Using Color Management For Color Adjustment – Synthetic Profiles

Synthetic Profiles – Big Change Small Price

How can you change the appearance of a digital image without changing the numbers that assign the colors in it? Change what those numbers mean, by changing image’s ICC profile. Using abstract or synthetic profiles, you can make massive changes to an image with little to no cost, changes that would ordinarily cause big problems using standard methods, such a posterization and noise. It’s a practice known to color geeks and few others. When you’ve got a big job to do, it can get you out of a pinch in a hurry.

In most cases we think of using color management to accurately match colors when moving between different color spaces; ICC profiles are used to describe different color spaces and to make precise transformations to values moved from one to another to maintain consistent appearances. In very rare cases, when profiles are assigned to image files without a color conversion, the appearance of the image changes; values stay the same, but their meaning changes so the image looks different. So when you use this unorthodox method of color adjustment, you get a change in appearance without changing the values in the file and this is particularly useful when you want to pay a very small price for making very big changes.

This is worth restating. What exactly is the difference between assigning an ICC profile and using an ICC profile to perform a color conversion? Using an ICC profile to convert color changes values to maintain the appearance of an image. Assigning an ICC profile changes the recipe for colors without changing the values in an image, so its appearance changes.

Real / Abstract / Synthetic Profiles

You could say there are “real” and “abstract” profiles. Real profiles describe the color capacity of real-world devices, like monitors and printers. Abstract profiles describe theoretical color spaces that don’t refer to specific devices, like the standard editing spaces we all use in everyday digital imaging – sRGB, Adobe RGB (1998), ProPhoto RGB, etc. Both real and abstract profiles are designed to maintain a consistent color appearance. So what’s a synthetic profile? It’s an ICC profile that is designed to change color appearance or to solve a color problem.

Color Settings

Color Settings Custom RGB option

Creating Synthetic Profiles
You can create synthetic ICC profiles with Photoshop. Go to Edit > Color Settings and making sure More Options is checked go to Working Spaces > RGB > Custom RGB. In the final window that appears, you’ll use three variables to create a synthetic profile; Gamma, White Point, and Primaries.

Gamma affects brightness and contrast. Gamma is the midtone adjustment applied to compensate for nonlinear characteristics of capture and display systems. It’s the slope of the input-output curve. A slope of 1 is linear or with no change between input and output. Values larger than 1 make shadows darker; values less than 1 make shadows lighter. ColorMatch RGB and ProPhoto have gammas of 1.8. sRGB and Adobe RGB (1998) have gammas of 2.2. You can set a value as low as .75 and as high as 3.0.

Gamma is the most useful setting of the three; it’s excellent for making industrial strength adjustments to exposure. It has one variable.

White Point is the color temperature of white produced by combining red, green, and blue primaries at maximum strength. It’s measured in Kelvin degrees Fahrenheit. 5000K is the temperature of daylight (at high noon) and the industry standard viewing light. A higher value is cooler (bluer); a lower value is warmer (yellower).

White Point is useful for gross color adjustment; the results are best fine-tuned with other tools in Photoshop. It has two variables.

Primaries are the chromaticities (hue and saturation) of the red, green, and blue components that define a color space. Each primary is specified by an x and y coordinate. There are nine defaults to choose from including Adobe RGB (1998). If you’d like to start with values from other color spaces (including the other standard editing spaces like sRGB, ColorMatch RGB, Apple RGB, and ProPhoto RGB), using the RGB drop down menu specify a color space first, this sets the starting point, and then pull up to Custom RGB, where you can modify those values.

Primaries is the most complex and difficult to use of the three; it requires a lot of experimentation; it’s capable of making exotic color adjustments that can’t be duplicated with other tools in Photoshop but it’s much harder to predict and control. It has six variables.
To make it easier to preview the results of your explorations with synthetic profiles, discard the profile of the image you are viewing. Go to Edit > Assign Profile > Don’t Color Manage This Document. Photoshop uses the current Color Spaces Working Spaces settings to display files without ICC profiles. If you don’t do this, you’ll have to save a synthetic profile and then take the extra step of applying the profile to see the results, which will slow you down considerably.

