1. 很少发生：infrequence 很少发生 | infrequency 很少发生 | infrequent 稀少的
2. 出现频率较少的像元增强：Equalization Enhancement 均衡化增强 | Infrequency 出现频率较少的像元增强 | Reset Brightness 恢复原始亮度
3. 很少发生; 罕见 (名)：infrequence 很少发生; 罕见 (名) | infrequency 很少发生; 罕见 (名) | infrequent 稀少的, 罕见的, 珍贵的 (形)
4. 稀少/罕有：infrequence /稀少/罕有/ | infrequency /稀少/罕有/ | infrequent /稀少的/珍贵的/罕见的/希/