They always say, “Never judge a book by its cover”, but it looks like MIT may slowly be breaking that traditional. Well sort of.
MIT researchers have developed an imaging technique that is capable of detecting letters through stacked sheets of paper. The camera was able to correctly identify the contents on the top nine sheet layers.
The lab printed one letter per page, and stacked it into a pile. Using a combination of terahertz radiation and a character recognition algorithm, they were able to read through multiple paper layers. This essentially equates to not opening a book and reading the first nine pages.
The technology has a bright future with the university as it can be used to analyze the contents of old books and other documents that historians may have otherwise been afraid to even touch due to their fragility. This new technique now allows them to take a sneak peek without compromising the integrity of whatever document is being analyzed.
Terahertz radiation offers a unique advantage over X-rays or sound waves as it is able to penetrate through multiple layers. As this type of radiation is absorbed in different amounts depending on the structure in comes in contact with, the scientists then used cameras to detect the varying levels of reflected radiation.
Each reflection is unique depending on the material it bounces off, they then used that to determine how many layers the signal passed through. As it also reflects differently off ink and paper, they were able to input that feedback into the character analyzer to put together a picture of what may be printed on those sheets.
According to MIT, their character analysis software is so good that it cracks most of those websites that use verification captchas with ease.
They also factored in an algorithm to filter out ‘noise’ generated when reflected signals repeated bounce back and forth between pages.
At the moment, the camera can determine the distance between as much as 20 pages, but signal reflection becomes so weak that the reader cannot interpret contents beyond the 9th page.