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Paper 2 Title: a study of Human Target Tracking Using uv and ir target Features By

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Paper 2

Title: A Study of Human Target Tracking Using UV and IR Target Features


Hemamalini Kannan

A selection of UV and IR filters has been used for this study to explore target tracking and / or target appearance using the UV and IR electromagnetic bands. Each filter is mounted on a Sony Mini DV camcorder (Model Number: DCR-TRV17 NTSC)1. Targets are video- taped in various scenarios chosen to explore several cues like color and texture of clothing, clustered environment etc. The images obtained in this study are actual ones taken in real time situations. No modifications are made to them.

The filters used in this study are constructed of optical precision ground and polished German glass and is differentiated from each other by its wavelength. They appear to be black and as a flat black glass to the human eye. Each filter has a different material thickness.

The filters used in this study are the following:

  • X-Nite 330nm

  • X-Nite 715nm

  • X-Nite 780nm

  • X-Nite 830nm

  • X-Nite 1000B

  • X-Nite XDP

X-Nite 330nm is a UV Pass / Visible Block Filter. It has a peak transmission at 330nm at 85%. The transmission takes place at 270nm and 375nm at 50%. There is a minor peak at 720nm which allows a small amount of visual and infrared light to pass through the filter. As insects view their world largely in UV range, flowers look unusual under UV than under visible light than under IR light. Another field of relevance for UV filter is in forensics to find traces of marks or writings invisible to the human eye, which is accomplished with the use of this filter. Another method would be to directly photograph on test object with UV light.

X-Nite filters having a cutoff at 715nm, 780nm, 830nm, 1000nm are infrared filters blocking visible filters and allowing only infrared light to pass through. X-Nite 715nm allows 715nm through 1200nm, X-Nite 780nm allows 780nm through 1200nm, X-Nite 830nm allows 830nm through 1200nm, X-Nite 1000 allows 1000nm through 1200nm and X-Nite XDP is a high-resolution infrared filter. The XDP filter is a different animal from the 830 and 1000nm filters.  In some respects, it is closer to the 1000nm filter but gives greater detail because the filter has a Dual Profile light transmission curve.  One peak is near 1000nm and one is much lower. There are many fields where these filters are in use

  • Infrared photography: Infrared camera film is recognized for its tremendous high speed. Furthermore the pictures taken seem dissimilar when observed in the infrared range as opposed to the visual range. This feature is advantageous in seeing through the clouds, detecting forged documents and even in Forensic departments for crime scene analysis.

  • Infant monitoring: This filter is very useful for a parent to view their child in absolute darkness without any disturbance.

1 The images taken by the camcorder might be slightly different from the actual images as the lens of camcorder is coated with UV and IR block.

  • Industrial Purposes: X-Nite filters are used for factory automation and inspections to locate faulty objects as one can see through the objects to determine invisible cracks that are not visible to the naked eye.

  • Hunting: Animals have a tendency to remain motionless when alarmed. However their warmth shows up as the infrared light allowing the hunter to see them even at night.

  • Plant vegetation and aerial photography: IR is very helpful in finding illegal marijuana fields, charting a variety of plant augmentation and much more as vegetation looks very different under IR.

Furthermore this filter is also used to attain some “X-Ray effects” – in that by adding an infrared filter to the camera and operating it in daylight one can view through certain variety or texture of clothing. This is more prominent on dark synthetic fabrics.

The following graph displays the electromagnetic spectrum and comparison of different filters used in this study.

Figure 1 – Electromagnetic Spectrum

Figure 2 – Wavelength Vs Transmittance graph for X-Nite 330nm filter.

Figure 3: Wavelength Vs Transmittance curve for X-Nite filters 715nm, 780nm, 830nm and 1000nm.
The table below shows the different scenarios under which targets are video captured.





Outside/Inside City Streets, Greenery, Open/ Crowded space.


Animals Vehicles

Doors, Stationary vehicles, Buildings, Windows, Furniture

Trees, Buildings, sky, clouds, sun effects, flowers and plants

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