Wednesday, October 29, 2008

Noise Reduction Face-Off -- Neat Image, Topaz Denoise, ACR 5

I've been a heavy user of noise reduction for years now. I latched onto Neat Image pretty early and have been happily using it until very recently. I became a tad disgruntled when I purchased Photoshop CS4 and found that the 32 bit plugins I owned did not work in the 64 bit version of CS4 ... obviously Adobe created no thunking layer to bridge the two worlds.

And only PTLens (excellent lens distortion plugin) was already shipping a 64 bit version, at no extra charge. I got upset because I had not managed to install both version of CS4, so I was unable to use my favourites. Luckily, someone mentioned on a forum that both were installed by default, and I remember having a glitch in my install and having to redo it. So I explored the installer yet again and managed to get everything installed for both 32 bit and 64 bit CS4.

By this time, I had found Topaz Adjust and Topaz Denoise, and although they have no 64 bit versions, the plugins intrigued me. They use a new noise reduction technology (so they say) for Denoise and a cruder, but sometimes nicer, method in Topaz Adjust. Topaz Adjust can do amazing tricks with contrast, detail and color, and creates effects that range from Orton to Dragan. Really arty stuff. With a gentle touch on the controls, it can do a really nice job of simple contrast and detail adjustment.

Topaz Adjust was on sale for $38 usd and Topaz Denoise was thrown in for free, as it was new. This was unresistable to me, so I acquired it. And I have certainly enjoyed the plugin. One example of a fairly tame adjustment to add some pizzaz is this close up of the facade of the Parliament Buildings in London. I shot it from the top of a bus on a tour. The weather was mid-day sun and the image has a rather boring snap shotty look to it.

After a little work with Topaz Adjust, the image seems to become vibrant and detailed. There is just more interest in looking at it. And the balance of colour and contrast is such that it will look much nicer in a print. It almost sparkles now.

Definitely something to look at for the price.

Now, Topaz Denoise is a more interesting beast. It handles details better than anything I've ever seen. You can absolutely hammer a background or sky to smooth plastic and the details in the rest remain almost untouched. It has its issues of course, sometimes it bands smooth areas like skin, but for complex images with lots of noise, it can work magic.

Downside? It's unbelievably slow in its best mode. A 12mp image from a D300 can take 10 ro 15 seconds for Neat Image to process. The same image in Denoise can take 6 minutes!So choose your images with care. Neat Image remains a superb general purpose noise removed.

And what about ACR 5? Turns out that you can get great results with that one too. And there is no time penalty at all. Dial in the noise settings and the conversion does the noise in the same time as everything else. Very impressive.

I decided to perform a simple test on a jpeg from a few years ago. A balloon race late in the evening shot by a D70s at high-ish ISO (800.) There is some noise, but I nailed the exposure and it's not bad. Mostly color noise and a bit of grain.

Here is an image containing four crops at 100 percent ... double click on the image to see the full size. You'll see some grain that is mostly removed by Neat Image and completely wiped out by Topaz Denoise. Denoise is almost too effective. ACR 5 does a nice, balanced job. Note how the trees and leaves in the background are hardly affected at all. I used a bit of Y channel sharpening at high frequency to pull Neat Image back into line. Topaz Adjust hardly touches detail. And ACR 5 is pretty good so long as you control the amount of luminance noise you allow it to touch. I added a touch of sharpening to ACR 5 as well.

Any of these would print very well and I would not presume to choose between them. I plan to keep and use them all. Again, double click on the image to open the large version.


Matt said...

Thanks for the very interesting comparison! The second photo does indeed look more impressive and more vibrant. However, it also looks more processed to me - there is some posterization in the sky and a white halo around the building. I guess it depends on your personal style. So far I have used only Neat Image. Perhaps I should try out other options, too!

Kim Letkeman said...

Yes, Topaz does push the processing very hard when the dials are turned up a bit. It especially pulls out noise and acts a lot like shadow/highlight at times, creating halos around edges. In this kind of photo, I find it acceptable as the point is to move towards painting and away from documentary photography.