Dominant Color Extraction Using Perceptual Rules to Produce Ambient Light Derived From Video Content
First Claim
1. A method for dominant color extraction from video content encoded in a rendered color space (RGB) to produce, using perceptual rules, a dominant color (DC) for emulation by an ambient light source (88), comprising:
- [1] Performing dominant color extraction from pixel chromaticities (Cp) from said video content in said rendered color space to produce a dominant color by extracting any of;
[a] a mode of said pixel chromaticities;
[b] a median of said pixel chromaticities;
[c] a weighted average by chromaticity of said pixel chromaticities;
[d] a weighted average of said pixel chromaticities using a pixel weighting function (W) that is a function of any of pixel position (i, j), chromaticity (x, y, R), and luminance (L);
[2] Further deriving the chromaticity of said dominant color in accordance with a perceptual rule, said perceptual rule chosen from any of;
[a] a simple chromaticity transform (SCT);
[b] a weighted average using said pixel weighting function (PF8) so further formulated as to exhibit an influence from scene content that is obtained by assessing any of chromaticity and luminance for a plurality of pixels in said video content;
[c] an extended dominant color extraction (EE8) using a weighted average where said pixel weighting function is formulated as a function of scene content that is obtained by assessing any of chromaticity and luminance for a plurality of pixels in said video content, with said pixel weighting function further formulated such that weighting is at least reduced for majority pixels (MP); and
[3] Transforming said dominant color from said rendered color space to a second rendered color space (R′
G′
B′
) so formed as to allow driving said ambient light source.
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Abstract
Extracting and processing video content encoded in a rendered color space to be emulated by an ambient light source, using perceptual rules for intelligent dominant color selection. Steps include quantizing the video color space; performing dominant color extraction by using a mode, median, mean, or weighted average of pixel chromaticities; applying perceptual rules to further derive dominant chromaticities via [1] chromaticity transforms; [2] a weighted average using a pixel weighting function influenced by scene content; and [3] extended dominant color extraction where pixel weighting is reduced for majority pixels; and [4] transforming the dominant color chosen to the ambient light color space using tristimulus matrices. A color of interest can be further analyzed to produce a true dominant color, and past video frames can guide selection of dominant colors in future frames.
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Citations
20 Claims
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1. A method for dominant color extraction from video content encoded in a rendered color space (RGB) to produce, using perceptual rules, a dominant color (DC) for emulation by an ambient light source (88), comprising:
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[1] Performing dominant color extraction from pixel chromaticities (Cp) from said video content in said rendered color space to produce a dominant color by extracting any of;
[a] a mode of said pixel chromaticities;
[b] a median of said pixel chromaticities;
[c] a weighted average by chromaticity of said pixel chromaticities;
[d] a weighted average of said pixel chromaticities using a pixel weighting function (W) that is a function of any of pixel position (i, j), chromaticity (x, y, R), and luminance (L);
[2] Further deriving the chromaticity of said dominant color in accordance with a perceptual rule, said perceptual rule chosen from any of;
[a] a simple chromaticity transform (SCT);
[b] a weighted average using said pixel weighting function (PF8) so further formulated as to exhibit an influence from scene content that is obtained by assessing any of chromaticity and luminance for a plurality of pixels in said video content;
[c] an extended dominant color extraction (EE8) using a weighted average where said pixel weighting function is formulated as a function of scene content that is obtained by assessing any of chromaticity and luminance for a plurality of pixels in said video content, with said pixel weighting function further formulated such that weighting is at least reduced for majority pixels (MP); and
[3] Transforming said dominant color from said rendered color space to a second rendered color space (R′
G′
B′
) so formed as to allow driving said ambient light source. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for dominant color extraction from video content encoded in a rendered color space (RGB) to produce, using perceptual rules, a dominant color (DC) for emulation by an ambient light source (88), comprising:
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[0] Quantizing at least some pixel chromaticities (Cp) from said video content in said rendered color space to form a distribution of assigned colors (AC);
[1] Performing dominant color extraction from said distribution of assigned colors to produce a dominant color by extracting any of;
[a] a mode of said distribution of assigned colors;
[b] a median of said distribution of assigned colors;
[c] a weighted average by chromaticity of said distribution of assigned colors;
[d] a weighted average of said distribution of assigned colors using a pixel weighting function (W) that is a function of any of pixel position (i, j), chromaticity (x, y, R), and luminance (L);
[2] Further deriving the chromaticity of said dominant color in accordance with a perceptual rule, said perceptual rule chosen from any of;
[a] a simple chromaticity transform (SCT);
[b] a weighted average using said pixel weighting function (PF8) so further formulated as to exhibit an influence from scene content that is obtained by assessing any of chromaticity and luminance for a plurality of pixels in said video content;
[c] an extended dominant color extraction (EE8) using a weighted average where said pixel weighting function is formulated as a function of scene content that is obtained by assessing any of chromaticity and luminance for a plurality of pixels in said video content, with said pixel weighting function further formulated such that weighting is at least reduced for assigned colors attributable to majority pixels (MP); and
[3] Transforming said dominant color from said rendered color space to a second rendered color space (R′
G′
B′
) so formed as to allow driving said ambient light source. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. A method for dominant color extraction from video content encoded in a rendered color space (RGB) to produce, using perceptual rules, a dominant color (DC) for emulation by an ambient light source (88), comprising:
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[0] Decoding said video content in said rendered color space into a plurality of frames, and quantizing at least some pixel chromaticities (Cp) from said video content in said rendered color space to form a distribution of assigned colors (AC);
[1] Performing dominant color extraction from said distribution of assigned colors to produce a dominant color by extracting any of;
[a] a mode of said distribution of assigned colors;
[b] a median of said distribution of assigned colors;
[c] a weighted average by chromaticity of said distribution of assigned colors;
[d] a weighted average of said distribution of assigned colors using a pixel weighting function (W) that is a function of any of pixel position (i, j), chromaticity (x, y, R), and luminance (L);
[2] Further deriving the chromaticity of said dominant color in accordance with a perceptual rule, said perceptual rule chosen from any of;
[a] a simple chromaticity transform (SCT);
[b] a weighted average using said pixel weighting function (PF8) so further formulated as to exhibit an influence from scene content that is obtained by assessing any of chromaticity and luminance for a plurality of pixels in said video content;
[c] an extended dominant color extraction (EE8) using a weighted average where said pixel weighting function is formulated as a function of scene content that is obtained by assessing any of chromaticity and luminance for a plurality of pixels in said video content, with said pixel weighting function further formulated such that weighting is at least reduced for assigned colors attributable to majority pixels (MP); and
[3a] Transforming said dominant color from said rendered color space to an unrendered color space (XYZ);
[3b] Transforming said dominant color from said unrendered color space to said second rendered color space, assisted by [3c] matrix transformations of primaries (RGB, R′
G′
B′
) of said rendered color space and second rendered color space to said unrendered color space using first and second tristimulus primary matrices (M1, M2);
and deriving a transformation of said color information into said second rendered color space (R′
G′
B′
) by matrix multiplication of said primaries of said rendered color space, said first tristimulus matrix, and the inverse of said second tristimulus matrix (M2)−
1.
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Specification