public static YCbCrForwardConverter <TPixel> Create() { var result = default(YCbCrForwardConverter <TPixel>); result.colorTables = RgbToYCbCrTables.Create(); return(result); }
/// <summary> /// Initializes the YCbCr tables /// </summary> /// <returns>The initialized <see cref="RgbToYCbCrTables"/></returns> public static RgbToYCbCrTables Create() { RgbToYCbCrTables tables = default; for (int i = 0; i <= 255; i++) { // The values for the calculations are left scaled up since we must add them together before rounding. tables.YRTable[i] = Fix(0.299F) * i; tables.YGTable[i] = Fix(0.587F) * i; tables.YBTable[i] = (Fix(0.114F) * i) + Half; tables.CbRTable[i] = (-Fix(0.168735892F)) * i; tables.CbGTable[i] = (-Fix(0.331264108F)) * i; // We use a rounding fudge - factor of 0.5 - epsilon for Cb and Cr. // This ensures that the maximum output will round to 255 // not 256, and thus that we don't have to range-limit. // // B=>Cb and R=>Cr tables are the same tables.CbBTable[i] = (Fix(0.5F) * i) + CBCrOffset + Half - 1; tables.CrGTable[i] = (-Fix(0.418687589F)) * i; tables.CrBTable[i] = (-Fix(0.081312411F)) * i; } return(tables); }