When you’re ready to save your synthetic profiles, use Color Settings’ RGB drop down menu and pull up to Save RGB. (Don’t use the Save button on the right side of the Color Settings dialog; instead of saving an ICC profile, this saves all of the Color Settings as a .csf file, useful for syncing multiple Adobe applications.) When you finish creating a synthetic profile click Cancel in the Color Settings dialog; you don’t want synthetic settings to become your default RGB editing space as they are used when creating new files.

If you want to archive or share synthetic profiles, you can copy the profiles out of the folder they’re saved in. (On a Mac, profiles are saved with this path – Library > Color Sync > Profiles.)

To apply a synthetic profile go to Edit > Assign Profile command. You can see before and after appearances by checking the Preview box on and off.

Exploring Your Options

Because using synthetic profiles is so abstract, it’s useful to explore your options by comparing the results of multiple profiles side-by-side. While you’re exploring your options, at any one time, have a minimum of two identical files open in Photoshop so that you can carefully assess the results of different profiles.

Make a number of synthetic profiles based on your standard editing space (My standard editing space is ProPhoto RGB.) with different gamma settings varying in .1 or .2 increments. When you save your synthetic profiles, use a standard naming convention to tell the differences between them, such as SYN ProPhoto G2.2, SYN ProPhoto G2.4, etc.

Once you’ve applied a synthetic profile, should you then convert the file to a standard editing space? You don’t need to. Your synthetic profile uses the standard ICC language and should be accurately read by any software that is ICC compliant. One advantage to keeping it in the synthetic color space is that your file will accurately inform you about its creation. But if it makes you feel better, you won’t pay much of a price if you convert to a standard editing space; the few minor quantization errors associated with such color conversions are almost always invisible to the naked eye.

Fine-Tuning Your Results

While you’ll be able to perform the lion’s share of color adjustment using a synthetic profile, most images will benefit from additional fine-tuning through standard image editing practices in Photoshop.

With just a little experimentation, you’ll find you too can make big changes to your images and pay a small price using synthetic profiles. Using synthetic profiles is color adjustment without editing values; they change no values, but they do change the meaning of those values – and thus their appearance. Don’t believe it? Check your Histogram when you assign a profile. You won’t even see it move! It is kind of unbelievable. Try it. See it with your own eyes. You’ll quickly become a believer too.

Read more on Color Adjustment here.
Learn more in my digital printing and digital photography workshops.

Photoshop’s Color Lookup Makes Complex Color Effects Easy

  Original Image

The Color Lookup Pastel8Hues creates very strong color effects.

Any Color Lookup adjustment layer can be modified with Blend Modes. 

The Color Lookup Adjustment

Originally designed for color grading film and video, Photoshop’s Color Lookup feature offers novel ways to adjust color that will quickly reveal new possibilities in your images. Capable of performing extremely complex calculations extraordinarily efficiently, color lookup tables (LUTs) work by looking up a source color in a table and using the replacement color specified in the grid to transform it for the final destination.

Like Match Color and Gradient Map adjustments (See my last two articles for Digital Photo Pro.) the color effects Color Lookup generates are so complex they are not easy to previsualize. Like anything new, this takes practice. And these are new! Experiment and you’ll find many rich possibilities. Unlike Match Color, Color Lookup is loaded with presets that will allow you to quickly explore many different effects, ones that are far more sophisticated than Gradient Map presets. In this way, using them can be as easy as using many smartphone app effects.

Color Lookup offers three types of LUTs, each with its own drop down menu which contains multiple presets – 3D LUT File (27 presets), Abstract (15 presets), and Device Link (5 presets) for a combined total of 47 presets. While you can only apply one Color Lookup with a single adjustment layer, you can use multiple adjustment layers to successively apply as many Color Lookups as you like. Perhaps not infinite, the possibilities are many.
What is the difference between these three types of LUTs?

3D LUTs

3D LUT File
Dependent on color space, 3D LUT presets load and export files with 3DL, CUBE, LOOK, and CSP extensions. While Gradient Map adjustments use one channel (the grayscale values of the combined RGB channel), these lookup tables use all three color channels. They do not generate 3D effects as their name might suggest.

Abstract Profiles

Abstract
Abstract presets load and export ICC profiles. These settings are not color space dependent so they maintain consistent appearances during conversions to alternate color spaces and are favored when the color space of a file is likely to change during a workflow, as it may when moving files across different output devices or to video.

