Working to Eliminate Camera "Noise"

[Markie Madden]

Okay, for someone who is used to old film cameras and only using the point and shoot feature of a digital camera, "noise" was something new to me. After purchasing a new Canon Power Shot and taking some photos and sharing them, someone suggested going to Shutterstock and selling some of the best ones.

I submitted 10 of my best shots and was rather disheartened that ALL 10 were rejected, and camera "noise" was one of the culprits. At first I thought they must mean they're looking for shots already set up as stock images, like a picture of a model on a plain background. You know, so it's easy to cut the model out and use it in something else. But I started searching for camera "noise" and what it means.

I've learned ways to help reduce this in the camera before I take a shot, but I've also been trying to figure it out using Paint.net. But whenever I try to reduce the noise in any shot, I can't seem to see any difference between the before image and the after. I usually take both the radius and strength all the way to the left. What am I doing wrong?

[racerx]

Post an example image so we can see what kind of noise.

 

Also in the future, try to use lowest ISO setting that you can get away with. Personally I always shoot in Aperture Priority and try to keep it wide open for portrait shots and around F-9 for daytime sports/wildlife shots. 

Edited August 10, 2015 by racerx

[Markie Madden]

Hi Racer, thanks for replying! I think this one is one of the photos I sent to Shutterstock, but I don't remember. I've since learned how to reduce the noise by setting the ISO lower on the camera. But when using Paint.net to clean some up that are already taken, it doesn't seem to alter the photo.

[MJW]

Is the problem sensor noise or JPEG noise or both? Sensor noise is the sort of random graininess that appears especially in dark areas. JPEG noise is a sort of blocky halo of noise that occurs near sharp boundaries. Make sure you're using the highest quality (lowest compression) JPEG setting.

[Markie Madden]

Thanks MJW! For the JPEG compression, are you talking about the setting in the camera, or within Paint.net?

[MJW]

The camera. If I recall correctly, the factory default setting on some cameras is around medium-high quality rather than the highest quality setting (Fine rather than Superfine, for the PowerShot). JPEG noise is, in my limited experience, considerably more difficult than sensor noise to reduce in an editor like Paint.net, so you should do everything you can to avoid it.
 
EDIT: Though I had the camera's setting in mind, you should also be very careful to not add additional JPEG noise when you edit the image. In looking at your photo carefully, it appears to me that most of the objectionable noise is due to JPEG artifacts. At least some of the problems were introduced when the photo was edited, since I can clearly see JPEG edge noise around the watermark. The JPEG blocking artifacts in the background areas of more or less constant color also seem to me more apparent than I usually see in photos with a reasonable level of compression.

 

If you edit photos in Paint.net, save the images in PNG rather than JPEG format. PNG is a "lossless" format, meaning you save the images exactly as they are in PDN. Every time you save a photo in JPEG format, it gets recompressed, so additional artifacts are added. If you need to submit edited photos in JPEG format, save as a JPEG image as the final step and use the highest quality setting.

 

Also, unless you have to submit the photos near the maximum size supported by your camera, it's probably a good idea shoot the photos at, say, twice the final desired size in width and height. That way, you can resize the image to the smaller final size, which will average together several pixels, helping to cancel the noise. In any event, shooting at a large size gives you more headroom for cropping.

Edited August 10, 2015 by MJW

[Eli]

Hello Markie, some of our photo experts may correct me but when looking at your sample picture, I can see that it is pixelized and there is noise and JPG artifacts. This is probably due to the limitations of the image sensor installed on your camera. Four years ago, I was searching for a camera and a friend (photographer) told me that if I wanted to have quality photos I should invest on a Canon 7D or a 5D. Because of my budget I was going to buy a Power Shot but my friend showed me the differences in quality and so I decided I would buy one when the prices drop down ( I am still waiting  ).

 

For the pictures you have already taken you may use JPGNoise reduction. This effect will improve the quality but do not overdo it as you may loose details.

 

 

Edit: Forgot to add some steps.

1. added a little noise (to give some texture/grain to those little areas that did not have details)

2. softenned the grain with gausian blur.

3. applied the JPGNoise reduction effect.

 

I did not try it but perhaps sharppening may bring more detail.

Edited August 10, 2015 by Eli

[racerx]

I think your image is pretty clean aside from Jpeg Compression artifacts. You should save as a lossless format when you finnish editing such as TIFF. Every time you re-save as a jpeg, you loss quality in the re-compression. You should submit your images in TIFF format or at the very least PNG or jpeg @ 100%.

 

I'm not a fan of using noise reduction unless I have to. I don't like loss of detail. BoltBait's excellent Gaussian Blur+ is a good one to use because you can apply it to specified color channels as apposed to the whole image. I like to duplicate the image layer, apply the filter to the top layer, then adjust opacity slider to get the best desired result. If you switch the top layer to "Overlay" Mode it will increase contrast and boost colors.

