Reduce Noise using 32-bit Photoshop Image Stack Averaging

You don't need Photoshop Extended to do image averaging. You can use 32-bit compositing to simplify the job:

Stack the images in layers. Use the LINEAR DODGE (ADD) blend mode to sum all the layers. You will blow out the image way past white. No worries. Kick into 32-bit mode and dim the sum back into a usable range. For a true average, dim it by a factor of (1 / N layers)

The spotty filtered images are an extreme example of noise. Average only 8 together already starts to make the photo come back - what you call 'an arty look.' If I repeated the process with 800 source images the arty look would be so subtle it would appear to be the original photo. To see a more literal example with high ISO grain, look here:

http://www.digitalartform.com/archives/2006/03/high_iso_noise.html

Category:

Education

Tags:

• noise
• reduction
• degrain
• photoshop
• howto
• tutorial
• image stack
• image stacking
• image average
• image averaging
• photoshop extended

[jeffhrose]

But who would want a picture like that? How is that noise reduction when the original had no noise to reduce and the finished picture was worse than a noisy picture???

[digitalArtform]

@jeffhrose There is no 'original picture.' All you have is extremely grainy surveillance camera footage, no single frame of which makes any sense at all. That's where you are starting.

[digitalArtform]

@jeffhrose I'll give you a concrete example. In the movie ID4 the Empire State Building footage (just before it exploded) was extremely grainy. That's all I had. A grainy shot. I replaced each frame with a running average of the previous 20 frames and the shot became so low in grain that it looked great in the movie. Once it explodes it's grainy again (no averaging was possible due to things being in motion) but who could notice since debris was flying everywhere, anyway.

[EpicsodeOne]

Thia video is HAUNTING ME WITH ITS WTFness!

[digitalArtform]

@EpicsodeOne See the new video response for a better explanation

[Iloveyougagaloo]

Is this a how to fuck up a picture tutorial?

[digitalArtform]

@Iloveyougagaloo See the new video response for a better explanation

[AT2336]

what is this

[jeffhrose]

I see what you are getting at, perhaps if you had used a very grainy picture to start with it would have been more obvious:)

[digitalArtform]

@jeffhrose See the new video response for a better explanation

[digitalArtform]

@EpicsodeOne See what you can do to make it go viral.