Selective color modification

Abstract

An apparatus and method .Iadd.is described .Iaddend.for the modification of the color of television pictures in arbitrarily selected regions of the color space and of the picture. A region within which color modification is to take place is defined by establishing the bounds, or limits, for the region. Apparatus is described by which a determination can be made whether any given picture element lies within the region. For those picture elements which lie within the region, modification voltages are added to the television signals to accomplish the desired color modifications. Display apparatus is described which facilitates setting of proper bounds for the color modification region.

I claim: 
     
       1. A color modification system for color television pictures, said pictures being represented by three color signals corresponding, respectively, to the three attributes of a color, wherein there are: means for controlling three modification amounts, one for each of the three color signals,   means for controlling upper and lower boundaries for each of the three color signals,   means for finding when the three color signals simultaneously lie within their respective upper and lower boundaries, and   means for adding the three modification amounts to each of the three color signals, respectively, only when the three color signals are found to lie simultaneously within their respective upper and lower boundaries.   
     
     
       2. The color modification system of claim 1 wherein .[.the.]. said color attributes.[.and the.]..Iadd., .Iaddend.said modification amounts and .[.the.]. said boundaries are all in terms of red.Iadd., .Iaddend.green and blue. 
     
     
       3. The color modification system of claim 1 wherein .[.the.]. said color attributes.[.and the.]..Iadd., .Iaddend.said color modification amounts and .[.the.]. said boundaries are all in terms of luminance.Iadd., .Iaddend.I and Q. 
     
     
       4. The color modification system of claim 1 wherein .[.the.]. said color signals are red.Iadd., .Iaddend.green and blue, and wherein .[.the.]. said color modification amounts controlled and .[.the.]. said boundaries controlled are in terms of luminance.Iadd., .Iaddend.I and Q, and wherein there are: means for calculating red.Iadd., .Iaddend.green and blue modification amounts for addition to .[.the.]. said color signals from .[.the.]. said color modification amounts controlled in terms of luminance.Iadd., .Iaddend.I and Q, and   means for calculating red.Iadd., .Iaddend.green and blue upper and lower boundaries for .[.the.]. said color signals from .[.the.]. said upper and lower boundaries controlled in terms of luminance.Iadd., .Iaddend.I and Q.   
     
     
       5. The color modification system of claim 1 wherein those portions of the picture to be modified are displayed by providing.[.:.]. means for blanking out all parts of the picture for which .[.the.]. said color signals do not all simultaneously lie within their respective boundaries.   
     
     
       6. The color modification system of claim 1 wherein .[.the.]. said upper and lower boundaries are provided by: means for calculating said upper and lower boundaries from window parameters, and   means for controlling said window parameters, said window parameters being the mean and difference of .[.the.]. said upper and lower boundaries.   
     
     
       7. The color modification system of claim 1 wherein said upper and lower boundaries and said modification amounts are controlled by .[.the.]. signals from a digital computer. 
     
     
       8. The color modification system of claim 7 wherein a sequence of television pictures represent a multiplicity of scenes in sequence and wherein there are.[.:.]. means for changing the boundaries and modification amounts at the start of each scene.   
     
     
       9. A color modification system for color television pictures, said pictures being represented by three color signals corresponding, respectively, to the three attributes of a color, and by two position signals corresponding to location in the picture plane, wherein there are: means for controlling three modification amounts, one for each of the three color signals,   means for controlling upper and lower boundaries for each of the three color signals,   means for controlling upper and lower boundaries for each of the two position signals,   means for finding when the three color signals and the two position signals simultaneously lie within their respective upper and lower boundaries, and   means for adding the three modification amounts to each of the three color signals, respectively, only when the three color signals and the two position signals are found to lie simultaneously within their respective upper and lower boundaries.   
     
     
       10. A method for color modification of a scanned color picture, wherein there are three color attributes for each picture element, comprising the steps of: selecting a color space region by setting upper and lower boundaries for each of the three color attributes, and adding modifications to .[.the.]. said three color attributes of each of .[.the.]. said picture elements only for those of .[.the.]. said picture elements whose color attributes all lie within .[.the.]. said color space region.   
     
     
       11. A method as described in claim 10 wherein the final selection of the color space region is facilitated by viewing said color picture with all of said picture elements not lying within .[.the.]. said color space region blanked out. 
     
     
       12. A method as described in claim 10 wherein the final selection of .[.the.]. said color space region is facilitated by.[.:.]. viewing a chrominance plane plot and a luminance plot of .[.the.]. said picture, said plots displaying the location of .[.the.]. said color space region.   
     
     
       13. A method as described in claim 10 wherein for .Iadd.each .Iaddend.picture element there are two location attributes describing the location of .[.the.]. said picture element in the picture plane, and wherein: a picture region is also selected by setting the upper and lower bounds for each of .[.the.]. said two location attributes, and   .[.the.]. said modifications are added to .[.the.]. said three color attributes only for those picture elements for which .[.the.]. said location attributes lie within .[.the.]. said picture region.   
     
     
       14. A method as described in claim 13 wherein the final selection of said picture region and said color space region is facilitated by viewing chrominance plane, luminance and picture plane plots of .[.the.]. said picture, said plots displaying the location of .[.the.]. said regions. .Iadd. 
     
     
       15.  A system for modifying the color representation of an object in a color picture comprising: means for defining a region in a color space, the color space being defined by color coordinates and the region including the color representation of the object, the color representation having color components with each color component being a value along the respective color coordinate; and   means for modifying the color representation of the object within the region to produce a new color representation for the object. .Iaddend. .Iadd.16. A system as recited in claim 15 further comprising means for delimiting on a display the object, the color representation of which is within the region. .Iaddend. .Iadd.17. A system as recited in claim 15 further comprising means for defining a window within the color picture encompassing the object so that only the color representation for the object is affected by the modifying means. .Iaddend. .Iadd.18. A system as recited in claim 17 further comprising means for delimiting on a display the object within the window, the color representation of which is within the region. .Iaddend. .Iadd.19. A system as recited in claim 18 wherein the region defining means comprises means for establishing boundaries with respect to each color coordinate. .Iaddend. .Iadd.20. A system as recited in claim 19 wherein the modifying means comprises:   means for determining when all color components of the color representation of the object lie within the respective boundaries; and   means for combining a selectable modification amount for each color component of the color representation when all color components of the color representation lie within the region to produce the new color representation for the object. .Iaddend.