Imaging Techniques - Sharpening Images in Photoshop

Most digital images benefit from some level of sharpening. The level required will obviously depend on the image and its intended output (screen, print, etc). As we all know there are more than a zillion ways to do the same thing in Photoshop. Below are just two of many methods to sharpen images. One is fairly strait forward which will work 70-80% of the time and the other is a little more involved. Both techniques have been taken from the tutorial on the following website http://www.photoshopsupport.com/tutorials/sharpen-an-image/photo-sharpening.html

ORIGINAL IMAGE

1st Method - Simple High Pass Sharpen

1. Duplicate the background layer and set its blending mode to Overlay.







2. With the duplicated background layer selected. Select Filter > Other > Highpass.
3. Increase the pixel radius until the you feel you have the right amount of sharpening. Around 1.0 to 3.0 works well but will depend on the image. Best to look at the image at 100% for this.





4. Select the paintbrush too and select a soft edged brush. Set the colour to a mid tone grey.
5. Paint over the parts of duplicated background layer which do not need sharpening. E.g. Skin.

ORIGINAL CLOSE UP

WITH HIGHPASS SHARPEN

Note: keep an eye out for colour fringing with this process. If it occurs try the 2nd method below to reduce it. 

2nd Method - Unsharp Mask/ Smart Sharpen

Use this method to avoid colour fringing and saturation issues.

1. Duplicate the background layer.
2. With the duplicated background layer selected. Select Filter > Other > Highpass.
3. Increase the pixel radius until the you feel you have the right amount of sharpening. Around 1.0 to 3.0 works well but will depend on the image. Best to look at the image at 100% for this.





4. Select Image > Adjustments > Threshold to apply a Threshold adjustment to the layer. Drag the slider just below the histogram to isolate the edges that require sharpening. The aim of moving these sliders is to render all of those areas you do not want to sharpen white .



5. Refine the image by painting over the parts of the image which don't require sharpening with a soft edged white brush.



6. Go to the Channels palette and Command-click the RGB thumbnail to load the edge detail as a selection.
7. Go back to he layers palette and duplicate the original background image again and drag it to the top of the layers.











Turn off the visibility of the High Pass layer.
With the new background copy selected Option-Click the new mask icon.



8. With the mask selected, select Filter > Blur > Gaussian Blur and apply a 1.5 pixel radius blur to the mask.
9. Now select the image thumbnail for the background copy. Zoom into 100% then select Filter > Sharpen > Smart Sharpen or Unsharp Mask. Adjust the Amount slider to between 80 and 150%.



10. Change the blend mode of the sharpening layer (the uppermost layer) to Luminosity mode. Luminosity mode will restrict the contrast changes to brightness only, and will remove any changes in saturation that have occurred due to the use of the Unsharp Mask. The changes are often very subtle so this technique is only recommended when you become aware of the problems of color fringing due to increased saturation.

ORIGINAL CLOSE UP

AFTER UNSHARP MASK

First Monitor Calibration - Digi Darkroom

Below is the results of a monitor calibration performed on an Eizo SX2462W monitor on workstation 4 in the digital darkroom. The calibration was carried out using an X-Rite i1Display Pro calibration device and ?i1Profiler software.

http://www.eizo.com/global//products/flexscan/sx2462w/product_photo_02.png

http://www.borge.com.au/images/X-Rite%20i1%20Display%20Pro.png

Setting	Target Value	Achieved Value
Display	Wide Gamut CC	NA
White Point	D6500K	6577K
Luminance	120	116
Contrast Ratio	Native	673:1
Flare Correct	Off	NA
Ambient Light Control	Off	NA

As can be seen in the table above the white point was closely matched to the target value of 6500K but the luminance was slightly lower. Overall the display is achieving a very close output to the requested industry standard.