in praise of RawTherapee, "Amaze" demosaicing algorithm

Started Jun 10, 2011 | Discussions thread
OP RussellInCincinnati Veteran Member • Posts: 3,201
point of the posts is demosaicing *differences*

GaryW: The unsharp mask of 1 is too much, especially for the top photo, at least. The RL Deconvolution sharpens all by itself. You may not need any further sharpening. But if it's already sharp and you insist on sharpening, try a .5 radius first. The top photo looks like it's buzzing a bit too much for my taste. But it is sharp.

Yes, now that you mention it, the top photo in my post yesterday of the magazine halftone is a bit "buzzy". I appreciate your hint Gary, and will experiment with a smaller sharpening radius. Hmm, that's a fragment of a 1 meter wide enlargement on my monitor, would it still be buzzy at any normal print/display size?.

Anyway, the overall point of interest in this thread is not to show a workflow that is "good" in any absolute sense. Rather it's to show the difference between AHD demosaicing in my quite typical Picture Window Pro program, versus Amaze demosaicing+RL Deconvolution in Raw Therapee. Is there a difference in apparent sharpness, or fine detail, even though both programs' images were put through the same final unsharp masking? Apparently yes.

Maybe I should have just stuck with my original quite clear comparison a few weeks ago (that included RL Deconvolution for the Amaze images) and left it at that, even though that picture was not taken under well-controlled conditionn For some reason had mis-spelled AHD demosaicing as "ADR algorithm" in the picture labels:

Adopting RT Raw Therapee has been for me like getting a whole new set of lenses. And along with RT's 5-pass false color suppression routine, as shown above, it's solved maybe half of Nex moire problems. Without blurring anything.

By the way RL Deconvolution sharpening (am thinking of it as "pre-sharpening", since it does not sharpen so much as to screw up later resizing of an image) is faintly related to the technology involved in the new "lightfield camera", mentioned in another contemporaneous thread of this Sony Nex forum.

Put another way, let's say you like the image quality step-up from bothering to process raw images, rather than accepting Sony in-camera JPEGs. If so, then am suggesting/showing there's a similar jump up in quality to go from most raw file processors, without the newish AHD demosaicing, to Raw Therapee, with its Amaze demosaicing+RL Deconvolution.

If you don't mind spending 1 minute processing each raw file, on a dual core 2.1 gigahetz Intel box. RT does support multiple CPUs (e.g. dual or quad core) well.

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