Automatic colorizing

The images I use were not supposed to be fully isolated or colorized, so I have to be careful about what objects I use. But this hat is fine. The edges are not very smooth, but it’s still manageable.

Now let’s make a selection of the hat. In this particular case, I’ll use the Quick Selection Tool, hoping that it will manage to preserve the fine details on the edges. Whatever tools you choose to use, the result shall be the same: an accurate selection of the object or a part of the object you want to colorize. The rest can be recorded in an action to make things easier. For a start, I’ll create a new set of actions and call it “Colorizer”. Then I’ll create a new action in this set, call it “Colorize” and start recording straight away.

First of all, we need to modify the selection. Most selections created from a path require feathering, and in some cases, we’d like Photoshop to use some advanced techniques of edge detection. Bad news: you can’t record Refine Edge in an action, as it will turn into a pumpkin the moment you’ll try to run it. Despite the fact that you can still access and use the Refine Edge panel by holding shift and clicking on the Select & Mask command in the Select menu, it will still be recorded as a Select & Mask step. So you have to live with it. Fortunately, we don’t really need serious modifications at this point, and Select & Mask can handle feathering, smoothing and edge shifting.

In the Select & Mask step, we refine the selection, keeping the possible problems in mind. In this particular case, I know that there might be a bunch of fine hairs that are not included in the selection, and they will not be colorized and might stick out later. So I’ll shift the edge outside, and hopefully, it won’t shift too much to cover any of the background. I’ll also feather it, but just a little bit. Now we can proceed to the colorizing part. But before we do it, we have to take some precautions. I’ve mentioned blending modes a while ago, and blending means conditions. Some blending modes do not blend just anything. We’ll be using the Soft Light blending mode, and if you try it to blend it with an underlying layer that has some black or white areas, it won’t work. By black and white, I mean pitch black and absolute white – areas filled with 0;0;0 and 255;255;255 RGB colors. So in case, there are some glares or very dark shadows with no information, we want to prevent Soft Light from failing. How can we do that? By removing the black and white from the image. I’ll access the Levels panel and type the new numbers in the output levels: 5 instead of 0 and 250 instead of 255. It will get rid of black and white pixels by lowering the contrast, but the contrast drop won’t be too drastic to become an issue. Another thing with the Soft Light blending mode is that it will give us weird color shifts despite the color of the top layer we’re blending. If the lower layer has any color, it will shift. So it will be only natural to desaturate the image we’re working with to make colorizing easier and more predictable. I’ll do it by pressing Ctrl-Shift-U which is the Desaturate command shortcut. There’s another case when the Soft Light blending mode won’t blend – that is when the top layer is 50% gray, but I doubt you’ll ever try to colorize something with gray.

Great. Now we’re ready to do some blending. After making sure the selection is still there and active, click on the “Create new fill or adjustment layer” button in the layers panel, it looks like a black and white circle. Pick “Solid Color” in the drop-down menu and then choose the color you want to paint your object to. You can choose any color from black to white, just remember that painting dark objects to white is the hardest task, as it’s not easy to make it look natural. We’ll get to that in a few minutes, but for now let’s start with something simple, like blue or red. After pressing OK, we get this new color fill layer applied on the background through a mask, which appeared because of the selection we had prior to creating the layer. You can alter the mask by clicking on it and painting on it with a black or white normal brush. Black will remove the effect, and white will apply it. Transparency also works – a mask can be solid or semi-transparent. But I hope that you won’t need to twiddle with the mask at all. Now change the blending mode of the top layer from Normal to Soft Light. Why Soft Light? The deal is that I wanted to create a universal colorizer, something that you can use when you color black to white or white to black. As Soft Light is a contrast blending mode, it can be used in both situations, while darkening and lightening modes can only be used to lighten or darken. At the same time, it preserves contrast which is so easy to lose and hard to gain.

At first glance, it doesn’t look so good. The deal is that Soft Light works in a subtle way, and even at 100% opacity, the effect won’t be too drastic. We could use Hard Light to make the image change significantly, but it’s not worth it. What you need to do is duplicate it as many times as you need. And you don’t need to put this in an action, as every time the quantity of layers you need to reach the desired effect might be different. Most of the time it takes three, but who knows. For precise adjustment, you can change the opacity of any of the layers to reduce the effect. With three layers of Solid Color Fill through Soft Light, the hat changed its color significantly, and it’s pretty close to the color we need. So that’s it for the “Colorize” part of the action set, no we can proceed to the volumizing part – this time we’ll try to add some volume to the image so that it won’t look flat if such a problem occurs. It depends on the image, of course, and on the color you’re trying to paint it to. Sometimes the result of just the “Colorize” action will be surprisingly good, so good that you won’t need anything else. But sometimes it won’t be so easy, so you have to master the volume adding part as well.

