTORATION Shooting Negative Storage Negative NITROSCAN Interpositive Shooting Internegative Print Photochemical Way Processing After restoration, the images are back on the server from there they can be directed towards the imager for the shooting operation in order to directly obtain the internegative and the restored print.

RESONANCES Digital Sound Restoration Original sound RESONANCES, is a project dealing with digital sound restoration. Subsidized by ANR (Agence Nationale pour la Recherche) and led by the University of La Rochelle in partnership the CMM - Ecole des Mines (Center of Mathematical Morphology of the Paris School of Mines), LNF and CNC. Scan and digital graphic sound restoration Restored sound

RESONANCES DV, VA then Digital Since 1930, and the advent of talking motion picture, the sound track of the motion picture is recorded on the photographic film emulsion, beside the picture, as a visible recording of the modulation. SDDS SRD At the beginning, the modulation was recorded by making density variable (DV) Then density was made constant and it is the variable area (VA) of the transparent zone that carried the modulation. DTS ANALOG VA To day, the analog soundtrack of the copies is still existing in variable area beside digital SRD, SDDS and DTS.

RESONANCES Negative noise and distortions The simultaneous transfert of the picture and the sound on positive copies by means of the printing machine needs a negative sound master. Only positive optical sound can be read by the analogical projector's sensor. It is not possible to read a negative optical sound without noise in silences and harmonics distortions in high frequencies which cause hisses and sibilants. Negative noise is caused by the predominantly transparent area in silence which lets through an important bright flux and as a result an important background noise owed to thermal agitation of the photoelectric cell and the reading of the impurity of the support (grains, physical defects and dusts). After printing, the positive silence area is coloured black and stands in the light way and then limits noise quantity corresponding to breath. Corrected peaks Swelled peaks Filled slacks Negative optical sound deliberately overexposed Optical sound printing Peaks and slacks correction Positive optical sound corrected by printing Corrected slacks The distortions of negative sound track are wanted. In fact, during the negative sound track recording an overexposure is deliberately applied (swelling of peaks and filling of slack periods) to compensate for the inverse phenomenon of diffusion which occurs during printing positive sound (erasing the peaks and digging slack periods). The printing of an intermediate element is therefore necessary to read an negative optical sound and extract low frequency modulation.

RESONANCES Original negative treatment Nowadays, digital sound restoration is processed after transforming the positive optical sound information into an electrical signal. However algorithms of digital process have difficulties to discern real from parasite sound, i. e. the slam of a door from a defect caused by dust. The soundtrack can be damaged by scratches, because it is close to perforation, or mould. RESONANCES proposes to treat directly the original negative soundtrack without the printing of a positive soundtrack. RESONANCES proposes an effective automatic treatment directly in the image field of the optical negative or positive sound track. Indeed, the graphic representation of sound track offers considerable assets : - The defects which we have just evoked are visible. A long vertical scratch or a side mould could not be part of the initial sound. There is no need to know the sound equivalence of the image to treat it. - In variable area the tracks are symmetrical, which is normally not the case for defects. Similarly, in variable density, the restoration can be based on the fact that at every moment the sound should correspond to a horizontal segment of width and level of grey. Scanner audio

RESONANCES Digital Graphic Sound Restoration

YESTERDAY RESTORATION Photochemical restoration Film screening Negative Repairs Interpositive Printing Internegative Printing 35 MM

YESTERDAY RESTORATION Photochemical restoration Film screening Negative Repairs Interpositive Internegative Printing Digital restoration Internegative Scan or TC Restoration Shooting Print 35 MM

NITROSCAN WAY ! NITROSCAN ! 1. Original picture film repairing to be moved via the printing machine pins 2. Original picture film wet printing to obtain interpositive scanning 3. 1. Interpositive scanning 4. 2. Picture digital restoration 5. 3. Internegative shooting original scanning for

NITROSCAN WAY Photochemical restoration Film screening Negative Repairs Interpositive Internegative Printing Digital restoration Internegative Scan or TC Nitroscan Restoration Shooting Print 35 MM

RESONANCES WAY 1. Film sound repairing to be move via the reading sound machine pins 2. Original sound film wet printing to obtain positive sound necessary to be read 3. 4. Sound reading and digitizing 2. Simultaneous sound digitization Digital sound restoration and restoration 5. 3. Optical sound transferring

NITROSCAN & RESONANCES SYSTEM Synchronisation Picture restoration Sound restoration Negative sound Negative Resonances Nitro. Scan Restoration Resonances

NITROSCAN & RESONANCES SYSTEM VOD PAD DVD JPEG 2000 Synchronisation Picture restoration Sound restoration Negative sound Negative Resonances Nitro. Scan Restoration Resonances

NITROSCAN & RESONANCES SYSTEM VOD PAD DVD JPEG 2000 Synchronisation Picture restoration Sound restoration Negative sound Negative Resonances Nitro. Scan Restoration Resonances Photographic or Electronic Preservation?

NITROSCAN & RESONANCES SYSTEM PHOTOGRAPHIC OR ELECTRONIC PRESERVATION ? Lascaux : 187 centuries Photographic : 5 centuries Electronic : 0. 3 century ?

NITROSCAN & RESONANCES SYSTEM VOD PAD DVD JPEG 2000 Synchronisation Picture restoration Sound restoration Negative sound Negative Resonances Nitro. Scan Restoration Resonances Analog or Digital Shooting Preservation ?

NITROSCAN & RESONANCES SYSTEM ANALOG OR DIGITAL SHOOTING PRESERVATION ? « They keep well what is humanly visible » Peter Adelstein Image Permanence Institute of Rochester In five centuries the world and the men vision will still be analogical. Hence in five centuries, whatever its degree of complexity, technology will always have to allow for the pick up of analogical pictures of the world and, even more so, of analogical pictures stored on films. It is less sure whether signs encoded today will be equally useful in future.

NITROSCAN & RESONANCES SYSTEM VOD PAD DVD JPEG 2000 Synchronisation Picture restoration Sound restoration Negative sound Negative Resonances Nitro. Scan Restoration Resonances Sound Shooting Preservation ?

NITROSCAN & RESONANCES SYSTEM SOUND SHOOTING PRESERVATION ? Picture preservation solution is applicable for the sound because it is a picture too. Picture D O S L D B D Y S D A N A L D O T G S Sound Picture and sound shooting on one and the same photographic polyester support must occur in the same recording operation. Sound shooting should be both analogical and digital, (sites exist and differs), analogical for mono or stereo versions, and digital for multi-channel versions.

NITROSCAN & RESONANCES SYSTEM VOD PAD DVD Digital production JPEG 2000 Synchronisation Picture restoration Sound restoration Negative sound Negative Resonances Nitro. Scan Photographic preservation B&W Selections Restoration Resonances Red selection 35 mm Cinema Green selection Blue selection Print Picture & Sound Shooting

THE END Thanks to Pathé for his collaboration and Bourvil & Jean Gabin for their exceptional participation LNF Éclair Group – Nitroscan & Resonances – Christian Comte 28/09/2009 - www. nitroscan. eu