removing streaks from a monochromatic sky

In 1987 I took a photograph in Maine on Kodachrome 25. The sky is quite evenly monochromatic.

However, the Kodak processing lab was having problems, resulting in lighter streaks in that sky. I succcessfully scanned the transparency and have tried using cloning and the healing brush to remove these streaks which are just a little lighter than the surrounding areas but my results have always been unsatisfactory. There is a distinct grain pattern in the sky in the Kodachrome image and both the healing brush and cloning change this grain.

Can someone suggest a way to remove these streaks?

"HowardG" wrote in message

Can someone suggest a way to remove these streaks?

Copy the sky to another layer. Try Surface Blur.

"HowardG" wrote in message

In 1987 I took a photograph in Maine on Kodachrome 25. The sky is quite evenly monochromatic.

However, the Kodak processing lab was having problems, resulting in lighter streaks in that sky. I succcessfully scanned the transparency and have tried using cloning and the healing brush to remove these streaks which are just a little lighter than the surrounding areas but my results have always been unsatisfactory. There is a distinct grain pattern in the sky in the Kodachrome image and both the healing brush and cloning change this grain.

Can someone suggest a way to remove these streaks?

I'd start as pico suggests - isolating the sky on its own layer and applying surface blur. One shortcut would be to use the blue channel as the starting point for a mask, using curves or levels to bump the contrast. You may also find the b channel of Lab makes a good mask.

It sounds, as if you'd like to retain the gain texture of the sky. To do this, dupe the sky layer over itself, and use Filter>Noise>Add Noise to add monochromatic noise until you get the look of the original grain. Adjust the opacity of the duplicated layer to fine tune the appearance.

A completely different tack that retains more of the original sky texture - paste the b channel of Lab to the layer mask, and use it to restrict the results of the clone tool, or shift the entire sky enough to hide the marks, using the mask to control the areas that are changed.
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Mike Russell - www.curvemeister.com