令一幅黑哂的剪影相, 變返光, 及不減光位 detail 的方法

[chiuching]

可以救番0的正相喇.

[peterso]

[quote="KYO"]1. 先係Image>Mode 到 將張相 轉做 "LAB color"
2. 此時睇睇 channels, 你會見到 Lab, Lightness, a 和 b 四個channels. 將Lightness個channels copy出來.
3. 係Lightness copy channel 做"高斯模糊".
4. 之後再將Mode 轉回 RGB color mode. (可click layer 既 background一下將畫面轉回正常彩色)
5. 係Select>Load selection, 於Channel撰剛才的 Lightness copy, 並撰上Invert. 此時會見到相片既暗位已經select

[tonytsui]

[quote="KYO"]1. 先係Image>Mode 到 將張相 轉做 "LAB color"
2. 此時睇睇 channels, 你會見到 Lab, Lightness, a 和 b 四個channels. 將Lightness個channels copy出來.
3. 係Lightness copy channel 做"高斯模糊".
4. 之後再將Mode 轉回 RGB color mode. (可click layer 既 background一下將畫面轉回正常彩色)
5. 係Select>Load selection, 於Channel撰剛才的 Lightness copy, 並撰上Invert. 此時會見到相片既暗位已經select

[debug]

ok, 如果想保留光暗 details, 又令 d 暗位光返

用 PS
1) Duplicate 個背景, 令到有兩個 layer
2) 將果個 duplicate layer 去色 (desaturate)
3) 在果個 duplicate layer 度, 做一個 Invert (反色) 的 effect
4) 將果個 duplicate layer 的混合選項由 "正常" 改為 "疊加" (from Normal to Blending Mode)
5) 在果個 duplicate layer 做一個 "高斯模糊" (Gaussian Blur), 強度會影響光暗位的 details
6) 將所有 layer 用 "level" 推光
7) 再用 curve 調節 R, G, B 各 channel 的平衡 (呢步非必要, 我呢幅相有 d 偏綠, 所以先加高紅色少少)

睇o下個成果 !!










詳情


http://luminous-landscape.com/tutorials/understanding-series/u-contrast-masking.shtml

I have also written a tutorial on contrast masking before

http://av100fun.com/viewtopic.php?t=870 ... sc&start=0

[bullwong]

[bruce999]

好多高手

有排學

[DonDon]

睇左都唔明!

[Dlok]

[Dlok]

[tiramisu]

嘩!!!!!!!!!!!!!起死回生.....妙手回春....

[比比仔]

[bt-forum]

I have also written a tutorial on contrast masking before

http://av100fun.com/viewtopic.php?t=870 ... sc&start=0

O依! 我同你個方法完全一樣, 似乎我地都係同出一個師父..


不過你個例子係用人像來做, 我亦試過把呢個方法 APPLY 落人像度, 但幾次都失敗, 原因係呢個方法, 令塊面有 D 灰斑o係度 (你可以看看你個 EXAMPLE, 都有的), 所以我而家只係用o係風景度

[debug]

I have also written a tutorial on contrast masking before

http://av100fun.com/viewtopic.php?t=870 ... sc&start=0

O依! 我同你個方法完全一樣, 似乎我地都係同出一個師父..


不過你個例子係用人像來做, 我亦試過把呢個方法 APPLY 落人像度, 但幾次都失敗, 原因係呢個方法, 令塊面有 D 灰斑o係度 (你可以看看你個 EXAMPLE, 都有的), 所以我而家只係用o係風景度

Contrast mask is a very well-known technique and has been descirbed by many person besides Michael Reichmann of Luminous Landscape. There are slight variations inthe techniques as described by different persons, but they all basically do the same thing.

Every technqiues has it's pros and cons and while improving the image in one aspect, may introduced unwanted artifacts. Contrast Mask is no different.

You really have to experiment to know how to use it properly. It is in fact possible to use contrast mask on portraits without introducing artifacts like "塊面有 D 灰斑". The reason why you saw those artifacts on the pic I used to demoed the technique was because the pic I used was borrowed on the forum from someone else. It was only a web sized jpg file. there would be a lot less artifact if I had done the technique on a full resolution jpg or tiff file. Also I did not mentioned at my tutorial page about using Levels and/or curves +/- other image adjustments to further improve the image. It is possible to minimise or practically completely remove all the artifacts if you do the right post processing. the reason I did not mention it was because I wanted to keep the tutorial simple and didn't want to make it to complicated.

[lazy pig]

[Arsenal]