| 摘要 |
<p>PURPOSE: To obtain video images continuous in real time at a relatively high speed by selecting a gray level value so as to correspond to a change positioned between a prescribed first percentage and an actually obtained second percentage and clipping picture elements based on input gray level values intrinsic to the respective video images. CONSTITUTION: An input gray level for which an input picture element number provided with a highest gray level is 5% is defined as a gray level G5. In order to find a gray level value G0 to be obtained, gradient change between the gray level point of 4.5% picture element clipping and the gray level point of 4% picture element clipping is retrieved by every 0.5%, the gray level point G1 is decided as a clipping level value, a clipping gray level G0 is present between the gray level value G5 of 5% picture element clipping and the gray level value G1 of 1% picture element clipping and the gray level point GA positioned on a diagonal is decided based on the clipping gray level G0. In the meantime, the clipping gray level point G8 on a low gray level side is also decided by considering a low luminance picture element group and retrieving the significant change of characteristic gradient between the 5% clipping and 1% clipping of the low luminance picture element group similarly to above-mentioned operations.</p> |
