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This image was processed entirely in Images Plus
5.75. Calibration, stacking and initial arcsin stretch done in Images
Plus . The stretched image was run through the
Feature Mask tool to separate the stars from the rest of the image.
This was then used as a mask and the original image was again arcsin
stretched using the mask. This allowed the DSO to be brightened
significantly without star bloat. The Feature Mask tool was then used
on this image and the mask was used with several iterations of a curve
adjustment with a screen combine to further enhance the nebula. Erosion
was used with a mask to further reduce the small stars left by the
Feature Mask tool. The red in the nebula was boosted using the additive
colour balance tool applied with a mask. The mask was generated using
the selective colour luminance mask tool. Next the blue in the nebula
was enhanced using the same technique as the red enhancement. Masked noise reduction
was used to reduce the background noise in the nebula only image. A
mild deconvolution was applied using the original mask made with the
Feature Mask to sharpen the nebula slightly.
Next the saturation of the star only image was
increased and the stars slightly blurred and the two images were merged
using the new merge split combine method in the combine images tool.
The final image was binned to reduce its size for web display.
There are other methods for splitting the stars
from the rest of the image, packages such as Straton and Photoshop
methods that allow similar processing but none are as simple
to use as the new Feature Mask tool in Images Plus and none have the
advantage of being fully integrated into the image processing software.
Mask methods require some blurring to reduce the
impact of stars. This blurring shows up in the stretched image as can
be seen in the mouse over image that was processed using masks
generated from the image using a layered technique.
The Feature mask produces a detailed mask without any blurring that can
be used for masked stretching. Because there is no blurring of the mask
required the stretched image remains sharp and detailed.
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