How to Use LAB Color in Photoshop to Add Punch to Your Images

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Have you ever wished you could stretch out the color palette of your picture? Or that you could separate colors that looked too flat or close together?

Well, with Photoshop, you can – by converting your picture to something called LAB colorspace and adjusting the color there. That might sound complicated, but it is actually pretty simple. If you have ever made a levels or curves adjustment, you already know everything you need to know to accomplish this.

Grand Canyon

The left side of the picture is an unadjusted Raw file. The right side of the picture is the same except for a curves adjustment layer done in the LAB color space.

In this article, you will learn two things. First, you will learn the five simple steps to achieve color separation using the LAB color move. You can follow these steps without even understanding how any of this works and it will work just fine for you. Second, after walking you through the steps, you will see how this move works. That way, if you want to apply this move to your photos in a more nuanced fashion later it will help you to do so.

The LAB Color Move

So let’s walk through the steps of “the move.” There are five steps in this process, all of which are simple and can be accomplished in 30 seconds or less.

1.  Convert to LAB Colorspace

First, you have to convert your picture to the LAB color space. To do that, just click “Edit” on the top menu, then choose “Convert to Profile.” When you do so, a dialogue-box will pop up.  From the drop-down, choose “LAB color.” That’s all there is to it.

Convert to Profile Dialogue Box

For now, your picture looks exactly the same. All you have done is changed the way Photoshop renders color in your image (more about this later).

2.  Create A Curves Adjustment Layer

Next, you will need to create a curves adjustment layer. There are a few ways to do this, but if you don’t already have your own way, just click on “Layer” in the top menu, then choose “New Adjustment Layer,” then “Curves.” Click “OK” in the box that pops up.

Creating a New Curves Adjustment Layer

3.  Scoot in the Endpoints of the A Channel

Everything so far has been mere prelude to get you to this point, and you haven’t actually changed your picture at all yet. You have converted to the LAB colorspace and created an an adjustment layer to work on. Now the fun begins.

You will see a drop-down menu near the top of your adjustment layer and the current selection will be “Lightness.” Click on it and you will see three choices: the Lightness (or L) channel, the A channel, and the B channel. Select the A channel.

You will immediately notice that your histogram changes dramatically. Most likely, it now looks like a big spike in the middle. Don’t worry about that – that’s the way most histograms look in LAB color.

What you are going to do is grab the left (black) endpoint and drag it toward the middle of the histogram a little bit. There is no set amount to move it, but if you are looking for a little guidance drag it until the Input number reads -90.  Your picture probably just turned an ugly shade of green but don’t worry about it. Now, grab the right (white) endpoint and pull it to the left. In fact, pull it to the left the exact same amount that you moved the left endpoint to the right. You can use the Input numbers below to make sure you are moving each side in the same amount.

A Channel - before and after adjustments

That should fix the green cast. But don’t worry too much about what your picture looks like right now. Let’s go on and perform the second part of the LAB move.

4.  Scoot in the Endpoints of the B Channel

What you are going to do here is exactly what you just did in the step above, but this time you are going to do it in the B channel. So, go back to the drop-down that currently reads “A” channel. Click on that and now select the “B” channel.

As you did above, just scoot in your endpoints toward the middle of the histogram. So grab the left (black) endpoint and drag it toward the middle a little bit. Your picture just turned a shade of blue but don’t worry about it. Now, grab the right endpoint and pull it to the left the exact same amount that you moved the left endpoint to the right. Again, input values of about 90 should get you roughly where you want to be.

5.  Inspect Your Handiwork

Now it is time to see the “before” and “after” pictures of your image; this is one of the benefits of working with layers. On the right side of your screen where your layer is shown, you will see a little eyeball just to the left of each layer. For the curves adjustment layer you just created, click on the eyeball. When the eyeball disappears, you will see your picture before the adjustments you just made. Click again to see the eyeball with your changes to the image.

Eyeball On and Off - Showing Changes in Image

On the left, the eyeball is on, so the changes will be shown. On the right, the eyeball is deselected, so the changes will not be shown.

Do you see how your color range has been increased? The colors should also appear more rich and vibrant. If you are not noticing much of an effect, try scooting in the endpoints of the A and B channels a little bit more (say, down to 80 if you are using the input numbers). On the other hand, if the colors look too garish to you, drag the sliders out a little bit (to say, about 110 on each side). Or you can reduce the effect by decreasing the opacity of the curves adjustment layer.

MonumentValley-halves

That’s it, you now know the LAB color move. Go ahead and switch back to your original colorspace and perform any other edits you want on your picture. Then, try this move out on a few different pictures. You will probably find that it doesn’t help pictures that already have vibrant colors, but it can perform miracles on certain landscapes you previously found too flat.

