This could help with raster to vector conversion programming.

Start with a vector randomly generated. Here are 3 examples.

Example 1 |
Example 2 |
Example 3 |

Lets try to determine if the colored pixels make a vector or not.

A vector |
Not a vector |

A vector can only have 2 varying segments not counting the truncated ends.

The 2 varying segments can only be 1 pixel apart in size.

A vector |
Not a vector |

A vector can only have 2 varying pixel patterns not counting the truncated ends.

The 2 varying pixel patterns can only be 1 segment apart in size.

Example vector 1 |
Example vector 2 |

A vector can only have 2 varying pixel patterns made by the smaller pixel patterns not counting the truncated ends.

The 2 varying pixel patterns can only differ in size by 1 of the smaller pixel patterns.

Example vector |

A pixel pattern can build a new pixel pattern which can build another new pixel pattern forever.

To determine if some colored pixels make a vector or not, pixel patterns can be derived to new orders of magnitude until they reach the size of the possible vector.