Reviews

Photoshop Online Reviews Jan. 2006
Review of Sharpness Editor: Photoshop User Rating 4 out of 5 stars. "An outstanding collection of filters. Unique photo-sharpening plug in" - Dave Huss. See the full review here (The last star missing was because of a poor tutorial. This has been remedied).

Digital Camera Magazine May 2004.
"This filter is superb and delivers everything it promises... Amazing value. 95% VALUE.
See the review here.

Benefits
of the plugin

Sharpen images without the defects of other sharpeners: negative contours.
Sharpen images with no noise enhancement.
Three original sharpening methods based on optical parameters.
True optical blur of defocus.
Selective sharpening - restrict to edges, color or value.
Anti-alias otherwise jagged edges.

The Sharpness Editor plugin filter works with these image modes (Windows and Mac)...
8 & 16 bit / channel: RGB, Grayscale, Duotone, CMYK, Multichannel, Lab.

Sharpness Editor
filter controls

This is the Sharpness Editor plug-ins control panel at one fourth size. Click on the photo or the links to see the plug-in at full size. The filter has these sets of controls:

1. Sharpen method
2. Anti-aliasing
3. Edges only
4. Brightness range
5. Color-range
6. Memory

Example

The Sharpness Editor plugin is the only sharpener on the market that can sharpen without creating negative edge lines.

The excellence of Power Retouche - Examples of the sharpening methods

Single pass

The following were sharpened with a single pass at 150% and size 1.

We did not use Fix Edges here since we wanted to show the superiority of the individual methods as they plainly are.

If you want to compare the appearance of edge artifacts, look at the lock of hair to the left and at the curve of the thumb.

Notice the general sharpening is the same, but the main difference lies in three particular aspects:
1. Contrast enhancement
2. Treatment of texture and variation in nearly uniform areas.
3. Contour and edge artifacts.

The Sharpening control set

The Sharpen control set

These are the main sharpening controls.

Sharpen image % controls the actual sharpening. The other controls modify the sharpening algorithm.

Since we have solved the old dilemma that sharpening created unwanted artifacts in proportion to the degree of sharpening, we have been able to extend the sharpening range to 1000 instead of the classic 500.

Sharpen Method ...

The plugin filter offers four sharpening methods and a better blur...

Gentle Unsharp Mask
Sharpness Editor
Enhanced Unsharp Mask
Smart Sharpen (for Portraits, JPEGs etc.)
Blur (true de-focus)

Extra high quality

All methods are far superior to any other known sharpening and blur, yet we have still been able to obtain even higher quality by tweaking the algorithms a bit. But since the processing time is higher with the quality optimization, we decided to let the user decide by checking the Extra high quality.

Blur radius, pixels

This slider asks for the size of the blur. We decided to go with the odd convention, used by Photoshop and other photo software, and set radius to half of the visible size. The example to the right has a visible blur of three, but the correct setting for that is 1.5.

In general set the value low rather then high. It's better to do multi pass at a low setting than a single pass at high.

Fix Edges %

This is Power Retouches unique invention. It determines how much the plugin filter should look for negative contour edges and how much it should fix them.

Hard threshold

This slider sets a threshold below which no sharpening should be done. It is the same you will find in most photo software.

Soft threshold

Soft threshold is also unique to Power retouche. One of the problems with regular (hard) threshold is that you either sharpen or don't sharpen and the effect will be that some parts are blurry, while others are sharp. Soft threshold applies a fuzzy edge to thresholding and eliminates the ugly either-or of hard threshold.

The Anti-aliasing controls

Anti-aliasing

"Anti-aliasing" means a special and local softening of the staircase steps digital images get along curves or oblique lines. When you sharpen such an anti-aliased curve or oblique line, you might also remove the anti-aliasing, which is unfortunate. Just as sharpeners prior to Power Retouche had no means to get rid of the edge lines, so sharpeners had no means to preserve the desirable anti-aliasing. Incredible as it may sound, we have devised methods to distinguish between blur and anti-aliasing.

We have implemented two different means to preserve anti-aliasing. Level 2 is stronger than level 1.

The edges only controls

Edges only

The range controls

The range controls are common to most of the Power Retouche filters. They let you restrict filtering to either a limited range of brightness levels or a range of colors (or both).

Both sets of range controls have an button, Inv., that make the sliders swap place (select the inverse). Thus you can filter a specific range, f.ex. sharpen everything but the bright blue sky. Then rerun the filter, click inverse, then blur only the bright blue sky to either create depth or remove noise.

Retouch Levels

Retouch Levels is common to many Powerretouche plugins. It will change the amount the sharpening is applied to lights, mid tones and darks respectively.

Brightness range

Color range

Pixels darker then the From slider and brighter than the Up to slider will not be filtered.

Colors to the right of the From slider and to the left of the Up to slider will be filtered. This means if the top slider is to the left of the lower, then colors between the two sliders will be filtered. If the top slider is to the right of the lower slider, then colors in between will not be filtered. Thus any selection is possible.

