In this project, I took two images in my room for rectification and three sets of three images outside which I then stitched together into one panorama. I used an inverse warp which would take a center image and compute the warp from the center image to the left or right image. Then, using that warp, I would interpolate the pixels that would go there. For rectification, the center image was the four points I used as a rectangular template.
Rectification is changing the perspective in an image to align with a template. For these examples, I took some photographs which include a planar surface but the image doesn't appear to be looking at the planar surface. I rectified them using a template of four points representing a plane to make it look as if the camera was looking at the specified planar surface.
In this part of the project, I took three images, and picked one to be in the center. Then I warped each left and right images towards the center and put them together into one mosaic. For warping, I did an inverse warp with interpolation just as we did in rectification and I did not warp the center image. I blended the warped images by finding the overlap between each warped image and center image and create linear mask decreasing from 1 to 0 in one image and 0 to 1 in the other image. I multiplied each column index of the resulting mosaic by this mask and summed each warped image's columns together.
I learned in this project that there are a lot of cool applications for warping! I also learned what helped develop good and bad mosaics. I think my Safeway and Philz examples are not done as well because there is a lot of detail up close where as the Wheeler hall example has more detail farther away from the camera. I also think that if I were to improve upon this, I would try to select more points when building out the mosaic.