A target extraction method based on region of interest is presented to solve the difficult problem of infrared image target identification technology.Firstly

the regions of interest are detected by using two-dimensional maximum entropy method

on the basis of this

the local classification method is applied to the local neighborhood of each pixel in the region of interest

in order to analyse the pixel gray characteristics;Secondly

the spatial position characteristics of every pixel point is builded by calculation of chamfer distance

and is combined with the gray characteristic;Finally

the new determination method of threshold value is defined to fetermine the ownership of every pixel point

to achieve the separation of background and extraction of target.The results of experiments indicate that the proposed method has a higher accuracy and stability comparing with the classic otsu method and maximum entropy method in infrared target extraction

it has a certain value for problems of low contrast and difficult recognition of infrared image.