Sadie - Saturation Control

Sadie is an advanced tool for adjusting image saturation -- the intensity of colour. Sadie includes controls for Greys, Chromes, Shadows, Midtones, Highlights, and Global Boost. Each control allows you to affect saturation of a specific portion (or all of) of your image. With these controls at hand, you'll have an easy way to enhance the overall colour of your image both subtly and dramatically.

Download Freeware Now

Windows, Linux and Macintosh builds are available now.
Windows, Linux and Mac versions included in the same download. Read the Sadie Release Notes, then access the download area.
You'll find installation instructions as INSTALL.txt in the zipfile.
Please provide feedback at the email address above.

Purchase SadiePRO Professional Version Now

Windows, Linux and Mac versions included in the same download. SadiePRO is now available for Windows, Macintosh (Intel and PPC), and Linux. The PRO version adds a drop list control which allows you to choose which colourspace Sadie uses for its internal processes. This gives you a choice: HSV, HSL, or Sadie Freeware's "Visual." These options allow you to change the effect Sadie has when your image nears maximum possible brightness, by either adding more colour (HSV), adding more white (HSL), or simulating increased dynamic range (Visual).

SadiePRO: $10 USD

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Sample Output

Sadie Silo Before Info

Sadie Silo After Info

Desaturated Concrete

I decided I liked the concrete better as a monochromatic texture, without all the rust stains and water marks in it. With Sadie, I just moved the "grey" slider to zero. This removed all colour from anything in the image that was mostly desaturated already.

Sadie Duck Before Info

Sadie Duck After Info

The "Fujichrome" Slider

Real Fuji film gets some of its amazing colour rendition from a special cyan-sensitive layer. Sadie doesn't emulate that, but it can almost seem to give the same Fuji-punch to an image just by moving the Midtone slider to about 0.3. Perhaps there's something to that, after all.

Sadie Flower Before Info

Sadie Flower After Info

Inverse Saturation

Purples are hard for the camera to record, especially ones that have lots of UV reflectance -- like this flower's delicate tendrils. I couldn't just push the saturation of the whole image up to compensate, because the green background was already almost too saturated. What to do? Inverse saturation -- increase the saturation of greys, decrease the saturation of chromes. The pale purples become more saturated, the intense greens ease off. Just the thing!

"Before" shots taken with Sadie disabled, "After" shots taken with Sadie enabled -- no other changes to Bibble's settings occurred.

User Interface

SadiePRO 1.0 Screenshot Info

Enable

The enable checkbox controls whether Sadie's settings affect the image. By clicking the checkbox off and on, it is easy to see the effect Sadie contributes to the image.

Method (SadiePRO only)

Sadie Standard processes pixel values using a colourspace modeled after YIQ. It has good results in most situations, even when dealing with extreme saturation. Most images look quite natural when their saturation is changed. SadiePRO offers you two additional colourspaces, allowing you to choose how luminance is adjusted when saturation is increased or decreased. This selection box allows you to choose which you would like to use.

Visual - the YIQ based colourspace used in Sadie Standard.
HSLum - the Hue, Saturation, Luminance colourspace. Distinguished here by its attempt to keep perceived luminance values fairly constant.
HSValue - the Hue, Saturation, Value colourspace. Perceived luminance values tend to decrease with increasing saturation; increase with decreasing saturation. Bibble's saturation slider uses HSV -- if you like Bibble's native saturation effect, use this colourspace.

See below for graphics that show the differences between the colourspaces.

Reset

Clicking the reset button forces all of Sadie's sliders to neutral effect and shuts off Enabled checkbox.

? Button

Click this to get the version number, author and homepage URL of the plugin.

Adjust by Saturation

The sliders in this group alter the saturation of areas of the image that are distinctly less and more saturated (more grey vs more intensely coloured). Both sliders affect all pixels to some extent to maintain a smooth crossover. Each slider has a checkbox next to it -- turn it off to remove the effect of that slider; turn it on to reactivate the slider.

Greys

Adjusts saturation of parts of the image that are relatively unsaturated, e.g. greys, beige, black, white, and so on.

Midsat (SadiePRO 1.2)

Adjust the saturation of moderately saturated colours. Excellent for pushing saturation up a little to compensate for the flat, desaturated look that prints often take.

