The concept of image processing
In principal, all astronomical images must be processed/enhanced in order to display all the information they contain. The reason this has to be done is because of the limited ability of our display devices to reproduce the whole range of brightness levels in the image data. In fact the level of brightness in astronomical images can vary over many orders of magnitude - from super bright stars to extremely faint gas that is a part of a nebula. Astronomical images have to be processed to make this hole range of brightness visible simultaneously. Because the image data has to be modified in an extrem way and the degree of modification is largely given by the tast and judgment of the astrophotographer limits of what is right and wrong in image processing have to be dispensed. Details could be created and/or misrepresented. That is the point where individual opinions and personal preferences prevail. So preparing images for general viewing is mainly an art that should be guided by scientific notions and attention to detail. So it is my goal to process astronomical image data in a way the scientific correctness is retained whereas the image appears aesthetically giving rise to inspire the spirit and imagination of everyone looking at it.