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DxO has released a new AI-based tool for noise reduc­tion in dig­i­tal images.

DeepPRIME - A revolution in digital noise reduction

In my review of DxO’s RAW con­vert­er, DxO Pho­to­Lab 4, I exten­sive­ly test­ed the new AI / Deep Learn­ing based noise reduc­tion tech­nique Deep­PRIME (only includ­ed in the Pho­to­Lab 4 Elite ver­sion) for high-ISO images. In short, I was so impressed with the results that I decid­ed to buy DxO Pho­to­Lab 4 Elite, despite its rather high price, sole­ly because of its sen­sa­tion­al noise reduc­tion. In the mean­time, I updat­ed to the cur­rent Ver­sion 5 of PhotoLab.

Since then, I’ve been using the Deep­PRIME algo­rithm fre­quent­ly on my high ISO images. It allows to achieve impres­sive results even from pho­tos tak­en at ISO 12,800. or above. Rough­ly speak­ing, the results with Deep­PRIME are a good 2 stops clean­er than those I can achieve with Light­room Clas­sic. That means that an ISO 12,800 image processed with Deep­PRIME is com­pa­ra­ble in terms of noise to an image processed in Adobe Light­room at ISO 3,200.

How­ev­er, I still don’t use the oth­er fea­tures of DxO Pho­to­Lab at all, as I still pre­fer to do all oth­er image edit­ing and tag­ging in Adobe Light­room Clas­sic (LRC). In my opin­ion, LRC is much more intu­itive to use and, above all, much faster. LRC also offers exten­sive man­age­ment of images, which allows me to orga­nize my now more than 180,000 images very well.

Since I use only DxO’s noise reduc­tion Deep­PRIME and want to con­tin­ue my image pro­cess­ing in LRC, it would there­fore be nice if DxO would deliv­er Deep­PRIME as a sep­a­rate mod­ule, since I cur­rent­ly do not need any of the oth­er fea­tures of PhotoLab.

My wish was granted

DxO has now ful­filled my wish. Since a few days, DxO Pur­eRAW is avail­able. To see how the new pro­gram per­forms in my work­flow, I installed and test­ed it. In par­tic­u­lar, I want­ed to see how it com­pared to my cur­rent pro­cess­ing with Pho­to­Lab’s Deep­PRIME module.

You can down­load a tri­al ver­sion of DxO Pur­eRAW* direct­ly from DxO. It can again be used for 31 days with­out any restrictions.

What does DxO PureRAW offer?

DxO Pur­eRAW is a stand­alone pro­gram that exclu­sive­ly works with RAW files. These can be processed with three dif­fer­ent noise reduc­tion algo­rithms (HQ, PRIME, and Deep­PRIME). In addi­tion, DxO-devel­oped opti­cal cor­rec­tion fil­ters which cor­rect lens-spe­cif­ic dis­tor­tions, vignetting and chro­mat­ic aber­ra­tions are applied. Fur­ther­more, the result­ing images are auto­mat­i­cal­ly sharp­ened. These cor­rect­ed pho­tos can then be saved as JPG files or DNG-RAW files. After­wards, you can pass them to anoth­er pro­gram for fur­ther processing.

Handling

Han­dling is very straight­for­ward. After start­ing the pro­gram, an emp­ty pro­gram win­dow appears.

To select images for edit­ing, they can be either dragged and dropped from a file explor­er win­dow into it (this also works with fold­ers, as long as they do not con­tain sub­fold­ers) or they can be select­ed by click­ing on the “+” sym­bol via a dia­log box.

If nec­es­sary cam­era and lens mod­ules are not present yet, DxO Pur­eRAW will ask if they should be loaded:

These are then dis­played in the work­space in tiles. Dou­ble-click­ing on a tile opens the image in detail view, the mouse scroll wheel can be used to change the mag­ni­fi­ca­tion and the image sec­tion can be moved with the mouse. I test­ed the pro­gram once again with a pho­to of our cat Tom (he loves gift wrap­ping), tak­en at an ISO of 12,800:

The han­dling of the pro­gram is very straight­for­ward. Sim­ply select the images to be devel­oped (in the exam­ple there is only one). Then click on the but­ton “Process pho­tos” and a dia­log box with a few options opens up immediately:

