This article is for dummies. In it, the frequency decomposition method is described in as much detail and detail as possible and an attempt is made to answer basic questions about this. In addition, chips and life hacks are inserted into the article, not only for retouching photos in Photoshop, but also for working with the program in general.
Introduction
Frequency decomposition in Photoshop raises many questions. And if two years ago there was little information about this, now there are answers on the Web, of course, but all of them are fragmentary and not always clear. It is because of this that it’s difficult for beginners to figure out the frequency decomposition in Photoshop.
Tutorials from professionals on the Internet are given for a reason. Many companies put up for retoucher vacancies the requirement to know how to do frequency decomposition in Photoshop at least at the minimum level. But even technology freelancers will have to come in handy - they will increase both speed and quality of work.
What it is?
Frequency decomposition is frequency decomposition. The term is used not only in the field of portrait processing, but also in mathematics, music, etc. For a retoucher, this means that the photo is laid out in several layers (frequencies), for example, a layer of details and a layer of tone, each of which is edited separately from the others.
Since this article is included in the lessons of "Photoshop" for beginners, it will pay attention to both explaining the principles of frequency decomposition directly and the little things that professionals have long been familiar with.
History
Computer graphics and processing are based on mathematical laws, although creators sometimes do not care about them. Thus, the frequency decomposition came from the Fourier decomposition into frequencies: first, the radio technicians borrowed the mathematical method, then the musicians and, finally, retouchers.
Lessons from Photoshop for beginners rarely contain this information, and they really aren’t needed in mathematical formulas. However, what frequencies are will be considered a little further.
Why is this needed?
Frequency retouching is used when it is necessary to process ala naturel. In other words, if the end result should be a natural rather than glossy finish. Also, the processing described below is much more accurate and high-quality and means the highest degree of skill.
Unlike conventional processing methods
Glossy retouching of photos in Photoshop is done using masks and various types of blur. This makes the skin on the portrait too soapy and "visible that it is processed." For certain formats, this result is desirable, but in the case of natural portraits, processing should not be visible. This is done by separating the layers from each other - retouching one of them, we do not affect the rest.
Can only portraits be used?
Of course, there is no “use only for portraits” taboo for this technique. And although on this, and on a number of other articles on the Internet, you might think that it is for them that it is most effective, it is not. Portraits make up the lion's share of the photo market, and their retouching always comes first, but the frequency decomposition is universal and perfect for any shots where there is a need to edit parts separately from each other.
How many frequencies to lay out?
There are two types of frequency decomposition in Photoshop:
- The leather is laid out in two frequencies - tone and details. On the first layer, the skin is smoothed, on the second, defects (wrinkles, pimples, etc.) are removed.
- Decomposition is carried out at three frequencies - high, medium and low. We consider in more detail below.
First steps
Regardless of which of the methods it is decided to use, you first need to open the photo in Photoshop and make several copies of its layers - the amount depends on the method. In the first case, two copies of the layer are created, in the second - two.
Frequency decomposition in "Photoshop" into two layers
As mentioned above, the skin tone is taken as the first layer for this method, and the details as the second.
After creating two copies of the layers, it is recommended that you create a separate group of layers for them. This is optional, but it is considered a good form for retouchers and generally simplifies the work. Groups in "Photoshop" - a chip professionals.
Also, for the convenience of work, it is recommended to give the appropriate names to the layers: “Tone” and “Details”, with “Details” being placed above “Tone”.
Next, retouching photos in Photoshop starts in normal mode: open the Tone layer and apply Gaussian Blur to it.
The blur values usually range from 7 to 10 (the higher the number, the larger the image. In some cases, it can reach 15). The exact number is selected by the retoucher independently - depending on the size of the photo and by eye. Perfect blur - when the skin is smoothed out, but the shape and basic details are still readable.
After that, go to the second layer. It must be preliminarily prepared. In order to “cut through” all the details, the “Color Contrast” filter is used. In Photoshop, the English language sounds like a High Pass. It is located in the menu Filter (Flter) - Other (Other). In general, this article describes the frequency decomposition in Photoshop step by step in Russian, however, those who use the program in English will also be useful.
The sharpness of Color Contrast can be adjusted in the same way as Gaussian Blur. The value is similar - if the number 12 is selected for the Tone layer, it will be 12 for the Details. The result of applying the filter is a gray embossed image.
Second phase
For the Details layer, the Blend Mode changes to Linear Light. If the image turns out to be too contrasting, go to the Curves tab and reduce the contrast. Alternative: reduce the contrast "the old fashioned way" by reducing the "Contrast" parameter.
Frequency decomposition itself has already been done - all that remains is to remove the defects with a dot brush. This is a simple but painstaking job. It is recommended to take a small brush with a slightly flattened shape (set in the parameters). She needs to go through the entire image and remove the defects.
Attention! When removing small pimples and facial wrinkles, you should leave those lines that make the photo anatomically correct and affect the similarity on the faces in the portrait.
Remarks
The simplest technique is described, but there is another version of this technique. In the manner described below, frequency decomposition can be performed in Photoshop CS6 and higher.
When working with the “Details” layer, instead of the “Color contrast” filter, go to “External channel” (Image tab), select the “Tone” layer from the drop-down list (this is not a typo, really select the “Tone”) and click OK.
The Blend Mode then also changes to Linear Light. All of the following actions are performed in the above order.
Important! If the Gaussian Blur turns out to be uneven, and the larger the value of the parameter too blurs the details, you can blur the uneven areas a second time using the Lasso tool. He is able to select the necessary parts of the image, after which the blur is applied only to the selected areas.
