You have to do it manually.
Think of it like an animation.
Each segment of your picture is a slide.
textureFileName "[insert picture name here]"
startTopLeft [0, 0]
frameSize [102, 102]
frameStride [102, 102]
this is an example of a texanim file.
the file name should be obvious.
the num Frames sets how many frames your animation has.
Frames per row sets how many frames are on a row. As the animation plays, the frame will move across and tick the counter up one, when the number reaches the final frame, it will go down a row and reset the framesperrow counter.
startTopLeft defines where the top left coordinate of your starting frame is. This is in pixels.
FrameSize sets how large the starting frame/every frame is, also in pixels.
FrameStride is how far the pixels move over to reach the next frame.