Frequency decomposition in Photoshop

Adobe Photoshop program Ideal for all types of users. It can be used by both beginners in the field of image editing and professionals in this field. The very first thing that scares beginners when working with this program is that it has a lot of different tools. Today we will talk about how to implement such a photo retouching method as partial decomposition in Photoshop. The essence of this method is that the photograph needs to be decomposed into frequencies. There are several types of details in every photograph, namely large, small and medium. Frequency decomposition in Photoshop involves creating three layers with parts of different sizes.

In order to do the frequency decomposition in Photoshop, you will need 2 basic tools. The first one is high pass(color contrast) and the second one is Gaussian blur(Gaussian blur).

What should the user do? First you need to consistently apply the High pass filter. That is, first we apply this filter with the radius set to 15px. After this, only elements up to 15px will remain in the photo. And so you can successively reduce the radius of application of the filter. Let's take a closer look at the use of frequency decomposition in Photoshop.

You have uploaded a photo to the program. Now you need to divide it into three components: 0-3px, 3-10px, >10px. The first thing you need to do is duplicate the photo onto the first layer. We do this using the High pass filter, setting the radius to 3px. It is not difficult to guess that the resulting image will be gray. Now this gray image needs to be set to blend mode"Linear light".

With this overlay, the contrast of the new image will automatically increase by 2 units. You need to reduce the contrast by about 2 times. To do this, press the key combination "Cntrl+M" and adjust the curve that appears. You need to set parameters 64-0, 192-255 on it.


Then carry out similar actions, but with a radius of 10px. That is, use a High pass with this radius and then use the Gaussian Blur tool with a 3px radius. Thanks to the last action, we remove details less than 3px. And here again we reduce the contrast by 2 times. We do this the same way as in the previous stage. Finally, you need to set the image to blend mode"Linear light".

The last stage is the simplest. You just need to apply a Gaussian Blur with a radius of 10px. This completes the frequency decomposition process. You just saw for yourself that Photoshop program has enormous, one might say limitless, possibilities. But to work in it at a high level, you need to go through a considerable stage of training and practice.