Meet the GIMP #62: Noise in the Dark!

Posted in Graphics on April 28, 2009

Meet the GIMP #62: Noise in the Dark!

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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Tags: Design, GIMP, Meet the GIMP, UFRaw, Broadcasting, Screencasts, noise, noise removal, selective noise removal