Changing \000 to \0 is just an improvement for the storage size. It will not change anything for drawing it.
But there can be a danger with changing it: as you know a TI.Image string contains also normal characters. Lets say you got a part that looks like this:
"\000122" (two pixels)
When you change it, this will happen:
"\0122"
Suddenly, you created a new character, "\012".
You should do some checks on the image data before changing it