How it Works

Upon learning this move, you may have questions about how this works and why you couldn’t just do it without switching to the LAB colorspace. I will explain that in the remainder of this article.

Sailboats-halves

How LAB differs from your usual colorspace

For starters, we need to have a general understanding of how LAB differs from RGB color. So first you should understand how colors are rendered in RGB, and then we will move on to show how LAB differs.

RGB color

RGB histogram

Histograms of the RGB channels

The RGB colorspace is the standard used in digital photography. This is the colorspace that your camera uses, and the one that Photoshop defaults to. RGB simply stands for Red, Green, Blue, and that tells you a bit about how it works. In this scheme, the camera or computer starts with these three colors and then combines them to create a whole host of different colors. Thousands of them, in fact. If you are having trouble getting your head around how really light colors (say, yellow) can be created by combining red, green, and blue, understand that there are many different shades of red, green, and blue, starting with very, very light (bordering on white) shades. In fact, the way that RGB and LAB deal with lightness is a key difference between them, as you will see.

When you look at a histogram for a picture in RGB, you are seeing a combination of the values for each color channel. You can see each of the individual color channels by clicking on the drop-down labeled “RGB” in your curves adjustment layer. When you do so, you will notice that the histogram for each of the channels is different, but not that different.

LAB color

LAB histogram

Histograms of the LAB channels

The LAB color space goes about defining colors differently. Whereas RGB defines color by a combination of red, green, and blue values of different shades, LAB uses three different channels. They are: Lightness, something called the A Channel, and the B Channel. Hence, Lightness, A Channel, and B Channel are shortened to L-A-B, LAB.

But what are these channels? Let’s start with Lightness, partially because it is first, but also because it is likely to be the most familiar to you. It represents the relative brightness of the pixels without regard to color. So Lightness is kind of like a greyscale image, where each pixel is defined by how close to white or black it falls on the scale. The Lightness histogram probably looks like something you are used to. The values of a properly exposed picture with good contrast should spread out over most or all of the histogram.

The A and B Channels will likely be unfamiliar to you. Whereas the Lightness Channel defines the lightness of the pixels without regard to color, the A and B channels define color without regard to lightness. Color and lightness are addressed separately in LAB, not together as they are in RGB (more on this in a bit).

Let’s talk about the A Channel first. The “A” doesn’t actually mean anything. They just call the two color channels A and B. The A Channel is just a definition of color values based strictly on how much green on one hand, or magenta on the other, are contained therein. The very middle is actually gray, and the hues get progressively more green to one side and progressively more magenta to the other.

The B Channel works the same way as A, except that it defines color by how much blue on one side, and yellow on the other, it contains.

It might help to think about it like this. Whereas RGB renders color by defining each color as some combination of red, green, and blue, LAB renders color by defining each color as some combination of green, magenta, blue, and yellow, with lightness addressed separately. However, while each color gets its own channel in RGB, colors share channels in LAB (two per channel).

If you are starting from scratch with the LAB colorspace, try playing with it. Load a few of your pictures, go into LAB, then go into the three channels on a curves adjustment layer. Look at the effects of sliding in the endpoints of just one side of the histogram. You should start to see how the A Channel is a measurement of the balance of green or magenta. The B Channel is a measurement of the balance between blue and yellow.

The Power of LAB

Here is the really interesting bit and why LAB is so different, and in many ways superior to RGB. Look at the histogram of the A Channel of your picture. There is, no doubt, a spike in the middle. That is because LAB is such a ridiculously broad color space that all the colors you and I would consider “normal” are bunched up in the middle of the histogram. If you go outside of that bunch in the middle, you would soon get some really psychedelic colors, and beyond that you would get into impossible or imaginary colors that are outside the realm of anything we can actually use.

The impossible colors don’t matter, but what does is the effect on the histogram that all this creates. Having the colors of your image all bunched up in the middle of the histogram means that you have lots of room to scoot in the endpoints of the histogram and effectively stretch the color palate.

This move is not possible in RGB. Typically, in RGB you will not have enough space on the sides of the histogram to scoot in the endpoints. The colors will usually be stretched over most of the histogram. But even if you have room to do so on the histogram, in RGB it will affect the brightness and the color balance of the picture.

The other reason LAB is so powerful is the separation of lightness from color.  As a result of this separation, resetting the black point and the white point in the histogram of the A or B channels affects only color.  You can stretch out the colors without making them lighter or darker.

Before and after LAB color enhancements.

Before and after LAB color enhancements.

Conclusion

Just knowing and using the basic LAB color move will significantly impact your pictures in ways that were not previously possible. It is more than just an increase in saturation – it’s stretching the color palette.

