The latest build 1065 of the PixInsight Core application introduces a new Boosted STF AutoStretch feature. Boosted STFs are like normal automatic screen stretch functions but more aggressive. They allow for more in depth inspection of raw data, and are also quite useful for visual inspection of special control images such as integration rejection maps.
For quick access to the boosted AutoStretch feature we now have a dedicated atomic tool button:
Note that the Ctrl+A (Cmd+A on Mac OS X) keyboard accelerator still invokes the normal autostretch feature, as usual. For now there is no accelerator assigned to boosted autostretch.
With default parameters, the difference between boosted and normal automatic STFs is considerable. The next screenshots show the difference for an HDR M42 image (courtesy of Vicent Peris and José Luis Lamadrid).
Normal STF AutoStretch
Boosted STF AutoStretch
Boosted STF AutoStretch parameters can be configured. Open the ScreenTransferFunction tool and Ctrl-Click (Cmd-Click on Mac OS X) the atomic icon to the left of the window. This opens the STF AutoStretch dialog:
The boosted AutoStretch feature can be controlled with two parameters:
boosted clipping factor and
boosted background factor. These parameters are just multiplicative factors for the normal
shadows clipping and
target background parameters, respectively. The default values usually work well in most cases.
Another important difference in the latest version is that STF AutoStretch parameters are persistent across PixInsight Core sessions. The four parameters can be saved and retrieved by clicking the corresponding buttons on the dialog above.
