Digital imgae processing is one of the fastest-growing subjects in information technology in the past decades.Image pre-processing, the basis of digital image identification and image processing, plays an important role in image analysis.As one of the major techniques in image pre-processing,the method of keeping the colors invariant is widely used in image identification, image segmentation，image enhancement and image compression to normalize the pictures in which colors may change due to lighting conditions.Digital image processing is now widely used in aviation and astronautics, telecommunication,medicine and industrial manufacturing.Many methods can be used to keep the colors invariant.
After analyzing and reviewing the results of other studies on the existing algorithms for color invariants in image pre-processing and comparing these algorithms,this paper chooses to deal with histogram equalization and iterative method using Matlab.A sampling test of the above two algorithms proves the validity of them.Also attmepts are made to improve these two algorithms.
The two algorithms are compared in terms of time performance and efficacy.Finally, the sampling test leads to a valid conclusion.At the same time, this paper summarize the two algorithms by pointing out their pros and cons and proposes a solution to raise their processing speed.
题主原文有些重复的地方，如下，我翻译时自己整合了一下。
并对详细的研究其中的迭代算法和直方图均衡化算法，利用MATLAB编程语言实现这两种算法，通过样本测试及分析其结果，以证明这些算法的有效性，并尝试对这些方法进行优化处理。
本论文详细地研究了上述算法，并用MATLAB实现了这些算法，通过样本测试及分析其结果，以证明这些算法的有效性。