png_get_cHRM

function png_get_cHRM(

  png_ptr: png_structp;

  info_ptr: png_infop;

  white_x: Pdouble;

  white_y: Pdouble;

  red_x: Pdouble;

  red_y: Pdouble;

  green_x: Pdouble;

  green_y: Pdouble;

  blue_x: Pdouble;

  blue_y: Pdouble

):png_uint_32;