Video display control device
View Patent ↗A video display control device includes a video signal processing section that corrects a video signal and outputs a video signal after correction to a display, and a backlight controlling section that controls a light emission amount of a backlight. A control data generating section allocates to a low gradation region of the video signal a high gradation region dynamic range of the video signal in which a video signal corresponding to a black band region is excluded. The backlight controlling section controls a light emission luminance of the backlight so as to cancel out an increase or a decrease in the mean luminance of the video displayed on a screen.
1. A video display control device that controls displaying of a video on a display having a screen and a backlight for emitting light toward the screen, the video display control device comprising:
a black band detecting section that detects a black band region of a video signal input to the video display control device;
a characteristic detecting section that detects a mean luminance and a value of histogram related to a luminance of a video signal, corresponding to a characteristic amount detection region which is a predetermined region of the video signal input to the video display control device;
a control data generating section that generates control data for correcting the video signal based on values detected by the characteristic detecting section;
a video signal processing section that corrects the video signal based on the control data generated by the control data generating section and outputs a video signal after correction to the display; and
a backlight controlling section that controls a light emission amount of the backlight based on a difference between the mean luminance of the video signal and a mean luminance of the video signal after the correction,
wherein the characteristic detecting section sets a video signal of a region excepting the black band region detected by the black band detecting section, as the video signal of the characteristic amount detection region;
wherein the control data generating section generates control data for the video signal processing section to perform correction of allocating a dynamic range of a high gradation region of the video signal of the region that is set as the characteristic amount detection region, to a low gradation region of the video signal; and
wherein the backlight controlling section controls a light emission luminance of the backlight so as to cancel an increase or decrease of the mean luminance of video displayed on the screen in accordance with an increase or decrease of the mean luminance of the video signal after the correction with respect to the mean luminance of the video signal.
2. The video display control device according to claim 1 , wherein the characteristic detecting section makes a change so that no black band region is included in the feature detection region in accordance with black band region information from the black band detecting section.
3. The video display control device according to claim 1 , wherein the control data indicates a gamma characteristic of the video signal after correction performed by the video signal processing section, the gamma characteristic being determined in accordance with a relative magnitude of a value of a histogram of the high gradation region and the value of the histogram of the low gradation region; and
wherein the gamma characteristic of the video signal after the correction has a feature that the slope of the region of which the value of the histogram is relatively large, is made larger than the other.
4. The video display control device according to claim 1 , wherein in correction of allocating the dynamic range of the high gradation region to the low gradation region, the control data generating section determines an amount or a rate of the dynamic range of the high gradation region allocated to the low gradation region in accordance with the value of the histogram of the high gradation region.
5. The video display control device according to claim 4 , wherein in the correction of allocating the dynamic range of the high gradation region to the low gradation region, the control data generating section increases an amount or a rate of the dynamic range allocated to the low luminance region in a case that the value of the histogram of the high gradation region is smaller than a first threshold value, and decreases the amount or the rate of the dynamic range allocated to the low gradation region in a case that the value of the histogram of the high gradation region is larger than a second threshold value.
6. The video display control device according to claim 5 , wherein the control data generating section decreases the more the amount or the rate of the dynamic range allocated to the low gradation region in accordance with a magnitude of the value of the histogram of the high gradation region, in a case that the value of the histogram of the high gradation region is larger than the first threshold and is smaller than the second threshold value.
7. The video display control device according to claim 1 , wherein the video signal processing section performs no correction on the black band region in accordance with black band region information from the black band detecting section.
8. Video display control device that controls displaying of a video on a display having a screen and a backlight for emitting light toward the screen, the video display control device comprising:
a black band determining section that determines a black band region of a video signal input to the video display control device;
a characteristic detecting section that detects a mean luminance and a value of histogram related to a luminance of a video signal, corresponding to a characteristic amount detection region which is a predetermined region of the video signal input to the video display control device;
a control data generating section that generates control data for correcting the video signal based on values detected by the characteristic detecting section;
a video signal processing section that corrects the video signal based on the control data generated by the control data generating section and outputs a video signal after correction to the display; and
a backlight controlling section that controls a light emission amount of the backlight based on a difference between the mean luminance of the video signal and a mean luminance of the video signal after the correction,
wherein the characteristic detecting section sets a video signal of a region excepting the black band region determined by the black band determining section of the video signal input to the video display control device, as the video signal of the characteristic amount detection region;
wherein the control data generating section generates control data for the video signal processing section to perform correction of allocating a dynamic range of a high gradation region of the video signal of the region that is set as the characteristic amount detection region to a low gradation region of the video signal; and
wherein the backlight controlling section controls a light emission luminance of the backlight so as to cancel an increase or decrease of the mean luminance of video displayed on the screen in accordance with an increase or decrease of the mean luminance of the video signal after the correction with respect to the mean luminance of the video signal.