| Author | Message | ||
     den Member Username: Den Post Number: 184 Registered: 03-2006 |
In a previous thread, the ColorCorrect transform without a mask and loaded with a *.colorcorrect file was suggested as a method to achieve high impact preference saturations and minor hue changes. As a further consideration, the HSL Saturation Contrast Mask suggested/described here, provides a further method for ‘fine’ control of an image’s saturation levels. This mask can be used with the ColorCorrect transform or the ColorCurves transform in HSV,S or HSL,S mode. The Saturation transform could also be used but ColorCurves offers the best control. How the derived ‘HSL Saturation Contrast Mask’ tones relate to its image is difficult to describe and visualize, but this is not as important as the results that can be obtained by using it. The mask uses the characteristics of the HSL color space and the image’s absolute gray tone/color differences from a 50% neutral gray. This mask has more ‘fine’ detail then either an extracted HSV,S or HSL,S channel, if these were to be considered for use as a saturation mask. Illustration1: the MacBeth sRGB color chart and its HSL Saturation Contrast mask.   Illustration2: the MacBeth sRGB color chart’s HSV,S [top] and HSL,S [bottom] extracted channels.   A more direct ‘HSL Saturation Contrast Mask’ workflow than that described in the linked TIP posting is presented below [see Step1]. Additionally, as an application example, the ColorCurves - HSL,S mode is chosen. The HSL color space often times provides a more translucent/ethereal ambience or ‘Lightness’ in saturation color than is possible in the HSV color space or with the ColorCorrect transform. A suggested workflow: Img0 = original or start image Step1: Generate the ‘HSL Saturation Contrast Mask’. Open or click on Img0. Open the Composite-Absolute Difference transform where Input Image = Img0, Amount = 100, Overlay = 50%solid gray color, Overlay Amount = 100. Click OK, creating Img1a. Click on Img1a and open the Levels&Color transform in HSL color space [important] and select ‘Full Range’ and set Saturation = -100% [minus 100%]. Click OK, creating Img1b. Click on Img1b and open the Convert transform and select, 8-bit Black/White. Click OK, creating Mask1; the ‘HSL Saturation Contrast Mask’. Step2: Mask1 applied example. Click on Img0 and open the ColorCurves transform in HSL,S mode where Input Image = Img0, mask = Mask1. Form an HSL,S smooth curve = [0,0], [10,10], [50,85], [100,100]. Adjust the mask black and white amounts and the [50,85] control point to preferences while monitoring the Preview. Click OK, creating high impact sRGB color image, Img2.  May your ‘good’ images be made ‘better’; your ‘better’ image be made ‘superior’; and your ‘superior’ image be made ‘excellent’!…. | ||
| den Member Username: Den Post Number: 185 Registered: 03-2006 |
...hmmmm.. appears the posting is a bit different than the 'preview'... The Macbeth chart HSV,S channel is on the LEFT and the HSL,S channel on the RIGHT. Also, as an alternative to Converting to 8-bit BW, Img1b in Step1, one could: Click on Img1b and open the Mask Tool - Brightness Curve and 'lower left Apply' leaving the mask tool 'active'... then click on Img0, open the ColorCurves HSL,S mode where Input Image = Img0 and Mask = 'the active mask'... and then complete Step2 as described. One could even increase the 'active mask's' contrast by forming a 'S' contrast curve before the 'lower left Apply' although this may potentially result in an overly aggressive pixel to pixel saturation gradients. |
