CS194-26: Image Manipulation and Computational Photography

Image Warping and Mosaicing

Denis Li, cs194-26-aem



Overview

In this project, I used created image mosaics by transforming images into the same perspective and then stitching the images together to form a single panorama.

Image rectification

By selecting the 4 corners of a shape in an image, we can rectify it by computing the homography from the points to a rectangle and then performing the transformation on all of the points in the image.




A painting
painting rectified
A pattern
pattern rectified

Image Stitching

By defining correspondences between image, we can then transform images to a base image and stitch them together to from a panorama. The more correspondences there are, the more accurate the homography as more points reduces the error on each particular point. To blend images together more seamlessly, I used a alpha mask.

Generated mosaic (after cropping)
Generated mosaic from other picture's point of view(after cropping)

We can do this with 3 images as well!

Generated mosaic (after cropping)

We can get some cool effect if we take the 2 pictures at different times.

Generated mosaic (after cropping)
Cropped to a more interesting section

Summary

Homography are cool! In this project learned how panoramas and that it really is just a perspective transform.