JP2005079994A5 - - Google Patents

Claims (15)

In accordance with an input image signal, the image on the light valve is changed, and the amount of light incident on the light valve is changed by a dimming element.
Temporarily storing the input image signal for a predetermined storage time or a predetermined number of frames;
Detecting a scene change in the accumulated input image signal;
Determining a dimming parameter for controlling the amount of light of the dimming element according to the detected scene;
Transmitting the accumulated image signal to the light valve as a delayed image signal for reproduction; and
Generating a dimming control signal for controlling the dimming element based on the dimming parameter, and controlling the light amount of the dimming element in synchronization with the image signal to be reproduced;
A video display method characterized by comprising:   When the scene change is detected, if the maximum value of the brightness gradation in the frame of the image signal is equal to or less than a predetermined constant change amount, a step of detecting the frame during that period as one scene is included. The video display method according to claim 1, further comprising:   When the scene change is detected, if the average value of the brightness gradation in the frame of the image signal is equal to or less than a predetermined constant change amount, the step of detecting the frame during that period as one scene is included. The video display method according to claim 1, further comprising:   When detecting the scene change, the method includes a step of obtaining a histogram shape for each frame of the image signal, and detecting a frame whose period of change in the histogram shape is equal to or less than a predetermined change amount as one scene. The video display method according to claim 1.   5. The video display method according to claim 1, further comprising a step of determining the dimming parameter according to the scene based on a brightest gradation in the scene.   6. The video display method according to claim 1, further comprising a step of determining the dimming parameter according to the scene based on information of a histogram in the scene.   The video display method according to claim 1, further comprising a step of storing information on the dimming parameter together with a frame number at the start of the scene. When a scene change is not detected in the image signal within the accumulation time, determining a dimming parameter based on the image signal within the accumulation time;
When a scene change is not detected in the image signal within the accumulation time and a frame that is incompatible with the determined dimming parameter is detected, a new dimming parameter corresponding to the detected frame is detected. Changing the dimming parameter used for reproducing the image signal step by step from the current dimming parameter to a new dimming parameter;
The video display method according to claim 1, further comprising: An image display device that changes an image on a light valve according to an input image signal and changes a light amount incident on the light valve by a dimming element,
Image storage means for temporarily storing the input image signal for a predetermined storage time or a predetermined number of frames;
A scene change detecting means for detecting a scene change of the accumulated input image signal;
A dimming parameter determining means for determining a dimming parameter for controlling the amount of light of the dimming element according to the detected scene;
Image reproduction means for transmitting the accumulated image signal to the light valve as a delayed image signal for reproduction;
A dimming control means for generating a dimming control signal for controlling the dimming element based on the dimming parameter, and controlling the light amount of the dimming element in synchronization with the image signal to be reproduced;
A video display device comprising:   When detecting the scene change, if the maximum value of the brightness gradation in the frame of the image signal is equal to or less than a predetermined constant change amount, means for detecting a frame during that period as one scene. The video display device according to claim 9, further comprising:   When the scene change is detected, if the average value of the brightness gradation in the frame of the image signal is equal to or less than a predetermined constant change amount, means for detecting the frame during that period as one scene. The video display device according to claim 9, further comprising:   When detecting the scene change, the image processing apparatus includes means for obtaining a histogram shape for each frame of the image signal, and detecting a frame whose period of change in the histogram shape is equal to or less than a predetermined change amount as one scene. The video display device according to claim 9.   13. The video display device according to claim 9, further comprising means for determining a dimming parameter according to the scene based on a brightest gradation in the scene.   The video display apparatus according to claim 9, further comprising a unit that determines the dimming parameter according to the scene based on information of a histogram in the scene. When no scene change is detected in the image signal within the accumulation time, means for determining a dimming parameter based on the image signal within the accumulation time;
When a scene change is not detected in the image signal within the accumulation time and a frame that does not match the determined dimming parameter is detected, a new dimming parameter corresponding to the detected frame is detected. Means for gradually changing the dimming parameter used for reproducing the image signal from the current dimming parameter to a new dimming parameter;
The video display device according to claim 9, further comprising: