How can white clipping be avoided, and what are the drawbacks of doing so?
Some codecs allow alternative mappings, the most common being a “straight-through” mapping so that Y=16 maps to RGB=16,16,16 and Y=235 becomes 235,235,235. No white clipping occurs; bright highlights survive rendering unscathed. There are two consequences to this. One is that the nominal brightness range in RGB is only 16-235 instead of 0-255; this represents a slight loss of precision in the RGB color space that may result in lower transcoding accuracy, especially over multiple generations. The other is that on the computer screen, exported still pix may look slightly washed out: blacks will only be dark gray, and whites will be light gray instead of crisp white. The first problem is sometimes visible, but usually not significant in practice, as far as I can tell (multigeneration tests using the better codecs with both 0-255 and 16-235 settings show only minor differences after five compression passes). And compared to the loss of all superwhites, it’s a low price to pay. Compared to
