image editing

Hello, I need to be counseled on building a low/mid range Tower hackintosh dedicated to still image work (16 Go RAM sould be enough). I need to build it ASAP so I ask for the easiest software/[no] tweaking 'config'. I mainly/only need to be advised about the proc, motherboard, graphic board and...

Recently, images that I edit in Preview (e.g., by rotating the image) or Pixelmator (e.g., by painting on an image or applying a filter) have something screwy happen to the colors. I'm attaching two examples: the image on the top left was rotated twice then saved, producing the image on the...