This post addresses the subject of the appropriate human data compression format. Though an interesting idea, I think that the proposed method is too low in resolution. You acknowledge the lossiness, but I think it's just going to be too much.

Although the method you advocate is probably the best thing short of cryonics, I doubt there is any satisfactory compression method that can make anyone that's more similar to you than a best friend or a family member who gets stuck with your memories. It's better to have too much data than too much.

Because we share the same evolutionary past as all of our conspecifics, the biology and psychology of our brains is statistically the same. We each have our quirks of genetics and development, but even those are statistically similar among people who share our quirks. Thus with just a few bits of data we can already record most of what makes you who you are.

I'm not confident in this part. Although a large percentage of human biology and psychology are identical, the devil is in the details. From a statistical perspective, aren't humans and chimps practical identical also? Percentage similarity of traits is probably the wrong metric, since small quantitative differences can have large qualitative impact.

Your idea of a generic human template, with various subtemplates for quirks, is also interesting, but still too low resolution.

Under what metric do we say that you and I have the "same" quirk, even if our phenotypes look superficially similar? How much data is discarded by the aggregation?

Even if we assume that the notion of a generic human template is meaningful, there are almost as many ways that people can deviate from the generic human template as there are people, and there would have to be that many quirky subtemplates. It's possible that we could compress human phenotypic deviation into a lower number of templates than the number of people, but I don't think we are anywhere near having a satisfactory way to do so. In the least, storing the deltas of human phenotypes might cut down on the data we all have in common.

The problem with lossy measures of phenotype such as memories and our current ability to measure quirky deviations from the average is that they discard too much information: the genotype, and other low-level aspects of phenotype.

Let's start with the genotype problem. In the future, we synthesize a human with the same phenotype as our crude records of you (your memories, and your quirks according to the best psychometric indexes currently available). We will call this phenotype set X. Yet since multiple genotype can converge towards the same phenotype (particularly for crude measures of phenotype), the individual created is not guaranteed to have the same genotype as you, and probably won't. Due to having a different genotype, this individual could end up having traits outside X that you didn't have. They will have the same set of phenotypic traits as you that were recorded, but they may lack phenotypic traits that weren't recorded (because you method of recording discarded the data), and they may have extra phenotypic traits that you didn't have because keeping those traits out wasn't in the spec.

Fundamentally, I think it's problematic to try to reverse-engineer a mind based on a record of its outputs. That seems like trying to reverse-engineer a computer and its operating system based on a recording of everything it displayed on its monitor while being used. Even if you know how computers and operating systems work in general, you will still be unable to eliminate lots of guesswork in choosing between multiple constructions that would lead to the same output.

If you know a system's construction, you may be able to predict its outputs, but knowing the outputs of a system doesn't necessarily allow you to work backwards to its construction, even when you know the principles by which systems of that type are constructed.

I think the best reconstruction you will get through this method won't be substantially more similar to you than taking your best friend (who has highly similar personality and interests) and implanting him with your memories. At best, you would get someone similar enough to be a relative of yours.

We really need to preserve your genotype; otherwise, future scientists could make an individual with all your memories and crudely measured personality traits, but a different personality and value system (in ways that weren't measured), who wakes up and wonders what they heck you were doing all your life. We would need a solution that has all the phenotypic traits recorded for you, with the constraint that the individual created has the same genotype as you.

Yet even such a solution would still be discarding too much information about biological traits that influence your phenotype yet are not recorded in your genetic code, such as your prenatal development. It's been shown that prenatal factors influence your brain structure, personality, and interests. So we need to record your prenatal environment to be able to create a meaningful facsimile of you. Otherwise, we could end constructing someone with the same genotype, memories, and psychometric measures as you, who nevertheless had a different brain structure; such a person would probably be less like you than a twin of yours who was implanted with your memories, because your twin shares a similar prenatal environment to yours, while your copy does not. A different brain structure would create a similar problem to having a different genotype: a different brain that has the same recorded phenotype as you will differ from you in unrecorded aspects of phenotype.

I would worry that a record of every single thought and behavior you have, both from yourself and observers, would still not be enough to reverse-engineer "you" in any meaningful way. Adding the constraint of matching your genotype would help, but we still don't have a way to compress biological factors other than genotype, such as prenatal development. We have no MP3 format for humans.

The best record of your prenatal development that we have is your body and brain structure, so these would have to be stored along with your memories. Preferably at a rather cold temperature.