Vibrance vs. Saturation and PWP's Remap transform
Posted: March 7th, 2012, 3:33 pm
Ref 1: http://www.thelightsright.com/VibranceVersusSaturation
Introduction: Something to realize here is the difference between making saturation changes in the RGB color space and HSV color space.
In the RGB color space, saturation is NOT independent of Luminance [gray tone] and when making changes with a RGB Brightness curve, saturations will generally decrease with an increase in Luminance and increase with a decrease in Luminance... ...for the most part, these changes to saturation/Luminance are not objectionable and there is little shift in hues.
But for the HSV color space where Saturation is independent of both Hue and Value [gray tone], it is possible to increase the SkinColor hues/saturations greater than preference when attempting to achieve Mid/High saturation preferences resulting in a strong 'burnt red-orange' appearance to Low/Mid saturations... ...hence the possible need for SkinColor protection for both people and non-people image scenes.
The key to understanding the Remap transform is that it is essentially the ColorCorrect transform with a different User Interface and improved gradient [feathering] controls for preference color/tone changes:
...(a) both function in the HSV color space model.
...(b) Remap uses ColorPairs instead of ControlPoints with arrows.
...(c) Remap has a Chroma radius control for each individual ColorPair whereas ColorCorrect has a universal 0->1.0 radius slider for all ControlPoints.
...(d) Remap has a readily available Brightness (HSV-V) control for each individual ColorPair whereas ColorCorrect's ControlPoint brightness [HSV-V] requires a specific control point to be 'active'.
...(e) Remap's Tightness is essentially the same as the ColorCorrect 0->1.0 radius slider providing global application of the individual ColorPair Chroma/Brightness settings. Note: Tightness is maximum at a value of 1.00 and minium at 0.00... ...an opposite effect to the ColorCorrect Radius setting.
...(f) Remap [PWP6 v6.0.9] is currently limited to eight ColorPairs whereas ColorCorrect essentially has no such limitation.
Because of improved ColorPair gradient controls that Remap offers, concerns that saturation changes are not uniform while still true should not be as great as with the ColorCorrect transform.
The following reference image is available for you to download and use to set RGBCMY ColorPairs for general High Impact saturation image changes... the pairs change HSV-V from 50 to 60%; HSV-S from 33 to 90% with no change in HSV-H. The 0, 25, 50, 75, and 100% gray tone [HSV-V] pairs can be used when neutralizing an image's color casts or blocking Brightness [HSV-V] changes. The SkinColor pairs can be used when saturation changes are to include Vibrance...
Example: Original image...
...End Post 1 of 2...
Ref 2: Remap transform discussion during PWP5 Beta testing: http://dl-c.com/forum/comments.php?Disc ... e=1#Item_0Vibrance increases the saturation for an image, but unlike the Saturation command, it includes two important protections:
•Skin tones are protected. This prevents skin tones from taking on a red or yellow cast.
•Highly saturated colors are protected against clipping. This avoids unwanted color shifts and loss of important detail.
Introduction: Something to realize here is the difference between making saturation changes in the RGB color space and HSV color space.
In the RGB color space, saturation is NOT independent of Luminance [gray tone] and when making changes with a RGB Brightness curve, saturations will generally decrease with an increase in Luminance and increase with a decrease in Luminance... ...for the most part, these changes to saturation/Luminance are not objectionable and there is little shift in hues.
But for the HSV color space where Saturation is independent of both Hue and Value [gray tone], it is possible to increase the SkinColor hues/saturations greater than preference when attempting to achieve Mid/High saturation preferences resulting in a strong 'burnt red-orange' appearance to Low/Mid saturations... ...hence the possible need for SkinColor protection for both people and non-people image scenes.
The key to understanding the Remap transform is that it is essentially the ColorCorrect transform with a different User Interface and improved gradient [feathering] controls for preference color/tone changes:
...(a) both function in the HSV color space model.
...(b) Remap uses ColorPairs instead of ControlPoints with arrows.
...(c) Remap has a Chroma radius control for each individual ColorPair whereas ColorCorrect has a universal 0->1.0 radius slider for all ControlPoints.
...(d) Remap has a readily available Brightness (HSV-V) control for each individual ColorPair whereas ColorCorrect's ControlPoint brightness [HSV-V] requires a specific control point to be 'active'.
...(e) Remap's Tightness is essentially the same as the ColorCorrect 0->1.0 radius slider providing global application of the individual ColorPair Chroma/Brightness settings. Note: Tightness is maximum at a value of 1.00 and minium at 0.00... ...an opposite effect to the ColorCorrect Radius setting.
...(f) Remap [PWP6 v6.0.9] is currently limited to eight ColorPairs whereas ColorCorrect essentially has no such limitation.
Because of improved ColorPair gradient controls that Remap offers, concerns that saturation changes are not uniform while still true should not be as great as with the ColorCorrect transform.
The following reference image is available for you to download and use to set RGBCMY ColorPairs for general High Impact saturation image changes... the pairs change HSV-V from 50 to 60%; HSV-S from 33 to 90% with no change in HSV-H. The 0, 25, 50, 75, and 100% gray tone [HSV-V] pairs can be used when neutralizing an image's color casts or blocking Brightness [HSV-V] changes. The SkinColor pairs can be used when saturation changes are to include Vibrance...
- Hi-Impact-RemapPairs_33-90sat_60tone.jpg (22.38 KiB) Viewed 2785 times
- IMG_8223_original_400px.jpg (47.08 KiB) Viewed 2809 times