Abstract: An information-presentation device (100) contains a viewing screen (108) and an image-gathering component (106). The viewing screen presents first and second reference icons (136 and 138) having an adjustable reference characteristic controlled with substantially only a single adjustable parameter. The image-gathering component provides the screen with frames of a video image of a scene in which first and second scene locations (152 and 154) have a scene characteristic whose value is to be approximately determined. A user first causes the first reference icon to be approximately superimposed on the first scene location in a captured frame of the image. The user then causes the second reference icon to be approximately superimposed on the second scene location in the captured frame as the adjustable parameter is adjusted to enable the reference characteristic to approximately match the scene characteristic and thereby provide a measurement of the scene characteristic.

Abstract: An information-presentation device (100) contains a viewing screen (108) and an image-gathering component (106). The viewing screen presents first and second reference icons (136 and 138) having an adjustable reference characteristic controlled with substantially only a single adjustable parameter. The image-gathering component provides the screen with frames of a video image of a scene in which first and second scene locations (152 and 154) have a scene characteristic whose value is to be approximately determined. A user first causes the first reference icon to be approximately superimposed on the first scene location in a captured frame of the image. The user then causes the second reference icon to be approximately superimposed on the second scene location in the captured frame as the adjustable parameter is adjusted to enable the reference characteristic to approximately match the scene characteristic and thereby provide a measurement of the scene characteristic.