# US 5,703,627 A · Method for colorflash reduction by copying color values between active and inactive window applications so as to minimize differing color cells between corresponding color maps > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,627 A - Document ID: US5703627A - Status: Granted - Kind: A - Application number: 08/670,537 - Filed: 1996-06-27 - Granted: 1997-12-30 - Earliest claimed: 1995-03-08 - Assignees: Apple Computer, Inc. - Inventors: James A. Young - Web page: https://patentgrep.com/patent/US5703627A ## CPC - G09G 5/06: using colour palettes, e.g. look-up tables - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) ## Abstract A method for reducing colorflashing by performing residual color allocation and default colormap sharing in a computer system that employs a default colormap to display color. The residual color allocation technique copies color values from a private colormap into corresponding non-allocated (free) cells within the computer system default colormap. While copying into the free cells in the default colormap the free cells are temporarily set to have an allocated status. After copying, the copied cells are reset to a free status. In this way, other clients may allocate the default map's free cells to perform residual colormap allocation. Since the default colormap's copied cells are the same as corresponding cells in the private map they do not flash when switching color focus between the default colormap and the private colormap. The default colormap sharing technique is employed in the case in which a private colormap does not require a specific set of colors, and can adapt to a given set of colors. Default colormap sharing is performed by copying allocated cell color values from the default colormap to corresponding cell locations within the private colormap. The residual color allocation and default colormap sharing techniques may be implemented when a given client (which uses a private colormap) creates/defines the color values in its corresponding private map. This generally occurs when the client's corresponding application window is opened. The technique of the present invention may be subsequently implemented when clients redefine colors within their corresponding private colormaps. ## Claims ### Claim 1 A method for reducing color flashing when changing color focus between first and second colormaps in a computer system having a screen and a means for storing sets of color values, said computer system displaying a first area in said screen corresponding to a first application, said first application employing said first colormap, said screen also displaying a second area corresponding to a second application, said second application employing said second colormap, said first colormap having a first set of color values with associated index locations and said second colormap having a second set of color values with said associated index locations, said method comprising the steps of: 1) identifying allocatable index locations in said first colormap's associated index locations; 2) changing said identified allocatable index locations to temporarily allocated index locations; 3) copying color values having corresponding index locations as said temporarily allocated index locations from said second colormap into said allocated index locations of said first colormap so as to minimize differences between said first and second colormaps wherein said first colormap comprises said copied color values from said second colormap and a portion of said first set of color values; 4) changing said temporarily allocated index locations to allocatable index locations in said first colormap. ### Claim 2 (depends on 1) The method as described by claim 1 wherein said first colormap is a default colormap provided by said computer system and said second colormap is a private-type colormap created by said second application. ### Claim 3 (depends on 2) The method as described by claim 2 wherein each of said color values is a combination of a red color value, a green color value and a blue color value. ### Claim 4 (depends on 3) The method as described by claim 3 wherein it is implemented when said second application defines said second set of color values. ### Claim 5 (depends on 3) The method as described in claim 3 wherein it is implemented when said second application redefines at least one of said second set of color values. ### Claim 6 A method for reducing color flashing when changing color focus between first and second colormaps in a computer system having a screen and a means for storing sets of color values, said computer system displaying a first area in said screen corresponding to a first application, said first application employing said first colormap, said screen also displaying a second area corresponding to a second application, said second application employing said second colormap, said first colormap having a first set of color values with associated index locations and said second colormap having a second set of color values with said associated index locations, said method comprising the steps of: 1) identifying allocated index locations in said first colormap's associated index locations; 2) copying color values from said allocated index locations of said first colormap into corresponding index locations in said second colormap so as to minimize differences between said first and second colormaps wherein said second colormap comprises said copied color values from said first colormap and a portion of said second set of color values. ### Claim 7 (depends on 6) The method as described by claim 6 wherein said first colormap is a default colormap provided by said computer system and said second colormap is a private-type colormap created by said second application. ### Claim 8 (depends on 7) The method as described by claim 7 wherein each of said color values is a combination of a red color value, a green color value and a blue color value. ### Claim 9 (depends on 8) The method as described by claim 8 wherein it is implemented when said second application defines said second set of color values. ### Claim 10 (depends on 8) The method as described in claim 8 wherein it is implemented when said second application redefines at least one of said second set of color values. ### Claim 11 A method for reducing color flashing when changing color focus between first and second colormaps in a computer system having a screen and a means for storing sets of color values, said computer system displaying a first area in said screen corresponding to a first application, said first application employing said first colormap, said screen also displaying a second area corresponding to a second application, said second application employing said second colormap, said first colormap having a first set of color values with associated index locations and said second colormap having a second set of color values with said associated index locations, said method comprising the steps of: 1) identifying allocatable index locations and allocated index locations in said first colormap's associated index locations; 2) changing said identified allocatable index locations to temporarily allocated index locations; 3) copying color values having corresponding index locations as said temporarily allocated index locations from said second colormap into said temporarily allocated index locations of said first colormap so as to minimize differences between said first and second colormaps wherein said first colormap comprises said copied color values from said second colormap and a portion of said first set of color values; 4) copying color values from said allocated index locations of said first colormap into corresponding index locations in said second colormap wherein said second colormap comprises said copied color values from said first colormap and a portion of said second set of color values; 5) changing said temporarily allocated index locations to allocatable index locations in said first colormap. ### Claim 12 (depends on 11) The method as described by claim 11 wherein said first colormap is a default colormap provided by said computer system and said second colormap is a private-type colormap created by said second application. ### Claim 13 (depends on 12) The method as described by claim 12 wherein each of said color values is a combination of a red color value, a green color value and a blue color value. ### Claim 14 (depends on 13) The method as described by claim 13 wherein it is implemented when said second application defines said second set of color values. ### Claim 15 (depends on 13) The method as described in claim 13 wherein it is implemented when said second application redefines at least one of said second set of color values.