Sharpness with Photoshop
It is a method to increase the sharpness, only on the edges, without creating a deterioration on the darker areas or full color.
We bring our photograph on Photoshop and select the channels panel.
Deselect all the channels, except green and duplicate.
We go on> Filters> Stylize> Find Edges. The image will be like a drawing, showing only the edges. Now press ctrl + I to invert. It's like I created a mask (black areas), while the edges are white.
Let's go to> Filter> Other> Maximum that allows you to increase or decrease the edges of our mask in question.
Set the radius you desire, I set 2, it is very important to remember the value of the radius.
Now we go on> Filter> Noise> Median. This filter has the function to smooth the edges, so do not ever put a value that exceeds 4. In my example I set 2.
Now go on> Filter> Blur> Gaussian Blur. Now we set the value of the radius, what I had put in "Maximus," which was 2.
Now back on the channels panel and premiamio ctrl + click, starting the selection of areas. Activate visibility on the RGB channel and return on the layers panel. Last step is> Filter> Sharpen> Unsharp Mask, set the desired values. I personally never put (in general) a factor of over 100, radius a maximum of 3, the threshold between 0-1-2-3.
If you want to see the initial difference, with the end result, before setting the unsharp mask, duplicate the layer, to have a point of reference and see the before and after.
I hope you enjoyed this tutorial and return useful!