CS194-26 Project 5: Image Warping and Mosaics

Christine Zhu

Overview

In this project, implementing the necessary components to warp and combine one image with another, forming a 'panoramic image' of sorts.

Part 1: Shoot and Digitize Pictures

To start out, we need two photographs from the same point of view in different directions. The two photographs must have overlapping fields of view. I have chosen two photographs outside a mall in Boston, displayed below:

Part 2: Recover Homographies

In the next step, we must compute or homography matrix H, which will allows to perspective warp one image into our desired perspective of the second image. To do this, we use the least squares method after constructing our equations A*h = y where h contains the 8 unknowns of our homography matrix and A contains combinations of our x,y correspondance points in both images. Below we can see our correspondance points in the two images and the resulting warp of the first image into the second image's perspective. I have downsized the size of the original images due to computation time.

Here are some more examples of image rectification, with a textbook and a laptop. Again, the warped images have been downsized so they may seem slightly blurry. As new points were manually selected, they may not be a perfect rectangle, however the general principle of warping the original image into a top / front facing image is maintained.

Part 3: Image Mosaics

Now that we have ensure our homography is working correctly, we will attempt to stitch together images for image mosaics. An example on the first Boston images is show below along with 2 more mosaic images. The previous downsizing still applies.