Let’s quickly see what these motion models look like. Once these parameters are known, warping one image so that it aligns with the other is straight forward. Different image alignment algorithms aim to estimate the parameters of these motion models using different tricks and assumptions. In a typical image alignment problem we have two images of a scene, and they are related by a motion model. Well, it’s time for some vision magic! Motion models in OpenCV Therefore the three channels were often mis-aligned, and naively stacking them up leads to a pretty unsatisfactory result shown in Figure 1.
The Miethe-Bermpohl camera was a mechanical device that took these three images over a span of 2-6 seconds. It is not trivial to generate a color image from these black and white images (shown in Figure 3). They are now in the public domain and we get a chance to reconstruct Russian history in color! The most notable among his photographs is the only known color photo of Leo Tolstoy.įortunately for us, the Library of Congress purchased a large collection of Prokudin-Gorskii’s photographs in 1948. In 1909, with funding from Tsar Nicholas II, Prokudin-Gorskii started a decade long journey of capturing Russia in color! He took more than 10,000 color photographs. In the hands of Sergey Prokudin-Gorskii the Miethe-Bermpohl camera ( or a variant of it ) would secure a special place in Russian history. Learn More Figure 3 : Three images captured on a vertical glass plate by a Miethe-Bermpohl camera. A very good description and an image of the camera can be found here. This camera, also referred to as the Miethe-Bermpohl camera, had a long glass plate on which the three images were acquired with three different filters. In German the word “Dreifarben” means tri-color. Perhaps the most popular among these cameras, the Autochrome, was invented by the Lumière brothers.Ī competing camera system was designed by Adolf Miethe and built by Wilhelm Bermpohl, and was called Professor Dr. Although revolutionary for its time, the method was not practical.īy the early 1900s, the sensitivity of photographic material had improved substantially, and in the first decade of the century a few different practical cameras were available for color photography. The photographic material available at that time was sensitive to blue light, but not very sensitive to green light, and almost insensitive to red light. He took three grayscale images of a Ribbon ( see Figure 2 ), using three different color filters and then superimposed the images using three projectors equipped with the same color filters. Six years later, in 1861, English photographer Thomas Sutton produced the first color photograph by putting Maxwell’s theory into practice. The idea that you can take three different photos using three primary color filters (Red, Green, Blue) and combine them to obtain a color image was first proposed by James Clerk Maxwell ( yes, the Maxwell ) in 1855. Ribbon by Maxwell and Sutton was the first color photo ever taken by superimposing 3 grayscale images. A Brief and Incomplete History of Color Photography Figure 2.
This post is dedicated to the early pioneers of color photography who have enabled us to capture and store our memories in color. In this post we will embark on a fun and entertaining journey into the history of color photography while learning about image alignment in the process.
Good image alignment stacking software code#
You can download the code for all the examples shown in this post from the download section located at the bottom of the post. The image on the right is a version of the same image with the channels brought into alignment using a function available in OpenCV 3.
The color channels of the image are misaligned because of the mechanical nature of the camera. The image was taken by a Russian photographer in the early 1900s using one of the early color cameras. The image on the left is part of a historic collection of photographs called the Prokudin-Gorskii collection. Right : The same image with the channels aligned. Left: An image from the Prokudin-Gorskii Collection.
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