Chroma boost on sdr and hdr display adapted signals for sl-hdrx systems

A device comprising electronic circuitry configured for:

• obtaining a current multi-components image;
• using tone mapped luma component and corrected normalized chrominance components derived from the current multi-components image classify colors of pixels of the current multi-components image in a plurality of color classes;
• determining for each color class, data representative of said color class, comprising a dominant luminance value representative of a luminance at which a color in said class is predominant and determining (from said data representative of said color class a value representative of a gain of chrominance representative of a maximum allowed chroma value for a chrominance component in said color class;
• and
• encoding the dominant luminance value and the value representative of the gain corresponding to each class as metadata representative of a Saturation Gain Function in a bitstream, said function defining a color correction to apply to a pixel of the current multi-components image in function of a luminance of said pixel.