PHYS397R-Astrophotography
(1 credit - Spring 2015)

Processing Planetary Movies using Registax

This page explains how to take raw .avi movie files of planets or the Moon and process them to produce much sharper and clearer images. As an example, Figure 1 shows the power that the program Registax has in significantly improving the quality of planetary image.

Fig. 1: Example of the difference between Jupiter's appearance in the raw .avi movie file (left) and Jupiter after processing the movie file through Registax (right).


The general procedure to process .avi movie files like the Jupiter one above is the following:
  1. Open the Registax program
  2. Open your .avi movi file in Registax by clicking on Select...
  3. Examine the quality of your movie by grabbing the yellow slider bar on the bottom and scrolling through all of the individual frames that make up the movie. Note how many total frames are in the movie (usually 300-1500).
  4. On the left side click on the circle next to Best Frames, and enter in the box on the right a number that is 75% of the total frame number. (So if there are 1000 total frames, enter 750 in the box).  
  5. To ALIGN all of the frames click the checkbox Align by Center of Gravity, then click once on the red circle that appears in the middle of your image. 
  6. Now on the upper left side, click on Align. This will align all of your best 75% images on top of each other. 
  7. Now on the upper left side, click on Limit. This will limit the # of images used to the best 75%. 
  8. Now on the upper left side, click on Stack. This will stack the best 75% on top of each other. 
You should now have one blurry image now on the screen, but don't worry, you'll make it better!


     In this next part, which may take some time, you are going to sharpen the single image that appears on the screen. 
  1. To Sharpen the image: Examine the red box in Fig. 2 below, change all of your settings to match those. This should make the image sharper, but maybe still too dark. 
  2. To Brighten the image: On the upper right side, click on Histogram, you will get a box like that in Fig. 3. Now do two things: a: Click on the Direct Box and b: Move the right side slider bar until it is just to the right side of the "mountain".

Fig. 2: To sharpen the image: Start by setting all of the values in the red box to the values listed above.



Fig. 3: To make the image brighter: a. Click on the Direct Box and b. Move the right side slider bar until it is just to the right side of the "mountain".


If you are happy with the image on the screen, click Save Image on the upper left corner. If you want it to be better, play around by adjusting things in the red box in Fig. 2. Specifically, move the yellow slider in Layer 1 to the left to make image smoother, and to the right to make it sharper, just play around until you get what you think looks best....