A simple method to colour balance digital photographs for remote assessment of tissue viability in acute burns

Mr Simon Chong1, Dr David Becker2

1Waikato Hospital, Hamilton, New Zealand, 2Waikato Hospital, Hamilton, New Zealand

Abstract:

Key to the practice of plastic surgery is the visual assessment of tissue perfusion via colour, most prominently when determining the depth of acute burns.

Digital imaging devices such as cell phones have provided a convenient means for remote assessment and referral of acute burns. However, most are optimised for use by inexpert photographers in non-medical applications. Accurate reproduction of colour is thus often compromised by environmental lighting, inconsistent use of flash illumination, and software bias. Digital devices will automatically optimise image parameters based upon the content of the image. White and black objects will be recognised and preferentially used to determine exposure and colour balance.

These variables often combine to produce a colour-inaccurate image with limited diagnostic utility and potential for misdiagnosis and liability.

We hypothesise that the routine placement of a white cotton swab within the photographic field of an acute burn will permit standardisation of colour balance across a variety of digital imaging devices.

Standardized photographs of a variety of burns will be taken with different devices. Six images will be taken: flash and non-flash with no swab present, flash and non-flash with a standard white cotton swab placed within the image framing, and flash and non-flash with a standard Pantone white colour swatch within the image.

The accuracy of the swab white balancing could be assessed with quantitative analysis utilizing Adobe Photoshop. Specifically, the variances in each Red Green Blue (RGB) colour channel could then be expressed as a percentage variance from the swatch-containing images.


Biography:

David is a Plastic Surgery registrar. Upon graduating from Otago University with an MBChB and Bachelor of Medical Laboratory Science in 2014 he worked in Dunedin as a house officer and surgical registrar; both in General Surgery and Plastic Surgery while completing a Postgraduate Diploma of Surgical Anatomy. Currently he is working at Waikato Hospital in Hamilton New Zealand.