Images of the Russian Empire:
Colorizing the Prokudin-Gorskii photo collection

15-463: Computational Photography
Ming Han Teh

Background

The requirements for this project can be found on the course website.

Technique

The image strip is composed of BGR glass plates. I divided the image strip into 3 equal parts (along the height).

I then aligned the image by using exhastive search with an image pyramid of scaling factor 0.5. For this pyramid, my top most image must have a width of less than or equal to 300 (i.e. the base case). For the exhastive search, I used a window of [-15,15] for my top most image and [-2,-2] for the rest of the images. I tried both the Sum of Squared Difference (SSD) and Normalized Cross-Correlation (NCC) to compute the metric, but did not found much difference in results in the two. Hence, I settled on SSD as it was fast and more efficient. This technique worked well for some small images and the alignments were still off for most of the images.

In implementing the bell and whistles, I realized that the white and black borders were affecting the metric scoring and hence the alignment was off. I then used a navie algorithm to crop away the white and black borders on the original image strip before processing it. This algorithm was implemented by taking means along each columns and rows, and then thresholding for black and white via a for-loop along both axis. I also used used the edges() function for the top image on the pyramid before using the search + SSD algorithm on it. This was used for the smallest image to match the key features of the image. However, it was not used for the rest of the images because it resulted in too much imprecision. Finally, I also implemented the autocrop for the final image to trim away some of the color bands at the edges. This was implemented by calculating the SSD for each pixel for each R,G,B pairs and suming up. I then calculated the mean along the columns and rows, and threshold them via a for-loop along both axis.

Images

00088v.jpg

Result 1:
displacement of [-3,0] of Green wrt Blue
displacement of [5,-1] of Red wrt Blue
Result 2:
displacement of [-9,3] of Green wrt Blue
displacement of [-19,5] of Red wrt Blue

01880v.jpg

Result 1:
displacement of [6,2] of Green wrt Blue
displacement of [12,2] of Red wrt Blue
Result 2:
displacement of [-14,2] of Green wrt Blue
displacement of [-26,4] of Red wrt Blue

00757v.jpg

Result 1:
displacement of [0,0] of Green wrt Blue
displacement of [4,0] of Red wrt Blue
Result 2:
displacement of [-8,3] of Green wrt Blue
displacement of [-14,5] of Red wrt Blue

01031v.jpg

Result 1:
displacement of [1,1] of Green wrt Blue
displacement of [4,1] of Red wrt Blue
Result 2:
displacement of [-5,1] of Green wrt Blue
displacement of [-8,1] of Red wrt Blue

00911v.jpg

Result 1:
displacement of [2,-1] of Green wrt Blue
displacement of [6,-3] of Red wrt Blue
Result 2:
displacement of [-10,-1] of Green wrt Blue
displacement of [-10,-2] of Red wrt Blue

00888v.jpg

Result 1:
displacement of [6,0] of Green wrt Blue
displacement of [10,-1] of Red wrt Blue
Result 2:
displacement of [-7,1] of Green wrt Blue
displacement of [-14,0] of Red wrt Blue

00889v.jpg

Result 1:
displacement of [1,-1] of Green wrt Blue
displacement of [5,-1] of Red wrt Blue
Result 2:
displacement of [-7,2] of Green wrt Blue
displacement of [-13,3] of Red wrt Blue

00106v.jpg

Result 1:
displacement of [4,0] of Green wrt Blue
displacement of [9,-1] of Red wrt Blue
Result 2:
displacement of [-4,1] of Green wrt Blue
displacement of [-6,-1] of Red wrt Blue

00137v.jpg

Result 1:
displacement of [6,4] of Green wrt Blue
displacement of [10,7] of Red wrt Blue
Result 2:
displacement of [-7,5] of Green wrt Blue
displacement of [-14,8] of Red wrt Blue

00907v.jpg

Result 1:
displacement of [0,-1] of Green wrt Blue
displacement of [4,-1] of Red wrt Blue
Result 2:
displacement of [-7,0] of Green wrt Blue
displacement of [-12,-1] of Red wrt Blue

