Science at Parramatta High
(3a) — September 30 1999
Saturn
Please excuse the large size of the gif. Its the full 640x480 pixels of the Mavica.
Above is the image from the Mavica, with minor image processing to reduce the file
size. All I've done is:
- reduce the palette from 24 bit jpeg (RGB) to 7 bit (greyscale),
- delete some electronic "noise" (largely jpeg compression artefacts)
from the background, in particular at the edge of the image,
- equalise the background to solid black (actually, part of the above point),
- save the image in gif format.
The "noise" I deleted was all electronic "artefacts". At first I thought I might have captured
a one-pixel moon (Mimas, Tethys, Enceladus?) just above the top right tip of the rings, but
sadly my search through ephemerides suggests there wasn't one there at that time (1:10am
Parramatta local [GMT+10], 30/9/1999).
With the background all-black (as it very nearly was anyway), conversion to gif
seemed the obvious way to save file space.
And how! 1.5k is not bad for a full 640x480 file.
Here is the compact result,
with a little tweaking, and a one pixel white border.
File size = 276 bytes!
Below (it should be loaded by now) is the completely raw image, straight off the
Mavica disk. No image processing at all. I promise! I've even kept the original
Mavica filename.
Feel free to load this into your graphics program and play with the contrast and brightness.
See if you can dig a moon or two out of the noise.
Return to near occultations,
lunar eclipse or
Saturn.
Go on to Jupiter or
the moon - same magnification.
Information about the telescope and
camera used for other photos in this series (not the Mavica).
© PHS
