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Tanel

Local Contrast Enhancement v1.2 (2008-12-24)

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This plugin (LCE for short) allows to clarify flat or hazy looking photos. It also adds depth or three-dimensional look sometimes. For most of photos you won't need it, but sometimes it's very useful: for distant landscapes or clouds for example. By default the effect is very subtle - to provide enhanced, but still natural looking result.

Menu location: Effects > Photo.

Download as part of my plugin pack.

localcontrast_screen.png

Updated to version 1.2 (2008-12-24)!

Changes: few UI and code optimizations.

Updated to version 1.1 (2008-08-31)!

- Compatibility fix for paint.net 3.36

Controls:

Amount - percentage of contrast to be added

Radius - width of contrast detection area

Smoothing - reduces the effect gradually at extreme shadows and highlights, to avoid overprocessed look or color clipping.

Amount 10-30 should be sufficient for natural result.

Radius should be chosen according to image size. There is no rule here but generally: the larger the image, the greater radius you may need. 60 is about optimal for screen size image. 90 or more for large (>3MP) images. 30 for web size images.

Smoothing at default setting 5 prevents color clipping in extreme shadows and highlights. Increasing it mutes the effect in shadows and highlights even further. Reducing to zero turns shadows/highlights preserving off.

Notes:

Similar effect was possible with Sharpen+ plugin, but this one is specially configured for contrast enhancement and is twice faster.

Contrast is applied to pixel's brightness only, preserving original hue and saturation.

Try also special contrast effects: with several (3-4) passes at reducing radius and growing amount (for example Amount/Radius: 10/60->20/30->30/10).

Below are some links to tutorials describing the LCE technique using Photoshop's Unsharp Mask.

This plugin does the same, but avoids color shift and clipping problems noted in those pages.

<!-- m -->http://www.cambridgeincolour.com/tutori ... cement.htm<!-- m -->

<!-- m -->http://www.earthboundlight.com/phototip ... -mask.html<!-- m -->

<!-- m -->http://www.luminous-landscape.com/tutor ... ment.shtml<!-- m -->

<!-- m -->http://www.lonestardigital.com/photoshop_quicktips.htm<!-- m -->

(note: radius 50 in Photoshop is about equal to radius 100 in Paint.NET)

Samples:

lce_sample1.jpg

1st pic - original

2nd pic - LCE, defaults

Resized to 40% for web sample.

lce_sample2.jpg

1st pic - original

2nd pic - Advanced Greyscale plugin: R 100, G 50, B 0

3rd pic - LCE, 4 passes: Amount/Radius 10/60->20/30->30/10->40/5 (Smoothing always 5).

Resized to 33% for web sample.

Remember the look of good old b/w photos?

Enjoy! 8)

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Thanks, Tanel, for another excellent plugin!

I've used your Shadow/Highlight plugin to effectively recover details in many photos with horrible exposure settings. Tried using this Local Contrast Enhancement after the Shadow/Highlight plugin and found that the photos looked even better.

Thank you!!!

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Hmmm. When used on a drawing this plug-in makes some pretty peculiar effects. But peculiar, as in; i got to figure out how to use this to my advantage. :wink:

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This is important!

Since I've updatet to 3.36, LCE doesn't work for me! Before it worked without a problem, now I get everytime something like this:

waterfallxz2.jpg

Does anyone else has this problem? I really need LCE!

If no-one can be of aid I have no choice and will have too downgrade backwards to 3.35.

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