My pre­ferred options - method Deep­PRIME and out­put to DNG are already acti­vat­ed. There­fore, all that remains is to select the des­ti­na­tion fold­er and click Process. Then the algo­rithm already starts. But now you need to be patient. As I wrote in my arti­cle on DxO Pho­to­Lab 4, noise reduc­tion with Deep­PRIME takes its time. On my lap­top with 8-core AMD Ryzen 7-4800U and inte­grat­ed Radeon graph­ics, I have to wait about 2 min­utes until Pur­eRAW is done with an EOS-R5 CR3 file and asks what to do with the cre­at­ed DNG file:

Results

Here, the result can now be com­pared direct­ly with the source mate­r­i­al, or the file can be trans­ferred to anoth­er pro­gram (e.g. Light­room or Pho­to­shop) for fur­ther pro­cess­ing. Nat­u­ral­ly, the first thing that’s of inter­est here, is the com­par­a­tive view, which DxO has inte­grat­ed into Pur­eRAW in a very nice way. By default, the orig­i­nal and processed ver­sions are dis­played side by side, and you can move the tran­si­tion area to the left or right as you wish.

The four small icons at the bot­tom right allow you to con­fig­ure the view. The 1:1 switch enlarges the image, so that one image pix­el cor­re­sponds to one mon­i­tor pix­el. This is the only way to real­ly com­pare the two images. The image can be moved with the mouse and fur­ther enlarged or reduced with the mouse scroll wheel. With the two icons on the right you can choose between split and switch view. All in all, the result of the Deep­PRIME algo­rithm is real­ly impressive:

Here is anoth­er example:

After com­ple­tion, the DNG files can then be trans­ferred to anoth­er pro­gram for fur­ther pro­cess­ing using the Export to … but­ton, in my case to Adobe Light­room Clas­sic. There, all fur­ther pro­cess­ing steps (e.g. white bal­ance, expo­sure cor­rec­tion, tag­ging) can be done in the usu­al way.

Comparison with DxO PhotoLab

Over­all, the results of Pur­eRAW are very good, the oper­a­tion is unbeat­able straight­for­ward and sim­ple. Unlike the Deep­PRIME algo­rithm in Pho­to­Lab, how­ev­er, no para­me­ters can be set. There­fore I com­pared the results of the Deep­PRIME denois­ing between Pur­eRAW and Pho­to­Lab. Again, I used the pho­to of our cat Tom from my Pho­to­Lab 4 test:

The fol­low­ing images con­tain crops from it enlarged to 200%.

First, as a start­ing point, the result of my noise reduc­tion (Lumi­nance 60) in Light­room Classic:

And here you can see what Deep­PRIME can squeeze out of the image:

Again, I real­ly like the result. Espe­cial­ly impres­sive is how the algo­rithm still works out the indi­vid­ual hairs from the very noisy image above. The dif­fer­ence between the pro­cess­ing in Pur­eRAW and Pho­to­Lab is small. How­ev­er, I noticed that the DNG in Pur­eRAW is already clear­ly sharp­ened. In my pro­cess­ing in Pho­to­Lab Elite, the DNG returns to Light­room with­out much sharp­en­ing, so it needs to be sharp­ened there. I did that in the above image on the right with the LR default set­ting (Amount 40, Radius 1.0, Details 25 and Mask­ing 0). With the already sharp­ened DNG file sup­plied by Pur­eRAW, no more sharp­en­ing at all should be applied in LR (amount 0), because the image will already appear sig­nif­i­cant­ly over-sharp­ened at the LRC default set­ting (amount 40).

Conclusion

DxO’s Deep­PRIME noise reduc­tion deliv­ers results that are absolute­ly stun­ning. With mod­ern dig­i­tal sen­sors, the pos­si­bil­i­ty of noise reduc­tion now allows shoot­ing at ISO val­ues that one would not have dared to dream of a few years ago. Not to men­tion the era of ana­log film pho­tog­ra­phy: there, the end of the line was usu­al­ly already reached in col­or at ISO 400 and B/W at ISO 1,600. I now con­fi­dent­ly use ISO val­ues up to 12,800 with my Canon EOS R5.