Device Link Profiles

Device Link
Also dependent on color space, this format is smaller and more portable than 3D LUTs.
3D LUT and Device Link presets are color space (sRGB, ColorMatch, Adobe1998, ProPhoto, etc) dependent and are recommended for use in the color space they were created in – all of the RGB presets were designed for use in sRGB. (LAB supports only Abstract presets. CMYK also supports Device Link but not 3D LUT presets.) This won’t stop you from generating impressive color effects other color spaces. You can use many presets with color spaces other than the ones they were intended for, although the visual appearance they generate will be somewhat different. You need to keep this in mind when you’re trying to achieve consistency between different files. Be mindful that if you make a color space conversion with an active Color Lookup adjustment layer, the appearance of the file will most likely change during conversion. (To get around this, you can merge the effect into a layer before making the color space conversion.) Remember this when you create your own Color Lookup presets.

Adjustment Layers offer Blend Modes like Color.

 Layer Styles offer Blend If sliders that remove effects from shadows and /or highlights.

Get Even More Control
At first glance, you might be tempted to think that you have limited control over Color Lookup effects. You either like an effect or you don’t. Don’t move on too quickly. Take another look. You actually have lots of control. When you apply a Color Lookup table as an adjustment layer, you can modify the effect by using Opacity and/or Fill (globally reducing strength with a slider), layer masks (locally reducing strength with a brush), Blend If Sliders (removing the effect from shadows and/or highlights with sliders), and blend mode (modifying the ways color adjustments are calculated). Even with all of this control, it’s likely that you’ll want to further refine the effects of a preset with additional color adjustments, using other tools, like Curves and Hue/Saturation.

Make Your Own Presets
You can also generate your own Color Lookup presets. To do this create a color effect you like with any with any combination of adjustments layers, Opacity and Fill, Blend If sliders, blend modes. (Layer masking and transparency will not be included, because alpha channel information in alpha channels is not included in the recipe.) Then go to File: Export: Color Lookup Table, name the file, and click OK. (I recommend the titles you give your presets include the color space you created them in.) These files are stored in Photoshop’s Presets folder or if they’re saved as ICC profiles in your operating systems Profiles folder. You can now use your custom preset at any time on almost any file by making a Color Lookup adjustment layer and choosing your preset. You can share your custom Color Lookups with others by giving them these exported files. Color LUTs created in Photoshop can even be used in other programs such as After Effects, Premiere, SpeedGrade and other applications that use color LUTs.

Using Color Lookup adjustment layers is one way of creating a condensed layer stack but it comes with a price – you won’t be able to adjust or mask individual adjustment layers. If you’d like to do this, as an alternative solution, you can place all of the adjustment layers into a Group and drag and drop the Group from one file into another when needed.
If you want to produce a Color Lookup preset and achieve the greatest consistency in appearance between multiple images you’ll want to use a file that is representative of a majority of the images it will be used on and include a professional color chart like X-Rite’s Color Checker. (This is especially important when processing video.)

Using Photoshop’s Color Lookup you can choose to create color effects as subtle or dramatic as you like. This game-changing color adjustment tool may seem exotic at first because it offers a new way of thinking about and seeing in color. Once you become more familiar with this mindset you’ll truly begin to see with new eyes. Isn’t that what it’s all about?

Read more on Color Adjustment here.
Learn more in my digital printing and digital photography workshops.

See Color In New Ways With Photoshop’s Gradient Maps

Before and after the Gradient Map     

Whether used subtly or dramatically, Photoshop’s Gradient Map color adjustment tool can open up new ways of seeing and working with color for any artist. Photoshop’s Gradient Map assigns new colors to existing brightness values. With it, you can enhance existing colors, transfer colors from one image to another, or create entirely new color relationships. It can be wild!