This move is only possible in the LAB colorspace because:

  • The LAB colorspace is so broad that there is always room to scoot in your black points and white points on the histogram.
  • Separating the lightness values from the color values, and putting the lightness values on its own channel (the L channel) means that you can impact the colors without affecting the brightness or contrast of the image.

The the basic move is just the beginning of what you can do.  From here you can make additional adjustments to the A and B channels that will remove color casts by moving in one side more than the other.  Or you can apply masks and affect color in specific areas of your image.  Start with this basic LAB color move and you’ll see immediate improvement and soon will start seeing other possibilities.

Read more from our Post Production category

Jim Hamel shows aspiring photographers simple, practical steps for improving their photos. Check out his free photography guides and photography tutorials at Outdoor Photo Academy. The free tips, explanations, and video tutorials he provides are sure to take your photography to the next level. In addition, check out his book Getting Started with Photography.

  • Thanks, and good question. It had been a while since I converted with using Image-Mode, but I had a vague recollection that I didn’t like it for some reason. I just went into Photoshop and did it to refresh my recollection and it worked ok. The only issue I found was that I needed to flatten the image before converting back to RGB or else Photoshop discarded the changes along with the layer. So it it works the same way for you, then make sure you flatten before you convert. But otherwise, it will work fine. I have seen others recommend this way, actually.

  • Wow. That’s a lot of color work. Impressive. Yes, I’m sure that has served you well in photography and particularly in your prints.

  • Thanks for the reply.

    Converting the image back from LAB to RGB using “Convert to Profile” will also flatten the Layers – it’s just that Photoshop doesn’t first ask you if this is ok!

    So that’s also something to be aware about when using “Convert to Profile” to change back.

    Hence, your recommendation to perform the Curves correction & then convert back to RGB before commencing any other image adjustments (where it’s important to retain layers), is a good one!

  • Ted Dudziak

    Thanks for this article. I tried it on a landscape and what a difference. I usually use the Vibrance control in Camera RAW but switching to LAB seems to give another control dimension. What I think I will do is to use it if my other techniques do not produce the result that I am looking for. I had applied the Vibrance control on the image that I tried this technique with.

    I think the take away from the color space comments below are that you need to convert back to the color space that your printing lab, printer or whatever is using.

    I noticed that when the color space is changed back the adjustment layer disappears. I have not tried using it on a smart layer but I would suspect that it will also disappear as well since the color space is a more native characteristic to the image than other adjustments.

  • This really is a great adjustment but I have one problem. I can’t save in JPEG. Is there something I’m missing?

  • You have to convert back to RGB in order to save in JPEG. Try that and that ought to fix it. If that does not work let me know.

  • You are correct the adjustment layers disappear when you convert between color spaces. Your supposition that this would also occur with smart layers is also correct. I’m glad you are getting results with the technique.

  • Ted Dudziak

    It works

  • MeowPaw

    Aahh i see… You got my question right 🙂 Thanks for your answer!! I just need to make something clear in my mind. If I have a photo in RAW and I convert it in LAB, I like what I see, what I have to do in order to be able to get a JPG or PNG file? I think I got lost in translation hehehe
    Sowwy for being a pain >_<

  • Michael Owens

    An excuse to spam a link for a piece of software. Clever spam but spam all the same.

  • It should work exactly the same if you start with a JPEG. Just remember to convert back to RGB when you are done with your edits if you want to save your file as a JPEG.

  • MeowPaw

    Got It! Thanks a lot Jim 🙂 happy Sunday!

  • Jorge

    You all know that Nik Color Efex 4 (Remove color cast filter) does this in about 2 seconds right?

  • I love Color Efex 4, but that’s not really correct. The point of the basic LAB color move described in this article is to stretch colors apart, not correct a color cast. So it is a different issue entirely.

    But even when it comes to correcting color casts, using LAB in Photoshop is much more precise and powerful. The histogram in LAB will show you the exact color cast you have and let you change it more precisely using curves than just the little color and strength sliders in the Nik filter. I am actually working on an article about that as a result of one of the comments to this article so stay tuned if you would like more info on that.

  • Great article. I found this as a possible replacement to Clarity in LR with the addition of color adjustment as well.

  • Jonathan J. Weir

    I noticed my photographs gaining a hazy appearance upon changing back to the rgb format. Anyone else experience this? Am I doing something wrong?

  • Kunal M

    Hi Jim,

    Agreed…. it’s a hidden photoshop gem (never hearrd of earlier). I tried it & the results were amazing; it really transformed the image into a vibrant & more live one. Thanks a ton for that!

    2 questions –
    1. After doing intial adjustments, how can I locate the LAB adjustment window again to re-modify the image?

