The image pattern recognition can accurately identify and locate the target, but image pattern recognition is unable to
accurately recognize the distorted targets (the targets rotated in plane or scale changed), which has restricted the
development of the image pattern recognition. In order to solve the problem of inaccurate recognition for distorted target
in cluttered background among the image pattern recognition, the distorted target images and the training images are
edge extracted by canny operator. The Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter is
synthesized with the edge extracted training images. The low frequency information of the distorted target images and
the filter is enhanced. Then the edge extracted distorted target image is filtered by the OT-MACH filter. Thereby, the
distortion tolerance of the OT-MACH filter is expanded. It can respond higher correlation peaks and have higher
distortion tolerance to recognize various types of distorted targets in cluttered background. By this method, which the
space edge extraction combines with frequency domain filtering, the scale distortion tolerance is 0.72~1.42 times; the
rotation distortion tolerance can reach up to 70 degrees. In order to prove the feasibility of this method, a lot of computer
simulation experiments have been done with the canny operator and the OT-MACH filter.
With the development of the technology of infrared, infrared optical system has been widely used in many fields, especially in tank target detection and recognition. The difficulty and key in the designing of LWIR optical systems for working under temperature range of -60°C~80°C is athermalization. In this paper, the infrared telephoto lens is designed which is composed of four pieces of lenses. The working temperature range is -60°C~80°C. In order to balance the chromatic aberration and thermal aberration, two aspherical surfaces are used in this cooled athermalized infrared optical system. The effective focal length is 100mm and the F-number is 2.The full field of view is 7.0°. The curve of MTF is close to diffractionlimit curve. Within the working temperature, the value of MTF at 17cy/mm is always large than 0.4. The result shows that the infrared optical system achieved better athermal performances at the working temperature range.
Infrared optical system has been widely used in many fields, especially in target detection and recognition. While the
virtue of infrared optical system is that it can not only detect great distance but also detect the target in the poor
conditions such as turbid air or smoke, flog and snow. Hybrid optoelectronic joint transform correlator (HOJTC) is very
useful for target detection and recognition. Exploiting the Fourier transform property of a lens, it can implement target
detection in real time. Designing perfect optical system is one of key technology of target detection.
In this paper, the infrared detector which we adopted is infrared focal plane arrays with working waveband 3-5μm. Its
resolving power is 30 lp/mm. For the infrared optical system, the effective focal length, relative aperture and the field of
view should be large enough to ensure the long distance and large field of view target can be detected. In hybrid
optoelectronic joint transform correlator, the light weight and big aperture of infrared optical system is required. For this
purpose, an aspheric surface is introduced and the telephoto lens is composed of the three pieces of lenses. The MTF
curve of the telephoto lens is close to diffraction limit. The result shows that the aspheric surface can not only simplify
and reduce the structure and weight of the system respectively, but also can effectively improve the image quality of the
system. This telephoto lens can be used in HOJTC for infrared target detection.