This invention relates to a color control simulator for a picture reproducing machine, and more particularly to a color control simulator for obtaining proper color control conditions such as density correction, color correction, gradation correction and output intensity correction for a picture reproducing machine for making color separation printing plates.
In the prior art, a picture signal picked up from an original picture is separated into color separation signals of primary colors such as red, green and blue, and then the color separation signals are controlled in order to obtain color control conditions in a picture reproducing machine such as a color scanner. The color control conditions for the picture reproducing machine depend on fundamental conditions such as color balance, highlight and shadow densities of an original picture, requests from clients, and so forth, and thus they are determined by an operator according to his experiences by controlling adjusting means such as potentiometers.
However, it is very difficult to set up the color control conditions of a particular picture, for example, seasonable impressions such as autumn tints, and cherry blossoms, and recollection images in mind such as skin of a man, a grass blade, and sky. Hence, the color control conditions are set up while the output values of the picture reproducing machine are observed through a monitor.
When such a particular finish different from a standard one is required, as is often the case, the setup of the color control conditions for the particular picture involves time investment. Further, an unexpected color image is often obtained owing to a mistake of the operator, characteristics of the picture reproducing machine, or the like.
In order to overcome the aforementioned disadvantages, a machine for setting up color control conditions has been developed, wherein in order to reduce the manual steps as far as possible, the fundamental conditions of a standard picture are input into a computer and are operated therein, thereby obtaining the color control conditions, and wherein the adjusting means are automatically set up according to the color control conditions obtained.
Such a machine is effectively operated when a standard finish is required from a standard picture. However, this machine need the measurement of the density values and so forth, corresponding to highlight and shadow points on the picture as the fundamental conditions of the picture. Accordingly, as is often the case, pictures having no distinct highlight and/or shadow points cannot be processed by this machine.
In the conventional machine, the characteristic differences among the picture reproducing machines to be used are not considered, and thus the picture reproducing machines cannot be used to best effect in parallel with this conventional machine. Consequently, in this case, a particular picture apart from the standard one is processed, the color control conditions of the picture which is mounted to the picture reproducing machine should be determined by adjusting the adjusting means while the output values of the picture reproducing machine are monitored, and, on this occasion, nobody knows how much such an adjustment affects the portions other than the standard points of the adjustment, which is an inconvenient situation.
Meanwhile, a color control simulator having the same operational circuits or systems as those used in the picture reproducing machine, has been proposed, wherein the color control conditions to be input to the picture reproducing machine are determined by an operator while monitoring the output values. In this case, this simulator includes the same color control circuits or systems as those of the picture reproducing machine as if another picture reproducing machine were provided, and thus avoids the high cost of acquiring such a machine, only for the adjusting function.