To make selection easier, you can turn on Mask Unchanged.

Graduated effect

The graduated effect controls are common to many Powerretouche plugins.

Using graduated effect will apply full effect at one side and no effect at the other.

You can use this to sharpen f.ex. the foreground of a landscape and leave the background slightly blurred, or vice versa. This will create a greater sense of depth. See below examples.

Saving settings and comparing two settings

Memory

If you want to switch between two settings to compare them, you can use the Swap memory. It will even save settings across invocations within a single session of the host. It does not save to a file.

Save & Open

If you want to save settings to a file, you can use the Save and Open buttons.

The individual methods

A novel unsharp mask

Our Gentle Unsharp Mask ("Gentle USM" for short) and Sharpness Editor ("Shed" for short) use a common novel "unsharp mask", though it is not unsharp mask in the traditional sense. Enhanced unsharp mask is, as the name implies, a modification of classic unsharp mask. Smart sharpen is a modification of the enhanced unsharp mask. All methods produce less artifacts than classic USM (unsharp mask) does.

Gentle unsharp mask, "Gentle"

This method is for clean images since it will sharpen low level variations such as texture and surface structure as much as high contrast edges. That means your original image should be quite free of impurities and noise.

Use it ...
1. With top quality digital cameras or scans.
2. In multi pass sharpening in combination with the Sharpness Editor method.
3. When you want surface texture and low level details sharpened or enhanced.
4. In combination with soft threshold.

Sharpness Editor, "Shed"

This is the all-round method suitable for all kinds of images.

Enhanced unsharp mask

This is an improvement of classic unsharp mask - accordingly it has some of the negative defects of classic USM and relies more on the use of Fix edges and Thresholding to counteract the defects of USM.

Smart sharpen

This has its name because it does the inverse of Adobe Photoshop's "Smart Blur". It is calibrated for sharpening JPEG images without sharpening the artifacts, and sharpening edges the most. You can achieve the same by using Hard Threshold and Soft Threshold with Enhanced Unsharp Mask. This is just a quick standard setting for JPEGs.

Blur (true de-focus)

This is an example of gaussian blur...
Common gaussian blur does not spread in the manner light spreads, but ours does. We call our blur true de-focus because that is what it is.

This is an example of Power Retouche blur...
Notice how differently the eyes react to the two kinds of blur. The gaussian blur registers as a smear and does not entice the eyes to attempt to focus. Power retouche blur registers as out of focus and makes the eyes attempt to focus. Hence it is the proper blur to use when wanting to blur backgrounds as if out of focus.

The method adjustment controls

Fix edges

Fix edges lets you tune the sharpening methods so that unwanted specular edges can be avoided. Traditional unsharp mask draws a negative line along edges of some contrast.

Setting Fix edges to about 80-90% gives a nice balance between sharpening and edge fixing (for all degrees of sharpening). Remember that Fix Edges lower than 80% does create more or less visible edges in proportion to the degree of sharpening. Higher might reduce the apparent sharpening. If you want to be completely rid of them, use 100%.

Hard threshold is absolute

Hard threshold sets a low limit to what will be sharpened. The slider is best used to control how minute variations in otherwise monochrome areas should be treated and also as a crude means to avoid enhancing low noise.

If you set it at 1 or 2 it speeds the filter up by skipping almost uniform areas, like an empty sky or a monochrome background. Higher than 2 will show as a lack of sharpening in the texture of uniform areas. On the downside you might find the uniform area becomes patched with areas that are sharpened and areas that are still blurred. That usually happens with settings above 3, but could be a problem at lower settings, so keep an eye for that if you want hard threshold. To remedy this patching, we invented the soft threshold.

If you are very critical and have high quality images, you will probably want the texture sharpening too, then leave hard threshold at 0.

Soft threshold is relative to Hard threshold

This is, as far as we now, also novel for our sharpener. Soft threshold will fade out the sharpening effect in the range down to the hard threshold. Soft Threshold is relative to Hard threshold and Hard threshold is absolute.

If hard threshold is 3 and Soft threshold is 7, the values from 10 to 3 get sharpened less and less. If Hard threshold is 5 and Soft threshold is 10, then the fade out will be from 15 to 5. In practical use this relative value makes much sense, since you will maintain the fade-out range even while moving the hard threshold.

Multi pass Sharpening

Multi pass sharpening

We would like to advocate multi pass sharpening as the means to achieve optimal results. This goes for any sharpener, not just ours. (The above examples were sharpened with a single pass).

Multipass-sharpening at low settings is the best way to use any sharpener for quality results, our tool is no exception. But our tool lets you push results much further than common Unsharp Mask since you won't create negative contour lines if you set Fix Edges to at least 80%.

There are several good reasons for using multi pass sharpening, one of them - paradoxical as it may sound - could be speed, since you may get better results with two runs at blur size 1 than one run at blur size 2 or 3. But multi pass is not necessary to enjoy the benefits of this filter. Single passes will produce better results than any other sharpener.

