I'm developing an application which uses a Canon DSLR to sequentially shoot an object from different views. Often the object is too big to fit in frame so I have to make more than one series of photos.
It's really important for the photos to be distorted as little as possible (the photos are then merged into one and result image is used in mathematical algorithm). For that purpose it's really important to know which part of image is least lens-distorted.
I suppose the least lens-distorted rectangular part of a shot is defined by focal length of the lens I'm using, but I'd like to know which part it is exactly, or at least how to calculate that part.
Could anyone help me in clarifying this?
The object always has a shape of cylinder. It is placed between two shafts which rotate the object (rotation is controlled by software). So, the goal is to get an image that represents the surface of this object.
The process is as follows:
- I set the number of rotations to be made - call it 'n'. On each iteration the object is rotated by 360/n degrees, and for each iteration camera shot is made.
- Once n rotations (and shots) are made, if object doesn't fit in camera frame, carriage, that holds tha camera shifts to the side and repeats this process for the new portion of the object. Otherwise process finishes.
Here's an example of photo for better understanding:
Algorithm takes a part of image, which represents 360/n degree part of object's surface and saves it. After finishing the process, those pieces are merged into one and the result looks something like that:
I hope this clarifies the process a bit more.