[PDF] Frequency Separation: Stain Removal Masters Academy

78597_3MA_Frequency_Separation_Stain_Removal.pdf

Frequency Separation: Stain Removal

Frequency Separation: Stain Removal © Ben Willmore, All rights reserved2

Frequency Separation: Stain Removal

In this lesson, I'm going to show you how the frequency separation technique can be used to enhance and correct a photograph. In this example, I'm going to re - move a water stain from the front of a girl's dress. The actual process of frequency separation will not be covered in this lesson because it was covered in detail in a previous Masters Academy lesson. I will instead be using an action to set up my document for frequency separation.

Loading the action files

With this lesson, you'll receive two action files that will be included with the course downloads (Ben's Frequency Separation actions). You can load an action file by double-clicking on it. When Photoshop comes to the forefront on your screen, you'll know that the action has been loaded. You can find it by opening the Actions panel and scrolling to the bottom. (The most recent actions will appear at the bot - tom of the list.) Note that if the Actions panel is not visible in your interface, you can access it by going to the Window menu and choosing Actions.

If, for some reason, the actions did not

load by double-clicking on them, you can try a di?erent method. Click on the little menu in the top right corner of the Actions panel and choose to

Load Actions. You'll be prompted to

navigate to the location on your hard drive where the action files are stored.

In the video example, there is an im

- age of a girl and she has a large wa- ter stain on the front of her dress. We want to remove this stain by using the frequency separation technique.

What this technique is going to do for

When the frequency separation actions have

been loaded, you can find them at the bottom of the action list inside the Actions panel. Frequency Separation: Stain Removal © Ben Willmore, All rights reserved3 us is separate the fine details of the image from the color and brightness of the im- age. The fine details (including the texture of the dress) will be placed on one layer and the general color and brightness will go onto a di?erent layer. Then, we'll be able to take a simple soft-edged brush and paint over the color/brightness layer in order to remove the stain. Within the action folder (Ben's Frequency Separation), there are two actions: Fre - quency Separation-Choose Low and Frequency Separation-Choose High. The one you use will depend on what information you want to see at the time that you are choosing how much should be moved onto a separate layer. If you would like to view the fine details, use the "Choose High" action. If you would like to see the ba - sic shapes and colors, use the "Choose Low" action.

Running the Frequency Separation Action

In this example, we want to

view just the shapes and col - ors, so we're going to click on the "Choose Low" action and then hit the Play button at the bottom of the Actions pan - el. The action will go through a series of steps and it will pause with the Gaussian Blur filter open. Here, we want to use the Radius slider to find the highest possible setting where we can still see the spot on the dress but can't see any texture or detail in the dress. In this case, we left the setting at

27.5 and then clicked OK.

The frequency separation paused with the Gaussian Blur filter open. Here, we need to find the highest possible Radius setting where we can still see the spot on the dress but cannot see any texture. Frequency Separation: Stain Removal © Ben Willmore, All rights reserved4

The action will continue and, when it's done,

the image will go back to looking normal. If we look in the Layers panel, however, we will see that there are now three layers.

The bottom, Background layer contains the

original picture. We don't really need this layer and it could be discarded if we want - ed to clean up the Layers panel. The oth- er two layers are the High Frequency layer and the Low Frequency layer. Half of the image data is on the High Frequency layer and the other half is on the Low Frequency layer. If we want the image to look normal, both of these layers need to be visible.

After running the frequency separation

action, we're left with three layers: The original image layer (Background), High

Frequency layer and the Low Frequency

layer. At left is a view of the High Frequency layer, which contains only the fine details. At right is a view of the Low Frequency layer, which contains the colors and tones. Frequency Separation: Stain Removal © Ben Willmore, All rights reserved5

Retouch the Low Frequency layer

We'll turn o? the visibility of the Background layer and the Low Frequency layer. This leaves us viewing the High Frequency layer. We can see that there is little to no color in this layer but we can see all of the textures in the image. What we can't see, however, is the water stain on the dress. We'll then turn o? the visibility of the High Frequency layer and turn on the visibility of the Low frequency layer. Here, we can't see any fine details, but we can see shapes, color and brightness. We can also see the water stain on the dress, so this is the layer we're going to need to correct. We want to work non-destructively so that if we make a mistake, we can easily re - cover from it. To do this, we'll do our retouching work on an empty layer. We'll make sure the Low Frequency layer is active and then we'll click on the New Layer icon at the bottom of the Layers panel. This will place the new, empty layer directly above the Low Frequency layer. We'll make sure that this new layer is active and we'll re - name it to "Retouch" just so we remember what the layer's purpose is in the future.

