A video image exposure adjustment method

Abstract

The invention discloses a video image exposure adjustment method, which belongs to the field of image processing and includes steps: S1, according to the color space category of the material, linearize the data of the RGB channel of the material; S2, in the linear color space, calculate The brightness value of the pixel point; S3, calculate the exposure level corresponding to the brightness value of the pixel point; S4, calculate the increment of exposure degree according to the exposure adjustment parameter; S5, adjust the exposure of the pixel point according to the increment of exposure degree; S6, Add Gamma to the data after exposure adjustment, and convert the data from linear color space to camera color space. The invention can make the exposure adjustment effect conform to human visual perception characteristics, and can adjust the exposure of the material in the absence of raw data, the adjustment effect is consistent with the adjustment effect of using CameraRaw, and can ensure that the saturation of the picture before and after adjustment is maintained unanimous.

Description

technical field

[0001] The present invention relates to the field of image processing, and more specifically, to a method for adjusting video image exposure. Background technique

[0002] The exposure adjustment of the video image screen is an important link in the post-production adjustment of film and television creation. By adjusting the parameters, the brightness of the color in the screen can be increased or decreased. The traditional video image exposure adjustment method has the following problems: 1. The change of brightness with the adjustment parameters does not conform to the characteristics of human visual perception, and the change of screen brightness caused by the change of adjustment parameters does not conform to the perception effect of human eyes on brightness; 1. When the brightness of the picture is increased, the saturation of the color in the picture will also change together, which will easily cause the problem of color distortion.

[0003] For probl...

Examples

Embodiment 1

[0062] Embodiment 1: as figure 1 As shown, this embodiment provides a video image exposure adjustment method, including steps:

[0063] S1, according to the color space category of the material, linearize the data of the RGB channel of the material, and convert the data into linear;

[0064] S2, in the linear color space, calculate the brightness value of the pixel;

[0065] S3, calculating the exposure level corresponding to the brightness value of the pixel;

[0066] S4, calculating an exposure increment according to the exposure adjustment parameter and the exposure level;

[0067] S5, adjusting the exposure of the pixel according to the increment of the exposure;

[0068] S6, performing Gamma calculation on the data after the exposure adjustment, and converting the data from the linear color space to the camera color space.

Embodiment 2

[0069] Embodiment 2: On the basis of Embodiment 1, in step S1, include sub-steps:

[0070] S11, determine the camera color space used when shooting the material, and determine the category of the camera's photoelectric transfer function OETF;

[0071] S12, using The function linearizes the RGB channel data of the material, and converts the RGB data into a linear color space. The conversion formula is as follows:

[0072]

[0073] In the formula, Represents the inverse function of the photoelectric conversion function of the camera; Indicates the value on the RGB channel of the material; Represents the value of the RGB channel converted to the linear color space after linearization.

Embodiment 3

[0074] Embodiment 3: On the basis of Embodiment 1, in step S2, calculating the pixel brightness includes adopting the following brightness calculation formula:

[0075]

[0076] In the formula, Represents the brightness value of a pixel in a linear color space; , , Respectively represent the values ​​​​on the R, G, and B channels of the pixel points converted to the values ​​​​in the linear color space; , , Respectively represent the weight coefficients of the R, G, and B channels.

technical field

[0001] The present invention relates to the field of image processing, and more specifically, to a method for adjusting video image exposure. Background technique

[0002] The exposure adjustment of the video image screen is an important link in the post-production adjustment of film and television creation. By adjusting the parameters, the brightness of the color in the screen can be increased or decreased. The traditional video image exposure adjustment method has the following problems: 1. The change of brightness with the adjustment parameters does not conform to the characteristics of human visual perception, and the change of screen brightness caused by the change of adjustment parameters does not conform to the perception effect of human eyes on brightness; 1. When the brightness of the picture is increased, the saturation of the color in the picture will also change together, which will easily cause the problem of color distortion.

[0003] For probl...

Examples

Embodiment 1

[0062] Embodiment 1: as figure 1 As shown, this embodiment provides a video image exposure adjustment method, including steps:

[0063] S1, according to the color space category of the material, linearize the data of the RGB channel of the material, and convert the data into linear;

[0064] S2, in the linear color space, calculate the brightness value of the pixel;

[0065] S3, calculating the exposure level corresponding to the brightness value of the pixel;

[0066] S4, calculating an exposure increment according to the exposure adjustment parameter and the exposure level;

[0067] S5, adjusting the exposure of the pixel according to the increment of the exposure;

[0068] S6, performing Gamma calculation on the data after the exposure adjustment, and converting the data from the linear color space to the camera color space.

Embodiment 2

[0069] Embodiment 2: On the basis of Embodiment 1, in step S1, include sub-steps:

[0070] S11, determine the camera color space used when shooting the material, and determine the category of the camera's photoelectric transfer function OETF;

[0071] S12, using The function linearizes the RGB channel data of the material, and converts the RGB data into a linear color space. The conversion formula is as follows:

[0072]

[0073] In the formula, Represents the inverse function of the photoelectric conversion function of the camera; Indicates the value on the RGB channel of the material; Represents the value of the RGB channel converted to the linear color space after linearization.

Embodiment 3

[0074] Embodiment 3: On the basis of Embodiment 1, in step S2, calculating the pixel brightness includes adopting the following brightness calculation formula:

[0075]

[0076] In the formula, Represents the brightness value of a pixel in a linear color space; , , Respectively represent the values ​​​​on the R, G, and B channels of the pixel points converted to the values ​​​​in the linear color space; , , Respectively represent the weight coefficients of the R, G, and B channels.

Images