对于BMP格式的图象,其前54个字节未文件头信息，从第55个字节开始到结束的所有数据，都是图像颜色数据。如果仅仅修改图像颜色数据而不修改文件头信息，则bmp图像大小不变且可以正常使用。当然，为了控制图像的质量，对于数据的植入方式，我们需要稍加斟酌。一个bmp图像要隐藏我们指定的信息，储存空间必不可少。为了保证信息植入前后图像的质量不发生明显的变化，我们只有把信息写到bmp图像颜色数据的每个字节的低位上。这样，每个字节的改变量不超过0Fh，对图像品质的影响非常小，用肉眼几乎分辨不出来。在源码包中有对比图，大家可以亲自对比验证。

原理即 ：用原来bmp图像颜色数据的相邻两个字节的低位来存放隐藏信息的一个字节的内容。



如隐藏信息的某个字节数据位为 3E ，bmp图像颜色数据两相邻字节的内容为：5F 27 ，处理后该相邻字节的内容变为53 2E。这样处理，一张mbp图像可以存放其自身长度2分之1大小的信息，效果不错。-The BMP format images, its former 54-byte file header information is not, from the first 55 bytes beginning to the end of all the data is color image data. If you only modify the data without modifying the color image file header information, then bmp image size unchanged and can be normal use. Of course, in order to control image quality, for the implantation of the way the data, we need a little discretion. A bmp image to hide our designated information, storage space is essential. Information in order to guarantee the quality of images before and after implantation no obvious change, we can only put information wrote bmp image color data for each byte on the low. In this way, each byte to change the volume of not more than 0Fh, the impact on image quality is very small, almost to tell with the naked eye do not come out. Source package has at contrast map, everyone can personally verify comparison.

　 Principle namely: bmp image with the original color data of adjacent two of the l