Image stacking
Stacking images is the term for the combination of
multiple images into a single image. This effectively
stacks the aligned images on top of each other
then using an algorithm combines the images.
Screen image during wavelet processing.
Layer 6 provides the roughest sharpening down to layer 1
giving the finest control over the image. Even after stacking and consolidating all of the good data there is still a
seemingly unfocused
poor image. Applying
the wavelet filters really
pulls out the detail of
the image and creates
a stunning image from
what at first sight looks
like a poor image.
When you have the
wavelets adjusted to
your liking you can
then start using the
The stacked image.
various functions in
the panel to the left
to make some further adjustments. I will often save the
image at this point and then edit it in PhotoShop, a professional image processing package. I normally apply
Image alignment
The images are aligned by selecting a
number of reference points then rotating
the image so that these points are in the
same position in each of the images.
a high pass filter to it, followed by an unsharp mask.
I have used a partial image of the Moon here as it is
large and easy to see
the effects go the process. The same steps
apply to processing
planets, but they can
be a little trickier due
to the much smaller
size of the object. My
setup does not allow
a full image of the
Moon. To get a full image I would need to
create about six imThe stacked image with wavelets.
ages and then merge
them all together.
To do this I would have to take all the source videos at
the same time. This is because the Moon does actually move slightly and the illumination of the surface
changes from day to day, and even hour to hour.
You can now see
how technology can
transform the wobbly
object on the video
into a brilliantly sharp
clear final image.
Compare the before
and after images to
see difference stacking and application
of wavelets makes to
bring out detail in the
The final processed Moon image.
otherwise fuzzy shot.
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