5
4

1 回答 1

1

它看起来不正确。在计算中的某个地方累积了错误。

有序抖动不需要浮点算法。它可以在纯整数计算中实现。

预先计算矩阵中的值也很好。

这是 C 中的代码，它使用矩阵 16x16 执行 3bpp 有序 diter (Bayer) 以获得最佳结果。

const   int BAYER_PATTERN_16X16[16][16] =   {   //  16x16 Bayer Dithering Matrix.  Color levels: 256
                                                {     0, 191,  48, 239,  12, 203,  60, 251,   3, 194,  51, 242,  15, 206,  63, 254  }, 
                                                {   127,  64, 175, 112, 139,  76, 187, 124, 130,  67, 178, 115, 142,  79, 190, 127  },
                                                {    32, 223,  16, 207,  44, 235,  28, 219,  35, 226,  19, 210,  47, 238,  31, 222  },
                                                {   159,  96, 143,  80, 171, 108, 155,  92, 162,  99, 146,  83, 174, 111, 158,  95  },
                                                {     8, 199,  56, 247,   4, 195,  52, 243,  11, 202,  59, 250,   7, 198,  55, 246  },
                                                {   135,  72, 183, 120, 131,  68, 179, 116, 138,  75, 186, 123, 134,  71, 182, 119  },
                                                {    40, 231,  24, 215,  36, 227,  20, 211,  43, 234,  27, 218,  39, 230,  23, 214  },
                                                {   167, 104, 151,  88, 163, 100, 147,  84, 170, 107, 154,  91, 166, 103, 150,  87  },
                                                {     2, 193,  50, 241,  14, 205,  62, 253,   1, 192,  49, 240,  13, 204,  61, 252  },
                                                {   129,  66, 177, 114, 141,  78, 189, 126, 128,  65, 176, 113, 140,  77, 188, 125  },
                                                {    34, 225,  18, 209,  46, 237,  30, 221,  33, 224,  17, 208,  45, 236,  29, 220  },
                                                {   161,  98, 145,  82, 173, 110, 157,  94, 160,  97, 144,  81, 172, 109, 156,  93  },
                                                {    10, 201,  58, 249,   6, 197,  54, 245,   9, 200,  57, 248,   5, 196,  53, 244  },
                                                {   137,  74, 185, 122, 133,  70, 181, 118, 136,  73, 184, 121, 132,  69, 180, 117  },
                                                {    42, 233,  26, 217,  38, 229,  22, 213,  41, 232,  25, 216,  37, 228,  21, 212  },
                                                {   169, 106, 153,  90, 165, 102, 149,  86, 168, 105, 152,  89, 164, 101, 148,  85  }
                                            };

//  Color ordered dither using 3 bits per pixel (1 bit per color plane)
void    makeDitherBayerRgb3bpp( BYTE* pixels, int width, int height )   noexcept
{
    int col = 0;
    int row = 0;

    for( int y = 0; y < height; y++ )
    {
        row = y & 15;   //  y % 16
        
        for( int x = 0; x < width; x++ )
        {
            col = x & 15;   //  x % 16

            pixels[x * 3 + 0]   = (pixels[x * 3 + 0] > BAYER_PATTERN_16X16[col][row] ? 255 : 0);
            pixels[x * 3 + 1]   = (pixels[x * 3 + 1] > BAYER_PATTERN_16X16[col][row] ? 255 : 0);
            pixels[x * 3 + 2]   = (pixels[x * 3 + 2] > BAYER_PATTERN_16X16[col][row] ? 255 : 0);
        }

        pixels  += width * 3;
    }
}

这是此实现的结果： 在此处输入图像描述

有关抖动的更多算法、源代码和演示，您可以查看此处

于 2021-06-30T09:52:00.830 回答