Abstract: A method for generating image specific global tone curves is disclosed. A reference white tone mapping optimization module generates a global tone curve based on parameters that account for properties of an input image and a target device on which to reproduce an output image generated from the input image using the global tone curve. Such parameters may include a peak value and a reference white value of the input image and a headroom value of the target device. Some parameters, which can be configured or derived, may include a standard-definition range exposure parameter and a high definition range to standard-definition range mix parameter that influence the position and shape of the global tone curve to allow for soft clipping of highlight values of the input image. The global tone curve may include a linear segment and a curved segment, such as a Bézier curve segment.

Abstract: In a calibration method, high-accuracy reference values obtained using a high-accuracy optical sensor are received, low-accuracy reference values are determined from reference colors captured from a display using a low-accuracy optical sensor having a lower accuracy than the high-accuracy optical sensor, color measurement values are determined from one or more colors captured from the display using the low-accuracy optical sensor, and the color measurements values are adjusted based on one or more color conversion equations to obtain adjusted color measurement values. The one or more color conversion equations are based on the high-accuracy measurement values and the low-accuracy measurement values. The high-accuracy reference values are reused for calibrations of one or more other low-accuracy optical sensors.