The goal of this project was to produce colored images from the digitized Prokudin-Gorskii glass plate images using image processing techniques. The first step was to extract the three color channel images and then align them by one of two processes:

For smaller photos (.jpg), I searched over a [15, 15] window of displacement between two photos and took the one with the least sum squared differences. Then the 3 color channel images would be aligned by the produced offsets. In addition, I had to crop out the borders to improve the SSD so I cropped out .15 of the photo from each side.

Monastery R: [3, 2] G: [-3, 2]	Cathedral R: [12, 3] G: [5, 2]
Settlers R: [15, -1] G: [7, 0]	Nativity R: [8, 0] G: [3, 2]

For bigger photos (.tif), the higher resolution made the previous approach too inefficient, so I used the pyramid method instead. I recursively called the previous align method on a scaled version of the photo with a [-15, 15] window, and then began scaling the image back and calling on the align method on it with a smaller window. At first I was encountered a bug that I was stuck on for a while before realizing that I needed to multiply the offset by the factor I was scaling it by (in this case 2) to keep my results accurate.

Icon R: [89,23] G: [41,17]	Lady R: [116,12] G: [55,9]	Self Portrait R: [176,37] G: [78,29]
Turkmen R: [116,28] G: [56,21]	Three Generations R: [111,11] G: [52,14]	Train R: [87,32] G: [43,6]
Harvesters R: [124,13] G: [59,17]	Village R: [138,22] G: [65,12]

I also encountered a problem with emir.tif (from piazza I could see that some other people did as well) because it had a dominant presence of blue. To fix this, I aligned it images against the green channel instead of the blue channel.

Emir R: [57,17] B: [-49,-24]

Extras

Nomad R: [68,52] G: [23,43]

Monks G: R: [15,6] G: [6,4]

Project 1: Images of the Russian Empire

Sally Yen 26404499

Extras