A method of facilitating user interaction with an image displayed on a touch surface of a large scale touch system is disclosed. Images of the touch surface are captured with sets of camera devices positioned in series along the length of the touch surface. Each set of camera devices comprises at least two laterally spaced camera devices having overlapping fields of view oriented to look generally across the touch surface. The captured images are processed to detect user interaction with the touch surface. A scaled version of at least a portion of the displayed image is displayed on the touch surface at a user accessible location in response to an associated input gesture made at an arbitrary location on the touch surface. The scaled version is displayed adjacent the location of the input gesture. Coordinates of the displayed scaled version to the corresponding coordinate portion of the displayed image are mapped so that user interactions with the displayed scaled version are translated to interactions with the displayed image. A writing input region can be further displayed on the touch surface adjacent a user accessible location in response to an associated input gesture made at an arbitrary location on the touch surface. The writing input into the writing input region via pointer interaction with the touch surface is detected and the detected writing input is displayed as text in a text display region on the touch surface at a location spaced from the writing input region. The position of at least one of the writing input region and the text display region on the touch surface is changed in response to user interaction with the touch surface. At least one portion of the displayed image can be reproduced on the touch surface at a user accessible location in response to an associated input gesture made at an arbitrary location on the touch surface and coordinates of the reproduced portion to the corresponding coordinate portion of the displayed image are mapped so that user interactions with the reproduced portion are translated to interactions with the corresponding portion of the displayed image.
