ASTROPHOTOGRAPHY - TIPS Last updated: 26 January 2007

Subject:	Outline for Meade Image Processor
Sent:	Friday, January 26, 2007 10:58:19
From:	Ted Rafferty (raff650@erols.com)
Below is an outline I use for post processing using the Meade Image
Processor on frames from the Meade DSI-I that some of your reader might
find useful. The Meade Image Processor is a pretty nice image processor,
but the manual for it isn't very well written. I am still learning about
image processing, so this outline should be viewed as a
work-in-progress.

Though it was written for the DSI-I, it should provide guidance for
processing frames from other imagers. The steps that are particular to
the Mead color imagers are the FITS3P frames. And the steps that are
particular to the DSI-I are the ones involving the frame sizes. If the
imager is monochromic, the R, G, and B frames will be created by
separate exposures, and the steps following the "Split DSI Colors" would
apply.

Ted Rafferty

Gaithersburg, Maryland

-----------------

Post Processing using the Meade Image Processor on Frames from the Meade
DSI-I Imager

Rafferty

9/24/06


A. Taking Frames

1) Options: Color, High Gain, No Dark Applied

2) Saving Process: FITS3P, Save All Raw Images

3) Take a series of frames (6 or more)

4) Take a series of darks (at least 5) for the exposure time used

B. First Stage of Post Processing

1) Copy raw frames and dark into a separate folder (you might need to go
back to the original, unprocessed, frames).

2) Open Image Processor (AutoStar Suite > Image > Image Processor)

3) Separate the Darks by colors (Group > New (load group) > Group >
Split DSI Colors)

4) Process each color groups (blue, green, and red) of the Darks
separately. Load one color group of Darks (Group > New (load group)) and
then combined them into a single image (Group > Combine (I use
"average")). Save the combined dark image (File > Save Fits Image)
giving it a name that indicates its color and exposure time. Repeat the
steps for the other two color groups of the Darks.

5) Examine series for bad frames (Group > New (load group) > Examine).
Step through the series to see if there are any frames badly trailed. If
there are bad frames, delete them from the folder.

6) Separate frames by colors (Group > New (load group) > Group > Split
Color)

Process frames by one color at a time. You should see that the four new
frames have been created for the darks and each of the original frames
with an R, B, G, and L in their names to indicate which color group they
are in.

7) Calibrate frames (Group > New (load one color group) > Calibrate
(select the matching color dark and check "Include Dark Frame"). Flats
can also be applied in this step if you have them (select the matching
color flat and check "Include Flat Frame").  This will create a new
frame for each frame with its name starting with "Calibrated_".

8) If you want to fix hot or cold pixels, apply a filter to the frames
(such as the median filter), etc you should do them before the next step
(i.e. before the frames are resized).

9) To improve the quality of the final results, change the size of the
frames so they can be Drizzled. The dark and raw frames are 508 by 488
in size and you will want to resize "Calibrated" frames to 1295 by 976
(Group > Resample). This will create a new frame for each frame with its
name starting with "HotFixed_Calibrated".

10) Repeat steps 6 and 8 for each of the colors except for L until you
have sets of "HotFixed Calibrated" frames for the red, green, and blue.

11) Align all three colored frames using a two-star alignment (Group >
Align > Two Star). The Align process will also combined the frames into
a single image, but ignore it except to see that the alignment of all
frames was successful. It is important to align all three colored frames
to aid in a later step when creating a colored image.

12) Now you want to create three images from the three color sets of
aligned frames. The aligned frames have names starting with "Aligned".
Select a group of a single color and combined them (Group > New (load
one color group) > Combine). I saw little difference between using
average, median, or sum.

13) The combined image can now be enhanced using the Process Icons
Toolbars displayed below the "File, View, etc" line. This step is worth
experimenting with. And since it has a "Preview" option, it is easy to
undo things that didn't work. The two I mostly use are the Image
Convolution (selecting Normal or Smooth) and Image Prescale (Select Std
Dev > OK for the first part and Preview the Linear and Log for the
second part, you can do Log more than once to push the image. You might
also want to try the "Histogram Equalization", which pushes the image.),
once you have the image the way you want, select OK. Save the combined
image as a BMP (File > Export Display as...) using a name that indicates
which color it is. Since you will be merging the three color images
together, what you do to one color image you should do the same to the
others.

14) Repeat step 11 for each of the colors except for L until you have a
single image for the red, green, and blue.

15) Combine the three colors together. First open the red frame (File >
Open) and then do Color > RGB Merge... Select the name for the G and B
frames.

16) Experiment with the color balance using the Preview option. You can
adjust the color balance in this step and apply offsets to better align
the three colors (though, since all the frames had been aligned to one
another in step 9, applying offsets is likely not necessary).

17) Once you get the image the way you want save it (File > Export
Display As..) and be sure to indicate that it is with all three colors.

18) To create a black and white version of the image, open the color
image (File > Open) and, from the "BMP Image Plane Selection" select
"Load as Mono".

19) Additional processing can be done on the black and white image that
can not be done on the color image, including resizing the frame back to
648 by 488 and doing adjustments in Process.

20) Save black and white image (File > Export Display As..) and be sure
to indicate what it is a black and white frame.

If you want a 648 by 488 color image, you will need to resize the three
1296x976 color images to 648x488 before you merge them together (File >
Open > Process > Resample).