Respuesta: Calibrando JVC HD950
Una recomendación para los que citan. Hay que poner el origen de la cita. Para saber quién dice qué y desde donde. Eso le da más credibilidad. Y nos permite contrastar fuentes. Que algo esté escrito en inglés no lo hace más verídico.
Tienes toda la razón. A partir de ahora añadiré el origen de las citas que cuelgue.
"Typically, RGB for digital video is not full range. Instead, video RGB uses a convention with scaling and offsets such that (16, 16, 16) is black, (235, 235, 235) is white, etc. For example, these scalings and offsets are used for the digital RGB definition in the CCIR 601 standard."
http://en.wikipedia.org/wiki/RGB_color_model
"In each 8 bit luminance sample, the value 16 is used for black and 235 for white, to allow for overshoot and undershoot. The values 0 and 255 are used for sync encoding. The Cb and Cr samples use the value 128 to encode a zero value, as used when encoding a white, grey or black area."
The Rec. 601 video raster format has been re-used in a number of later standards, including MPEG."
http://en.wikipedia.org/wiki/Rec._601
"Y′CbCr is not an absolute color space, it is a way of encoding RGB information. The actual color displayed depends on the actual RGB colorants used to display the signal. Therefore a value expressed as Y′CbCr is only predictable if standard RGB colorants or an ICC profile are used."
http://en.wikipedia.org/wiki/YCbCr
"Digital representation
Rec. 709 coding uses “studio-swing” levels where reference black is defined as 8-bit interface code 16 and reference white is defined as 8-bit interface code 235. Interface codes 0 and 255 are used for synchronization, and are prohibited from video data. Eight-bit codes between 1 and 15 provide footroom, and can be used to accommodate transient signal content such as filter undershoots. Eight-bit interface codes 236 through 254 provide headroom, and can be used to accommodate transient signal content such as filter overshoots and specular highlights. Bit-depths deeper than 8 bits are obtained by appending least-significant bits. Ten-bit systems are commonplace in studios. (Desktop computer graphic systems ordinarily use “full-swing” encoding that places reference black at code 0 and reference white at code 255, and provide no footroom or headroom.) The 16..235 limits (for luma; 16..240 for chroma) originated with ITU Rec. 601.[1]"
http://en.wikipedia.org/wiki/Rec._709
"The color space of Full RGB is from 0 - 255, which is the standard for computer monitors.
With TV's the majority support a limited color range(because of broadcast standards) that chops off 16 from the top and bottom, giving you a range of 16 - 235.
If you run with Full RGB on a TV that does not support it, the reality is that you lose all the detail in the shadows or dark places and the colors are over saturated.
Blu ray discs are coded in native 16 - 235 range.(Note: They use Y Pb/Cb Pr/Cr not RGB)"
"I think people are confused as to what FULL and LIMITED RGB are for - they are NOT to do with Deep Colour and xycc colour.
They are to do with support for legacy RGB DVI displays which support only 0-255 RGB levels and not the broadcast/studio standard of 16-235 RGB levels which almost all HDMI displays should support, and is the levels standard used for DVDs and BluRays.
Many displays will cope with either setting and deliver near identical results - though will need re-calibration depending on which one you chose. If you do not recalibrate, then FULL will appear to have deeper, crushed blacks and thus more saturated colours, and brighter whites. However with correct calibration on a studio level capable display there should be no difference. Additionally Limited levels will allow blacker-than-black and whiter-than-white to be passed through, whereas Full levels can't allow this as anything below 16 or above 235 in studio levels terms is mapped to 0 or 255 in Full (aka PC level terms)
AIUI Super White is the option to allow Whiter than White to be passed rather than clipped - and as such is only available in YCrCb (and possibly Limited RGB options)
You have a modern HDMI set - you shouldn't need to use Full you should be using Limited.
Full is only required on older sets with PC level RGB DVI inputs - all HDMI sets should support studio/broadcast level RGB inputs as standard - and thus are designed to accept Limited inputs.
In FULL mode the source - which is 16-235 - is remapped to 0-255 - so blacks which are encoded on the BluRay source at level 16, are not output at 16 and instead reduced to 0. Whites which are encoded on the BluRay source at level 235 are scaled to hit 255. Anything below 16 or above 235 (so called Blacker than Black and Whiter than White information) is clipped in FULL mode - it is NOT passed.
The key thing to understand is that broadcast TV, DVDs, HD-DVDs and BluRay are mastered with black at 16 and White at 235 (whether RGB or YCrCb representation are used - and Cr Cb are 16-240 centred around 127) These are known as studio or broadcast levels - and have a narrower black-to-white range to allow for below-black and above-white excursions to be carried without clipping - which is an important issue when you are mixing analogue and video sources (Transitions can cause spikes in analogue circuitry that will go past black and white levels, if these are clipped, they will cause ringing - i.e. artificial black/white edge distortion - when converted back to analogue.)
The fact that FULL and LIMITED are not simply different ways of displaying a signal with the same range - as you suggest - is clearly visible when you flip between modes - as in FULL mode the black level drops and white level increases. This is NOT what would happen if the switch was simply between passing <16 and >235 or not and keeping black at 16 and white at 235 - you would get no black or white level shift. But you do.
Super White is the option that allows whiter-than-white to be passed - not FULL.
FULL is simply an option Sony added to remap 16-235 studio levels to the older DVI RGB standard (previously uncatered for in PS3) using PC levels of 0-255. It is NOT to do with passing blacker than black or whiter than white - as it clips <16 and >235 levels in the remap process. This is important for projectors and owners of older HDTVs with DVI inputs added for use with PCs rather than video sources."
http://boards.ign.com/ps3_general_board/b8267/176262471/r176328023/
Un saludete
he estado midiendo los colores de la pestaña, y tiene valores por debajo de 16 en la captura de PC y esto son números correctos nada de sonda, lo dice un programa informático.
