Project 5: Lightfield Camera

In this project we used lightfield data from Stanford Light Field Archive to refocus images based on depth and mimic different aperture sizes by varying the sample size of images.

Procedure

Using a data set of a 17x17 grid of images, I could refocus an image by averaging all the photos after shifting them toward the center. I identified the center at (8,8) and used the provided (u,v) coordinates as the center. Then for all the images in the grid I would find the offset of their (u,v) coordinates from the center and shift them by the offset * α. α is a constant that varies the point of focus on the chessboard depending on its value. In my implementation I took the absolute values of the coordinates, so my values of α are probably opposite of expected behavior (in my case, the bigger the α the depth of focus is further away).

Results

Procedure

In an image, a smaller aperture (the width of the opening of the lens) creates a larger area of focus. To mimic this effect, I only sample images within a certain radius around the center of the 17x17 grid. Then I would do the same procedure as the previous part (using α = .05) on that sample to create the effect.

Results