Abstract: Methods and apparatus embodying techniques useful in systems for creating and modifying documents. A state history of a document for storing document states is maintained; and, whenever an interesting operation has occurred, the state of the document is automatically captured as it exists after the operation. The captured state is added to the state history. In another aspect, the techniques identify for a user on a display device a set of states that the document has been in by operation of the system; and enable the user to designate any arbitrary one of the identified states for further operations. The techniques may provide both linear and non-linear history.

Abstract: Methods and apparatus for graphically representing current data values and possible data values associated with a quantifiable image property. A method includes the steps of displaying to a user a line that represents a range of current data values, displaying to a user a two-dimensional coordinate space in which the two dimensions are respectively parallel to and normal to the line, and representing a range of possible data values by distances along the normal dimension of the coordinate space from corresponding current data values on the line.

Abstract: Methods and apparatus embodying techniques useful in systems for creating and modifying documents. A state history of a document for storing document states is maintained; and, whenever an interesting operation has occurred, the state of the document is automatically captured as it exists after the operation. The captured state is added to the state history. In another aspect, the techniques identify for a user on a display device a set of states that the document has been in by operation of the system; and enable the user to designate any arbitrary one of the identified states for further operations. The techniques may provide both linear and non-linear history.