00029u.tif

Result 1:
displacement of [77,-6] of Green wrt Blue
displacement of [88,-12] of Red wrt Blue
Result 2:
displacement of [-84,15] of Green wrt Blue
displacement of [-156,32] of Red wrt Blue

00087u.tif

Result 1:
displacement of [54,0] of Green wrt Blue
displacement of [102,1] of Red wrt Blue
Result 2:
displacement of [-75,38] of Green wrt Blue
displacement of [-138,55] of Red wrt Blue

00128u.tif

Result 1:
displacement of [36,2] of Green wrt Blue
displacement of [85,3] of Red wrt Blue
Result 2:
displacement of [-41,25] of Green wrt Blue
displacement of [-97,38] of Red wrt Blue

00737u.tif

Result 1:
displacement of [38,-2] of Green wrt Blue
displacement of [49,-1] of Red wrt Blue
Result 2:
displacement of [-81,6] of Green wrt Blue
displacement of [-142,14] of Red wrt Blue

00822u.tif

Result 1:
displacement of [62,3] of Green wrt Blue
displacement of [101,-4] of Red wrt Blue
Result 2:
displacement of [-65,24] of Green wrt Blue
displacement of [-118,33] of Red wrt Blue

00892u.tif

Result 1:
displacement of [-16,-8] of Green wrt Blue
displacement of [59,-15] of Red wrt Blue
Result 2:
displacement of [-59,1] of Green wrt Blue
displacement of [-109,4] of Red wrt Blue

00992u.tif

Result 1:
displacement of [49,-5] of Green wrt Blue
displacement of [73,-13] of Red wrt Blue
Result 2:
displacement of [-76,14] of Green wrt Blue
displacement of [-138,20] of Red wrt Blue

01043u.tif

Result 1:
displacement of [-18,3] of Green wrt Blue
displacement of [48,-11] of Red wrt Blue
Result 2:
displacement of [-86,10] of Green wrt Blue
displacement of [-126,16] of Red wrt Blue

01085u.tif

Result 1:
displacement of [97,10] of Green wrt Blue
displacement of [104,23] of Red wrt Blue
Result 2:
displacement of [-71,31] of Green wrt Blue
displacement of [-117,59] of Red wrt Blue

01734u.tif

Result 1:
displacement of [8,-2] of Green wrt Blue
displacement of [212,-4] of Red wrt Blue
Result 2:
displacement of [-34,28] of Green wrt Blue
displacement of [-61,49] of Red wrt Blue

00895v.jpg

Remarks: Example of own choosing from LoC website.
Result 1:
displacement of [7,2] of Green wrt Blue
displacement of [12,0] of Red wrt Blue
Result 2:
displacement of [-8,2] of Green wrt Blue
displacement of [-14,3] of Red wrt Blue

00299v.jpg

Remarks: Example of own choosing from LoC website.
Result 1:
displacement of [1,0] of Green wrt Blue
displacement of [7,0] of Red wrt Blue
Result 2:
displacement of [-11,0] of Green wrt Blue
displacement of [-12,2] of Red wrt Blue

00645u.tif

Remarks: Example of own choosing from LoC website.
Result 1:
displacement of [28,-9] of Green wrt Blue
displacement of [103,-17] of Red wrt Blue
Result 2:
displacement of [-94,6] of Green wrt Blue
displacement of [-193,-9] of Red wrt Blue

00234u.tif

Remarks: Example of own choosing from LoC website.
Result 1:
displacement of [40,-8] of Green wrt Blue
displacement of [138,-21] of Red wrt Blue
Result 2:
displacement of [-101,5] of Green wrt Blue
displacement of [-143,13] of Red wrt Blue

Hybrid Images

Background

The requirements for this project can be found on the course website.

Technique

I use the guassian filter for the low pass filter, and for the high pass filtered image, I substracted the gaussian-filtered image from the original.

Images

DerekPicture.jpg vs nutmeg.jpg



algore.jpg vs jobs.jpg