Realtime sensitivity correction method and infrared imaging system

An infrared imaging system, comprising:

• (a) an infrared sensor having a plurality of sensor elements;
• (b) a high-temperature and normal-temperature reference heat sources having a predetermined temperature difference therebetween, which are each controlled to maintain different temperatures;
• (c) an optical system which scans a target object during an effective scanning period and scans said high-temperature and normal-temperature reference heat sources during a non-effective scanning period;
• and
• (d) a sensitivity correction circuit which compensates for sensitivity variations among the plurality of sensor elements constituting said infrared sensor, comprising
• a memory which stores high-temperature reference data and normal-temperature reference data obtained by scanning said high-temperature and normal-temperature reference heat sources during the non-effective scanning period, and
• a processing unit which calculates sensitivity correction coefficients from the high-temperature reference data and the normal-temperature reference data, and by using the calculated sensitivity correction coefficients, corrects infrared image data obtained by scanning the target object during the effective scanning period.

An infrared imaging system with a processing cycle time consisting of an effective scanning period and a non-effective scanning period, having an infrared sensor which acquires reference temperature detection data during the non-effective scanning period and captures infrared image data by scanning a target object during the effective scanning period, the system comprising:

• (a) reference temperature detection data storage means for storing the reference temperature detection data during the non-effective scanning period, for each sensor element contained in the infrared sensor;
• (b) noise level calculation means for calculating a noise level of each sensor element during the effective scanning period, referring to the reference temperature detection data stored in said reference temperature detection data storage means;
• (c) faulty element identification means, being activated during the effective scanning period, for identifying a faulty sensor element exhibiting an abnormal noise level exceeding a predetermined threshold, by examining the noise levels calculated by said noise level calculation means;
• and
• (d) pixel substitution means, activated during the effective scanning period, for replacing pixel data of the faulty sensor element with pixel data produced by another sensor element that is located in the vicinity of the faulty sensor element being identified.

An infrared imaging system with a processing cycle time consisting of an effective scanning period and a non-effective scanning period, having an infrared sensor which acquires reference temperature detection data during the non-effective scanning period and captures infrared image data by scanning a target object during the effective scanning period, the system comprising:

• reference temperature detection data storage means for storing the reference temperature detection data during the non-effective scanning period, for each sensor element contained in the infrared sensor;
• DC offset calculation means for calculating a DC offset value of each sensor element during the effective scanning period, referring to the reference temperature detection data stored in said reference temperature detection data storage means;
• faulty element identification means, being activated during the effective scanning period, for identifying a faulty sensor element exhibiting an abnormal DC offset value exceeding a predetermined threshold, by examining the DC offset values calculated by said DC offset calculation means;
• and
• pixel substitution means, activated during the effective scanning period, for replacing pixel data of the faulty sensor element with pixel data produced by another sensor element that is located in the vicinity of the faulty sensor element being identified.