HP LP2480zx HP LP2480zx LCD Monitor User Guide - Page 46

Figure A-7 Low Linear Region Response Curve A generalized model for the display response curve accommodating the addition of a linear section as shown above thus requires the specification of four parameters in addition to the "gamma" exponent value: For input values (I) ≤ A0: Y = I/A1 For input values (I) > A0′ Y = [(I + A2)/(1 + A3)]γ The response of the LP2480zx is automatically set to the correct standard as part of the color-space selection, using either the on-screen display (OSD) or using the HP Display Assistant software, or using the optional HP/X-Rite color calibration tools. Independently programming a custom response (as in the case of the user-defined custom color space preset) requires use of the HP/X-Rite calibration tools. Using the software provided with this calibration product, the display response may be programmed using the four-value-plus-gamma model described above. Several of the standard color space specifications supported by the LP2480zx require the use of the "four-value" model, as they include a linear section in the response curve as described above. Of course, even the simple "gamma-only" model may be accommodated within the four-value model, by setting the A0, A2, and A3 parameters to zero, and A1 to a value of 1.0. The values used to describe the response for the standard color spaces or output device specifications supported by the LP2480zx are listed in the table below. Table A-3 Response Curve Constants for Various Color Spaces Color space A0 A1 A2 A3 gamma (γ) sRGB 0.04045 12.92 0.055 0.055 2.4 ITU-R BT.709 0.081 4.50 0.099 0.099 2.22222 SMPTE-C 0.081 4.50 0.099 0.099 2.22222 Adobe® RGB 0 1 0 0 2.19922 DCI-P3 0 1 0 0 2.6 40 Appendix A Advanced Color Management Features and Usage