Declaration
type TIEVisionThresholdType = int32_t;
const ievTHRESH_BINARY = 0;
const ievTHRESH_BINARY_INV = 1;
const ievTHRESH_TRUNC = 2;
const ievTHRESH_TOZERO = 3;
const ievTHRESH_TOZERO_INV = 4;
const ievTHRESH_OTSU = 8; // must be combined with other values
const ievTHRESH_TRIANGLE = 16; // must be combined with other values