An infrared thermal imager autofocus system and method with temperature compensation

Abstract

The invention relates to an infrared thermal imager automatic focusing system and method with temperature compensation, belonging to the technical field of infrared thermal imaging processing. The system includes a high and low temperature environmental experiment box, a collimator, an infrared thermal imager, a focusing mirror, a sliding screw for the focusing mirror, a focusing motor, a screw position sensor, an FPGA embedded image processor, a motor servo controller and Thermal imager complete machine temperature sensor and other components; the present invention aims at the thermal imager complete system with large zoom ratio and long focal length optical system, compresses the autofocus search range, strengthens the boundary constraints of the climbing algorithm, and improves the automatic The reliability and real-time performance of the focusing method have significant advantages in engineering implementation.

Description

technical field [0001] The invention belongs to the technical field of infrared thermal imaging processing, and in particular relates to an automatic focusing system and method of an infrared thermal imager with temperature compensation. Background technique [0002] As far as the autofocus method and implementation are concerned, mature applications in visible light imaging systems are not uncommon. However, compared with visible light imaging systems, the size, structure and quality of infrared thermal imager optical systems make conventional autofocus methods difficult to apply Infrared camera. The infrared camera has the following characteristics: [0003] 1. The signal response rate of the infrared sensor is low and the noise is large. In order to obtain better quality infrared video, a larger clear aperture is required to obtain more infrared radiation, which leads to a larger volume and quality of the optical system , causing the movement of the matching focusing se...

AI Technical Summary

Problems solved by technology

Usually, even if the automatic focusing method suitable for visible light can realize the automatic focusing method functionally, the long focusing stroke will lead to real-time performance degradation, which cannot meet the requirements of engineering realization.

[0005] 3. The parfocality of the optical system of the infrared thermal imaging camera drifts greatly with temperature. If it is not compensated before auto-focusing, it is difficult for the usual auto-focusing method to traverse the entire focus under full-temperature work in a short time. journey

For the second method of artificially increasing the sampling window intervention of the image definition evaluation function, on the one hand, adding manual intervention loses the meaning of the automatic focusing method; , even if manual intervention actively participates, there is no way to start, and its method is still ineffective

The above two improved automatic focusing methods ignore the influence of ambient temperature on the parfocality of the infrared thermal imager, and can only be more suitable for laboratory verification, and cannot provide a method for engineering realization

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