At least for me, the input file doesn't work in Phonegap.
You need use the Phonegap API to get picture and select the source where come from, like photolibrary, camera or savedphotoalbum.
See more info about camera.getPicture: http://docs.phonegap.com/en/2.1.0/cordova_camera_camera.md.html#camera.getPicture and about Camera.PictureSourceType parameter of cameraOptions method: http://docs.phonegap.com/en/2.1.0/cordova_camera_camera.md.html#cameraOptions