How to export images with specified infromation

[DHQZ]

I created a mesh model entity in ogre ,and I want to implement two things in ogre .One is doing manual annotation with the mesh model ,such as mark a human body mesh, different part with different color.Another is exporting 2D images which contains specified information such as the z coordinate of mesh and background pixels that most close to the camera in the scene. How can I implement this two purpose in ogre and which function can I use ?

[xrgo]

One is doing manual annotation with the mesh model ,such as mark a human body mesh, different part with different color

you have submeshes and set different materials with different colors when selected/annotated

Another is exporting 2D images which contains specified information

you can definitely write text in images and save the files. But I guess you can make them prettier with something like imagemagick, and it can be done inside your ogre app.

How can I implement this two purpose in ogre and which function can I use ?

There's no "a function" to do those things, start programming and when you have a more specific question come back and we can help you =).
good luck!