The best way to demonstrate the necessity of volume adding is to try and paint something black to white. The shadows fade away really quickly as the image becomes white, and that’s exactly when we need to add some strong contrast to increase the volume.

Now it’s a good time to make sure we have the Properties panel displayed, as we’ll soon be using it. If you don’t have it active already, you can access it by clicking on the Properties command in the Window menu. And if you feel like you don’t really understand what’s going on, take a break from the course and get yourself more familiar with layers, layer masks, layer styles, and effects – it will be impossible to use the actions without at least basic understanding of what they do and how.

I’ll go back in history to the step before we started recording the “Colorize” action, that’s when we had an active selection of the original image. It’s time to run the action, but before we do that, let’s just add a few windows popping up so that we can change the setup each time. The “Colorize” action has two steps that require users’ attention: the first one is the Select & Mask step – so click on the empty box to the left of it to toggle dialog mode on. The second one is the Make fill layer step, this is where we pick the color we need.

Now I’ll run the action, modify the selection the same way as before and then pick white as the color of choice. Then I’ll duplicate the resulting layer a couple of times, but as we’re going to increase contrast – and you have to remember that, I don’t make the image look white just yet. If I make it bright now, after contrast increasing the highlights will be blown out. So for now, three Soft Light layers is enough. Let’s record another action.

I’ll create another action in the same set and call it “Volumize”, as it will be used to add some volume to the image. First step will be “Select all layers” – you can just press Alt-Ctrl-A or go to the Select menu and press All Layers command. It will select all the layers we’ve just duplicated, except for the Background. Now I’ll put them all into a Group by right-clicking them in the Layers panel and clicking on the “Group from Layers” command. No need for any changes here, the name doesn’t matter and the blending mode should be Pass Through. Great, now while the group is selected, click on the “Create new fill or adjustment layer” button again, but pick Black & White this time. Look at the Properties window – we have Black and White adjustments there. To make this new layer style take effect on the masked area, not on the whole image, click on the leftmost button in the lower part of the panel. It looks like a rectangle with an arrow. When you click on it, the area around the hat won’t be affected by the Black & White effect anymore. Now change the blending mode to Hard Light. This exactly what we need to get our volume back – the shadows are still there, and the whole image turned white, it’s not gray anymore. But as all the images are unique, I can’t guarantee that the same step will work perfectly on pretty much everything.

Now click on the “Create new fill or adjustment layer” button again, but choose Levels this time. And when the Levels adjustments appear in the Properties tab, don’t forget to click on the rectangular-with-an-arrow button to make it attach itself to the layer mask. Otherwise, it will affect the whole image, and we don’t want that to happen. Well, congratulations! We’ve just finished recording the action, and there’s nothing else you need to be able to change the color of pretty much everything – only some manual tweaking of the Levels adjustment layer, and what’s even more tricky – some “blending if”. But don’t worry, I’ll show you how to do it.

Blend if is not an easy thing to learn. If this is the first time you hear about it, I strongly advise you to read some tutorials on the matter, as it’s not intuitive. I cannot allow myself to spend much time explaining how it works and I hope you already know it. But still. It is useful when you want to emphasize a glare on a shiny surface. To do so, you need to find the glare first. And this hat is actually not a good example of something glossy. So I’ll use another image for the Blend if explanation.

From now on, I won’t be making any selections manually, as we paid enough attention to this matter in the “Isolation” part of the course. I’ll be only loading selections I previously made from alpha-channels. Don’t know about you, but I always feel impatient when I watch a tutorial which is not about isolation, and I have to watch the author spend many minutes on isolation. So I won’t make you suffer like this.

Once again, we have this image, we have the selection, we want to change the color from black to white. I’ll give it a go with the “Colorize” action first. Three layers of Soft Light seem to be enough. Now I’ll run the “Volumize” action, and when it’s over we face two problems: first is that the bag turned white, but it stopped being glossy, and the other one is that the shadows are very noisy. The latter happened because the initial image had little details in the shadows, with them being so dark. I’ll try to deal with the glossy problem first, and then we’ll see what can be done about the shadows.

It’s actually a good time to try Blending if. We’ll emphasize the glare by making the Hard Light layer affect not the whole image, but just a part of its tonal range, the part we define manually. Click on the Black & White layer to select it, and then click on the “Add a layer style” button here in the Layers panel and choose Blending Options command or just double click the Black & White layer in the panel, the Blending Options tab will be opened so that you can twiddle with the Blend if sliders. You can also change the opacity of the Hard Light blending to something else if 100% seems like too much.

