Sometimes you’re in a hurry, want to produce a good quality image, yet don’t have a lot of tools at your disposal.

This article walks you through performing some adjustments that reduce noise in an image and boost contrast, some of which is lost during noise reduction.

Despite it’s seeming simplicity, the adjustments I show you how to make are actually quite powerful and the technique is used as the basis for performing similar adjustments using commercial software.

I assume you’re going to use Photopea.com for this adjustment, however, you could adapt this process to Photoshop or GIMP.

Result

This is an image of NGC 974, a grouping of galaxies, that’s been processed and has some noise in it. The left side of the image is the original as processed using MaxIM DL and the one on the right is processed using the steps in this article to reduce noise and boost contrast.

The noise reduction and contrast boost are very subtle, so you might have to repeatedly look between the two images to pick up the effect of the adjustments.

The noise in this image is in the form of ‘granules’ – grainy parts of the image that is apparent near the galaxies on the left side of the image.

The noise reduction blurs the noise thereby combining it into less grainy structures. The process doesn’t completely eliminate noise, however, it does reduce it.

The image on the right side has also been processed to boost some contrast that’s lost during the noise reduction process.

Reducing Noise

1. Open your noisy image, and from the menu select Filter – Blur – Gaussian Blur

2. Enter or select a Radius of about 2.2 pixels

3. From the menu, select Edit – Fade

4. Enter or select 40% on the Opacity slider and click Ok

5. From the menu, select Filter – Noise – Median

6. Enter or select 8 pixels for the Radius

7. From the menu, select Edit – Fade

8. Enter or select 15% on the Opacity slider and click Ok

You have now reduced the noise in the image – now let’s boost the contrast.

Boosting Contrast

I have shown this technique to you in other articles on this website, however, I repeat it here for your convenience.

1. From the Layers panel, duplicate the background layer (right-click the background layer, and select Duplicate Layer)

2. Select Image – Adjustments – Desaturate

3. Select Image – Adjustments – Invert

4. From the Layers panel, change the blending mode to Overlay (you can find the blending mode above the listing of Layers – it usually has the word Normal with a small arrow next to it)

5. Adjust the Opacity of the layer to about 50% (the opacity slider is next to the blending mode and usually shows 100% with a small arrow next to it)

6. Save or export your final image

Conclusion

In this article, I showed you how to reduce noise using two powerful adjustments and how to boost contrast that was lost during the noise reduction process. These techniques are straight-forward and easy to remember; however, they are used as the basis for performing similar adjustments in commercial specialized software.