Noise reduction tests: RT vs LR

Noise reduction tests: RT vs LR

Hello everyone !

I would like to submit to you a series of tests that I carried out to highlight the effect of noise reduction, of RawTherapee compared to Lightroom.

(N.B.: Not artificial intelligence noise reduction, which has only just been introduced at Adobe).

To do this, I developed a chart of noisy and non-noisy patterns, with gray levels and colors, in order to see the action of noise reduction on details in a non-raw image.

Here is this detail analysis chart:

This is a .png file. I opened this image in RawTherapee and in Lightroom, to compare how each handles noise on these different patterns.

And there, I had a very astonishing surprise: the noise reduction of RawTherapee is totally inoperative, while that of Lightroom shows its effects in a significant proportion.

To make this comparison, I used medium noise reduction in both software. I know that with these settings the noise reduction is already quite pronounced, in Lightroom as in RawTherapee:

RawTherapee:

Color space: Lab
Mode: Aggressive
Gamma: 1.70 (default)
Luminance slider control
Luminance noise reduction level: 25
Luma detail level: 50 (default)

I left the chroma noise reduction in global automatic.

Lightroom:

Luminance noise reduction level: 40
Luminance Detail Level: 50
Contrast: 50

Chroma noise reduction: 40
Chroma detail level: 50
Smoothing: 50

In both software, I enlarged the image to 300% to clearly see the changes made on the details.

So I made a series of screenshots to show you what happens in the two software, noise reduction disabled then noise reduction enabled. You will therefore be able to clearly see the parameters used and the transformations applied to these noisy charts.

Then I performed the same comparisons on an actual JPEG photo, using the same settings in both software. The only thing different is that I still enabled Impulse Noise Reduction in RawTherapee, at the default level of 50.

And there, no possible doubt: the noise reduction of RawTherapee is much more effective than that of Lightroom, with the parameters chosen naturally. This is what makes me prefer RT to LR, especially in terms of noise reduction: that of RT is both more effective while letting more details through.

Unfortunately, I cannot show you all these screenshots in this post, because of the limitations of the forum, so I offer them for download here, in .zip format:

Tests of noise reduction in RT and LR.zip (22 Mb)

Thank you for devoting some of your time to analyzing these results. Who can explain this mystery to me: on my chart of noisy patterns in PNG format, the noise reduction of RT changes absolutely nothing. While Lightroom does apply noise reduction. On the other hand, on the JPEG photo, the noise reduction of RT works marvelously well, and even better than that of LR.

Does anyone know enough about RawTherapee to explain this behavior to me?

Thank you for your attention and your feedback.

Good day !

3 Likes

Thank you!
It’s presently dinner time up here… But when back onto my main computer, I’ll look into your findings better. I have a hunch that RT has a few more tricks to use…

Have fun!
Claes in Lund, Sweden

Smaklig måltid :wink:

@preuthier thanks for the great job.

@preuthier What operating system are you on?
My RT cannot even open a .png…

Absolutely. There are so many ways to apply noise reduction in RT — I’ve spent countless hours playing around with different settings and adjustments. It’s such a versatile tool.

You have it activated in the options? It’s off by default.

2 Likes

Oh je!!!

Das war es :-(((
Danke vielmals!

MfG
Claes in Lund, Schweden

1 Like

Thank you for your anaylsis, I am not really understanding this image you included and I am unable to download the zip file. Would you explain what these squares are supposed to mean?