Slashdot Mirror
Correcting Lens Aberrations in Digital Photography?
Kavau asks: "I've recently entered the world of digital photography, and bought a pocket-sized digital. While the resolution and the color accuracy are very nice, I was utterly disappointed by the (lack of) quality of the zoom lens: It has a clearly visible barrel distortion, especially in wide angle, so that straight lines appear curved in the picture. This is especially annoying in architectural shots or cityscapes. While grumbling about this shortcoming, I suddenly realized that I am dealing with digital imaging here: In principle it should be no problem to measure the distortion, and then to correct it with a digital mapping. Other lens faults such as vignetting could also be corrected. Now, since I don't want to reinvent the wheel, here is my question to Slashdot: Do you know of any open-source tools that deal with issues such as (1) applying general analytic transformations to a picture, (2) specifically correcting for barrel distortion, or (3) determining the amount of distortion from test pictures? Also, since people probably had this idea before, does anyone have experience with this issue that he/she wants to share, or some resources to point out?"
Not the most computationally efficient method but I wonder if you could do this with povray.
Use the picture as an image map on a sphere or cylinder. Keep adjusting the frame and object size until the lines look straight. Make sure the object is self illuminating and you don't use external light sources...
Hmmmm, seems like it might work....
One should not theorize before one has data. -Sherlock Holmes-
Huh? Graph paper would do a MUCH better job at finding the lenses flaws, and make it fairly simple to correct them...that picture you have would barely do any good at all...just on the parts where there was detail. Even then, that would be insanely hard to implement in software compared to a grid. It might be better at finding focus or something...but thats not the point. The graph paper would show you exactly how the lense was deformed at practically every point on the lense (depending on density of the lines of course). All you would have to do to fix it would be straighten out the lines. I don't really see how that picture you posted could be used to find lense distortion...it just doesn't have enough detail. What is it specifically for?