Purple fringe--what to do about it and why [1/5] - "101 Jim-LeroyWVA-001.jpg" yEnc (0/1)

Some people think they see auras around other people. But digital cameras often think they see purple fringes around the edges of some objects, and it makes pictures look less sharp. To illustrate what can be done about the problem, I've used a picture that was uploaded by Andrew.

Image 101 shows the unmodified image. Image 102 is a magnified portion of the bottom of the fuselage, clearly showing the purple edge (blow up 101, and you'll also see it on the upper wing and the bottom of the wheel). Image 103 shows the problem corrected. How was it done? Paint Shop Pro's one-step purple fringe was ineffective in this case. Instead, I used PSP's Chromatic Aberration Removal tool. With it, you create samples (basically, rectangles containing problem areas so that PSP knows what colors it should treat as aberrations--I'm oversimplifying), and then simply let PSP take care of all instances of the problem. Image 104 shows the whole airplane corrected, done in just one step. Compare it with 101, and it simply looks sharper even though it really isn't!

Unrelated to the purple fringe problem, I was bothered by the fact that the upper wing seemed to be paler than the lower wing or tailplane. I was sure this was an artifact of lighting rather than any real color difference, so I darkened the upper wing a bit and kicked the saturation quite a bit to get much closer to a match, as seen in Image 105.

I prefer Image 105 to 101. How about you?