gamma.c

#include <avr/pgmspace.h> 

uint8_t gamma[256] PROGMEM = {
  0,
  0,
  0,
  0,
  0,
  1,
  1,
  1,
  1,
  1,
  1,
  1,
  1,
  1,
  2,
  2,
  2,
  2,
  2,
  2,
  2,
  2,
  2,
  3,
  3,
  3,
  3,
  3,
  3,
  3,
  3,
  4,
  4,
  4,
  4,
  4,
  4,
  5,
  5,
  5,
  5,
  5,
  6,
  6,
  6,
  6,
  6,
  7,
  7,
  7,
  7,
  8,
  8,
  8,
  8,
  9,
  9,
  9,
  10,
  10,
  10,
  10,
  11,
  11,
  11,
  12,
  12,
  12,
  13,
  13,
  13,
  14,
  14,
  15,
  15,
  15,
  16,
  16,
  17,
  17,
  17,
  18,
  18,
  19,
  19,
  20,
  20,
  21,
  21,
  22,
  22,
  23,
  23,
  24,
  24,
  25,
  25,
  26,
  26,
  27,
  28,
  28,
  29,
  29,
  30,
  31,
  31,
  32,
  32,
  33,
  34,
  34,
  35,
  36,
  37,
  37,
  38,
  39,
  39,
  40,
  41,
  42,
  43,
  43,
  44,
  45,
  46,
  47,
  47,
  48,
  49,
  50,
  51,
  52,
  53,
  54,
  54,
  55,
  56,
  57,
  58,
  59,
  60,
  61,
  62,
  63,
  64,
  65,
  66,
  67,
  68,
  70,
  71,
  72,
  73,
  74,
  75,
  76,
  77,
  79,
  80,
  81,
  82,
  83,
  85,
  86,
  87,
  88,
  90,
  91,
  92,
  94,
  95,
  96,
  98,
  99,
  100,
  102,
  103,
  105,
  106,
  108,
  109,
  110,
  112,
  113,
  115,
  116,
  118,
  120,
  121,
  123,
  124,
  126,
  128,
  129,
  131,
  132,
  134,
  136,
  138,
  139,
  141,
  143,
  145,
  146,
  148,
  150,
  152,
  154,
  155,
  157,
  159,
  161,
  163,
  165,
  167,
  169,
  171,
  173,
  175,
  177,
  179,
  181,
  183,
  185,
  187,
  189,
  191,
  193,
  196,
  198,
  200,
  202,
  204,
  207,
  209,
  211,
  214,
  216,
  218,
  220,
  223,
  225,
  228,
  230,
  232,
  235,
  237,
  240,
  242,
  245,
  247,
  250,
  252,
  255,
};

uint8_t gamma_correct(uint8_t input) { return pgm_read_byte(&gamma[input]); }