RGB -> LAB -> RGB + Noise Reduction

chrisjlee

Edit: I accidently put this in the wrong category.

In terms of RGB to LAB to RGB workflow for a portrait at what point would you use for image reduction?

As of right now i would be doing the following steps to my images:

1. Open images
2. Retouch blemishes(RGB)
3. Covert to profile -> LAB
4. Shadow/Highlight if necessary on L channel
5. Curves Adjustment
6. USM on L channel
7. Convert to Profile -> sRGB
8. Neat Image noise reduction

Does that sound appropriate/ideal?

Richard

chrisjlee wrote:

Does that sound appropriate/ideal?

I think you would be generally better off reducing noise earlier in the process. You don't want to sharpen the noise.

chrisjlee

rsinmadrid wrote:

I think you would be generally better off reducing noise earlier in the process. You don't want to sharpen the noise.

Ah I thought it was the other way around.

DavidTO

chrisjlee wrote:

Ah I thought it was the other way around.

The general rule is blur early, sharpen late, I believe.

chrisjlee

DavidTO wrote:

The general rule is blur early, sharpen late, I believe.

now i'm uncertain but i'll go with you.

rutt

I guess I did a pretty bad job of summarizing Chapter 5 of the LAB book because I missed the single biggest point: the chapter's title: Blur early, sharpen late. Blurring here is basically noise reduction, though it also includes moves to make women's skin look better.

So Dan likes to blur immediately after the move to LAB if it happens, or in RGB otherwise. His point is that whatever unwanted noise or skin detail exists before curves, blending, sharpening, etc will only be emphasized in the process.

Dan taught me (and I've come to agree) that CS2's Surface Blur filter is the noise reduction tool of choice. Use it on a duplicate layer, starting with parameters like Threshold=9, Radius=3 (More threshold means more stuff gets blurred, the opposite as in USM.) After the blur you can use layer opacity, blending options, and/or a layer mask to fine tune. I have Neat Image, but I now vastly prefer this method.

chrisjlee

rutt wrote:

I guess I did a pretty bad job of summarizing Chapter 5 of the LAB book because I missed the single biggest point: the chapter's title: Blur early, sharpen late. Blurring here is basically noise reduction, though it also includes moves to make women's skin look better.

So Dan likes to blur immediately after the move to LAB if it happens, or in RGB otherwise. His point is that whatever unwanted noise or skin detail exists before curves, blending, sharpening, etc will only be emphasized in the process.

Dan taught me (and I've come to agree) that CS2's Surface Blur filter is the noise reduction tool of choice. Use it on a duplicate layer, starting with parameters like Threshold=9, Radius=3 (More threshold means more stuff gets blurred, the opposite as in USM.) After the blur you can use layer opacity, blending options, and/or a layer mask to fine tune. I have Neat Image, but I now vastly prefer this method.

I don't have cs2 but I have neat image.

rutt

chrisjlee wrote:

I don't have cs2 but I have neat image.

You can use the dust and scratch filter in older versions of PS to get a similar effect, just make sure you use a duplicate layer so you can fine tune afterwards. For that matter, you should use neat image on a layer as well for similar reasons.