krita-plugins 1.5-1 : image enhancement

Here are the last three plugins of the soon to be released krita-plugins, two filters: adjustable blur and unsharp mask and one tool: red-eye removal.

As for the tarball of those plugins, they should be available shortly, I will keep you informed.

Adjustable blur

It means you can adjust the size of the blur mask, bellow you can see how it works for the now classical Villa Savoye of le Corbusier:

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Unsharp mask

Like its name state it, unsharp mask will sharpen the edge of the image (yes sharpen and not unsharpen which would be uninteresting). It’s the adaptation of an photographic technique, that consist of first bluring the image to detect edges, and then using the difference between the original picture and the blur version, we can increase the contrast near the edges.

You can find a better explanation ont this website:

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Red-eye removal

Red-eyes might appears on picture taken with a flash (when you are able to keep your eye open). The red-eye removal tool will attempt to detect red eyes, if it fails, a simple click on a red eye will select it. Obviously, the Villa Savoye isn’t the best picture for demonstrating red-eye removal, so I will use a picture of me:

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And then you will be able to correct it:

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You have to note, that the autodetectionphase and the correction quality can vary significantly from one eye to an other, and it’s far to be perfect. ostly because, for the autodetection, at least for western-european and north-american, the skin isn’t white, but pink, and pink contains a lot of red, so you have to select a red zone inside a red zone.

As for correction, it tryes to make the eye less visible and not to restore it to what it should be like (in real life I have blue eyes not gray eyes like on the picture above), because that information is lost. The second problem is linked to the detection stage (wheter it is manual or automatic), you can have a small red ring usually of one pixel wide around the pixel, I am thinking about systematicaly increase the corrected area of one pixel.

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