The Compose module is easy-to-use, but extremely flexible compositing and channel extraction tool. As opposed to all other software, the Compose module allows you to effortless process, LRGB, LLRGB, or narrowband composites like SHO, LSHO and more composites, as if they were simple RGB datasets.
In traditional image processing software, composites with separate luminance information (for example acquired through a luminance filter, created by a synthetic luminance frame, or a combination of both), require lengthy processing workflows; luminance (detail) and color information needs (or should!) be processed separately and only combined at the end to produce the final image.
Through the Compose module, StarTools is able to process luminance and color information separately, yet simultaneously.
This has important ramifications for your workflow and signal fidelity;
Synthetic luminance dataset are created by simply specifying the total exposure times for each imported dataset. With a click of a button, synthetic luminance datasets can be added to an existing luminance dataset, or can be used as a (synthetic) luminance dataset in its own right.
Finally, the Compose module can be used to create bi-color composites, or to extract individual channels from color images.
Creating a composite is as easy as loading the desired datasets into the desired slots, and optionally setting the desired composite scheme and exposure lengths.
The "Luminance" button loads a dataset into the "Luminance File" slot. The "Lum Total Exposure" slider determines the total exposure length in hours, minutes and seconds. This value is used to create the correct weighted synthetic luminance dataset, in case the "Luminance, Color" composite mode is set to create a synthetic luminance form the loaded channels. Loading a Luminance file will only have an effect when the "Luminance, Color" parameter is set to a compositing scheme that incorporates a luminance dataset (e.g. "L, RGB", "L + Synthetic L From RGB, RGB" or "L + Synthetic L From RGB, Mono") .
The Red, Green and Blue buttons load a dataset in the "Red File", "Green File" and "Blue File" slots respectively. The "Red Total Exposure", "Green Total Exposure", "Blue Total Exposure" sliders determine the total exposure length in hours, minutes and seconds for each of the three slots. These values are used to create the correct weighted synthetic luminance dataset (at 1/3rd weighting of the "Lum Total Exposure"), in case the "Luminance, Color" composite mode is set to create a synthetic luminance from the loaded channels.
Loading an dataset into the "Red File", "Green File" or "Blue File" slots will see any missing slots be synthesised automatically if the "Color Ch. Interpolation" parameter is set to "On". Loading a color dataset into the "Red File", "Green File" or "Blue File" slots will automatically extract the red, green and blue channels of the color dataset respectively.
There are a number of compositing schemes available, some of which will put StarTools into "composite" mode (as signified by a lit up "Compose" label on the Compose button on the home screen). Compositing schemes that require separate processing of luminance and color will put StarTools in this special mode. Some module may exhibit subtly different behaviour, or expose different functionality while in this mode.
The following compositing schemes are selectable;
"RGB, RGB" simply uses red + green + blue for luminance and uses red, green and blue for the color information. No special processing or compositing is done. Any loaded Luminance dataset is ignored, as are Total exposure settings.
"RGB, Mono" simply uses red + green + blue for luminance and uses the average of the red, green and blue channels for all channels for the color information, resulting in a mono image. Any loaded Luminance dataset is ignored, as are Total exposure settings.
"L, RGB" simply uses the loaded luminance dataset for luminance and uses red, green and blue for the color information. Total exposure settings are ignored. StarTools will be put into "composite" mode, processing luminance and color separately but simultaneously. If not Luminance dataset is loaded, this scheme functions the same as "RGB, RGB" with the execption that StarTools will be put into "composite" mode, processing luminance and color separately yet simultaneously.
"L + Synthetic L from RGB, RGB" creates a synthetic luminance dataset from Luminance, Red, Green and Blue, weighted according to the exposure times provided by the "Total Exposure" sliders. The color information will consists of simply the red, green and blue datasets as imported. StarTools will be put into "composite" mode, processing luminance and color separately yet simultaneously.
"L + Synthetic L from RGB, Mono" creates a synthetic luminance dataset from Luminance, Red, Green and Blue, weighted according to the exposure times provided by the "Total Exposure" sliders. The color information will consists of the average of the red, green and blue channels for all channels, yielding a mono image. StarTools is not put into "composite" mode, as no color information is available.
The Hubble Space Telescope palette (also known as 'HST' or 'SHO' palette) is a popular palette for color renditions of the S-II, Hydrogen-alpha and O-III emission bands. This palette is achieved by loading S-II, Hydrogen-alpha and O-III ("SHO") as red, green and blue respectively. A special "Hubble" preset in the Color module provides a shortcut to color rendition settings that mimic the results from the more limited image processing tools from the 1990s.
A popular bi-color rendition of H-alpha and O-III is to import H-alpha as red and O-III as green as well as blue. A synthetic luminance frame is then created that only gives red and blue (or green instead of blue, but not both!) a weighting according to the two datasets' exposure lengths. The resulting color rendition tends to be close to these bands' manifestation in the visual spectrum with H-alpha a deep red and O-III appearing as a teal green.
Thanks to StarTools' Tracking feature the Color module provides you with unparalleled flexibility when it comes to colour presentation in your image.
The more pixels are in the mask, the more the Heal module will have to 'invent' and the longer the Heal module will take to produce a result.
The HDR (High Dynamic Range) module optimises local dynamic range, in order to bring out the maximum amount of detail that is hidden in your data.
The Heal module was created to provide a means of substituting unwanted pixels in an neutral way.
The Synth module generates physically correct diffraction and diffusion of point lights (such as stars) in your image, based on a virtual telescope model.
You can convert everything you see to a format you find convenient. Give it a try!