调整pdf的边缘及其行间距大小。首先把pdf保存为图片，然后用此程序调整边缘或行间距大小，把修改后的图片重新整合成pdf。此软件的目的是为了kindle用户编写。因为kindle的屏幕有限，除去多余的边缘和行间距，可以使kindle读书效率更高，减少过多翻页操作。-Adjust the line spacing pdf and the size of the edge. First, save the pdf as a picture, and then use this procedure to adjust the size of the edge or line spacing, the re-integration of the modified images into pdf. The purpose of this software is to kindle the user to write. Because of the limited screen kindle, to remove the extra edge and line spacing can make reading more efficient kindle, to reduce excessive flip operation.