Joint transform correlator is one of the most successful optical pattern recognizers which is composed of Ar+ laser, spatial
filter, Fourier transform lenses, EALCD (electrically addressed liquid crystal displays) and CCD (Charge Coupled
Device). It has many applications in industry and military. The bottle technologies are how to recognize the target in
clutter scene and how to increase the brightness of the correlation peak which represents the detected target.
In this paper, we researched joint transform correlator (JTC) for infrared target detection, and used wavelet transform
technology to increase the contrast of input image which contains target and reference objects, reduced the high
frequency noise and realized target detection in clutter scene. According to our requirement, we selected the two-order
spline wavelet, and made input image have discrete binary wavelet transformed. Because edge always contains much
information of image, we adopted the method of modular maximum to extract the edge of different scales after wavelet
transform mentioned above. In addition, combined with threshold division which could eliminate some of the clutter, we
could get the remarkable edge.
As experiment result, we detected the infrared image, both with computer correlation matched method and optical JTC
method. The experiments show that the wavelet transform technology is one of the best data processing methods for the
target detection in clutter background.