I’ll tell you honestly: it wasn’t the easiest thing for me to learn the Blend if concept. It’s not really intuitive, and I’ve had to spend many hours trying it on many different images in different combinations to get the hang of it. And I can’t afford to give you a detailed explanation of all its features, as it will take more time than I have for this particular section of the course, which is, I remind you, is called “How to colorize things”. But there’s a lot of free tutorials and articles dedicated to the “Blend if” if you feel interested. For now, let’s do this. I’ll make this new document and fill it with a black to white standard gradient. Then I’ll make a new layer on top of that and fill if with black. The blending mode is set to Normal by default, which means that when the top layer blends, the top pixels cover bottom pixels and that’s it.

Now let’s see how the “Blend if” works. I’ll click on the Layer 1 two times and the Blending Options panel will emerge. You can see that “Blend if” lets you pick Gray, which is the luminance channel, or work with each of the three RGB channels separately. Let’s stay with the basic, gray mode. There are two separate sets of sliders which you can move. The first set is responsible for “This layer”, which is the top layer. It’s black. So what happens if we move the leftmost, black slider, to the right. It stops blending! Why? Because we’re telling it: “Stop blending if the top layer is darker than the number we stopped at”. And as the top layer is black, it just stops blending straight away, and when it doesn’t blend, in normal mode it just disappears.

Same with the bottom layer. By moving the lower left slider from left to right, we’re telling it: “Stop blending if the bottom layer is darker than the number we stopped at”, and you can see how the gradient appears from under the black layer, as it stops blending. Same with the right side: start dragging white sliders to the left and the tonal range of the blending area will get more narrow. And that’s not it! Every big slider here is, in fact, a couple of small sliders, and they can be separated. To do so, hold Alt and drag one of them away. When you do so, you’re telling it: “Alright, now stop blending, but not in an abrupt way, do it gently for goodness sake, please” and that’s exactly what happens. You can get smooth transitions this way. Now, this is the necessary minimum that you absolutely have to know to do at least something with this extremely powerful “Blend if” feature. Let’s get back to our bag and see if we can persuade it to stop being flat.

As I said before, we want the bag to look glossy, so we have to find the glare that it had when it was still black. It’s a good time to click twice on the Black & White layer and start blend-iffing, or if-blending. And we have to tell it: “Okay, this hard light blend is great, but it’s too much, and I only want the glare, I don’t want you to make my shadows so noisy. So please, stop blending in the dark part of the tonal range”. It means that we have to move the left set of sliders of the Underlying layer to the right. I’ll do it slowly so that I know when to stop – as soon as I see the glare. Now there it is! When the bag becomes darker, it means it doesn’t blend there anymore, as our Hard Light layer makes things lighter. At 195 the glare appears in its full glory. But it looks awful, it looks too abrupt and unnatural. To get rid of this unpleasant effect, I’ll separate the black slider in two by holding Alt and clicking on it. And then I’ll move its left half to the left, and the right half to the right, just a little bit. Now let’s have a look at the result. First of all, I’ve managed to reveal the glare, and the bag looks much more glossy than it was. At the same time, I fixed the shadows and they are not so noisy anymore. The only problem that I see now is that the bag buckle looks unnatural and too dark. Can’t imagine anything dark like this on a white surface. But this is an easy thing to fix. If you hold Ctrl and click on the mask icon in any of the layers with a mask, it will make the selection active. I’ll invert it by hitting Ctrl-Shift-I on the keyboard, and then I’ll just lighten the buckle with something. In this case, I can even use the Dodge Tool set to Midtones, and its Exposure set to 50% or something strong like this. Now it looks much better.

Now you might be wondering why we have this Levels adjustment layer on top of everything and why we never use it. Well, why not! It’s there for the fine tweaking of the final result. Instead of reducing the opacity of Hard Light and Soft Light layers, it’s easier to just move a couple of sliders to make the painted part of the image a bit lighter, darker, more or less contrasted. As the bag still looks a bit gray, why not making it a bit brighter? To do so, I’ll click on the Levels adjustment layer, go to the Properties panel and move the middle slider to the left, and that’s it.

But what to do if the surface is still too noisy to your liking? It’s not a big deal, as in catalogue retouching, we can afford a bit of noise, as no one’s going to notice anyway. Not too much though! There are many ways how to reduce noise with the means of Photoshop, including the Reduce Noise filter in the Noise submenu of the Filter menu. But I prefer this: load the selection from the layer mask, zoom in to 100% scale, and then press Ctrl-Shift-A. This will bring the Camera Raw plugin, which has nice noise reduction options in the Details tab. You can access it by clicking on the button with two triangles. Here I’ll just move the slider to the far right, which is the maximum, and press OK. The noise reducing effect will be too much, of course, but in this case, I have the Fade window ready. Right after the Camera Raw filter takes effect, press Ctrl-Shift-F and then find the right value of fading to get the desired effect. This is much faster than twiddling with the noise reduction sliders. I think 50% is fine in this particular case.

