This invention provides a system and method for employing GUI-based non-numeric slide buttons and bar meters to setup and monitor operating parameters of a vision system (the term "vision system" as used herein including the above-described vision detector). Such parameters can include, but are not limited to the threshold at which a feature is activated in viewing an image. Operating parameters also include the under-lying range of contrast values and levels of brightness intensities (or by input inversion, the level of darkness) recognized and acted upon by the vision system. Graphical representations of operating parameters are displayed in a parameter box on the GUI with moving bars that are shaded, patterned or colored so as to provide a relative level between two extremes on a scale of the given operating parameter. The endpoints of the scale can be established by analyzing the relevant extremes on a subject image view. The current level of the given parameter is displayed as a bar that extends a distance along the scale that is proportional to the current level of the parameter along the scale. Input of operating parameter settings with respect to the scale is made by moving a setting slider along the scale between the extremes. The position of the slider establishes the user-input setting relative to the scale. In an illustrative embodiment, scales, level bars and setting sliders can also be displayed on the image view itself, adjacent to a given image view feature, which is the subject of the scale.