Stack Astronomical Images

Image stacking is a technique that is primarily used for improving astronomical images.

When you try to photograph a planet such as Jupiter through a telescope, the Earth's atmosphere continuously distorts the image so that the images usually look pretty blurry, they dance around a lot and they contain a lot of noise. However, by taking several hundred images, "registering" (aligning their centers) then "stacking" them (adding them all together pixel-by-pixel then dividing each pixel by the number of images) the blurriness diminishes and amazing detail often emerges. (You might also want to consider using the freeware program RegiStax which is a truly excellent image stacking program.)

The Stack Images control window:

Browse: Brings up a file selector window. Select an AVI file containing the images you want to stack. In the above example, the marsCropped-0009.avi file was captured using the "Create an astronomy Video" capture mode.

Progress: If the image stacking process is underway, the progress bar will proceed from left to right indicating the progress of the stacking algorithm. You can see in the above example that image stacking is about 1/10th finished.

Stack Images: Begin the image stacking operation. Stacking can be aborted using the Escape key or the Cancel button.

Cancel: If image stacking was NOT underway, this causes the "Stack Images" window to close. If image stacking IS underway, a message box pops up asking "Would you like to abort image stacking?". If you answer yes, the frames that have already been processed will be averaged and displayed in a Stacked Image Window.

Stacked Image window: After stacking has completed (either by normal completion or by Cancel or Escape key) a "Stacked Image Window will be displayed showing the result of the image stacking operation:


One original image          Stacked image

The stacked image window has a File menu item that will let you save the stacked image as a JPG file or a BMP file: