pdog182

First, I have to ask if the red dots in the subject's hair are in fact jpeg artifacts? The picture was taken with a sony digital camera. I'd like to hear any suggestions for getting rid of the annoying red dots. I've already tried removing noise in each channel with noise, blur, and unsharp mask filters, and have seen some improvement, but not enough. By the way, this picture looks a lot worse at full resolution.

pdog182

Here's the fix using the NeatImage software. I'd like to be able to do this in photoshop.

We do need a full size image pdog182, because I think that we're all guessing what you mean with the red dots in the hair and jpeg artifacts.

I can understand that the shot is too big to post on this board, but can you at least post a cropped section of the original, one that is not resized.

I think you did more than using Neatimage in the 2nd image

I use Neatimage myself for one year now.
I use it to remove noise and sharpen at the same time, but Neatimage never changes color or brightness values like it did in your example [confused]

pdog182

You're right. In fact, I over-brightened the original so you could see the red dots better. Here's a cropped version of the original, slight levels adjustment. The original is pretty dark

retired_paddza

I agree that a zoomed detail view would be helpful for seeing the exact problem... but from what I see and your description, I don't think you're dealing with pure jpeg artifacts.

Regardless, here's what I see so far. You have a very obvious red color caste. If you balance your colors a bit to remove that caste, you will probably alleviate the color spots in the process. I think you're getting some hotspots in your red channel probably due to lighting and ambient colors. If you tone down the red caste, it should also tone down those red spots while you're at it. If it is indeed noise, by blurring then unsharping a channel you're removing and then replacing the noise. If you must unsharp, I would suggest it in small doses and to the composite channel after you do a blur on the single color channel. Remember that applying a blur to each channel is just like applying a blur to the composite image. I'm not sure which you're doing from your decription, so I thought I'd throw that out. Generally when you're working with pixel noise like the kind introduced with bad digital shots, you only have to worry about one channel (usually it's blue with digital cameras). If you do a blur there, it will often fix a majority of the noise problems in a photo. You can usually do pretty heavy "fixing" on a single channel without shifting the color of your composite image. It's really case by case though.

Hope that helps some, if not, more detail on the photo will help diagnose the problem

This has nothing to do with jpeg artifacts.
Jpeg artifacts look like in my attachment.

Let me make one thing clear; Photoshop can't do what Neatimage can....period. What ever tricks you use; it's impossible.
Sad, but it's the truth. I can even proof it with every noisy picture Neatimage is based on a totally different approach.

Mindbender already posted all the information you need to do it in Photoshop.

I never use Photoshop to remove noise like this; you might be able to remove the noise, but you will also lose a lot of details.

retired_paddza

*sigh* That's what I get for typing a long message, you snuck in while I was writing my essay

Okay, it looks like you've got jpeg issues to me. Low funky lighting and not the highest quality file format are giving you some pretty common consumer level digital camera problems.

Here's what I did... I gaussian blurred the blue channel about 2 pixels to knock the edge off the major jpegies on that channel. Then I used a light blurring combined with a dust & scratches and a median noise to lighten the contrast on the distortion but still keep the lines from fuzzing out too much. Then I went back and normalized the midtones a little with a simple levels adjustment (very simple one actually, just clicked the midtones on the wall and poof, no more red). A little over saturated for me, so a minor desat with hue/sat adjustment. Then some curves just to bring the shadows out a little since there was a LOT of contrast (direct flash lighting would be my guess?).

This seemed to fix most of the issues to what looks like an acceptable level. It kind of depends what you want to do with the photo. You also need to do any other cleanup after that... some red-eye was removed, but an actual red-eye technique would benefit. Also, any other cloning or whatever I would do at this point after you've balanced the colors, so you don't have to go back and redo it.

Hope that helps.

The amount of noise you have is determined by the quality of the camera and the ISO setting.

retired_paddza

Gaussian, if you open the file in photoshop and check out the blue channel, you'll see what appears to be jpeg artifacts (or I've always attributed them to that).

You see that EXACT pattern in most consumer level digital cameras... heck, even in a lot of pro cameras. It's the blue CCD not receiving enough light data and getting to contrasty. Then with jpeg building it's algorithm based on image contrasts, it gets more distorted.

At least, that's how I understand it. Regardless, the solution is roughly the same as for pure jpeging, you simply do it to the individual channels.

OH... something I forgot in my run down. I tried to use unsharp and it just kept bringing back the noise... so I used a highpass/overlay instead and it seemed to work much better. I just masked out the hair and some of the face because it started to get noisey again.

I hate dealing with that stuff... digital noise is a pain because it's a lack of data in the photo, just as bad as if you'd underexposed or something. Sometimes it's worse because it's not a global problem... it's a bunch of little problems Good luck.

<edit> We're just playing thread-tag now aren't we. [bustagut] </edit>