| 摘要 |
PURPOSE:To extend the range of expression of contrast, by enabling step change in density, when the part less then threshold value of density characteristics of an output to input is observed macroscopically. CONSTITUTION:Taking that a density level Di of video elements is expressed through the combination of two density values DM and Dm, since the picture is distributed on a two-dimentional plane, in this invension, the original density Di is approximated in average in 2X2=4 video element unit macroscopically. The said density modulation can be controlled so that the average density over a plurality of video element sections after positive or negative density modulation is applied to the density level Di of the input video element signals can be approximated to the average density of the original signals corresponding to the same sections. |
