Transforming a photo of a cylinder to a flat canvas

[Natasha32107620u9hj]

I am trying to extract a frieze ono a tower on a childs toy to reproduce it on a plane. 

I have 8 photos of the tower but would like to merge them to get a flat picture. I have seen tutorials on how to take a flat picture and wrap it around a cylinder but not the other way round - 

any advice ?

[Abambo]

You haven't seen a solution to this because it is hard to do. You would need a scanner, scanning the object line per line, by turning a small amount each time. Or you will need to take numerous pictures of your tower and stitch the pictures together and compensate for the cylindrical distortion.

[Semaphoric]

How about putting the object on a turntable, and using the Panorama feature of a smart phone (keeping the phone stationary).

[Abambo]

That would be a great solution. I think, however, that my phone expects to move.

You surly need to put the subject on a turntable.

[Natasha32107620u9hj]

I did try the panorama feature of the iphone but I my camera couldn't work out what was happening with the background, If I could set my photo size to be long and thin and only capture the tower length then perhaps it could work but the photo includes too much irrelevent footage which doesn't move as the panorama captures the image.

[Abambo]

As a side note: there are 3D scanners out scanning both, the geometry and the texture. The latter is what OP wants to get. 30 years ago, at SIGGRAPH they demonstrated one of the first of those scanners, at that time still at a great price. My colleague had got a scan done of himself. He introduced that scan into a 3D scene, he was building, for the fun of it! 😉

[Natasha32107620u9hj]

I have 8 pictures but wanted to start with a cylindrical transform. The
difficulty is that the distortion increases towards the edges so I can't
just undistort it.

[c.pfaffenbichler]

Please provide the images (or lores thereof). 

How meticulous were you in making sure all 8 images were taken at exactly the same position relative to the axis and at 45˚ difference? 

[Natasha32107620u9hj]

Unfortunately I don't have the object that I am wanting to replicate - I am using photos from collectors and sellers in the States who don't necessarily know how to take the photos as instructed and the images are sent over facebook so are of an inferior quality. 

[c.pfaffenbichler]

That seems like a lot of work for a result that might just not live up to expectations. 

[D Fosse]

Indeed. This is unrealistic. This is reconstruction. It could take weeks.

[Natasha32107620u9hj]

Thanks I am trying that. for each photoraph I use the transform crop (which is a little complex as the only straight lines I have are of the edges of the cylinder - the base is curved and the top is curved as well. Then I use the skew transform to try and straighten the bottom (or half of it at least) and then I stretch the edges using the scale. I am sure I could do a calculation on how much each sectino needs to be stretched but for now it is very hit and miss.  Is there an easy feature to change the lighting of all the pictures to match ?