Medical image enhancement based on modified lut-mapping derivative and multi-scale layer contrast modification

It is not uncommon that low-contrast images in medical x-ray imaging would be acquired, which may interfere with the regular diagnosis. Thus, contrast enhancement is of critical significance in dealing with this problem. Multi-scale enhancement method, in recent years, is prevalent but has two weaknesses. Firstly, it could not effectively control the lut(Look up table) mapping in different layers, which may cause halo or grain noise. Secondly, it does not consider the relationship between coarse and detail signal, which may lead to amplified noise or artifacts. To solve the first problem, we propose a method using the modified lut-mapping derivative (MLMD) for intuitive tuning and expand it to multi-scale framework. For the second problem, a multi-scale contrast modification (MCM) function is designed to better suppress the noise or artifacts. The experimental results which integrate with MLMD and MCM show the potential of our method to prevail over the traditional ones and could lead to higher enhanced image quality.