Пример #1
0
        /// <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);
        }
Пример #2
0
        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);
        }