Raw Conversion and De-Mosaicing

Recently I was checking my emails and I came across a weekly update from DXO Labs. This was a regular email that pops up in my inbox with the latest threads in their support and user forums. I noticed a thread on a new product that they were now supplying called PureRaw. I was unfamiliar with the product so I wanted to see what exactly it was; I was already familiar with their existing products including the DXO Nik tools and their PhotoLab editing software.

The Nik tools will be familiar to many photographers as a suite of plug ins that extend other editing software such as Lightroom and Photoshop, alongside their own PhotoLab and Serif’s Affinity Photo. PhotoLab may be less familiar but is well known for its ability to “tap” into DXO Labs’ extensive research into how various cameras interact with various lenses. They effectively create add on modules that take this knowledge and make it available to Photolab to allow it to open a raw file and de-mosaic and de-noise the image and also remove optical aberrations and vignetting to get the editing process off to an excellent start.

I have long liked the benefit of this process but often found it problematic to add in to my image processing workflow which is predominantly centred around Lightroom and Photoshop; having to effectively round trip out to PhotoLab just to take advantage of its technical process in cleanly opening a raw file for a good starting point to the rest of the processing workflow, especially as I did not really take advantage of any of the other editing capabilities of PhotoLab

So what is PureRaw? Effectively it does one thing; It opens a raw file and uses that technical module Ai ability to demosaic, de-noise and optically correct it, producing a new DNG Raw File for further editing. That’s it, nothing else. But wow is it good at what it does.

I was really surprised at how quick and effectively it does that one task and this got me thinking; was it really that good? should I be using this technology or was it another step I did not really need to bother with? At our camera club we often discuss software workflows with advocates on all sides. So gradually a question began to form in my mind; is all software equal when it comes to the most basic function of simply opening and demosaicing a raw file prior to editing. I thought I would take a look and this is the not very scientific experiment I came up with.

I have a few different programs available to try, so I opened a selection of raw files in each and without actually beginning the editing process, I exported the file as a full sized Tiff file with no further adjustment. The exception was the PureRaw files which were opened using Adobe Camera Raw into Photoshop alongside the tiffs.

Harvest Mouse – Canon 7D2 + Tamron 90mm Macro @ 125 ISO, 1/160, f16

The harvest mouse shot above is a studio shot and so as expected, there is little noise in any of the shots. DPP is Canon’s own editing software and you would expect, that as they design the camera and the software, their software should be able to manage a good raw conversion; and it does not disappoint; little noise, and nice and sharp.

Man under red umbrella – Lumix GMC-GX7 + Lumix 25mm f1.7 @ ISO 800, 1/30 , f1.7

This being taken on a Panasonic camera means it could not be opened in Canon DPP, but the other options are here to show results from a smaller sensor in much lower light. In the rear edge of the umbrella there is noise apparent but Pure Raw seems to have rendered this image with less noise and better detail on the man’s face.

Robin – Canon 5D4 + Sigma 150 – 600mm S @ ISO 2000, 1/1250, f6.3

Luminar, Affinity and Lightroom all render this image with some background noise, which is understandable when you consider it was shot at ISO 2000. Canon’s DPP handles the noise OK but once again there is more detail in the Photolab and PureRaw images.

Night time shot – Canon 5D2 + Tokina 16 to 28mm f2.8 @ 20s f2.8

This image was included to push the limits. A long exposure at high ISO and you would expect a loss of definition and a lot of noise. This time even Canon’s DPP software shows quite noticeable noise but yet again the two offerings from DXO reduce the noise amazingly well. The detail in the tree in the PureRaw image is much better than any of the others. I did try to reduce the noise in the other programs but doing so also adversely affects the sharpness and definition as well and I was not able to match both the noise control or sharpness and detail of the PureRaw rendering.

I will definitely be using the PureRaw software in my workflow going forward.

Update – PureRaw is now on version 2 and provides excellent raw conversion, with a much better link up to Lightroom.

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