Tips on multi pass sharpening

The beauty of multi pass sharpening with PowerRetouche is you can sharpen to the equivalent of, say, 600% but never incur more damage than a fraction of that. That is because the second pass will sharpen at four times the setting with less damage. If you want to sharpen 600%, you can in other words doublepass sharpen once at 100% and once more at 125%, because 100 + 2*2*125 = 600. Yet it will only generate artifacts equivalent to 100 + 125% = 225%. If you doubt this odd and strangely overlooked fact, please try for yourself (I did several skeptical tests, before i decided to make this public!). In practical use just doublepass at one fifth of the amount you want. If you want 500, doublepass at 100, etc.

When deciding what method to use first, you should decide what is important to enhance and what might be a problem. If your image has noise, then you want to use Gentle USM last in order to not enhance the noise. If you used GUSM first, then the structure/noise enhancement would be enhanced also in the second pass with, say, SHED.

If on the other hand you image has already been sharpened with regular unsharp mask and therefore have those ugly negative contours along edges, then you will want to begin with GUSM in order to not aggravate the negative contours - and then finish with SHED.

You might want to use the first pass to enhance surface structure. For this purpose use our unique Gentle Unsharp Mask. It is ideal for sharpening areas with surface structure. And in this case avoid thresholding in the first pass, since the main purpose of thresholding is to leave noise blurred, hence also surface structure and texture. Use anti-aliasing level 2.

Also start with fairly low sharpening amounts (about 60 - 120%) and with a fairly low Fix Edges (about 50 - 80%). Remember the first pass is to secure surface variation, so some edge enhancement may be OK (if not set Fix Edges to 80 or higher).

Generally second pass should be more concerned with the final impression: if you need more texture, use GUSM, if you need more edges, use SHED or Edges Only.

If you use the Pro version, then second pass can give very good results if you convert the image to Lab mode, select the L channel (Lightness) only and do second pass sharpening on that alone (The Sharpness Editor even supports single channel 16 bit-Lab filtering). If you only sharpening the L channel, you will still have colored blur remaining. That's why first pass should be on all channels either in RGB or all three Lab channels. Here you will want Fix Edges somewhere from 80% and up, and sharpening amount somewhere round 100%.

If you need a third pass, it might be enough with edges only at very low settings.

Test - Sharpness Editor vs. regular Unsharp Mask

Two tests

Two tests were performed. The first to see how edges are treated and determine to what degree specular edge phenomena are generated. The second to show how single-pixel variations on a low level are treated and determine the degree such low level variations have their contrast altered so they end up standing out as noise instead of integrated variation of a monochrome hue.

It was found that...

1. Sharpness Editor does produce minor edge phenomena at Fix Edge settings below 80%. At 80% and above they are eliminated.
2. Fix Edges also handles unwanted enhancement of small pixel variations so they don't appear as speckled noise. Also 80% seems to be the borderline setting.
3. From both tests combined it appears that Photoshop's Unsharp Mask has detrimental side effects no matter how low or gentle the settings.
4. Photoshop's rescaling of the unsharp mask effect to 0-500% instead of the actual 0-100% is sound in the sense that the detrimental side effects of regular unsharp mask become too apparent above 100% to be disguised by the already present pixel variations.

Sharpness Editor vs. regular Unsharp Mask

Two tests

Two tests were performed. The first to see how edges are treated and determine to what degree specular edge phenomena are generated. The second to show how single-pixel variations on a low level are treated and determine the degree such low level variations have their contrast altered so they end up standing out as noise instead of integrated variation of a monochrome hue.

It was found that...

1. Sharpness Editor does produce minor edge phenomena at Fix Edge settings below 80%. At 80% and above they are eliminated.
2. Fix Edges also handles unwanted enhancement of small pixel variations so they don't appear as speckled noise. Also 80% seems to be the borderline setting.
3. From both tests combined it appears that Photoshop's Unsharp Mask has detrimental side effects no matter how low or gentle the settings.
4. Photoshop's rescaling of the unsharp mask effect to 0-500% instead of the actual 0-100% is sound in the sense that the detrimental side effects of regular unsharp mask become too apparent above 100% to be disguised by the already present pixel variations.

Test 1- Contour & Edge line Artifacts

Test for edge phenomena

The original image above was blurred with a gaussian blur (to be fair) at radius 0.5. We then tested to see if the image could be sharpened without leaving any traces of edge-artifacts. All the images have been enlarged 800% for the sake of clarity.

Observe there are no negative edge lines produced with Power retouche.

Test 2: Pixel level contrast alterations

It was found that neither sharpener could regenerate lost texture on a single pixel level of low contrast variations.

Regular unsharp mask produced a marked effect of contrast exaggeration rendering the surface structure as noise.

Sharpness Editor performs best with the Fix Edges less than 100% when it comes to regenerating surface texture.