Pur­eRAW’s results are almost iden­ti­cal to those that can be achieved with Pho­to­Lab 4. This is not sur­pris­ing, since the under­ly­ing algo­rithm Deep­PRIME is iden­ti­cal. The oper­a­tion of Pur­eRAW is sim­ple and straightforward.

How­ev­er, you don’t get this for free. DxO Pur­eRAW costs 129,-€, more than half the price of DxO Pho­to­Lab 5 Elite (219,-€), which also includes the Light­room plu­g­in and a com­plete RAW con­vert­er. How­ev­er, as an hol­i­day sea­son offer, Pur­eRAW is cur­rent­ly avail­able for €89.99.

Besides the rel­a­tive­ly high € costs, the pro­cess­ing with Pur­eRAW how­ev­er also costs:

Storage space and time

The DNG files cre­at­ed with DxO Pur­eRAW (and also DxO Pho­to­Lab 4) using the Deep­PRIME algo­rithm are more than twice the size of the CR3 raw files from my Canon EOS R5. The pro­cess­ing speed is high­ly depen­dent on the com­put­er hard­ware and the built-in graph­ics card, but you can safe­ly expect pro­cess­ing times in the min­utes range per image. As men­tioned above, my lap­top with the 8-core AMD RYZEN 4800U needs a good 2 min­utes for a 45 megapix­el RAW of my EOS R5.

I can’t test how this looks with more potent proces­sors and graph­ics cards at the moment, but would be hap­py to hear com­ments with tim­ings on oth­er machines. All in all, prob­a­bly no one will use Pur­eRAW on all his images. It makes more sense to process only the images that will cer­tain­ly ben­e­fit from it.

This now brings me to my next point:

Hello DxO - Please give me a Lightroom plugin!

I wish DxO would include a plug-in for Light­room with Pur­eRAW, sim­i­lar to Pho­to­Lab. Since pro­cess­ing with the Deep­PRIME algo­rithm is, as men­tioned, extreme­ly time-con­sum­ing, I only process those few images with it, that real­ly prof­it from the algorithm.

My usu­al work­flow is this: first, I import and edit all my images in Adobe Light­room Clas­sic, as I am used to. I have con­fig­ured Light­room so that all images are already denoised at import, depend­ing on their ISO val­ue. After import­ing, I first delete every­thing that is obvi­ous­ly mis­shapen - blur­ry images, glar­ing­ly wrong expo­sures, obvi­ous­ly bad images (some­times there are those even with me 😉 ) etc. The remain­ing images are reviewed one by one and briefly edit­ed (expo­sure, white bal­ance, key­word­ing). At last I rate the images and look at the bet­ter ones again more close­ly. Then I edit the best ones more extensively.

From them, I only trans­fer those images to Pho­to­Lab via the plug-in that require a bet­ter noise reduc­tion than the one inte­grat­ed in LRC. In my expe­ri­ence, this only applies to a small part of the pic­tures I take with very high ISO val­ues or where the shad­ows had to be increased con­sid­er­ably. For ISO val­ues up to about 1600, Light­room Clas­sic already does a pret­ty good job these days.

The new Pur­eRAW, on the oth­er hand, is designed to be exe­cut­ed as an inter­me­di­ate sta­tion even before the import of the new images into Light­room. How­ev­er, this would take a good 3 hours with 100 shots of my Canon EOS R5 on the one hand and dou­ble the mem­o­ry require­ment on the hard­drive from 4.5 to a good 9 GB on the other.

So I will con­tin­ue to use DxO Pho­to­Lab Elite, which I already bought, even though I only use it because of the Deep­PRIME algorithm.

How­ev­er, if I did­n’t have it yet, I would seri­ous­ly con­sid­er using Pur­eRAW. The results are just as good as with Pho­to­Lab 4/5, and the pro­gram is straight­for­ward and easy to use. Unfor­tu­nate­ly, though, Pur­eRAW does­n’t inte­grate into my usu­al edit­ing process with Adobe Light­room Clas­sic because of the (still) miss­ing plug-in.

I can only rec­om­mend any­one who has ever noticed noise in his or her pic­tures to down­load the tri­al ver­sion of Pur­eRAW* once and try the Deep­PRIME denois­ing. You can get amaz­ing results even out of old noisy images.

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