A process and system for automatically applying color correction to a region-of-interest

Abstract

A system and methods for creating user definable windows for applying image processing, particularly useful in a post-production color correction equipment. The system allows a user of an image processing system such as a scene by scene color corrector to define a color region of interest in an image for purposes of applying image processing only to the region of interest, with automatic tracking of that region of interest over a plurality of frames in a scene. The user defined window, comprising a closed polygon, is converted on a frame-by-frame basis to a matte that is keyed with image processing such as color correction values. The user defined windows can be edited and stored and recalled for use in other frames. The color region of interest is automatically tracked from a beginning frame to the ending frame of a scene, with a vector window defined for each frame, so as to adapt to and compensate for changes in shape, size, and geometry of the region of interest during the succession of frames in the scene.

1 . In a scene by scene color corrector, a process for automatically applying color correction to a selected region in plurality of frames in a scene, comprising: 
 (a) in response to user commands, defining a selected region in a first frame of the plurality of frames;    (b) generating a user defined window for the first frame corresponding to the selected region;    (c) for a subsequent frame of the plurality of images, generating a user defined window for the subsequent frame based on a color parameter associated with a prior frame;    (d) applying color correction to areas within the user defined window region in the subsequent frame.    
   
   
       2 . The process of  claim 1 , wherein the user defined window comprises a continuous polygon circumscribing the region.  
   
   
       3 . The process of  claim 1 , wherein the steps (c) and (d) are repeated for each frame of the plurality of frames.  
   
   
       4 . The process of  claim 1 , wherein the step of generating a user defined window based on a color parameter associated with a prior frame comprises the steps of: 
 determining a seed point derived from the user defined window of the prior frame;    starting at a point associated with the seed point, searching in the frame according to a predetermined methodology for picture elements that fall within a predetermined range of the color parameter;    defining a boundary based on a point in the frame at which the located picture elements fall outside of the predetermined range of the color parameter; and vectorizing the boundary to derive the user defined window.    
   
   
       5 . The process of  claim 4 , wherein the predetermined range of the color parameter comprises a user selectable variance.  
   
   
       6 . The process of  claim 1 , wherein the color parameter comprises the mean of the color value of a selected one or more picture elements.  
   
   
       7 . The process of  claim 6 , wherein the type of color parameter is selected from the group comprising hue, saturation, luminance, and RGB.  
   
   
       8 . The process of  claim 7 , wherein the color value of the selected one or more picture elements comprises the red (R), green (G), and blue (B) color values in an RGB color representation.  
   
   
       9 . In a scene by scene color corrector, a system for automatically applying color correction to a plurality of frames in a scene, comprising: 
 a component that defines a region in a frame in accordance with a color parameter of the frame;    a component that utilizes a region from a prior frame to define a region in a subsequent frame of the scene; and    a component that applies color correction to areas within the regions of the frames over the selected plurality of frames in the scene.    
   
   
       10 . The system of  claim 9 , wherein the region comprises user defined window, the user defined window comprising a continuous polygon circumscribing the region.  
   
   
       11 . The system of  claim 10 , wherein the component that utilizes a region from a prior frame to define a region in a subsequent frame comprises: 
 a component for determining a seed point derived from the prior frame;    a search component operative, starting at a point associated with the seed point, for searching in the subsequent frame according to a predetermined methodology for picture elements that fall within a predetermined range of the color parameter;    a component for defining a boundary based on a point in the subsequent frame at which the located picture elements fall outside of the predetermined range of the parameter; and    a vectorizing component for vectorizing the boundary to derive the region for the subsequent frame.    
   
   
       12 . The system of  claim 11 , wherein the predetermined range of the color parameter comprises a user selectable variance.  
   
   
       13 . The system of  claim 9 , wherein the color parameter comprises the mean of the color value of a selected one or more picture elements in the frame.  
   
   
       14 . The system of  claim 13 , wherein the type of color parameter is selected from a group comprising hue, saturation, luminance, and RGB.  
   
   
       15 . The system of  claim 13 , wherein the color value of the selected one or more picture elements comprises the red (R), green (G), and blue (B) color values in an RGB color representation.