Method of generating codes for animal marking
A method of generating animal identification codes is described. A first and second number are selected, then each number is compared respectively against previously used first and previously used second numbers in a pool. Such comparing uses a computed distance based on how the numbers will be encoded and marked on an animal, such as a Hamming distance of printed symbologies. If the distance computed for either the first or second number is below a distance threshold, that number is discarded and another number is selected. When both numbers pass the distance test, they are added as a pair into the pool. Pairs from the pool may be encoded and marked on an animal. The encoding of the first number may generate a human-readable mark while a different encoding of the second number generates a machine-readable mark.
1. A method of marking animals comprising the following steps:
(a) choosing a first number pair comprising a first H number and a first M number;
(b) placing the first number pair into a set of available number pairs;
(c) choosing a next number pair comprising a next H number and a next M number;
(d) computing an H distance between the next H number and at least a subset of all H numbers in the set of available number pairs;
(e) computing an M distance between the next M number and at least a subset of all M numbers in the set of available number pairs;
(f) comparing the H distance computed against an H distance threshold;
(g) comparing the M distance computed against an M distance threshold;
(h) discarding the next number pair if the H number is in a set of used H numbers;
(i) discarding the next number pair if either the H distance is less than the H distance threshold or the M distance is less than the M distance threshold; otherwise adding the next number pair to the set of available numbers;
(j) repeating from step (c) until the size of the set of available number pairs is equal to or greater than a set size threshold;
(k) selecting a selected number pair from the set of available number pairs; the selected number pair comprising a selected H number and a selected M number;
(l) marking the selected H number using a human-readable encoding on a first animal;
(m) marking the selected M number using a machine-readable encoding on the first animal;
(n) placing the selected H number into the set of used H numbers;
wherein the human-readable encoding and the machine-readable encoding are distinct; and wherein the H number and the M number are distinct.
2. The method of marking animals in claim 1 comprising this additional step, following step (n):
(o) repeating from step (k) until a terminating condition is reached.
3. The method of marking animals in claim 1 wherein:
the choosing in step (c) comprises choosing randomly.
4. The method of marking animals in claim 1 comprising the additional step:
(p) decreasing either the H distance threshold or the M distance threshold or both, responsive to the size of the set of available number pairs.
5. The method of marking animals in claim 1 wherein:
the size of the subset in steps (d) and (e) is the smaller of: (i) the number of available number pairs in the set of available numbers; and (ii) a number in the range of 5 to 100.
6. The method of marking animals in claim 1 wherein:
the output of the human-readable encoding of step (l) comprises one or more digits wherein each digit consists of a combination of seven line segments; and
the computing an H distance in step (d) comprises the sub-steps:
(d1) selecting a number pair, from the at least a subset of the set of available number pairs, comprising an H′ and an M′ number;
(d2) computing a Hamming distance between a first digit of the H number and a first digit of a H′ number;
(d3) repeating step (d2) for each respective digit in the H number and H′ number;
(d4) summing the Hamming distances from steps (d2) and (d3) to produce a Hamming sum;
(d5) repeating steps (d1) through (d4) for each number pair H′ and M′ in the at least a subset of the set of number pairs;
wherein a Hamming symbol set for the Hamming distance comprises the seven line segments;
wherein the H distance comprises the minimum of the Hamming sums.
7. The method of marking animals in claim 1 wherein:
the output of the machine-readable marking encoding of step (m) comprises a vine code comprising two or more leaves wherein each leaf of the vine code consists of a combination of V line segments; and
the computing an M distance in step (e) comprises the sub-steps:
(e1) selecting a number pair, from the at least a subset of the set of available number pairs, comprising an H′ and an M′ number;
(e2) generating an output marking Mm from M using the machine readable marking encoding of above; generating an output marking Mm′ from M′ using the machine readable marking encoding of above;
(e3) computing a Hamming distance between a first leaf of the Mm marking and a first leaf of the Mm′ marking;
(e4) repeating step (e3) for each respective leaf in the Mm marking and the Mm′ marking;
(e5) summing the Hamming distances from steps (e3) and (e4) to produce a Hamming sum;
(e6) repeating steps (e1) through (e5) for each number pair H′ and M′ in the at least a subset of the set of number pairs;
wherein a Hamming symbol set for the Hamming distance comprises the V line segments;
wherein the M distance comprises the minimum of the Hamming sums.
8. The method of marking animals in claim 1 wherein:
the animals are rodents.
9. The method of marking animals in claim 1 wherein:
the animals have no additional placed markings other than the markings placed by steps (l) and (m).
10. A device for marking animals in a vivarium using the method of claim 1 comprising:
a stored-program computer comprising software and memory adapted to execute the steps of claim 1 (a) through (k) and step (n);
a marking machine adapted to perform the steps of claim 1 (l) and (m).
11. A system for marking animals in a vivarium wherein;
the vivarium comprises animals marked by the method of claim 1 using the device of claim 10 .
12. A method of marking objects comprising the following steps:
(a) choosing a first number pair comprising a first H number and a first M number;
(b) placing the first number pair into a set of available number pairs;
(c) choosing a next number pair comprising a next H number and a next M number;
(d) computing an H distance between the next H number and at least a subset of all H numbers in the set of available number pairs;
(e) computing an M distance between the next M number and at least a subset of all M numbers in the set of available number pairs;
(f) comparing the H distance computed against an H distance threshold;
(g) comparing the M distance computed against an M distance threshold;
(h) discarding the next number pair if the H number is in a set of used H numbers;
(i) discarding the next number pair if either the H distance is less than the H distance threshold or the M distance is less than the M distance threshold; otherwise adding the next number pair to the set of available numbers;
(j) repeating from step (c) until the size of the set of available numbers is equal or greater than a set size threshold;
(k) selecting a selected number pair from the set of available numbers; the selected number pair comprising a selected H number and a selected M number;
(l) marking the selected H number using a human-readable encoding on a first object;
(m) marking the selected M number using a machine-readable encoding on the first object;
(n) placing the selected H number into the set of used H numbers;
wherein the human readable encoding and the machine-readable encoding are distinct.