Three frequency decomposition
Frequency decomposition into three layers in Photoshop is done according to the same rules as in two. On the other hand, the three-layer decomposition is closer to its ancestor, the Fourier decomposition, and with it it is easier to explain the principle of decomposition itself.
So, the upper, middle and lower frequencies are taken as a basis. In the area of retouching, information on the general shape appears in the upper frequencies, in the middle - the surface texture, as well as all defects and spots, in the lower - information about the light and transitions. After this description, it is easy to conclude that the “Tone” and “Details” layers are nothing but the upper and lower frequencies.
The middle frequencies in the above method merged with the high ones and edited independently, because the method of frequency decomposition into three layers is much more correct and better. Consider it.
Three-layer frequency decomposition in stages
Before decomposing, you should pre- process the photo. It is recommended that you create one copy of the layer.
Interesting! A copy of the layer can be created by clicking on the desired item in the context menu or by clicking on the corresponding icon at the bottom of the layers window. This action is also performed using the keyboard shortcut Ctrl + J. Keyboard combinations are of great importance in the work of Photoshop, they accelerate it and make it more comfortable. Of course, at first the combinations will not be remembered and will not be used on the machine, but to endure the transitional period of memorization to become a master is worth it.
On a new layer, a spot brush removes defects. This is less painstaking work than in the last paragraph, since there is no need to remove trifles - in this case, the size of the brush is taken larger and processed only what really catches your eye and will interfere with subsequent work.
Next, three copies of the processed layer are created. They are called, respectively, High, High, Middle, and Low. This is done, as mentioned earlier, for convenience. You can start retouching with both high frequencies and low frequencies - there is no difference.
In this article, let's go from top to bottom, that is, start with the Low.
A Gaussian Blur is applied to the Low layer. Unlike the method of decomposition into two layers, the blurring parameter can reach up to 30. The main thing is to choose a number at which the skin tone will be uniform.
For the High layer, the Color Contrast filter is selected. The Color Contrast value should be three times less than the Gaussian Blur.
Life: record the values of the parameters of the layers in their name. If the numbers are 30-10, they are easy to remember, but, working with 12.7, it’s better to write down all the same.
The Low layer will contain both bloom (blur) and contrast. The value of the blooms is equal to the value of “Color Contrast” in the “High” layer (in this example, 30), and the contrast value to the blur value to “Low” (10).
A group is created for all three layers. The decomposition is ready, you can start editing.
Why are each of the frequencies needed?
The Medium layer contains all the defects. It is completely undesirable to delete it. To remove irregularities, it is necessary to create a mask (Alt + mask icon at the bottom of the layer window), and then draw a black brush over the portrait in places where there are irregularities.
In the same way, the High layer can be treated to increase the evenness of the skin tone. They work with colors on the same layer - they darken and tint the necessary areas, align the colors.
Application possibilities
In addition to studio portraits, in which it is required to remove a pair of pimples, before retouching by the method of frequency decomposition in Photoshop, completely different goals will be set. So, it can be applied in such cases:
- It is necessary to correct the clumsy work of a makeup artist - in other words, to remake makeup. It is also possible to apply make-up from scratch. In the latter case, it is recommended to have a photograph of the same model with any other make-up during operation to ensure reliable application.
- Soft muffling of the skin texture - easy and accurate retouching, without the intervention of a point brush and a “washed-in” bloom.
- Shaving a man - requires a combination of frequency decomposition methods, with painstaking work, a good result is obtained.
Work speed
Despite the fact that the method seems simple, after the decomposition itself has been completed, work on all three frequency layers continues to be painstaking. An experienced retoucher works on such "little things" as shadows and highlights, image volume. Frequency decomposition is not a way to transform a photo in one click, but, on the contrary, the technique of its deep development.
Nevertheless, the mathematical base of the method suggests how it can be automated.
Software Methods
For "Photoshop" (and for "Ghimp", his "Linux" brother, by the way, too) there are special plug-ins, as well as action games. All of them do not fully automate photo retouching (ultimately, this is still a creative process), however, they perform programmatic actions to create the necessary layers and their settings. This greatly simplifies the frequency decomposition in Photoshop.
An action (action - an action, an operation) is a file with the ANT extension, which is a set of operations in Photoshop. It can even be called a mini-program. An existing action file is opened using the "Window" - "Operations" tab.
If you wish, you can create an action for frequency decomposition yourself - manually perform all of the above actions and go to the same tab "Operations", and then click on the icon for creating a new operation. For convenience, it is also recommended to create several actions to create separately the first, second and third layers.
Actions for downloading are available on Internet resources, but it is recommended that you create them yourself - first try the frequency decomposition manually, then understand how to use it, and then automate this process for subsequent use. In addition, downloading from the Internet always implies the ability to download a virus. So it's better to play it safe.
Like any programs, actions are editable, and editing what was written by someone else is more difficult. Moreover, each author makes the operation, first of all, "for himself", and only then, in a burst of generosity, puts it on the Internet for everyone to see.
conclusions
In general, frequency decomposition is a very powerful tool. The first method, in which the process is carried out in two layers, is closer to conventional retouching and only slightly opens the veil of decomposition. The second, representing a modified mathematical operation, provides tremendous scope for creativity. The article describes the minimal possibilities of use, since its purpose is to talk about the decomposition itself, what it represents and how to make it. And delving deeper into the topic a little more, you can find much more "chips".
In conclusion, it is also worth saying that owning a frequency decomposition will not make anyone a brilliant retoucher. Like any tool, it has power only in experienced hands. So, you need to see the final result even before the first step is taken, notice the little things and only then choose with which tool it is best to fix them.