Jan 042008
 

Friday. You know, I love these days. Always in a hurry, and always the stress to capture an image in the few minutes that it takes me to get from work to the railway station, on my way from Vienna to Carinthia.

If possible it was even a tad harder today than normally. Then, already on the train, browsing through the images of today, I found this image of a pit on Südtiroler Platz, and though it was fundamentally flawed, I kinda liked the textures, the metal, the coldness, and thus I decided to de-flaw it. That’s what I spent the next hour with.

I cropped off the top, I cloned out snow in the foreground and a plank, all with the intent of making the pit seem bottomless and its walls of indistinct height. Other than that I used a technique that I have used on “446 – Hide Away” two days ago as well.

This technique is pretty effective on noisy images or images with focus problems that you nevertheless want to print in high resolutions. Basically we want to do two things: accentuate what edges we have, and increase detail, but both without increasing noise.

One way to accentuate edges is high-pass filtering (“Filter / Other / High Pass”). You can vary the radius and mask the effect where you don’t want or need it, but as all sharpening techniques it also accentuates noise, which is exactly what we don’t want. There are two ways around that.

High-pass filtering is always applied to a pixel-bearing layer, and then the result is used with blending mode “Overlay”. One way to avoid increasing noise, is to duplicate the background (or “Copy Merged” – “Paste”, if you already have a layer stack), applying noise reduction to the duplicate and doing the high-pass filtering on that. Noise reduction algorithms smear away fine texture detail, but they leave hard edges intact.

In this case I used something else: I applied an Orton-like effect to the background, using one of the blur variants that I frequently use, and that’s what I call a “neutral blur” (as opposed to a “glowing blur”). Basically you make two duplicates of the background or the merged underlying layers, one of them in “Screen” mode, blurred with radius 30 (works fine for 10 and 12 megapixel images) and at 100% opacity, the other in mode “Multiply”, blurred with radius 5 and 60% opacity. The result has an Orton-like effect, but without any changes to saturation. As a side-effect, this pretty well eliminates noise.

A variant would use a “glowing blur”, and instead of “Screen”-30px-100%/”Multiply”-5px-60%, I would use “Screen”-30px-80%/”Soft Light”-5px-100%. Normally I group both blurred layers and sometimes change the opacity of the group.

With that “neutral blur” in place I applied high-pass sharpening, followed by “Filter / Stylize / Find Edges” on another merged copy. I have desaturated the result and used it in blending mode “Multiply” with an opacity of 50%. Finally I have applied the usual levels, curves, saturation layers.

Click at the thumbnail to the right to see how this looks at the various stages. In the end you have something that looks very similar to the original tonally, but it has no noise and much finer detail. Of course this is invented detail, but that does not matter. It is a similar situation to that where noisier images sometimes look more real than noise-free ones. Sometimes it does not matter what details you have, it suffices that there is detail at all.

EDIT: As requested, I have searched for an easy way to share the PSD file. Well, the original has more than 300 MB, thus I have cropped it to 200×200 pixels and eliminated a vignette layer that was irrelevant for the purpose of demonstration. The result was cut down to 1.3 MB. I have uploaded this file to a free public hosting service that gives 10 GB per month of free bandwidth, i.e. 700 downloads per month. Drop me a comment or an email if you encounter this limit. I’ll happily send the file to you per email, or I may even consider upgrading to a commercial hosting plan without bandwidth limit. Here is the link: http://www.box.net/shared/f7fjqcwsgg

The Song of the Day is “Down In The Hole” from the 1980 Rolling Stones album “Emotional Rescue“.

  4 Responses to “448 – Down In The Hole”

  1. Thanks Houdini! 🙂

    …that will surely eat away a good part of my weekend.

    That’s surely an impressive photo, that you posted today. Not only the textures and details, I particularly like the grey-brown color combination/contrast.

  2. I’m not sure I quite understand the exact sequence of events, or the number of layers involved. Could you either post a 1. xxx, 2. xxx, 3. xxx … listing of steps or perhaps post a link to an expanded .psd file? There are a lot of somewhat soft images I’d like to try this on, but I just can’t follow your steps all that well.

  3. Derek,

    I’ve put a link to a cut down PSD file to the bottom of the article. The two layers in the group “blur (neutral)” were simply merged copies of the layers below the group (i.e. from “orig” up including the group “clean”), and then I have applied a Gaussian blur to each of them, radius 5 to layer “multiply” and radius 30 to layer “screen”.

  4. Thank you. I’ve downloaded it and am practicing on my own images.

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