Using the Brush Tool to remove the stain

We'll activate the Brush Tool and make sure that we're using a really soft-edged brush. We'll make sure that the Opacity and Flow settings (within the Options Bar) are at 100%. Now we want to paint with the color that is found on the unstained part of the dress, so we'll activate the Eyedropper Tool. Before we use it to sample a color, however, we need to look in the Options Bar and make sure that the Sample menu is set to Current & Below. (This setting is important when you're working on an empty layer or when you have more than one layer visible.) Now we can use the eyedropper to click on part of the dress that does not contain the stain. This will set that col - or as the foreground color. Then, using a very soft-edged brush, we'll paint over the area where the stain used to be. We might need to use a smaller brush in order to be more precise in the area where the dress meets the girl's skin.

The Eyedropper Tool is

being used to sample the color from an unstained part of the dress. Frequency Separation: Stain Removal © Ben Willmore, All rights reserved6 To see what the final e?ect will look like, we can always turn on the visibility of the High Frequency layer. When we do, we can see that the stain is being removed but the texture is staying intact. We can even continue to work on the Retouch layer while the overlying High Frequency layer is visible. One thing to be aware of, how - ever, is the Eyedropper Tool's Sample setting. If we were to use the Eyedropper again to sample another color from the dress, we want it to sample from the Low Frequency layer. If the Sample setting is set to All Layers (like we had it before), then it will also sample from that overlying High Frequency layer. To get around that, we'd need to change the Sample menu (in the Options Bar) to Current & Be - low. Here's is a trick for quickly accessing the Eyedropper Tool. With the Brush Tool ac - tive, you can hold down the Option key (Alt on Win) and the tool will temporarily switch to the Eyedropper and you can use it to click and sample a color. When you release the Option key, it will go back to the Brush Tool.

The color we sampled

with the Eyedropper was set to the fore - ground color. Here, we are using the Brush Tool to paint with that col - or over the part of the dress with the stain. Frequency Separation: Stain Removal © Ben Willmore, All rights reserved7 Fine tuning the results with the Dodge Tool and the Sponge Tool We removed the majority of the water stain but came to a little problem when we got to the fold in the front of the dress. Sampling from a light area of the dress would make the fold look unnatural because it should be shadowed and, therefore, darker than the rest of the dress. It's currently darker, but it's too dark and it's also more saturated in color because of the water stain. We'll turn to a di?erent tool to fix this area. We'll activate the Dodge Tool, which is also stacked in the Tool Bar with the Burn Tool and the Sponge Tool. The Dodge Tool is designed to brighten things and this is what we'll use inside the fold of the dress. This tool will only work on the active layer, so we will need to click on the Low Frequency layer to make it active. Then, we'll use a small brush and paint within the fold of the dress, lightening it up so that the tone looks natural.

There is also another tool that could help

to refine this retouch job. If we feel that the fold of the dress is too saturated in color, we can switch to the Sponge Tool. The Sponge

Tool will make your image more or less col

- orful, depending on what the Mode menu is set to (in the Options Bar). We'll set the

Mode menu to Desaturate. We'll also adjust

the Flow setting, which determines how strongly each paint stroke will a?ect the im - age. We'd like to be able to gradually build up the e?ect, so we'll set the Flow to a low setting of 10%. We'll then slowly paint within the fold of the dress, building up the e?ect just enough to slightly desaturate the area.

This will make it look more natural because

shadow areas tend to be less saturated.

The Sponge Tool is used to desaturate

the area within the fold of the dress. In the Options Bar, the tool is set to a Mode of Desaturate and a Flow setting of 10%. Frequency Separation: Stain Removal © Ben Willmore, All rights reserved8

Comparing the results

We kept the original, Background layer so that we could compare the original im- age with our final, retouched image. To view the original image layer alone, we need to hide the visibility of all the other layers and there is a fast way of doing this. If we hold down the Option key (Alt on Win) and click on the eyeball icon to the left of the layer thumbnail, it will turn o? the visibility of every other layer, leaving the target layer visible. If we hold down the Option key and click on the icon again, it will remember what was previously visible and it will return the Layers panel to that state. Finally, we can flatten the image if we know that we won't need to make further changes. Alternatively, we can clean up the Layers panel by taking the two fre - quency separation layers as well as the retouching layer and placing them inside of a folder.

Here, we're comparing

the original image with the version we retouched using the frequency separation technique.

We cleaned up the Layers

panel by placing the frequency separation layers and the retouching layer into a folder.