The Prokudin-Gorskii photo collection was taken at the beginning of the 1900's before colour film existed. He wanted to have colour photos of the Russian Empire and set about taking photos with blue, green and red filters in front of the camera. The pictures were then taken on glass panes with all three colour channels next to each other. The images were supposed to be able to be recombined with a special type of projector. In 1948, the Library of Congress bought the whole collection of slides and they have been scanned and are available online. For this project we were given images of the slides with separate colour channels and were supposed to align and stack the channels and then output the colourized picture.
I used the plain and simple SSD function to calculate the differences between the colour channels for the different offsets to find the best alignment. I found out that the offsets that the SSD found was incorrect. To fix this, I cropped off 15% of the image and kept only the centre part of the image that did not have any border or blemish issues. This made the ssd alignment very close to perfect. Once I had the correct offsets, I used the original images for the final output because 15% cropped off is losing too much of the image.
