Power-saving image display system
A power-saving image display system includes a visual feature analyzer that receives input image data and generates a visual feature ratio representing a brightness ratio of a full image to a feature area; a visual feature spatial gain device that generates visual feature spatial gains according to the visual feature ratio and original spatial gains; and a brightness adjustment device that adjusts brightness values of the input image data according to corresponding visual feature spatial gains, thereby generating output image data.
1 . A power-saving image display system, comprising:
a visual feature analyzer implemented by a circuit or processor coupled to receive input image data and configured to generate a visual feature ratio representing a brightness ratio of a full image to a feature area and being defined as a ratio of an average brightness of the full image to an average brightness of the feature area;
a visual feature spatial gain device that generates visual feature spatial gains according to the visual feature ratio and original spatial gains; and
a brightness adjustment device that adjusts brightness values of the input image data according to corresponding visual feature spatial gains, thereby generating output image data.
2 . The system of claim 1 , wherein the visual feature analyzer comprises a feature area detector implemented by a circuit or processor configured to execute content analysis, contrast and color analysis, or edges and lines analysis to determine the feature area.
3 . The system of claim 1 , wherein the visual feature analyzer comprises:
a feature area brightness device implemented by a circuit or processor configured to execute arithmetic mean, median middle value, mode, or mid-range operations on the feature area to generate the average brightness of the feature area; and
a full image brightness device implemented by a circuit or processor configured to execute arithmetic mean, median middle value, mode, or mid-range operations on the full image to generate the average brightness of the full image.
4 . The system of claim 3 , wherein the visual feature analyzer comprises a full-to-feature comparator that generates the visual feature ratio defined as a ratio of the average brightness of the full image to the average brightness of the feature area.
5 . The system of claim 1 , further comprising:
a spatial gain lookup table (LUT) that stores the original spatial gains.
6 . The system of claim 5 , wherein the spatial gain LUT comprises:
a first LUT that stores original first spatial gains associated with a predetermined first visual feature ratio; and
a second LUT that stores original second spatial gains associated with a predetermined second visual feature ratio;
wherein each of the first LUT and the second LUT is divided into a plurality of blocks respectively corresponding to corresponding positions of an image.
7 . The system of claim 6 , wherein the predetermined first visual feature ratio is zero, and the predetermined second visual feature ratio is one.
8 . The system of claim 6 , wherein the visual feature spatial gain device generates the visual feature spatial gains by interpolation between the original first spatial gains and the original second spatial gains.
9 . The system of claim 8 , wherein a visual feature spatial gain is expressed as follows:
visual feature spatial gain=visual feature ratio*(original second spatial gain−original first spatial gain)+original first spatial gain.
10 . The system of claim 8 , wherein the interpolation comprises internal interpolation performed on the original first spatial gains and the original second spatial gains.
11 . The system of claim 1 , wherein the brightness adjustment device comprises a multiplier that multiplies the brightness values of the input image data by corresponding visual feature spatial gains.