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Fred Miranda wrote:
It is indeed very impressive. However there is noise increase. Check out the sky areas.
Yohan Pamudji wrote:
Does that mean it's just sharpening the image which is why the noise is more visible? Seems like the same result as sharpening. I don't know the underlying algorithms, but I'm cautiously skeptical.
I believe the answer to your question can be observed by comparing the "DLO + no USM" sample against the "no DLO + USM" sample. You should be able to see sharpening artifacts in the latter that are absent in the former; e.g., the boundary of high-contrast regions exhibits a sawtooth artifact. So it does look like the DLO algorithm is doing something more sophisticated than simple unsharp masking.
That said, it must be clarified that whatever Canon is doing to improve the sharpness of the image, it is a *form* of sharpening. What they claim, however, is that their algorithm takes into account the optical properties of the specific lens used. If true, then diffraction softness can be significantly mitigated as we have seen here. Unsharp masking, of course, is agnostic toward the optical system's characteristics--it works only with the original input data.
Unless their algorithm also takes into account various lens aberrations, I would not expect it to be useful for shots taken at apertures faster than about f/5.6 - f/8.
Regarding Fred's point--that noise appears to have increased as a result of applying DLO--this might be because (1) a small amount of "traditional" sharpening is automatically applied; or (2) deconvolution of the signal with respect to the point spread function may also have the effect of increasing the visibility of shot noise, due to the reversal of the spread.
If indeed this works as claimed, I think I'm going to be very eager to try reprocessing some of my shots--fortunately for me, I've always used DPP rather than Lightroom or Aperture as my raw converter, instead preferring to do final edits in Photoshop. This workflow suits me quite well and the best part is that I can now apply this DLO algorithm to my raw file, output the image as 16 bit TIFF, and then just paste it into a new layer on top of my PSD file, without having to redo all the PS edits.
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