Moving image processing apparatus, and control method and program thereof

1. A moving image processing apparatus comprising:

a brightness information acquisition unit configured to acquire, from an input video signal, brightness information indicating brightness of the video signal;

an illumination information acquisition unit configured to acquire illumination information about an environment of the moving image processing apparatus;

an adaptation coefficient calculation unit configured to calculate an adaptation coefficient for an observer based on brightness when the brightness indicated by the brightness information is less than a first threshold and the brightness indicated by the illumination information is less than a second threshold;

a correction coefficient calculation unit configured to calculate a correction coefficient to be used for image correction of the video signal based on the adaptation coefficient calculated by the adaptation coefficient calculation unit; and

an image correction unit configured to perform image correction on the video signal using the correction coefficient calculated by the correction coefficient calculation unit.

2. The moving image processing apparatus according to claim 1 , wherein the adaptation coefficient calculation unit is configured to calculate the adaptation coefficient using a function in which the adaptation coefficient to be calculated decreases during a period until a predetermined time elapses, using as a reference a time at which the brightness indicated by the brightness information becomes less than the first threshold and the brightness indicated by the illumination information becomes less than the second threshold.

3. The moving image processing apparatus according to claim 1 , wherein the brightness information detection unit is configured to calculate a luminance histogram based on scene analysis for each predetermined time for the input video signal and to acquire as the brightness information a maximum value in the calculated luminance histogram.

4. The moving image processing apparatus according to claim 1 , wherein the correction coefficient calculation unit is configured to calculate at least one or more correction coefficients from among a gamma correction coefficient, a luminance gain coefficient, and an RGB gain coefficient based on the adaptation coefficient calculated by the adaptation coefficient calculation unit.

5. A non-transitory computer-readable storage medium storing a program that causes a computer to function as the moving image processing apparatus according to claim 1 .

6. A method for controlling a moving image processing apparatus, the method comprising:

acquiring, from an input video signal, brightness information indicating brightness of the video signal;

acquiring illumination information about an environment of the moving image processing apparatus;

calculating an adaptation coefficient for an observer based on brightness when the brightness indicated by the brightness information is less than a first threshold and the brightness indicated by the illumination information is less than a second threshold;

calculating a correction coefficient to be used for image correction of the video signal based on the calculated adaptation coefficient; and

performing image correction on the video signal using the calculated correction coefficient.