Abstract: With the rapid development of the information society，image has become one of the important carriers which can transmit information.Because of the massive content of information of unprocessed image，it is extremely important to work hard at research and develop the technology for image coding.By researching and analyzing the run length encoding，an image compression method of non-restricted run length encoding is presented；the method sets the length flexibility and overcomes the limitations of the traditional run length encoding.Experiment indicates that the improved technique can greatly improve compression efficiency，and the compatibility of the new algorithm is more widespread，especially for the image compression of a large area of continuous shadow and the same color.The efficiency promotion is remarkable.The technique presents a new approach for the technique of static image compression.

Key words: image compression, non-restricted run length encoding, run-length-encoding

摘要： 在信息社会高度发展的今天，图像成为可以传递信息的重要载体之一。由于未经处理的图像信息量非常大，大力研究和开发图像压缩编码技术就非常重要。文中通过对行程编码算法的研究和分析，提出了一种非限制行程的行程码图像压缩方法，该方法灵活处理了行程长度，克服了传统行程编码中行程长度固定的局限性，实验表明运用这种方法实现静态图像压缩可以使压缩效率得到进一步的提高，适应性更加广泛，特别是对于存在连续阴影或者大量连续相同像素的图像压缩，效率显著提升。该方法为实现静态图像压缩开辟了新的思路和途径。

关键词: 图像压缩, 非限制行程, 行程长度编码