Frage von SemiLue:
During the compression of video signals, the RGB color space into the YCbCr color conversion.
In the MPEG compression are now, however, the luminance and Chrominanzwerte unterabgetastet. Why? I just throw away resolution information? That makes the idea of destroying high-definition television? And HDTV is still synonymous MPEG2 compressed.
Could someone explain this more precisely?
Antwort von stefanscholl:
Because you when in HD 3x RGB (RGB) 1.5 Gbit / s would have to be transferred, but did on the satellite channel for only 6-8 Mbit / sec available .... Everything in between is data reduction. In addition, synonymous only times the interfaces, which do ... etc. ...
Antwort von WoWu:
Hello SemiLue ...
The predecessor has already hinted ...
However, luminance is not sampled, only the chroma based on the fact that the human eye anyway is to deceive extreme and brightness, frequency and Richtungsempfindlich is. We can also subtleties anyway only to a certain extent, resolve. All of these "weaknesses" we now turn to the size of a TV image conversion and determined that the man the full resolution, would be transferred do not see ... So to say they do not.
In transform coding with psychovisueller weighting coefficients are higher with lower accuracy continuously encoded, because the eye is that increasingly insensitive. The approved distortion is not only synonymous but s.die spatial edges towards s.die still be adjusted, since the coefficients associated with certain images show the direction of preferences.
This is still the question of how many colors a man at all can distinguish synonymous to ... there are answers ... and the result you have described as a question .... more color would you like on your television did not see ... And so are the television systems unterabgetastet ... a form of data reduction, to transfer all possible and especially economical to make.
.... but soon we'll get a whole new color space for HD xvYCC offered .... then the synonymous uA Gold and Silver dar.
Well, if it did not bring?
Antwort von Quadruplex:
In the MPEG compression are now, however, the luminance and Chrominanzwerte unterabgetastet. Luminance? Sure?
The speaker's have already written: The human eye can be well over the ear slap - lest TV and movies do not work. Even in the studio working usually for good reason, with no more than 4:2:2 - so full Luminanzbandbreite, U and V color with payment. Has nothing to do with MPEG.
Antwort von Ratman:
Okay, I shall summarize, the RGB signal in the Y Cb Cr - signal and then converted the Chromina (ie, Cb and Cr) unterabgetastet. So much for the analog world.
But what if I digital RGB - have information? I have 8-bit Red Green 8-bit and 8-bit blue. The conversion after 8-bit Luminaz and two 8-bit chrominance extent is still understandable. But what do I do then? Quantize I just more to my 8-bit Y Cr Cb to comment? All encoder chips, which I found on the Internet have to accept only 8-bit wide signals s.Input.
Antwort von Quadruplex:
Oh, ever - because you can write essays drüber - and they are synonymous already been written ....
http://www.media-matters.net/docs/resources/DigitalFiles/General/Engineer'sGuidetoDecoding&Encoding.pdf
http://www-nt.e-technik.uni-erlangen.de/lms/lecture/seminar/seminar_ss03/documents/handout_human_perception_in_source_coding_audio_2.pdf
http://www.quantumdata.com/support/kb/general/qd_StandardTiming.pdf
http://www.tfh-berlin.de/~mixdorff/mmt2/files/Digitale_Bilder.pdf
http://www.tek.com/Measurement/App_Notes/25_15215/eng/VideoGlossary_part_3.pdf
