Blue stretch using restricted color range and soft transition boundary
AssigneeGenesis Microchip Inc.
InventorsSheena Luu, Andrew Mackinnon
Life of this patent
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Abstract
System and method for increasing the blue component of white and near white pixels while avoiding hard transitions and without affecting flesh-tone colors. Pixels that are bright enough and fall within a detection area in the UV-plane have their blue components increased and their red components decreased. The detection area is limited to avoid application of blue stretch to flesh-tone colors. A transition boundary is provided around the detection area for gradually decreasing the amount of blue stretch as pixels move away from the boundary of the detection area, thereby avoiding hard transitions between areas that are blue stretched and areas that are not blue stretched.
Claims29
A method for applying blue stretch to a pixel, comprising:
- determining whether the pixel falls within a detection area in the UV-plane and has a luma (Y) value greater than a luma threshold;
- applying blue stretch to the pixel when the pixel falls within the detection area;
- determining whether the pixel falls within a transition area surrounding the detection area in the UV-plane;
- and
- applying partial blue stretch to the pixel when the pixel falls outside the detection area but within the transition area, wherein partial blue stretch reduces visible boundaries between pixels that are blue stretched and pixels that are not blue stretched;
- whereby adjustments to pixels in one or more color ranges are kept small by limiting the detection area in the one or more color ranges of the UV-plane.
An apparatus for applying blue stretch to a pixel, comprising:
- a controller for:
- (a) receiving luma (Y) and chroma (UV) values describing the pixel;
- (b) determining whether the pixel falls within a detection area in the UV-plane and has a luma value greater than a luma threshold;
- (c) applying blue stretch to the pixel when the pixel falls within the detection area;
- (d) determining whether the pixel falls within a transition area surrounding the detection area in the UV-plane;
- and
- (e) applying partial blue stretch to the pixel when the pixel falls outside the detection area but within the transition area, wherein partial blue stretch reduces visible boundaries between pixels that are blue stretched and pixels that are not blue stretched;
- whereby adjustments to one or more color ranges are kept small by limiting the detection area in the one or more color ranges of the UV-plane.
Dependencies are inferred from the claim text.