What else? Sometimes when you turn something black into white, things might look weird. Let’s have a look at this bag for instance. I’ll make a round selection in the middle and this will be the area that has to be white for some reason. Okay. So I’ll use the “Colorize” action and then duplicate the resulting layer two times. Then I’ll use the “Volumize” action and oh my, this is a good time to use the “blend if” secret move to make it look more natural. I’ll shift the black slider to the right until I get the glare and then I’ll divide it in two and move both mini-sliders apart a little bit. And as the surface doesn’t look so white now, I’ll also modify the levels adjustment layer and that’s it. Now what? Look at these dark shadows around the shield in the middle. They are so dark and it seems unnatural that shadows like this might occur on a white surface. We have to get rid of them. But how?

There’s an easy way how to do if fast and without making any selections at all. I’ll switch all the additional layers off to have a good look at the base layer. Now we need to measure the color in the shadows to determine what exactly has to go away from the resulting image. I’ll zoom as much as I need to see these tiny shadows and check with the Eyedropper Tool, what’s their color. My sample size is set to 3 by 3 in average, which is perfectly fine. Make sure the Info panel is active – this is where I look up all the color and tones in the image. Okay, the eyedropper says it’s about 5:5:5 in the deepest shadows. Now let’s see what we need to preserve if we don’t want to ruin the image – we need to preserve all the other surfaces except the deepest shadows. The tool says the rest is all about 15:15:15 or even 18:18:18. The darkest I can find here is 12:12:12, and I’ll click on it, so that the color goes into my Foreground Color swatch. Great. Now I’ll grab the Brush Tool and switch its blending mode to Lighten. It changes the algorithm of painting with it entirely. Normal brush just paints everything into the color of the current swatch. In Lighten mode it compares the base color, which is our bag, with the color of the swatch. If the bag is darker, it will paint it to the color of the swatch. If it’s any lighter, it will be left untouched. And this is exactly what we need. Now I’ll switch all the adjustment layers back on and have a go with the new brush. If I paint over the shadowy areas, the shadows will be gone. The best thing about it is that I don’t need to be precise at all, because if I touch any other surfaces with the brush, they won’t change anyway. So I’ll just make the brush tip really huge and just zoom back out and click once on the bag to get rid of all the shadows at once. Easy, right?

I think one last example of weird shadows is necessary. Look at these shoes. Now I’m going to paint the black leather strap to white. My selection is ready, I’ll run the “Colorize” action, add a few Soft Light layers, then run the “Volumize” action, and look what we've got. First of all, the area between the shoes looks a bit noisy and dark. Same problem as before. But I still have my brush, which is color 12;12;12 and in Lighten mode. I’ll give it more juice, let’s say 20;20;20, and a few strokes with a soft tip at 30% opacity will get rid of it. Another problem is the following: as the selection was not the most accurate, the area between the strap and the sole looks weird, there’s a black line and it should not be there.

This one is easy, too. I’ll flatten the image to get rid of all the adjustment layers. Now I can pick any color, that is a little bit darker than the sole, and use it in the same Lighten mode to paint it gray. Just make sure you flatten the image first. And the last problem here is that the area under the strap looks a bit too dark. This kind of shadow is not likely to be dropped by anything that is white. So a small touch with the Lighten mode brush is necessary.

Don’t forget, that you can change brush blending modes very fast by using the respective shortcuts. You can switch to Normal mode by pressing Alt-Shift-N, to Lighten – Alt-Shift-G, to Darken – by pressing Alt-Shift-K. This is much faster than rummaging through the drop-out list.

One last thing. We spent most of the time in this chapter painting things from black to white, as it’s the hardest thing to do. Now let’s see how it works with more simple situations really quick. This bag is originally white, so let's paint it black to see if the process is any different. I'll make three copies of the Soft Light layer and run the volumizing action. The deal is that’s in some cases when you apply the volumizing action, it’ll turn the whole image very dark. If that happens, don’t forget that you can lower one of the Soft Light layers' opacity. It doesn’t have to be 100%. I'll reduce it to 30%, as 4 layers is actually a lot. Now the bag doesn't look very dark, but the volume has to be better than this. I'll use the Blend if trick and drag the white slider all the way to the left till it hits 50, and then split it in two and drag the right half to the right until about 65. Now the bag looks much more shiny than before, which is good.