REMOVE DUST, COLORFUL PIXELS AND OTHER IMPERFECTIONS

Instead of using theDuplicate Stamp Tool (Clone Stamp Tool) by Photoshop to remove dust, colored pixels and other imperfections in the image, here is a more efficient procedure for dealing with these defects. It requires more processing steps but when everything has been configured, it allows several imperfections to be quickly treated. It can therefore replace treatment # 4 of Image processing. I also use this method to effectively eliminate "Blooming" on the stars.

  1. Open the image to be processed in Photoshop
  2. In the window Layers (Layers), with the right mouse button, click on the layer Background and choose Duplicate layer. Rename the layer Copy background for  Dust layer.
  3. Click on the Dust layer to make it active and select Filter | Noise | Anti dust … (Filter | Noise | Dust & Scratches)
  4. In the window Anti dust, adjust the Radius (Radius) until dust, scratches or colored pixels disappear. At this stage the image will become blurry but you have to concentrate on the disappearance of the defects.
  5. Select Layer | Fusion mask | Hide all (Layer | Layer Mask | Hide All)
  6. Select tool Brush
  7. Configure the tool as follows:
  9. Put the tool Foreground color white andBackground Black 
  10. In the Dust layer, click on the fusion mask thumbnail to make it active
  11. Configure tool size Brush. Click on Form (Brush) and select the diameter 10 pixels for example: 
  12. Click on the defects to make them disappear (we can also paint them if the defects are larger than 10 pixels for example). It's really magical and fast too!

Here is an example of this treatment on cold pixels (black pixels) which remained even after the subtraction of the Black (Dark)

Before treatment:


After treatment:

The image is a portion of the galaxy NGC 3628. On the first image, we can see the cold pixels (black dots) very well. On the processed image the cold pixels have disappeared! The corrections made to the image leave no trace of correction.

Here is another example to eliminate Blooming around the stars:

      
Before treatment After treatment

Blooming has completely disappeared. No trace of the treatment can be seen. It's a really quick way to make it go away. In my opinion, this is one of the best "Deblooming" methods that Photoshop offers.

Richard Beauregard
Sky Astro - CCD

Revised 2021/04/06