Method and device for adjusting weighting values in light metering
AssigneeQuanta Computer Inc.
InventorsShuo-Li Shih, Hsin-Yu Chen
Life of this patent
Estimating the term…
Abstract
A method for adjusting weighting values in light metering is provided. An input image is divided into multiple metering zones. The input image includes a number of pixel data, and the metering zones correspond to a number of exposure weighting values. It is determined whether the color of each pixel datum of the input image is skin color. For each metering zone, an amount of the pixel data determined as the skin color is calculated. The corresponding exposure weighting values of the metering zones are adjusted according to the calculated results.
Claims14
A method for adjusting weighting values in light metering, comprising:
- dividing an input image into multiple metering zones, the input image including a plurality of pixel data and the metering zones corresponding to a plurality of exposure weighting values;
- determining whether color of each pixel datum of the input image is skin color;
- determining the color of each pixel datum which is determined to be skin color again according to a determination result of the pixel datum and determination results of a plurality of neighboring pixel data, wherein if the pixel datum and its neighboring pixel data are all determined as skin color pixels, confirming that the pixel datum is a skin color pixel and if at least one of the pixel datum and its neighboring pixel data is determined as not skin color pixels, confirming that the pixel datum is not a skin color pixel;
- calculating an amount of the pixel data determined as the skin color for each metering zone;
- and
- adjusting the corresponding exposure weighting values of the metering zones according to the calculated results, wherein the step of determining whether the color of each pixel datum of the input image is skin color comprises
- for a piece of pixel datum, calculating a first reference value and a second reference value according to ratios among a plurality of sub-pixel data of the pixel datum;
- and
- determining whether the first reference value and the second reference value are within a predetermined region, wherein the first reference value and the second reference value are calculated as follows:
- the
-
-
- first
-
-
- reference
-
-
- value
- =
- (
- R
- input
- G
- input
- )
- 2
- +
- (
- R
- input
- B
- input
- )
- 2
- -
- 1.4
- the
-
-
- second
-
-
- reference
-
- =
- tan
- -
- 1
-
- (
- (
- R
- input
- B
- input
- )
- /
- (
- R
- input
- G
- input
- )
- )
- -
- 0.7
- Rinput, Ginput, Binput indicate three sub-pixel data of the piece of pixel datum, respectively.
A device for adjusting weighting values in light metering, dividing an input image into multiple metering zones and adjusting corresponding weighting values of the metering zones, the input image including a plurality of pixel data, the device comprising:
- a determination unit for determining whether color of each pixel datum of the input image is skin color;
- a filter unit for determining the color of each pixel datum which is determined to be skin color again according to a determination result of a pixel datum and determination results of a plurality of neighboring pixel data, provided by the determination unit, wherein if the pixel datum and its neighboring pixel data are all determined as skin color pixels, confirming that the pixel datum is a skin color pixel and if at least one of the pixel datum and its neighboring pixel data is determined as not skin color pixels, confirming that the pixel datum is not a skin color pixel;
- a calculation unit for calculating an amount of the pixel data determined as the skin color for each metering zone;
- a weighting adjustment unit for adjusting the corresponding exposure weighting values of the metering zones according to the calculated results;
- and
- a color ratio calculation unit for calculating a first reference value and a second reference value according to ratios among a plurality of sub-pixel data of a pixel datum,
- wherein in determining whether the color of each pixel datum is skin color, the determination unit determines whether the first reference value and the second reference value are within a predetermined region, and the first reference value and the second reference value are calculated as follows:
- the
-
-
- first
-
-
- reference
-
-
- value
- =
- (
- R
- input
- G
- input
- )
- 2
- +
- (
- R
- input
- B
- input
- )
- 2
- -
- 1.4
- the
-
-
- second
-
-
- reference
-
- =
- tan
- -
- 1
-
- (
- (
- R
- input
- B
- input
- )
- /
- (
- R
- input
- G
- input
- )
- )
- -
- 0.7
- Rinput, Ginput, Binput indicate three sub-pixel data of the piece of pixel datum, respectively.
Dependencies are inferred from the claim text.