That’s just 10 bit color, which is a thing and does reduce banding but is only a part of the various HDR specs. HDR also includes a significantly increased color space, as well as varying methods (depending on what spec you’re using) of mapping the mastered video to the capabilities of the end user’s display. In addition, to achieve the wider color gamut required HDR displays require some level of local dimming to increase the contrast by adjusting the brightness of various parts of the image, either through backlight zones in LCD technologies or by adjusting the brightness per pixel in LED technologies like OLED.
That’s just 10 bit color, which is a thing and does reduce banding but is only a part of the various HDR specs. HDR also includes a significantly increased color space, as well as varying methods (depending on what spec you’re using) of mapping the mastered video to the capabilities of the end user’s display. In addition, to achieve the wider color gamut required HDR displays require some level of local dimming to increase the contrast by adjusting the brightness of various parts of the image, either through backlight zones in LCD technologies or by adjusting the brightness per pixel in LED technologies like OLED.