A channel mixer is a very flexible tool, able to realize subtle to extreme color modifications, grayscale conversions and much more. Unfortunately, channel mixers in most imaging programs (including Photoshop) are rather complicated. SF ColorMixer Pro eliminates this flaw with its built-in auto balance. This guarantees that the sum of all corrections is always zero and therefore white and black remain unchanged. Further, it is more straightforward to use and has some additional features.
SF ColorMixer Pro
SF ColorMixer is available in two different versions.
SF ColorMixer LE: The freeware version gives you only the basic functionality of a channel mixer, but the auto-balance function is built-in.
SF ColorMixer Pro 3.5: The new and full re-designed pro version has a comfortable graphical user interface (GUI) with 200% preview and functions for scrolling and navigating, 10 variation buttons and more (see here for more GUI details). This version is suitable for RGB, Lab and CMYK images with 8 and 16 bit color depth per channel.
Please note that the "basic" version (SF ColorMixer 2.1) is not longer available. If you own an old 2.1 version (basic or pro), you can upgrade to SF ColorMixer Pro here.
The download zip file includes two separate filters: a "normally" and a "scripting" version. You can install the version you wish or both. The license is valid for both. The scripting version is for use in a photoshop action or as a smart filter, the paramaters are saved in the action or in the smart object itself. But this version has some restrictions, e.g. the combination is not available (because of restrictions of the photoshop scripting interface).
Therefore an automatic version of the filter, which stores the parameters in a separate file, is also available (look here for details). This "auto" version works in the background without restrictions regarding variants and combinations, but cannot used as smart filter. Please download this version separatly.
SF ColorMixer Pro (Lab-Modus)
The following explanations refer only to the filter-specific characteristics of SF ColorMixer. The general functions of the SimpelFilter filters you find here.
The basis of the SF ColorMixer is similiar to the channel mixer (known from many imaging applications). But the common channel mixers own some disadvantages (see here for details). SF ColorMixer eliminates this flaw and has some additional features.
Operating is easy, all options and settings are explained at the left margin.
The SF ColorMixer Pro supports up to 10 setting variants and allows saving and combining all variants. A mouse click in the combining check box switches the mode on and off. In the neighbouring combobox you have to choose the combining mode:
Cumulative: Every blue marked variant will be applied to the result of the previous (blue marked) variant.
In the following modes the variants are applied separatly to the source image. The results are combined afterwards. In contrast to the Cumulative mode the variants are marked with red colors.
Darken: The minimum (darkest) value of all combined variants.
Lighten: The maximum (lightest) value of all combined variants.
Average: The average of the pixel tonal values of the combined variants.
Mix: The tonal values are mixed together. The result is similiar to the previous mode.
Neg. Mix: The mix of the inverted variants.
Multiply: The (normalized) tonal values are multiplied. The results are dark like the results of the Minimum mode.
Neg. Multiply: The inverted tonal values are multiplied.
Photoshop's or other programs' channel mixers would be very useful and flexible tools if only they would be less complicated to use.
At first, let us have a look at Photoshop's channel mixer (right screenshot): It contains three sub-dialogs, one for each of the output channels red, green and blue. Each sub-dialog contains three sliders for the source channels, labeled red, green and blue as well. At first (after opening the channel mixer) one of the sliders is positioned at 100%, the other two at 0%. This means that the color channels of the output image consist by 100% of the equally-named channels of the source image. The resulting red channel contains only the tonal values of the original red channel, the resulting green channel only the ones of the original green channel, and so on. In short: the image remains unchanged.
Effects can be created by changing the mixing ratio. E.g. one could drain all original red from the red output channel and instead add 100% of green to it (set the R slider to 0%, the G slider to +100%). Pure red areas will get black, magenta will get blue, cyan will transform into white, green into yellow. Pure blue and yellow will not be affected at all. The following two figures serve as an illustration (left: original, right: with the aforementioned settings).
A Channel Mixer not only allows for extreme color changes and de-familiarizations, but also for quality color corrections and modifications in saturation.
However, within all corrections one constraint must generally be fulfilled: The sum of all source channel percentages for each output channel must always be 100%. Otherwise blown-out highlights and plugged-up shadows (highlights and shadows being set to pure white or black, respectively) can occur. Differences within highlight and shadow regions will therefore be lost. Further, colorless (gray) image regions will be colored, an effect that is seldom aimed for.
This can be partially corrected using the "constant" slider, but only visually and not in an exact way. Furthermore, in Photoshop the slider is labeled misleadingly. It does not add or subtract a percentage of the given tonal value for the selected output channel, but always a fixed value instead. E.g. the setting +100% adds 255 to the tonal value of each pixel of the selected channel, +50% adds 127.
If for example the three color sliders are set in a way that their sum is 177%, it is not enough to set the "constant" slider to -77% to fulfill the 100% rule. As you can see in the example to the right, this would leave a color cast. In this case 196 tonal values are subtracted from all pixels of the red channel due to the setting of the "constant" slider.
SF ColorMixer from the SimpelFilter series avoids all these disadvantages. You can see the result using the SF ColorMixer LE with the aforementioned settings below:
SF ColorMixer LE
Without license the filter works as try-out-version. The try-out version has all the functionality of the licensed version, except that the filter applies watermarks to the image. In addition the maximum size of the filter dialog box is limited.
Please order the license key here.
Freeware plugin for Photoshop and compatible programs (Windows only), version 1.1 from 1 nov 2005.
SF ColorMixer LE is Freeware and can be copied and distributed freely as long as no charges are being taken.
The User interface page shows global functions and key shortcuts of the filters.
The Automation page shows how to use the filters in Photoshop actions and scripts.