    2. Same thing I am facing here as Jon…. I followed all your steps, per artcle. But unable to save it as JPEG or JPG format.When I saved, it was a huge file (5MB converted to 52 MB) & was unable to view it in windows picture viewer.
    Could you please explain, step by step, how to convert back it to RGB after doing adjustments thr LAB profile?

    Thank you.

  • Sure. I’m glad it is helping you.

    On your first question, I’m not sure I’m following you. But if you are using a Curves Adjustment layer, even after you have made the adjustments you ought to be able to click on the layer and bring the histogram back up, so you can re-adjust however you want. At least, you can do that until and unless you flatten the image or convert back to RGB.

    On your second question, yes you need to convert back to RGB in order to save as a JPEG. Here is exactly what to do to do that:
    -Once you have made you LAB adjustments and are done with all that, click on Edit in the top menu, the choose Convert to Profile, which is near the bottom of the list.
    -A diaglogue box will pop up. In the middle of it, there will be an option labeled Profile. Choose one of the RGB color options to get you back to RGB. Specifically, you can choose Working RGB or ProPhoto RGB. Either will work.
    -At that point, your journey to the land of LAB is complete and normality has resumed. You can now save you picture as a JPEG and do whatever else you normally would do to it.

    If this doesn’t solve your issues, just let me know.

  • Kunal M

    Thanks much, Jim !!!

    Will try it out.
    1st point – need to explore it, per your steps.
    2nd – cleared all my queries.

    Besides normal saturation, contrast etc settings, I was not that confident & knowledgeble to use the Photoshop. But with your simplified approach of teaching, could dare to start with the above article.

    Hence, It would be great if you could share such photoshop techniques & tips ie post production technique for beginners like me.

    Your other articles are also helpful.

    Please share your twitter id & facebook links.

    Thanks again. Appreciate it.

    Kunal
    zenkunal@gmail.com

  • atomantu

    Hey Jim! Great tutorial here. One thing I thought was why not use a levels adjustment layer instead of curves? Levels is a little simpler to use when you don’t need the fine control of curves. (Lamenting that Lightroom lacks levels…) Or am I missing something here? Another tip: save your curves (or levels) adjustments as a preset. Or make the whole thing an action!

  • atomantu

    One more tip: if you want to keep you Lab color layer in that mode for whatever reason, select your image layer and curves adjustment layer, plus any other layers you may have, and convert those into a smart object. Then change the image back to RGB. You’ll be back to a single layer file but the smart object will still contain the separate layers.

  • You can use levels, but I would stick with curves. If you are not comfortable with curves, keep in mind that you can just slide in the endpoints exactly as you would a levels adjustment layer. Good ideas on the actions and presets.

  • JSummar

    Another great article, Jim! Simple explanation. I went to try it, but it must not exist in Photoshop Elements, or maybe it’s located somewhere else. I have a Color Curves enhancement area, but no adjustment layer with these options. Please tell me this can be done in PSE???

  • Bad news . . . this is one of the few things that can only be done in full Photoshop (not Elements). It is almost worth the upgrade.

  • Ted Dudziak

    This is a fabulous way of making your images pop especially for landscapes. Adjustments are a bit heuristic so some patience is necessary for some images but the guidance in the article is good. The only thing to remember is that PS severely restricts the formats that you can save the image as indicated by the screenshot I have included. Convert back to RGB to get JPEG or other formats for sharing or posting.

  • Gail

    Wow this was a fantastic article! Thank you so much!! What an impact on just the first picture I tried it on. Beyond thrilled now! 🙂

  • Gail
  • Gail

    I went light but I was playing with it! I love it for quick tweaks but I always try to get it right in camera.

  • Awesome, thanks! Glad to see you’re putting it to good use.

  • Jim Campbell

    This was linked to today (7 March 2016) by the DPS Twitter account, so I read it and had a play around. Not sure if it’s because of PS upgrades since, or if it’s always been the case, but worth noting that when you change back to RGB colour space you either merge your new curves layer or you lose it!

  • Hussard

    Impossible to save Lab Color picture in Jpeg, you should have write about it in the introduction.

  • Bittersouite

    Lab is amazing. Very intuitive and powerful !

  • Cathy Starr

    I’m learning on the fly, and this article really made some fuzzy areas a bit clearer. Thank you for sharing!

  • marcdraco

    Very clear explanation Jim. I’ve seen this technique before but never really understood how it worked. Now all I have to do is figure out how to make it work with video. I have a compositor [Natron] that can break colour into LAB and back to RGB but the curves adjustment in the middle is proving a might bit tricky. 🙂

  • David Milo

    Thank you, great explanation! The big question–I guess–is: how can you preserve that broad colors pace when printing? Isn’t it converted to CMYK anyways?

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