Original

Curves

Set black point

Curves

Curves

Set black point

Curves

GradXTerminator

Set black point

 

In order to use the processing pages you need to click on the yellow bar on the top of the page, chose "Allow Blocked Content" and then click yes in the following dialog window.

By placing the cursor over the text in the upper left column, you can follow the processing steps and how it affects the image.

 

Processing

RGB

RGB+Ha

Ha

Combined

Invert mask