| 摘要 |
PURPOSE: An apparatus and method of controlling a brightness of an image signal in a moving image transmitting/receiving system are provided to partially or entirely control the brightness of an image, thereby obtaining an optimal contrast. CONSTITUTION: An apparatus for controlling a brightness of an image signal in a moving image transmitting/receiving system comprises a control point detecting portion for calculating a cumulative density function from an upper two-bit of an input image and dividing a desired axis into a desired number and then detecting the desired numbers of control points, and an image signal brightness control portion for calculating and dividing a signal output from an upper six-bit of the image and the control point detecting portion and then control a next brightness of a next frame of the image. In the apparatus, the control point detecting portion comprises a comparing portion(101) for comparing the upper two-bit of the image with a preset value, a first counting portion(103a) for counting a number of each frame of the image, a second counting portion(103b) for counting a signal of the comparing portion according to a parallel clock, a first signal selecting portion for selecting one of the signals counted in the second counting portion, a first multiplying portion for multiplying the signal of the first signal selecting portion by a pixel number of 255/#. |
