| 摘要 |
PURPOSE:To attain accurate reproduction, by picking up a negative photo film with a video camera, and performing the gamma correction of a photosensitive characteristic of the photo film in observing the film as a positive with a monitor receiver. CONSTITUTION:In the figure, 1, 2, 3 are picked up elements generating red, green and blue color signal components, e.g., charge coupled device (CCD). The outputs of the CCDs 1, 2, 3, are sampled at sample hold circuits 4, 5, 6, applied to A/D converters 7, 8, 9 and digital color signals DR, DG, DB are obtained. The relation between the signal voltage V of the color picture tube and a light emitting output L is L KV , where K is a proportional constant and gamma= 2.2. Taking the relative level of the chroma signals DR, DG, DB as (x) and the relative level of the chroma signals Dr, Dg, Db after gamma correction as (y), a data table performing the gamma correction of y=x1/ is stored in an ROM21. Through the gamma correction, a linear relation is obtained between a signal voltage (v) and the output L. |
