Imaging objects through fog may now be more clear. Imaging things in foggy weather circumstances may soon be improving. As researchers have discovered a strategy for enhancing photographs acquired on such days.
Modulation of the light source and demodulation at the observer’s end is require for this approach.
A team of researchers has developed a method for enhancing picture quality without requiring large amounts of processing.
The team from the Raman Research Institute (RRI), Bengaluru, an autonomous institute of the Department of Science and Technology; the Space Applications Centre, Indian Space Research Organisation, Ahmedabad; Shiv Nadar University, Gautam Buddha Nagar; and Universite Rennes and Universite Paris-Saclay, CNRS, France modulated and demodulated the light source at the observer’s end to achieve sharper images.
According to the Ministry of Science and Technology, the study was publish in the journal ‘OSA Continuum’.
The researchers proved the concept via lengthy trials at Shiv Nadar University on foggy winter mornings. They opted to illuminate the space with 10 red LED lights. They then varied this light source by altering the current flowing through the LEDs at a rate of around 15 cycles per second.
The researchers maintained a 150-meter gap between themselves and the LEDs using a camera. The camera record and transfer the picture to a desktop computer. Then, using the modulation frequency as a starting point, computer algorithms extracted the source’s properties.
“This refers to ‘demodulation,’ and it was necessary to demodulate the picture at a rate equal to the modulation rate of the source of light in order to get a clear picture,” the statement said.
Therefore, the modulation-demodulation methodology resulted in a significant increase in picture quality for the team. The duration of the procedure is dependent on the size of the picture.
Imaging objects through fog may now be more clear.
“Computational time for a 2160 X 2160 picture is around 20 milliseconds,” explains Bapan Debnath, a Ph.D. researcher at RRI and a co-author of the paper, noting that this is the size of the picture including the LEDs.
The rate was assessed in 2016 by Debanath’s colleagues.
The researchers performed the experiment many times, noting the incremental improvement each time. Once, they did not see a significant increase in picture quality when the fog intensity fluctuated throughout the observation. They spotted fog trailing over the area in this instance due to the high wind. The density of the airborne water droplets altered with time, reducing the effectiveness of the modulation-demodulation approach.
Following that, the investigators altered the experimental design. They created an external substance, a piece of cardboard placed 20 cm away from the LEDs, to reflect light back to the camera. The cardboard was in place 75 meters away from the camera. The reflected modulated light from the cardboard traveled through the fog and was then caught by the camera. They showed that their methodology increased the generated image’s quality greatly.
They observed that after demodulating the source. The picture quality was sufficient to differentiate the LEDs from the brightly reflected sunlight when the experiment was repeated in sunny circumstances.
The Ministry of Science and Technology of the Republic of India supported a portion of the research.
The approach is inexpensive, needing just a few LEDs and a standard desktop computer capable of performing the operation in a split second.
The technology has the potential to considerably enhance aviation landing tactics by giving the pilot a clear view of runway beacons, as opposed to depending only on reflected radio waves as is now the case.
The approach may aid in revealing obstructions in a way that would be obscure by fog in rail, marine, and road traffic. As well as aid in locating lighthouse beacons.
“More research is required to determine the technique’s use in such real-world circumstances, and the team is investigating if it can be used to move sources,” the announcement said.