 

[Markie Madden]

Okay, wow, lots of info so I'm going to try and get them in order. Okay, first of all, to answer MJW, I have set the (resolution?) to Superfine, assuming I'm filming in P mode rather than Auto. I've been trying different settings to see which I like better. I will definitely try saving as a png instead of jpeg. My watermark was saved as a pdn, will that add noise to the finished product? Should I save the watermark as png?

Next, for Eli: what is JPGNoise reduction? Is this already in Paint.net under Effects-Nose, or is it a plugin? I don't have any plugins yet. Can you add noise to certain parts of the image or just the entire thing at once? I've not tried the blue you mentioned, but I'll take a look at it. You say it reduces grain? I'll try it.

Finally, for Racer. I have a Gaussian blur setting, but by the way you talk I think you're meaning a plugin? Where can I get it? And let me see if I understand. You duplicate the layer (copy of the same image, right?), then you apply the file to only the top one?

Forgive me if these seem incredibly basic. I don't have much of a budget (okay, zero budget) for this hobby, but I'd like to do the best quality work I can with what I have available.

[Ego Eram Reputo]

I maintain a list of all the plugins for paint.net. With one exception, they are all free.

Find the list by clicking the link in my signature.

Note: due to the threat of viruses and malware - never download a plugin unless it's hosted on this forum or accessed via a link posted here.

[Markie Madden]

Thanks Ego! I'm on my phone at the moment but I'll check into it as soon as I can!

Also, since we're talking about blue and noise reduction via Paint.net, can you please tell me what the "radius" means? I think I can figure out what "strength" means. But I see the word radius in quite a few of the effects.

[Ego Eram Reputo]

Radius generally refers to the size of a round tool tip. This could be the size of a region taken as a sample, or the area that the effect is applied to.

E.g. for Gaussian Blur the radius is the size of the sample taken and blurred.

[MJW]

My watermark was saved as a pdn, will that add noise to the finished product? Should I save the watermark as png?

 

 

No, PDN files are fine. PDN is the special Paint.net file format that allows saving multiple layers. Usually Paint.net saves single layer files as PNG files, and multiple-layer files as PDN files. Neither will add noise the way JPEG will. (In case you wonder, there's no significance to my capitalization of PNG and PDN; it's just the way I'm used to writing them.)

[Markie Madden]

Ego, I know I can use the square or circular select tool to take a portion of an image and make it blur. I did that on a pic I took of my husband sound asleep cuddling the dog, and blurred his face like they do on Cops. Then I wrote in "And he tells me I spoil the dog..." and posted it on Facebook. It was so funny! So what you're telling me is if I select the entire image and click noise reduction, the radius then refers to the space in the selected area, e.g. the whole image. So if I take the radius all the way to the right, does that narrow the noise reduction effect or widen it?

Thanks for the clarification MJW! And I know the feeling about being used to doing things a certain way. I'm an author and you should consider yourself lucky that I'm not using the "technical" .jpeg with the leading dot! I've loosened up a bit since using my phone for most of my internet!

[Ego Eram Reputo]

Not quite.

When Gaussian blurring, a small radius will take a small group of pixels and blur/combine them together. A large radius will take a greater number of pixels and combine them. Thus the small radius will retain more detail, while a larger radius will lose more detail.

Try blurring any photo with a small radius vs a large one to see the difference.

Noise reduction uses the radius to determine the size of the sample. The sample size is the number of pixels polled to determine if the pixel in question is noise or not. As far as I remember it, a smaller radius will remove more noise than a larger radius.

[Markie Madden]

Thanks Ego, that's a good explanation. I will try it different ways and compare side by side so I can see what it looks like.

I finally had to put Paint.net away last night; you know you've been at it too long when you look at the tv and you can see pixels even in it

[TechnoRobbo]

Try TR's Photo Retoucher using the Defaults

 

http://forums.getpaint.net/index.php?/topic/32063-trs-portrait-retoucher/?p=428864

 

should get rid of jpeg artifacts

[Markie Madden]

Thanks TR! Now how do I install it?

I Googled it! (I remember a time when that wasn't a word!)

Edited August 12, 2015 by Markie Madden

[TechnoRobbo]

Click on this link:

http://forums.getpaint.net/index.php?/topic/32063-trs-portrait-retoucher/?p=428864

 

find link to the zip file in the first post

 

Follow the instructions in this link 

 

https://boltbait.com/pdn/InstallingEffects.php

 

Just replace the file name BoltBaitPack42.zip with  TRsRetouch.zip  in the instructions

[Markie Madden]

Omg TechnoRobbo, I think I love you! I've not had any decent photographs taken of me in years (cancer and chemotherapy did NOT improve my appearance), but I had my daughter shout some the other day because I needed new ones for my books. I noticed, after chemo, that my skin, especially on my face, has patches that stubbornly refuse to tan. So I have tan and white blotches all over my face! But your plugin worked wonders on the shots! So impressed!

[TechnoRobbo]

I'm glad I could help