Abstract: An algorithmic based method and apparatus for registering halftone color separations using edge based registration techniques. Digital pictures are taken at two locations on each film, and, following optimal thresholding of the data, the edges are located by application of a Laplacian of a Gaussian edge detection operator. Sampling is used to reduce the computational requirements, and full resolution is restored by interpolation. The edge locations are corrected for operator edge bias, and the corrected edge points are linked into segments which are registered by the parameter space method. The initial offset is corrected for size differences by application of least squares correction techniques.

Abstract: A method and apparatus for registering the halftone color separation films used in color picture processing. A digital picture is taken of two register points on each separation film, and the pictures (which may contain register marks) are analyzed by algorithmic processes in order to calculate the movement necessary to register the halftone picture details (or register marks). Based on the calculations, the films are punched to provide a pair of register holes in each film at locations which result in registration when the register holes are aligned on register pins during the final reproduction process. The algorithmic process involves determining the halftone screen angle, average interdot spacing and fractional area occupied by each halftone dot within its halftone cell and using this data to construct a continuous tone picture. Interpolation techniques are used to interpolate the continuous tone picture to a registration picture which is a 150 line screen picture square with the raw data picture.

Abstract: An image projector has a pulsed or similar light source of high intensity and high heat emission housed in an opaque box having a light-diffusing glass panel in its forward side which is spaced behind a vacuum film-holding plate having a glass center. Between the box light and the film-holding plate is a compartment which is open on the front and back and is sandwiched between the light diffusing glass panel of the box light and the film-holding plate such that no light escapes into the room. Said compartment thus comprises an isolation chamber which passes light to the film but not heat. The box light and the isolation chamber each has its own blower system and independent, specially baffled vents such that air between the two does not intermix. The vents are so designed as to permit discharge of the air but inhibit the egress of light therethrough.

Abstract: In a vacuum film holder, a mounting plate for situating film registration pins at locations coinciding with the vacuum channel which holds the film against the glass pane covering the center of the film holder frame. The plate bridges the vacuum channel and fits partially in a groove formed in the frame and partially in an aligned notch formed in the glass. Locator pins and cooperating diamond-shaped pins on the plate fit in holes drilled through the frame within the groove to assure proper location of the registration pin in coincidence with the vacuum channel. A special tool permits the plate to be easily removed without damaging the glass of the film holder.

Abstract: A special front lighting system for use in a relatively narrow room in which a large track mounted camera photographs subjects held on a subject holder. A pair of light sets located on support panels on opposite sides of the optical axis of the camera emit diverging light beams in opposite directions toward the side walls of the room. Mirrors are situated in the paths of the light beams to reflect light onto the subject holder with the same effect as imaginary light sets emitting beams directly toward the subject holder from locations outside of the room beyond the side walls. Light containment shields extend between each light support panel and mirror. The components of the lighting system are contained on self-supporting stands, each of which includes one light support panel, one light shield and one mirror panel hinged or otherwise held in a fixed position together.

Abstract: In a large, track mounted industrial camera or projector, a leveling arrangement for maintaining the track rails level when their support beams deflect under the influence of the weight of the camera and the rail mounted carriage which carries the camera toward a subject holder at one end of the track. Each rail is mounted on a rail base held down on the underlying support beam by a series of hold down screws. Adjustment screws are threaded through the rail bases and rest on the beams at their lower ends to control the distance of the rail bases above the beams. Each adjustment screw can be independently adjusted to compensate for beam deflection under actual loading conditions and for the variation in beam deflection along the length of the track. The overall track structure is stiffened to reduce beam deflection by an internal cable support structure secured to the rails and by a canopy secured to the beams.