Project 1: Colorizing the Prokudin-Gorskii Photo Collection

By Peng Li

Overview

Before color photography was available,Sergei Mikhailovich Prokudin-Gorskii took numerous pictures of Russia using red, blue and yellow filters which were later digitalized. In this assignment, I took the three color channel images and aligned them to together to produce the final image.
For the small scale images, I use brute-force search between [-15,15] using SSD (sum of squared difference) to measure how well the offset lines up. In calculating the SSD, I crop out border of the image both to reduce the effect of border and cicshift operation on the overall SSD.
For the big scale image, I use pyramid search by scaling the image from 1/32 to 1. I compute the offset for the small image first using brute force, then use this offset to estimate the larger image from [-4 4].
I noticed that the borders of the final images are colorized. Therefore, I also crop out the border of the aligned images to produce more pleasing results.

Small Scale Images

Original Aligned Result Cropped Result Alignments
Green Alignment: [6 1]
Red Alignment: [13 1]
Green Alignment: [5 2]
Red Alignment: [10 1]
Green Alignment: [-3 1]
Red Alignment: [-4 1]
Green Alignment: [1 0 ]
Red Alignment: [10 0]
Green Alignment: [6 -2]
Red Alignment: [13 -4]
Green Alignment: [6 2 ]
Red Alignment: [11 3 ]
Green Alignment: [6 2 ]
Red Alignment: [14 3]
Green Alignment: [6 2 ]
Red Alignment: [13 1]
Green Alignment: [7 1 ]
Red Alignment: [15 1]
Green Alignment: [8 0 ]
Red Alignment: [15 -1]
Green Alignment: [8 1]
Red Alignment: [15 1]
Green Alignment: [6 2]
Red Alignment: [12 3]
Green Alignment: [8 0]
Red Alignment: [13 0]

Large Scale Images

Cropped Result Alignments
Green Alignment: [43 6]
Red Alignment: [87 32]
Green Alignment: [13 -7]
Red Alignment: [133 -13]
Green Alignment: [60 13]
Red Alignment: [129 13]
Green Alignment: [24 20]
Red Alignment: [71 33]
Green Alignment: [55 9]
Red Alignment: [117 12]
Green Alignment: [77 45]
Red Alignment: [162 77]
Green Alignment: [71 38]
Red Alignment: [147 62]