Rotating parts of an image on an axis

[WillT]

Hi,

I have an image that I wanted to alter part of, and cannot work out how to do it. In the attached pic, the yellow marker on the far right is turned too far to the right (the black part of the cap shows it is too far right and not 'face on' to the camera). Similarly the green pen second in from the left has the same issue.

How can I isolate the markers with this issue, and rotate them vertically (on the axis as such) so that the images of these markers are directly 'face on' like the rest of the markers?

I have read about 3D conversions but not sure how to do it, and would have thought there is another way to resolve rather than having to convert the image to 3D? Appreciate any advice.

 

[Tom Mann]

There is no magic 3D PS technique based on this single image because it simply doesn't contain all the info needed to do 3D rotations of each object.

A 3D approach that actually is viable would be to learn one of the 3D rendering programs and reconstruct all the pens in it. If you think PS is difficult, these programs are even more difficult.

A low quality, tedious way to kinda-sorta do what you want using PS would be to make a copy of each of the clips, move each copy horizontally to be centered on its barrel, tweak each shape to correct for keystone distortion, and then reconstruct the strips of each barrel where the clips used to be located.

Another PS technique would be to take one of the pens with the clip in the correct position, make 10 copies of it, space the copies apart horizontally, and then change the color of each cap.

However, if you want realism, by far, the best way is to simply re-photograph the image using correct technique rather than trying to fix an error after the fact.

Specifically, if you use a longer FL lens, or, even better, a telecentric lens (http://en.wikipedia.org/wiki/Telecentric_lens) with a long stand-off distance, you won't have this problem.

T

 

[WillT]

Hi Tom,

Thanks so much for your detailed review, it is very helpful. You truly are a Photoshop Guru

Regards

Will