Background Improvement with Histogram Transfer

PixInsight
Linear Image Quality Enhancements

updated: 2025-09-28

Purpose	Using Histogram Transfer to improve the background
Activation	Menu: Process 🡺 All Processes 🡺 Curves Transformation Process Explorer: IntensityTransformations 🡺 Curves Transformation
Input	Deconvoluted and cropped image from previous step
Output	De-noised image with post-fix “*_BI.xisf” into sub folder "Work"
Previous Step	LocalHistogramEqualization or any image form chapter Improving the Image
Next Step	Background Improvement
Tutorial	https://www.youtube.com/watch?v=qg1QUVaCLqI (Part 11 Adding Saturation to your Final Image, starts at around 6m50s )

Step	Description	Action
1	Create a Luminance Mask this will create a B/W luminance image. Pull the tab of the B/W luminance image to the left side of the color image to apply the mask. Make the mask visible by pushing CTRL+K.
2	Invert the Mask to protect the foreground objects like stars and galaxies by pressing CTRL+Shift+I and hide the mask again with CTRL+K
3	Create a new Preview ALT+N of an area containing a smaller background section including a portion of the main target.
4	Open up Histogram Transform first reset the function, then open the preview (Preview01)
4	Open a Real-Time Preview on the selected Preview01
	Enable Track View
5	Moving the Shadows Slider Right will turning an amount of pixels (exactly 2126 pixels or 4.6197%) with a value of less than 0.043... to become totally black. By moving the slider more to the right, more pixels will be destroyed.
6	Close the Real-Time Preview
7	Apply the Settings on the Entire Image by dragging the little blue triangle an on your image.
8	Remove the Mask and the Preview Image Menu 🡺 Mask 🡺 Remove Mask
13	Close Histogram Transform
14	Save the Image to “*_i_c_DBE_ABE_BN_CC_HT_MLT_FS_CT_BI.xisf” and a JPEG copy to e.g. "20170921_M8_FUJXT1_7443-1" in this case	file name like “*final.xisf”