Posts Tagged ‘noise’

Episode 063: More Noises in the Dark!

Tuesday, September 30th, 2008
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Not so much progress on the noise side - I tried to reduce chroma noise with an option in UFRaw. The result is, well, see yourself in the image above (200% view).

1 - the noisy image

2 - the denoised image

3 - the denoised image with chroma noise reduction

4 - 1 and 3 combined with a mask for the edges.

I’ll explore soe more noise reduction options before I finish this image.

In the main part of this video you’ll see how to register an additional image into the already rotated and cropped  stack of layers.

The TOC:

Reducing Chroma Noise in UFRaw 03:00
Register an additional image into the layer stack 06:00
Moving the layer to a register point 06:30
Setting the center point for rotation 08:40
Cropping the layer to the image size 13:20
Checking the results 14:00
Recap 15:30
Why the Neon Filter? 16:20
When is an image finished? 18:10
Save as a new one layer image 19:40

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Episode 062: Noise in the Dark!

Tuesday, September 23rd, 2008
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I am through a bad cold and nearly through an iris inflammation and so I loved to talk - you get a double dose of MTG tonight. Philippe helped me out last week - and he will be a regular contributor after that success.

After I solve the mystery behind the menue entry “Edit/Fade” I tackle an old image. Taken 4 years ago with my old camera (Nikon D70) at ISO 1600 and f=1/1.8. It’s noisy.

I use the noise reduction from UFRaw and combine two results of the RAW conversion - one with and one without noise - to one. As with the selective sharpening I left the edges of structures noisy and kept the noise out of the structureless areas. Of course this is done with layers and masks. with this technique you keep the structures crisp and the noise out.

After finishing this video, I found out that UFRaw has a well hidden option for removal of chroma noise. More next week.

This image still needs some work on it - I’ll show that in the next episode.

Joel has a lot to say about noise and I’ll go into some other noise reduction techniques in the future.

The TOC:

03:15 Edit/Fade
09:55 The image in UFRaw
14:45 Noise
16:40 Noise reduction in UFRaw
19:10 Comparing the images
22:50 The Plan
23:35 Making a layer mask with “Edge Detect”
29:40 Recap
30:40 Fine tuning with another layer
38:50 Rotating
41:50 Cropping


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Posted in Gimp, Gimp video tutorial | 12 Comments »