Abstract: A process and circuit for blending a foreground image (B) with a background image (A), said foreground and background images being arranged in pixels and having color representations (R, G, B). The foreground foreground image (A) has a transparency parameter (T(x,y)) in accordance with a so-called alpha plane representative of the transparency profile to apply to the foreground image. The process involves the steps of: -applying a dithering method on said alpha plane in order to convert said transparency parameter (T) into a one-bit transparency parameter (T?); -use said one-bit transparency parameter (T?) for controlling a multiplexing unit having two inputs respectively receiving the foreground image (A) and the background image (B). In one embodiment, the one-bit transparency parameter T? into the two extreme values of a range of continuous values, for instance coded on 8 bits.

Abstract: According to one embodiment, a first extraction unit extracts a first group of pixels having a specific hue from an input image. A second extraction unit extracts a second group of pixels having large distance from a reference axis on a plane defined by a chroma axis and a luminance axis from the first group. A first transform unit executes a plurality of color-transform processing to the second group and obtains a plurality of third groups of pixels as the second group transformed by each color-transform processing. A reliability calculation unit calculates a reliability of each third group. The reliability is larger when pixels of the third group are more located in shape of a straight line on the plane. A selection unit selects a color-transform processing by which the third group has the largest reliability from the plurality of color-transform processing. A second transform unit executes the color-transform processing to the input image to obtain an output image.