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發表於 2010-8-22 09:46:16
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本文章最後由 len1978 於 2010-8-22 10:33 編輯
to len1978大 & 光大,
雖然 暗部還是完全看不到2-16(永遠是全黑),
但是亮部卻看得到235-253了^^b
hiton12 發表於 2010-8-21 22:35 
這個....小弟不知有沒有誤解。
現在絕大部分發行的HD影片,製作格式都是採用REC.709。
如果您使用測試片的話,位階16是參考黑階準位,位階235是參考白階準位。16以下看的到跟235以上看的到,影片的畫面表現就會看到黑底浮亮跟白色過曝的情況才對。
建議您多看看幾部HD影片,看看在暗部場景/亮部場景有沒有感覺奇怪的地方。
參考資料:
http://en.wikipedia.org/wiki/Rec._709
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.
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至於PS3的Super-White如何設定,請參考PS3用戶指南網頁的說法:
http://manuals.playstation.net/document/ct/ps3/current/settings/superwhite.html
其中有兩點提示是這樣寫的:
1. 需使用HDMI連接線連接支援x.v.Color(xvYCC)的電視機。
2. 需準備以x.v.Color錄製,AVCHD格式的影像內容。
所以我會認為大多數情況下這個設定值是要關閉,才會有正確的畫面表現。
如果您的投影機有支援XVYCC顯示,那麼可以打開這個功能,並找找使用X.V.Color製作的影片來看看效果。 |
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