Curves Notes; Scripting Notes - Canon CHDK Quick Start Manual

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Curves Notes

Custom Curves
Enables the use of custom "curve" profiles to adjust the exposure of your RAW and JPEG images. Please
read this long thread - Custom processing for JPEG (Tone curve, CA ...) :-
at the CHDK Forum, for its full functions and use.
http://chdk.setepontos.com/index.php/topic,932.0.html
As well as downloading a custom-curve editor (PC) to create your own profiles. (You may have to login
there to download any attachments in the posts.) For those of you new to curve adjustments to exposures
there's a nice little overview to what they do and how they might affect an image in this Curve
Anthology:
http://www.curvemeister.com/support/curvemeister2/help/Articles/CurveMoves.htm
Difference between CV and CVF curves: CV curves are the standard RGB curves. CVF curves are
special versions of the curves which intends to avoid color shift side effect of the RGB curves. They are
an approximation of the luminance curves. Except the SYSCURVES.CVF file, it is recommended to put
the curves files in the \curves directory.
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Scripting Notes

Well! where do we start, it is well known that Scripts and Scripting deserves a manual of it's own, but
for this limited size User Guide we will have to be content with a very brief overview.
Definition of a Script: A simple program in a utility language, another term for macro or batch file.
In computer programming, a computer script is a list of commands, or instructions, that are
executed by a certain program or scripting engine. They are usually just text documents that contain
instructions written in a certain scripting language (ie: uBASIC, Lua). This means most scripts can
be opened and edited using a basic text editor. However, when opened by the appropriate scripting
engine, the commands within the script are executed.
In CHDK, scripts are used to automate a command or multiple commands to the camera in order to
have the camera perform certain actions, ie: to hold the shutter open for a particular length of time,
or to force a particular Av or ISO setting, (and many more actions). Nearly anything you can do by
pressing buttons on your camera with your own fingers, you can also do automatically with these
.
script commands Note also that many scripts are universal for all relevant cameras, while others
are camera model specific.
Inventive script programmers, the experienced, and the not so experienced, have been active from
the beginning of CHDK, with many short and simple, and also the more complex scripts being
made freely available to the CHDK community. Scripts such as: motion detect, time lapse, USB
remote.