针对红外图像，采用双门限分割法进行图像分割，然后采用分段灰度变换法进行图像增强。根据具体图像，通过人机交互的方式确定2个阈值，将图像分割为目标区、过渡区和背景区3部分；按照每一部分的特点，设计不同的灰度变换，对图像进行分段线性增强，得到感兴趣目标区的最佳视觉效果。通过对16位红外图像进行实验，得到了满意的结果。实验表明,该算法灵活便捷，在增加对比度和去除噪声的同时，还抑制了背景，达到了预期的效果。

An infrared image processing solution is proposed. It uses bithreshold method to segment image and enhance the image with segmentation gray scale transform method．For a specific image，two thresholds are selected manually to cut the image into three parts (target area，transition area and background area).Based on the characteristic of each part，different gray scale transforms are designed to carry out image linear enhancement to get the best visual effect for the interested area. The satisfactory result is achieved with the experiment on 16 bit infrared images. The experiment shows that the algorithm is flexible and convenient. It can increase the contrast and decrease the noise while suppressing the background.