Surrounding Issues

Faithful Reproduction

Hence we arrive at the proposal for the various different presentation methods that this thesis will explore and analyse. Each presentation method has been invented for the purposes of manipulating the visual appearance of a single stream of image data in various ways that do not corrupt the aesthetics of the data. It is necessary for the original pixel data, from which thestimuliis derived,

Human Visual System Analysis

Presentation Method Design

influences/drives enhances/reveals

Figure 3.2– The feedback loop for the analysis of visual inspection, potentially supporting further under-standing of the Human Visual System (HVS) and the design of presentation methods

to not be manipulated in terms of image filters such as contrast or hue alterations. Nor should the spatial relationships of the data interpreted in any way to change the relative distances between arbitrary points within the dataset. This is critically important in both the chosen field ofWiSAR, but also the domains of security and medical imaging.

Manipulating the data can cause confounding issues that prohibit the correct identification of atarget. While the raw video feed from the visual sensor is manipulated by the various interfaces, software and firmware to convert the photons reflected off the landscape into digital images, such manipulation is done faithfully to ensure that the output from the system is an accurate representation of the original feature being observed. There is never an intention to change the data in a way which would make positive identification of a feature inaccurate. Therefore by only conducting image manipulations faithfully, the “towards realism” principle of this research is maintained.

Human Decision Making

The second issue bounding this research is the requirement for a human-being to be ‘in the loop’, i.e. the final decision must be made by a qualified individual before time and resources are consumed identifying the potentialtargeton the ground (in the case ofWiSAR) within the suitcase (security) or within the body (medical imaging). Regardless of the robotic decision making by artificial intelligence or machine learning algorithms (e.g. Pitt2012, p. 27), the final decision will always come down to a humans. This requirement is subject to the influence of the command

structures on decision making withinSARgroups that use aerial photography and the need to overlook the inherent noise in naturalstimuli. One of the many reasons for this restriction on not relying upon a computer-made decision is the innate human desire to observe the raw unfiltered material that the machine is interpreting. Human decision making desires the originalstimulito ascertain the presence or not of a legitimatetarget. Therefore there will remain for a very long time a mistrust in the computer vision domain to detect atarget, despite significant improvements in identification accuracy, and a need to view the information captured by the sensor so that the human can verify the analysis conducted by the machine.

Information Overload

Herein lies the fundamental issue: the quantity of information that must be interpreted. With the notional UAVflying over the terrain capturing as much information as possible with its multiple image sensors, each of increasingly higher resolution and frame-rate. In essence, the task is equivalent to the “needle-in-the-haystack” problem. This visual identification problem is exacerbated by both traditional and even current methods of sorting through t his visual data haystack. The additional requirement of viewing the data live or near-live in a mission critical stress-filled environment results in the classic system of a human-being viewing multiple monitors, each displaying a live feed at its native resolution and dimensions.

Computer–Human Bandwidth

This ineffective use of the bandwidth between the screens and theHVSis frequently misunderstood in the domains in which it is used such as the rescue, military or security services. In essence the task for the interaction designer is to maximise the effectiveness of this visual identification task.

Despite the cognitive and physicological processes ofvisual searchbeing well understood (to a degree, see chapter2), there is an inherent under utilisation of the bandwidth between the display and theHVS, for which this research is proposes a solution.

While the fundamental concepts ofvisual searchare beginning to be understood within the fields of Psychology andHCI, the applications of these concepts are far from developed, and are tied-up in an analysis process that is not conducive to such applications being made. Within the

field ofHCIin particular, there is an increasing use of the results and findings from cognitive psychology to develop improved design guidelines. This advice is generated in order for interaction designers to use what we already know regarding theHVS, thus incorporating this knowledge into user interfaces that permit those tasked with the complex and fundamentally difficult task of visual inspectionto conduct their task of visual identification more accurately. Therefore utilising the bandwidth between the display and human-decision making as efficiently as possi ble. Such efficiency is a demand of the increasing amount of data that must be explored in order to confirm the presence of atargetmatching the often vague or inconclusive search criteria, an issue that only a human-being can comprend at present, therefore highlighting the principle ofvisual inspection feedback.