Images of the Russian Empire:

Colorizing the Prokudin-Gorskii photo collection

Background

(from Course Website)

Sergei Mikhailovich Prokudin-Gorskii (1863-1944) [Сергей Михайлович Прокудин-Горский, to his Russian friends] was a man well ahead of his time. Convinced, as early as 1907, that color photography was the wave of the future, he won Tzar's special permission to travel across the vast Russian Empire and take color photographs of everything he saw including the only color portrait of Leo Tolstoy. And he really photographed everything: people, buildings, landscapes, railroads, bridges... thousands of color pictures! His idea was simple: record three exposures of every scene onto a glass plate using a red, a green, and a blue filter. Never mind that there was no way to print color photographs until much later -- he envisioned special projectors to be installed in "multimedia" classrooms all across Russia where the children would be able to learn about their vast country. Alas, his plans never materialized: he left Russia in 1918, right after the revolution, never to return again. Luckily, his RGB glass plate negatives, capturing the last years of the Russian Empire, survived and were purchased in 1948 by the Library of Congress. The LoC has recently digitized the negatives and made them available on-line.

Project Overview

The goal of this assignment was to take the digitized Prokudin-Gorskii glass plate images, break them down into the r, g, b sections. Then align these segments on top of one another to produce a full single RGB color image. In order to have the image look presentable, this project finds the optimum alignment for so that each image overlaps the best it can.

Approach

For jpg images, I used the Sum of Squared Differences (SSD) distance metric to score how well each pair of image matched. I used the suggested [-15, 15] range. Once the input image was tif (larger image), I used the image pyramid and recursively called this 3 times. Once it reached a smaller size, I ran the jpg image algorithm.