The Gradient Map

The Gradient Map interface looks difficult to use but with a few pointers you’ll find it surprisingly easy to use. While you can apply a Gradient Map directly to a layer (Images: Adjustments: Gradient Map), I recommend you apply Gradient Maps as adjustment layers (Layer: New Adjustment Layer: Gradient Map), to take advantage of both the greater flexibility and control you’ll gain over the final effect. Once activated, there are a number of default presets you can experiment with but it’s most likely that you will want to create your own. Simply click on an existing gradient in the Properties panel to activate the Gradient Editor. Click New. Click at the bottom of the gradient to add new colors. A pointer will appear, double click it or the Color box to choose a color. You can move the pointer to direct the color into different tonal values (Move left to target darker values and right to target lighter values. Alternately, enter a new number in the Location field.) while the diamonds left and right of it will control how each color fades into surrounding colors. You can add dozens of different pointers/colors, but for most applications I recommend you restrain yourself to as few as possible. You can delete a pointer/color by clicking on it and clicking Delete or by pressing the Delete key. When you create an effect you’d like to use more than once, type a Name and click Save; you can easily store, retrieve, and share these “grd” files.
The color effects you can generate with the Gradient Map are so powerful and so varied you simply must spend a little time experimenting with it to truly understand both how far you can go and how subtle you can get. Consider this kind of visual research time well spent.
After you’re done experimenting, then it’s time to deliver.
Working with the Gradient Map often takes a little finessing. You’re likely to be a little disappointed if you try and get the perfect colors with the Gradient Map alone. You can spend a great deal of time picking and repicking colors until you get it just right. Instead, try working more broadly, getting close to a desired effect and then fine-tuning the results.

Layer Blend Modes give more control

Layer Style removes effects from shadows and/or highlights

Here are the go to tools for fine-tuning the results of Gradient Map adjustment layers. Use the Opacity slider to reduce effects that are too strong. For selective opacity, add a layer mask. Use Blend If sliders (double click on a layer to activate them) to reduce or remove effect from shadows or highlights or both. If transitions created by Blend If sliders aren’t smooth enough, use a luminance mask.

Normal and Hard Light blend modes compared

Blend Modes can be used to add more control over the way colors mix. In particular, focus on the color blend modes (Hue and Color) and the contrast blend modes (Overlay, Soft Light, and Hard Light). Hue restrains the effect to that element of color only. Color restrains the effect to both hue and saturation, removing any effect on luminosity. In order of increasing intensity, Soft Light, Overlay, and Hard Light boost contrast and gradient colors will have a more transparent appearance.
Even with all of this control, it’s likely that you’ll find the best results are most often achieved by using this tool to create an interesting color foundation and then refining it with additional color adjustment tools like Curves and Hue/Saturation.
Once you’ve mastered the interface the real challenge begins – visualizing color possibilities. Pre-visualization can only go so far; instead use software as a tool for visualization. Instead of rushing to a single finished result, I prefer to work on multiple copies of an image to make side-by-side comparisons of a set of variations. The possibilities are seemingly so limitless that you must perform some experiments to find the best solution. If your experiments are both targeted and iterative, then you’ll generate many solutions that are more likely to be optimum.
Here a little color theory can be useful. Use dark colors in shadows and light colors in highlights; otherwise you may posterize or solarize. Use analogous colors (similar color families) to create transitions; transitions between complimentary colors tend to get muddy. Variations on earth tones work well for both realistic and antique effects. Variations on warm colors can add intensity, even fire. Variations on cool colors can generate nocturnal and even aquatic effects.
Remember, you can sample colors from one image and apply them to another. Gradient Map effects are distributed based on lightness values so keep this in mind when selecting and transferring colors.

Black and white conversion plus toning created with Gradient Map

Amazingly, you can even make successful color to black and white conversions with Gradient Maps – just use neutral colors. Again, for naturalistic effects, you’ll want to create progressions that move from dark to light, but the steps and the transitions in between can be varied substantially. Guard against posterization and excessive noise. You can even create black and white toning solutions with the Gradient Map; it’s excellent for split tone effects that target different hues into different tonal values.
Photoshop’s Gradient Map is an exotic color adjustment tool that can be a real game changer. If you truly understand the possibilities this tool opens up you will have learned to see in new ways. What could be more valuable?
Read more on Color Adjustment here.
Learn more in my digital printing and digital photography workshops.

Photoshop’s Match Color May Change The Way You See

Source

Target

Final Effect

Photoshop’s Match Color

Little explored and capable of opening up whole new frontiers in color adjustment, Photoshop’s Match Color is a tool every user should be aware of – even if it’s only to know what’s possible.

There are three primary reasons to consider using Match Color: one, to match two colors exactly; two, to remove strong color casts; and three, to creatively apply the color in one image to another.

Match Colors Precisely

When a precise color match is critical, for instance when matching the same products in two images, Match Color is hard to beat. And, in terms of easy of use, using it beats placing sample points and moving sliders to make the targets match. You can create statistics from and apply the effect to either an entire image or only a portion of an image using selections.

