Method and apparatus for interactively indicating image boundaries in digital image cropping

A method for cropping a computer generated image on a raster display, comprising the steps of:

• writing a digitized version of an original image into a first display buffer;
• writing a digitized version of a background image into a second display buffer;
• initially displaying the entire original image from the first display buffer on a display;
• generating a cursor on the display;
• determining whether the cursor is located anywhere on the original image;
• if the cursor is located on the original image determining whether a first command has been executed to designate x1 and y1 as a first corner of a sequential set of rectangular cropped image boundaries;
• moving the cursor over the original image while sequentially designating x2 and y2 as a second diagonal corner of the sequential set of rectangular cropped image boundaries;
• monitoring a current pixel address of a raster beam of the display during its sweep and causing the pixel value to be selected from the first buffer if the address is within the boundaries defined by the current values of x1, y1, x2 and y2 and causing the pixel value to be selected from the second buffer if the address is outside the boundaries defined by the current values of x1, y1, x2 and y2;
• determining whether a second command has been executed establishing final values for x2 and y2;
• and
• determining whether a third command has been executed indicating that the cropped image represented by the current values of x1, y1, x2 and y2 should be selected for further processing.

An apparatus for interactively indicating image boundaries in digital image cropping, comprising:

• first means for storing a digitized version of an original image;
• second means for storing a digitized version of a predetermined background;
• display means connected to the first and second storing means for selectively displaying portions of the original image surrounded by the predetermined background;
• means connected to the display means for generating a cursor on the display means;
• and
• means for enabling a user to move the cursor on the display means to sequentially designate a set of movable boundaries on the originally image to generate a series of cropped images contained within the boundaries, each cropped image being surrounded by a complimentarily shape of the predetermined background.

An apparatus for interactively displaying a selected portion of an image on a display and cropping the remainder of the image, comprising:

• a first display buffer to store the digitized version of the image;
• a second display buffer to store a digitized version of a predetermined background pattern;
• a display to receive an input and produce a visual image in accordance therewith, said display including a raster beam moved over pixels of the display in a predetermined sweep pattern;
• a processor responsive to user input to designate an adjustable boundary on the original image;
• a switch for selectively providing data from a selected one of the first or second display buffers to the input of the display;
• and
• a buffer selector to selectively provide data from a selected one of the first or second display buffers to the display's input depending upon whether a current pixel address of the raster beam is inside or outside of the adjustable boundary, thereby generating a series of cropped images within the boundary, with each potential cropped image being surrounded by a complimentarily shaped image of the predetermined background pattern.