ubuntu下,opencv3.x安裝一直downloading這個包,要看超時信息里的下載路徑,把它放到下載路徑中,比如我的opencv3.2.0源文件路徑為/home/han/software/linux_opencv/opencv-3.2.0/,要把protobuf這個tar.gz包放在/home/han/software/linux_opencv/opencv-3.2.0/opencv_contrib/modules/dnn/.download/bd5e3eed635a8d32e2b99658633815ef/v3.1.0下才行,bd一長串是這個文件的md5值,不用改.沒有contrib文件夾的去github上搜opencv-contrib下載后解壓到opencv-3.2.0文件夾中即可