Glenn Kennel

Digital Film Scanning and Recording: The Technology and Practice

This article reviews the design components of a CCD film scanner and laser film recorder. The key image-quality parameters are reviewed, including resolution, quantization, noise, and color. The subject of system calibration is explored. Issues that affect the exchange of images between facilities are described, including file format and image data storage. Some of the operational issues of digital film scanning and recording are also discussed.

High-Resolution Electronic Intermediate System for Motion-Picture Film

The production of motion-picture special effects can be a costly and time-consuming step in the production of motion-picture films. Although several electronic video systems have been proposed and demonstrated for use in special-effects generation, these lower-resolution video systems, including HDTV, do not operate transparently between film input and film output. They introduce a number of disturbing image artifacts to the final film element. This article defines the system requirements for a high-resolution digital image manipulation system that can be used to produce high-quality motion-picture special effects.

Noise in film-to-video transfers

Etude des diverses sources de bruit: bruit du au film, au systeme de telecinema, aux corrections gamma, gain, etc

Choosing Eastman Color Negative Film 5247 or Eastman Color High-Speed Negative Film 5294

Since the introduction of high-speed color negative films, the cinematographer is frequently faced with selecting between shooting medium-speed (EI-125) Eastman color negative film 5247 or high-speed (EI-400) Eastman color high-speed negative film 5294. As an aid in making this decision, several objective parameters are examined as a function of exposure. In addition, general guidelines are presented for choosing the most appropriate film for different exposing conditions.

Video Noise Reduction In Telecine Systems

A telecine is a motion picture scanner used to generate high quality video recordings of motion pictures. The noise characteristics of a telecine system were analyzed to determine a suitable scheme for reducing video noise across non-moving portions of a temporal sequence of images. It was found that while in principle median filtering is better than a scheme such as averaging, the improvement is not substantial and the simpler approach of averaging can very well be used.

Color Encoding for Digital Cinema Distribution

This chapter will describe the derivation of the color encoding and decoding matrices for digital cinema distribution. By the nature of the matrix math involved it is somewhat technical and probably of most interest to those interested in delving into the theory behind the color conversions.

Color Processing in the Projector

The color processing in the projector provides several functions. The first is a means to calibrate the projector so that the image on the screen matches the Reference Projector primaries, white point and peak white luminance. This calibration compensates for differences in the spectral characteristics of optical components in the projector, including the lamp, reflectors, prism and projection optics. It also compensates for environmental characteristics like discolorations introduced by the portal glass or the screen itself.

Digital 3D Presentation

Stereoscopic pictures, commonly called 3D, have been around for a long time. Binocular vision gives us the capability to perceive depth, with the brain decoding the depth information from the disparity between the images captured by the left and right eye. The first 3D movies were produced over 100 years ago, but they never caught on due to complexities in capturing and displaying stereoscopic pictures. The second wave of stereoscopic movie presentation occurred in the 1950s as moviemakers and exhibitors were seeking a new sensational experience to revitalize sagging attendance at the box office. Movies that exploited the 3D experience, such as “Bwana Devil” in 1952, “House of Wax”, and “Kiss Me Kate” played to avid fans. In 1953, 27 movies were released in 3D format, followed in 1954 by 16 movies, but this tailed off to one in 1955. Once again, the format was doomed by the complexity of dual camera rigs and the cost of double prints and dual projectors, each equipped with polarized filters. When a sophisticated movie was finally made in stereo it was too late, and Hitchcocks “Dial M for Murder” was released in flat format.

Reference Projector and Environment

Since the X′Y′Z′ color encoding for digital cinema distribution is an output-referred image state, it is critical that the reference projector that is used for the creative color grading decisions is characterized colorimetrically and calibrated to a common standard. Furthermore, because such imaging parameters as contrast and color gamut constrain what can be displayed, and therefore constrain the creative process, it is necessary to define some minimum performance parameters for the projector to be used in high quality mastering and cinema reproduction. The environment of the mastering room, particularly the ambient light, also influences the quality of the projected image.

Digital Display Technologies

In addition to DLP® technology, LCoS (liquid crystal on Silicon) technologies have been applied to large screen digital cinema presentation, including JVCs D-ILA™ (Digitally addressed Image Light Amplifier) and Sonys SXRD™ (Silicon Xtal Reflective Device) technologies. LCoS display technologies provide high contrast and high display resolution, with a high fill factor that minimizes the visibility of the structure evident in traditional transmissive LCD displays.