参考:http://stackoverflow.com/questions/8650407/how-to-copy-selected-files-from-android-with-adb-pull
"adb pull sdcard/mydir/*.jpg" it apparently doesn't interpret wildcards
You can move your files to other folder and then pull whole folder.
adb shell mkdir /sdcard/tmp
adb shell mv /sdcard/mydir/*.jpg /sdcard/tmp # move your jpegs to temporary dir
adb pull /sdcard/tmp/ # pull this directory (be sure to put '/' in the end)
adb shell mv /sdcard/tmp/* /sdcard/mydir/ # move them back
adb shell rmdir /sdcard/tmp # remove temporary directory