Table 2.
Comparison of performance of PAPA, the conventional EM-TV and the nested EM-TV for the test data. The pair (·, ·) represents the CPU time and the number of the complete iterations used.
| tol | 10−1 | 10−2 | 10−3 | 10−4 | 10−5 | 10−6 | 10−7 | |
|---|---|---|---|---|---|---|---|---|
| Alg. | ||||||||
| low-noise phantom | ||||||||
| PAPA | (12.3, 5) | (34.8, 14) | (109.6, 44) | (305.7, 123) | (759.5, 307) | (1464.3, 592) | (3954.8, 1599) | |
| Nested EM-TV | (14.1, 5) | (40.0, 14) | (122.8, 43) | (333.1, 117) | (872.4, 307) | (2207.3, 777) | (6184.5, 2179) | |
| EM-TV | (7.15, 4) | (−, −) | (−, −) | (−, −) | (−, −) | (−, −) | (−, −) | |
| high-noise phantom | ||||||||
| PAPA | (12.4, 5) | (35.3, 14) | (106.2, 42) | (295.3, 117) | (724.7, 289) | (1451.6, 580) | (4349.4, 1741) | |
| Nested EM-TV | (13.2, 5) | (38.1, 14) | (115.2, 42) | (304.5, 111) | (798.8, 291) | (2024.3, 737) | (5593.6, 2045) | |
| EM-TV | (9.01, 5) | (−, −) | (−, −) | (−, −) | (−, −) | (−, −) | (−, −) | |