Chromes

Adjusts saturation of parts of the image that are already quite saturated, e.g. vibrant colours such as green, blue, red, etc.

Adjust by Luminance

The sliders in this group box alter the saturation of areas that are distinguished by luminance -- the difference between black and white. Like the chrominance group, all image pixels generally affected to some degree by at least two of these sliders to create smooth crossover and predictable influence.

Shadows

Adjusts the saturation of darker image values.

Midtones

Adjusts the saturation of middle image tones, roughly corresponding to the "filmic" zone -- it's a tilted bell curve centred around 0.55 absolute brightness. I suppose you could call this the "Fujichrome" slider, if you didn't mind being attacked by lawyers.

Highlights

Adjusts the saturation of extremely light image values -- the very light pixels that midtones won't affect much. Different colourspaces have different ideas of "highlights" so you may find this slider having little effect, or lots of effect, depending on the "method" selection.

Overall Saturation

The Global slider adjusts the results of the all of Sadie's controls; it takes effect after everything else. It simply adjusts the saturation of the entire image. One interesting byproduct of this is that you can super saturate the image with the other sliders, then scale the "super saturation" back down with this slider to more reasonable levels.

Notes

Colourspace Comparisons

This section shows the effect of choosing among the colourspaces. Note that the spectrum image is already fully saturated -- there are no grey values in it -- and so when saturation is increased further, as shown on the right-side sample images below, you see how these colourspaces deal with adding saturation to saturation. Most of your images won't show such crazy/insane conversions because they'll have more normal ranges of colour.

Test Image

This is a section from one of my Sadie test images. It shows the full RGB colour spectrum, fully saturated, from white to black. You can see some contour lines in the blues/magentas/reds because they're there in the test image. They're not something Sadie introduced, but Sadie can certainly call attention to them. You won't notice contour lines like this in naturally created images.

Unaltered Spectrum Info

HSLum Colourspace (SadiePRO only)

HSL says, "white is white and nobody's gonna change that."

Sadie-HSL-Desaturated Info

Unaltered Spectrum Info

Sadie-HSL-Saturated Info

HSValue Colourspace (SadiePRO only)

HSV says, "I love intense colour, and white can go hang."

Sadie-HSV-Desaturated Info

Unaltered Spectrum Info

Sadie-HSV-Saturated Info

Visual Colourspace (Sadie Standand and SadiePRO)

Visual says, "You guys are boring! Look, bright! shiny! pretty! Wheee!"

Sadie-Visual-Desaturated Info

Unaltered Spectrum Info

Sadie-Visual-Saturated Info

Ok, technically, what visual does is allow saturation to increase beyond the fundamental limits of the RGB colour cube, and when it does so, it gets clipped. Thus, ultrabright (beyond RGB) orange will be turned yellowish, because in RGB-land, yellow is "brighter" than the brightest orange.

If you desaturate in Visual colourspace, the resulting B&W image will closely resemble the image that a B&W television might reproduce of a colour tv channel, as its output at fully desaturated is 0.30R + 0.59G + 0.11B.

Linear Adjustment except at Extremes

Sadie adjusts saturation linearly (by multiplication), except at extreme positive values. In these cases, Sadie applies a scaled minima to the saturation to ensure that no matter how small the original saturation was, there will be a visible impact of the slider. If Sadie did not take this approach, it would be impossible for near-grey tones to ever be fully saturated. I have spent a lot of time working on these algorithms so they feel seamless, but it is possible that some changes to them may occur in the future.

Sadie 0.9 "Super" mode

Sadie 0.9 "super" used a different colourspace than that offered in Sadie 1.0, so your old settings may not generate the same results. The old space suffered some problems with smooth saturation increases on hypersaturated bright colors (such as florals), and has been substantially reworked here as "Visual" which is the default space (and only space available in Sadie Standard).

Performance Issues

Sadie performs a lot of math, and when enabled you'll probably notice a significant change in the responsiveness of Bibble. It's probably best to use Sadie towards the end of your image tweaking, rather than diving right in at the beginning.

Legal

References

HLS colour space
HSB colour space
(my own) colour space

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