Enhancement or Concealment

Above these images are histograms, they represent the tonal distribution of the pixels in an image, showing how many pixels are present at each level of brightness. As you can see although the image may look clearer in the adjusted image the histogram shows that it actually has less visual information after manipulation. As a Visual Investigator, I specialise in examining video and photographic evidence, looking beyond the obvious to uncover details. One of the most powerful tools at my disposal is digital image enhancement, which can dramatically improve the clarity of poor-quality footage. However, while this technology offers numerous benefits, it also comes with risks that must be carefully managed in legal settings.

The Benefits

Digital enhancement allows me to adjust factors such as contrast, brightness, sharpness, and color balance, bringing out hidden details that may not be visible in the original footage. For example, I can clarify a shadowy figure in a surveillance video or make out crucial elements in poorly lit conditions. These enhancements can reveal key details that could be critical to a case. In my role, I watch footage repeatedly, applying various techniques to ensure every detail is uncovered. Once I identify something important, I annotate the original footage to help others see what I’ve observed. This process can bring crucial evidence to light and significantly strengthen a case.

The Dangers

However, the power of digital enhancement also comes with risks. Enhancing an image distorts the original data, potentially introducing bias or even misleading viewers. There is also the possibility that a skilled operator, knowingly or unknowingly, could manipulate an unclear image to resemble someone it doesn’t—especially if there’s a preconceived idea of what the person should look like. This creates a dangerous risk of confirmation bias, where enhancement leads the viewer toward a false conclusion.

Conclusion

While digital enhancement is an invaluable tool for investigators like me, it must be used carefully and transparently. The balance lies in using enhancement to clarify, not to alter or distort, ensuring that justice remains rooted in truth, not in artificially created clarity. Although not mandatory at the moment I think it is remiss of the courts not to insist that the original is always shown alongside an enhanced version. After all the original is the evidence.