Looking for an algorithm to generate an identicon/avatar from genome data I am looking to develop an app that generates a single identicon image that summarizes the genome information in visual form. 

Identicons are essentially a visual hash of of data. usually string data such as an IP address or name. In this case, rather than generating an identicon from a single piece of string data. I want to use the entirety of the genotype information (the 4th column) to summarize this data into a graphical representation as a way to visually identify someone from their partial genome. 

The input file is a tab-separated file consisting of 600,000 rows. Each row contains the chromosome identifier (There are 23 in total: 1-20, X, Y or MT), the position of the single nucleotide polymorphism (SNP) and the genotype (a two character variation of G,A,T or C). Below is a two line excerpt from the file.

#RSID        Chromosome   Position  Genotype
rs7537756       1         854250    AG
rs13302982      1         861808    GG


Using the Chromasome, Position and Genotype columns. I would like to generate an abstract identifying image from this data. Since there is far too much data, this image does not need to capture the data, only summarize it in a visual fashion. The goal is to setup a service that analyzes anyone's genome file and generates an identicon that is unique to them.

For more information on identicons See the wiki page
If all you want is uniqueness, you could use a visual hash.  Hash all of the data (say, with SHA256), then apply a visual hash.

A visual hash is a function $H$.  Given a short binary string $x$ (say, 256 bits long), the visual hash computes $H(x)$, a random picture that is a visualization of $x$.  The output of the hash is a visualization of the string -- a picture or image of some form -- with the property that different binary strings will lead to different images.  Also, $H$ is a deterministic algorithm, so if you hash the same binary string twice, you'll get the same picture both times.

Below I list some visual hash schemes that have been proposed, along with sample images produced by each scheme.

Random Art for PGP keys



https://user.xmission.com/~atoponce/art/

(As you'll notice, this is actually a visualization of multiple different schemes at once.)

See also the following research paper:

Hash Visualization: a New Technique to improve Real-World Security.  Adrian Perrig and Dawn Song.  Proceedings of the International Workshop on Cryptographic Techniques and E-Commerce (CrypTEC), Hong Kong, July 1999.

VizHash GD



http://sebsauvage.net/wiki/doku.php?id=php:vizhash_gd

JrSnowflake



https://wiki.debian.org/JrSnowflake

Older: README, source

OpenSSH's Visual Host Key

+--[ RSA 2048]----+
|   .+            |
|   + o           |
|  o o +          |
|   + o +         |
|  . o E S        |
|   + * .         |
|    X o .        |
|   . * o         |
|   .o .          |
+-----------------+


https://stackoverflow.com/a/3601278/781723