Remove Strong Color Casts

Match Color does an exceptional job of removing strong color casts. One of the primary reasons it was developed and most common uses for it is to remove the strong color cast in underwater images. It does an amazing job at revealing the complex color relationships below the color cast. Here, you don’t even need a source image. Just check Neutralize. If the effect is too strong you could use the Fade slider, but I recommend you apply the effect to a duplicate layer and use the Opacity slider of the layer or if you want to reduce the effect selectively, use a layer mask. Using this feature on images that don’t contain strong color casts often produces pleasing results too.

Create Complex Color Changes

This is where it really gets interesting. What if you took colors from a candy store and applied them to the sky? What if you took colors from a sunset and applied them to a landscape? What if … I know, I sound like a kid. You’ll feel like a kid when you use Match Color. It seems like anything is possible. When you first view the results, you’ll do a double or triple take. You have to see it to believe it.

The math is complicated, very complicated. The tool’s interface is simple and easy to use. Learning how and when to use it is deliciously challenging. With practice you can develop an intuitive feel for the direction color relationships will move in and start to think predictively when using Match Color, but the final effect it generates is usually so complex you have to see it to believe it.

Normal

Neutralize

Taming The Beast

Match Color samples the colors from one image and applies the resulting statistics to another image; all three elements of color Hue, Saturation, and Luminosity are taken into account in both the source and the target images. To do this a minimum of two files must be open at one time, a source and a target. Once saved, you can load these statistics in the future to any image, as long as it is in RGB. Match Color only works in RGB color mode. Not available as either a non-destructive adjustment layer or a Smart Filter, Match Color must be applied permanently to a layer, so consider applying it to a duplicate or composite merged layer.

You have limited controls over the results. The Neutralize check box; try it, you might like it – a lot. The Luminance slider; be careful of the image’s dynamic range when using it. The Color Intensity slider; in addition to saturation it also control how much variety in hue is generated – higher settings produces more of both. The Fade slider; it’s reduction of the effect is slightly different than applying the full effect to a layer and then reducing its Opacity, but the former cannot be localized so I prefer the latter. One check box, Neutralize, and three sliders give you some controls over the results.

You can either use all the colors in an image or only colors within a selection in a source image to create statistics from; after making a selection in the source image go to the target image and in the Match Color dialog box check Use Selection in Source to Calculate Colors.

One portion of source selected

Another portion of source selected

Alternately, you can modify the calculation by selecting a portion of the target image; after making a selection in the target image, apply Match Color and check Use Selection in Target to Calculate Adjustment. If you’d like to apply that effect to the entire image instead of just a portion of it, instead of applying the effect, check Save Statistics, then press Cancel, and when you reapply Match Color check Load Statistics.

Two sources applied consecutively

You can even apply several statistic sets progressively to the same layer to create still different effects.

Effect layered over original

Layer Blend Modes give more control

Layer Style gives you still more control

You can use the many power of layers to control how the new colors blend with the old. Reduce the layer’s Opacity to restore some of the original color; add a layer mask to do this selectively. Use the layer’s blend mode to control how the new colors mix with the original colors; in particular try the blend modes Color and Hue, which will use the new hues with the original luminosities. Use the layer’s Blend If sliders to remove the effect from shadows and/or highlights; alternately, use a luminosity mask. Applying Match Color to a new layer gives you a safety net (You can always return to the original color.), allows you to easily compare more variations, and gives you more control.

One of the strategies that really makes this technique shine is to first create an interesting color foundation with Match Color and layer options and then refine the colors further with additional color adjustment tools.

Controlling the effect with more any precision is challenging. You can change the colors of either the source or the target images before creating and /or applying the statistics. Use any tool in Photoshop. The question is how? (Here’s one tip. Inverting colors before sampling them often generates interesting results.) Doing this involves a lot of trial and error. Yet, these color experiments can sometimes be profitable. Once in a while, they lead to real breakthroughs. At a bare minimum, they’ll encourage you to think more flexibly about color.

Match Color is an exotic color adjustment tool that can be a real game changer. Try it and you’ll see and think about color in new ways. What could be more exciting?

Read more color adjustment resources here.

Learn more in my digital photography and digital printing workshops.