Using MTF with fixed-zoning method for automated gated imaging system in turbid medium

For a typical gated system, the gated images are recorded into video format in increasing gate opening time, each frame of the video recorded is basically to "slice" the targets at different distance from camera (based on time of light). In this paper, all enhanced target images within the field of view (FOV) are fused into one 3D image. Works had been done in 1) selecting a quantitative image quality index for automated tuning system so that sectioned images with better quality can be detected accurately in turbid condition and 2) applying a fixed zoning system - sectioning method by splitting input images into 25 equal sub-images to demonstrate the concept of flexible zoning method in future works. Modulation Transfer Function (MTF) can perform better in analyzing images under turbid condition thus is selected for this application. Experiment results show that the mid-band spatial frequencies from 21 to 61 demonstrate the degradation of image quality due to the turbid water backscattering noises. Thus, we propose to use MTF in the auto-tuning system to select best quality target from multiple images. Subsequently, image fusion is performed to fuse all selected sub-images into 3D extended targets in turbid condition.