The crop module is an easy-to-use image cropping tool with quick aspect ratio presets and switchable luminance and chroma preview modes.
The module was designed to quickly find and eliminate stacking artefacts across luminance and chrominance data, as well as help with framing your object(s) of interest.
Using the crop module is fairly straightforward. The desired crop is created by clicking and dragging with the mouse the area to retain. Fine-tuning can be accomplished by changing the X1, Y1 and X2, Y2 coordinate pair parameters.
8 quick-access crops are available to quickly achieve one of four popular aspect ratios. The button names ('3:2', '2:3', '16:9', 9:16') denote the aspect ratio, while the double minus ('--') or plus ('++') signs postfix denotes their behaviour;
A 'Color' button is available, which functions much like the Color button in the Wipe module. It is only available when Compose mode is engaged (e.g. luminance and chroma are being processed separately, yet simultaneously) and allows you to switch the view between the luminance and chroma datasets that are being processed in parallel. The later is useful if, for example, you need to crop stacking artefacts that only exist in the chroma dataset, but not in the luminance dataset. Because chrominance data always remains linear and is never stretched like the luminance dataset, a courtesy (non-permanent) AutoDev is applied, so you can better see what is in the chrominance dataset.
The Stereo 3D module can be used to synthesise depth information based on astronomical image feature characteristics.
Please note that other parameters such as the 'Threshold', 'Max feature size', 'Filter sensitivity' and 'Exclude color' have no effect in this mode.
AutoDev will keep solving for a global strecth that best shows the detail in your RoI.
Even the way StarTools displays and scales images, has been created specifically for astrophotography.
You can convert everything you see to a format you find convenient. Give it a try!