Patent ID: 10560605

Abstract:
Color correction methods relate device dependent sensor responses (RGB) to device independent color values (XYZ). The present invention discloses a new approach to Hue Plane Preserving Color Correction (HPPCC) using weighted constrained 3×3 matrices. Accordingly, the methods of the present invention employ hue angle specific weighted matrixing. Given a device RGB from which a device hue angle is derived, a corresponding transformation matrix is found as the normalized weighted sum of all pre-calculated constrained white point and training color preserving matrices. Each weight is calculated as a power function of the minimum difference between the device and the training color hue angle. The weighting function provides local influence to the matrices that are in close hue angle proximity to the device color. The power of the function can be further optimized for global accuracy. The methods of the present invention are termed HPPCC-WCM for Hue Plane Preserving Color Correction Weighted Constrained Methods. Experiments performed using different input spectra demonstrate that the claimed methods consistently improve the stability and accuracy of state-of-the-art methods for color correction.