HP DreamColor Z27x Calibration Best Practices for the DreamColor Z27x Professi - Page 12

Technical white paper | Calibration Best Practices for the HP DreamColor Z27x Professional Display - Z7X230/Z7X240 Firmware Release LUT Folder Structure A LUT folder must contain four text files. Each file has a name that identifies preset name, preset number, and type of information stored within the file, or "name-num-type." For example, if the preset name was "BT.709" and the preset number was "2", then each LUT file name would have the prefix "BT.709-2." The following files are required in a LUT folder: • name-num-PreLUT.txt: an ASCII text file which conforms to the 1D ASCII format. The first line of the LUT file is the declaration and indicates the number of LUTs in the file (usually 3, one each for red, green, and blue), the number of entries in each lut, and the bit precision of the LUT values. For example, LUTs downloaded from the Z27x have the following declaration: LUT: 3 1024 14-bit Optional comments may be used to store the color space preset the LUT was generated for, the type of LUT (PreLUT or PostLUT) and the beginning of each channel LUT. The Z27x automatically generates all of these comments to make the LUT file more human-readable. The following is an example of a LUT file: LUT: 3 1024 14-bit # BT.709 # # PreLUT # # Begin Red # 0 1 ... 16344 16383 #Begin Green # 0 1 ... 16344 16383 #Begin Blue # 0 1 ... 16344 16383 # END # • name-num-3x3.txt: an ASCII text file which contains the 3×3 matrix data. The first line of the LUT file is a declaration indicating it is a 3×3 matrix. The second line is an optional comment indicating the name of the color space preset the 3×3 matrix was generated for. Then follows three lines of three numbers representing the matrix. The entries on each line are tab delimited. The final line is an optional end comment. The following is an example of a 3×3 matrix file: # Lumen 3x3 Matrix # BT.709 # 710 43 9 314 900 30 -1 10 963 # End # • name-num-PostLUT.txt: an ASCII text file which conforms to the 1D ASCII format. See the name-num-PreLUT.txt entry above for information on the structure of this file. • name-num-PresetValue.xml: an XML file that contains the information that is to be displayed in the Color Space Information on-screen menu and passed to the host computer via the EDID. This file is based on the Studio Cal XML schema, but uses the root element. A sample preset value file is shown below: 12