[PDFBOX-4187] Refactor LosslessFactory alpha

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.9, 3.0.0 PDFBox
• Fix Version/s: 2.0.10, 3.0.0 PDFBox
• Component/s: PDModel
• Assignee: Tilman Hausherr
• Reporter: Tilman Hausherr
• Created: 10/Apr/18 16:26
• Updated: 21/Jun/18 20:27
• Resolved: 10/Apr/18 19:32

Description

While looking into the code for PDFBOX-4184 I noticed that we try to get the alpha data in different ways, despite that it is available in the main method when image.getRGB() is called. So I'm refactoring all this; as a side effect, my 16 bit change in PDFBOX-4184 is no longer needed.

I'll commit this in two steps; 1) changing the main method and remove the ones that are no longer being used; 2) split the main method in a gray and a color code.