/// <summary> /// Initializes the YCbCr tables /// </summary> /// <returns>The initialized <see cref="RgbToYCbCrConverterLut"/></returns> public static RgbToYCbCrConverterLut Create() { RgbToYCbCrConverterLut 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); }
public static YCbCrForwardConverter Create() { var result = default(YCbCrForwardConverter); if (!RgbToYCbCrConverterVectorized.IsSupported) { // Avoid creating lookup tables, when vectorized converter is supported result.colorTables = RgbToYCbCrConverterLut.Create(); } return(result); }