“Working with intuitiveness means to be close to a great mind!”
We thought we had created a unique method in giving color to our papers, but we have recently discovered that this method already existed and was already used as many as 100 years ago! In fact, the way we operate during Laser Scanner topographic surveys, for the coloring phase, resembles the modus operandi of U.S. astronomer Henrietta Swann Leavitt.
Leavitt began her work in 1893 at Harvard Observatory as a manual calculator, studying photographic plates of stars by making a variety of calculations. She was later hired by Edward Pickering to measure and catalog the brightness of stars in the observatory’s photographs. She thus noticed that hundreds of stars were variable in brightness calculations.
How did plate observation work?
Leavitt used two kinds of plates: one black and white, the other black and white negative. The superimposition of the two plates showed that there was a deviation, which is the measurement of parallax.
In our case we superimpose what the scanner sees with what the camera sees, to distinguish the two sources we have a color difference: the scanner plate has a blue reading color, the camera plate has a red reading color. The superimposition will result in a magenta tone, where the color is not magenta it highlights there’s a deviation.
Some areas are blue (and not magenta) even though there is no offset because the scanner does not see the sky or because the frequency response is very different between scanner and camera.
Having deliberately caused an error, we notice how the two plates are shifted and it shows two phenomena: one is all bluer the other is redder. Recall that in a normal case scenario, that is, without error, the color generated by the superimposition would have been magenta.
This is an operation that might be hard to explain but simple to do! That is why we show you what we have described: Coloring from Panoramic Images.
Behind each case of study there is as always a story: this time we like to think we only came second and we are still happy with the result, because it’s legit to be behind a great scientist!