Patent ID: 7215449

Claim:
A computer-based image-manipulation method for enabling anti-clipping, selective user control over a color-affecting parameter in a computer-presented color image which is intended to be printed, where clipping is defined by the occurrence of an unintended condition, based upon user control input, wherein that parameter assumes a value which lies outside a desired value range which is directly associated with the computer-recognized number value range of 0–255, said method comprising: furnishing suitable computer-responsive, change-value color controls that are selectively manipulable by a user to effect changes, ultimately, in such a parameter value, thus to vary a certain characteristic of color in the image, and applying predetermined governance over the actual value of the color-affecting parameter, including (a) implementing preliminary matrix processing of a user-chosen Chroma value, followed by (b) implementing for each respective color-space color, an anti-clipping algorithm in accordance with the algorithmic formula expressed as follows: OUTPUT = 255 4 ⁢ ( [ 1 + TANH ( [ INPUT + Δ ⁢ L - 128 - G + Δ ⁢ ⁢ R ] / G ) ] + [ 1 + TANH ( [ INPUT + Δ ⁢ L - 128 + G + Δ ⁢ ⁢ R ] / G ) ] ) whereby, no matter the input control implemented by the user, that user chosen value is constrained in relation to approaching either one of the two limit values in the mentioned range to an asymptotic-like approach toward such limit value.