工作原理分析
http://en.wikipedia.org/wiki/Geotagging
我刚才在自己没有开通数据服务的iphone测试了一下,还算安全,没有gps信息,手头没有其他手机可以测试
ExifTool Version Number : 8.49
File Name : IMG_0006.JPG
Directory : .
File Size : 417 kB
File Modification Date/Time : 2008:08:31 16:40:01-04:00
File Permissions : rw-rw-rw-
File Type : JPEG
MIME Type : image/jpeg
Exif Byte Order : Big-endian (Motorola, MM)
Make : Apple
Camera Model Name : iPhone
Orientation : Rotate 90 CW
X Resolution : 72
Y Resolution : 72
Resolution Unit : inches
Modify Date : 2008:08:31 17:40:01
F Number : 2.8
Date/Time Original : 2008:08:31 17:40:01
Create Date : 2008:08:31 17:40:01
Color Space : Uncalibrated
Exif Image Width : 1600
Exif Image Height : 1200
Gamma : 2.2
Compression : JPEG (old-style)
Thumbnail Offset : 423
Thumbnail Length : 10151
Image Width : 1600
Image Height : 1200
Encoding Process : Baseline DCT, Huffman coding
Bits Per Sample : 8
Color Components : 3
Y Cb Cr Sub Sampling : YCbCr4:2:2 (2 1)
Aperture : 2.8
Image Size : 1600x1200
Thumbnail Image : (Binary data 10151 bytes, use -b option to extract)