Abstract: A method of and an apparatus for interactively controlling the display of an image on a monitor screen has the image stored in digital data form defining the color content of pixels of the image. The method includes displaying a representation of the image of the monitor screen; selecting a first point on the image and a first point on the monitor screen at which the first image point is to be located; selecting with a cursor a second point on the image; moving the cursor relative to the monitor screen; and, during the cursor movement, repeatedly adjusting the representation of the image displayed according to one or more predetermined algorithms so that the second image point remains coincident with the cursor position while the first image point is fixed at the first screen point.

Abstract: Apparatus for interactively modifying an image represented by digital data defining the color component content of pixels of the image, comprises an image store for storing the said digital data; a display; look-up tables defining retouch curves for each color component; and a microprocessor for applying the image in the image store to the LUTs and thereafter to the display to display the retouched image. The microprocessor also enables an operator to modify the retouch curves so that a second selected image point is retouched to the color of a first selected image point by modifying a color component retouch curve for each color component used to define the original image such that a pixel located at the second selected point will be retouched to have the color content of a pixel at the first selected point.

Abstract: Apparatus for processing a digital representation of an image in which each pixel is defined by at least one digital color component value, the value comprising one of a first set of values defining a first scale of color component values. The apparatus comprises a store for storing digital color component values for the image pixels; and a first look-up table (LUT) addressed by a color component value from the store corresponding to a selected pixel, the first LUT generating a signal representing a modified color component value chosen from a set of modified color component values defining a second scale coarser than the first scale. Three second LUTs are provided which are addressed by the color component value from the store in parallel with the first LUT, each second LUT generating an error value signal, the sum of the error values being equal to the difference between the modified color component value and the color component value from the store as measured on the first scale.

Abstract: Apparatus for displaying an image defined by digital data representing the color content of the pixels of the image comprises a monitor; a first store for storing digital data representing an image at low resolution and a second store for storing digital data representing a magnified portion of the image at high resolution. A microcomputer is connected to the stores and to the monitor and an indicator assembly is acutable by an operator to select an area of an image displayed by the monitor. The microcomputer is responsive to a "magnify" signal from the indicator assembly to cause the monitor to display a portion of the selected after magnification, the portion being displayed within the selected area. The microcomputer suppresses pixels of the orginally displayed image within the remaining portion of the selected area, the degree of magnification being such that the magnified portion substantially fills the selected area.