To pass information from an android system to any other system via any protocol e.g TCP, UDP, RTP or whatever) you need to do the following steps:
First Method:
1) Put information in image as hidden text (Not as metadata) using watermarking algorithms (Just google them...)
2) When you get image in other system (e.g .NET) use that system libraries to get those data back via same algorithm yo previously used for watermarking.
Second Method :
1) Just Send information as System information along with image but be sure that you are not sending any data with is not supported on reciever system. (e.g Telnet in windows does't allow some system informations from android system) You may have to bypass them through firewall as well.
Do one of these steps and please let me know if that is helpful