How to sharpen an image? A hard question to answer in any standard way. For one it all depends on how soft the image is initially. Also most images have some areas that are softer than others, so a uniform amount of sharpening will not be ideal. Another factor to consider is noise, which is the by-product of the sharpening process and is something I want to avoid. So I only want to sharpen the parts of the image that require it.
The first method I will use is an Edge Sharpening technique. This is how it works.
1. Create a duplicate layer of my background. And set Layer mode to Luminosity.
2. Select all of the layer
Select > All (Ctrl A)
Edit > Copy (Ctrl C)
4. Select the channel palette and press the ‘Create New Channel’ button which is at the bottom of the palette, to the left of the ‘delete bin’ icon. You will see the screen go black as you create this new channel. Now paste your image into the channel.
Edit > Paste (Ctrl V)
Now deselect the image
Select > Deselect (Ctrl D)
5. Now I want to find the edges. These are the only parts of the image I want to sharpen.
Filter > Stylize > Find Edges
6. Now the edges might not be quite as defined as I require so I am going to adjust the levels of the image.
Image > Adjustments > Levels (Ctrl L)
I am going to move the left slider up to a value of 75. Remember that the black areas of the image will be sharpened at 100% down to 0% in the white areas. Click OK on your level box when you are happy. I tend to find that a value of 75 works well.
7. Now I want to create a selection from this Alpha channel that I can use for sharpening. To do this press the circular icon at the bottom of the channel palette. Now you will see a selection on your screen. I want to invert this selection as I want to sharpen inside the selection, not outside, as it is currently set. To do this I simply select
Select > Invert (Shift+Ctrl I)
8. Now delete that Alpha channel you have created by pressing the Bin icon, found at the bottom right of the channel palette. The Alpha channel goes and leaves you with a good selection on your image to apply sharpening into. Now just apply some USM.
Filter > Sharpen > Unsharp mask
Now remove the selection
Look at the results. If there are any areas that are oversharp select your rubber and simply rub out the sharpening applied there. When you are finished merge the two layers back together.
Layer > Flatten Image
Repeat this process until you feel the image is sharp enough, although there may be just a few places that need a little extra kick of sharpness. If I use the edge technique I will be oversharpening the titles and other places and will spend more time rubbing sharpness out instead of creating it! For this I will use a Layer Mask.
Layer Mask Sharpening.
1. First create a copy of your background layer.
2. Add a large amount
Here I have added 400% with a radius of 0.4
3. ?) Eek that looks bad and so it should! Now I need to hide that layer so I can just reveal the part I want. So select
Layer > Layer Mask > Hide All
Now the layer is masked as you can see from your layer palette.
4. Select you paint brush
Check the colour is selected on the toolbar. As you can see from the mask on the layer palette, there is a black square representing the mask. To reveal what is under the mask you need to have your foreground colour set to white. So set it to white, select the size of brush you require, with nice soft edges. Set the opacity of the brush to about 20% with a flow of 100%. Now all you have to do is paint over the soft areas of your image to make them sharp. If you go too far and slightly oversharpen a part of the image, just set your foreground colour to black and use your brush to ‘paint’ back the mask. If you look at your mask in the layer palette you can see where you have painted away the mask.
Now flatten the two layers and you should be finished. That is how to selectively sharpen using a layer mask. Now all you have to do is save your image at the highest quality setting (12) and it is ready to upload to the internet.
You might think that that is a whole lot of work and this sort of workflow will make processing every image a half hour job! Well if you followed this workflow manually it would take some time, but this is where Photoshop actions can really help. In the next section I will explain just how to record an action and show you how I have my actions arranged.