Monday, November 7, 2016

Is Photoshop a verb?

I'm momentarily out of my self-imposed exile to post this brief note on my old friend, Photoshop.

When processing images and video for the court, many agencies will try to do more with less. They will make the mistake of thinking that standard commercial photo editors will be fine. The software is often very inexpensive or even free. But, would you trust your case to just any piece of software?

In courtrooms and the media, there’s a common term for modifying images and video in a nefarious or bad way: it’s called “Photoshopping.” Fashion models are Photoshopped. Advertisements contain fantastic Photoshopped compositions. So the question is: now that Photoshop is a verb and not a forensic tool, do you want your evidentiary images and video to be Photoshopped?



Is it legal?

There are two major legal “standards” to deal with in the US: Frye and Daubert. There are some variations to these, like California’s modified Frye (Kelly-Frye). Then there are the various evidence codes. Each state has its own evidence code. The US Federal Government has theirs as well.

The Frye Standard
Where novel scientific evidence is at issue, the Frye inquiry allows the judiciary to defer to scientific expertise precisely as to whether or not it has gained “general acceptance” in the relevant field. The trial court’s gatekeeper role in this respect is conservative, thus helping to keep “pseudoscience” out of the courtroom.
In Frye states, Amped Software products meet the “general acceptance” threshold. Amped Software technology is used by all major law enforcement agencies in the US (local, state, and federal), most of Canada’s LE agencies, and around the world, in more the 60 countries as of today.

The Daubert Standard

In Frye states, it’s usually enough for a practitioner to inform the court that the tool in question has “general acceptance.” In Daubert states, and with the US government in Federal Courts, the Daubert standard goes from “tell me” (Frye) to “show me” (Daubert). If there’s a question about a particular tool or technique, either side can request a “Daubert Hearing.” Within the hearing, the tool/technique is demonstrated and questions as to process, science, etc. are asked/answered. If the judge is satisfied that the tool/technique passes the test, then the evidence is admitted.

Daubert places a heavy emphasis on science and the scientific method.
Has the scientific theory or technique been empirically tested? According to K. Popper (1989) in The Growth of Scientific Knowledge, “the criterion on the scientific status of a theory is its falsifiability, refutability, and testability”.

In the case of Amped Software products, the answer is yes. The source of the algorithms is scientific / academic texts and papers. They’re all from peer-reviewed and publicly available sources. The scientific status of the theory / technique is covered in each referenced source. In the case of Amped FIVE, the source of the algorithm, publication date, etc., for all filters used are all included in the report generated by the user.
All trial courts make a preliminary determination of admissibility. This job involves a preliminary assessment of whether the evidence is relevant, competent, and material. In short, can the evidence be properly applied to the facts in this case? This is the traditional “gatekeeping” function of courts.
This has more to do with the competence of the user than the tool itself. Has the practitioner properly used his/her tool? Is the practitioner qualified / trained in the use of the tool? Amped Software has trained hundreds of practitioners all over the world. Thus, this part of the gatekeeping is satisfied with the training.
Has the scientific theory or technique been subjected to peer review and publication? This ensures that flaws in the methodology would have been detected and that the technique is finding its way into use via the literature.
Again, all of the algorithms in Amped Software products come from peer-reviewed publications.
Can the technique and its results be explained with sufficient clarity and simplicity so that the court and the jury can understand its plain meaning? This is just the Marx standard, which is assumed to be incorporated in Daubert as it was with Frye.
This is the real beauty of the reports generated by Amped Software products. Amped FIVE’s report, for example, gives the user the plain English explanation, the more detailed scientific/academic explanation, as well as the filter settings, and the reference source for each filter that is applied within the workflow. No other product on the market does this.

Federal Rules of Evidence (Rule 702)
General acceptance is not a necessary precondition to the admissibility of scientific evidence under the Federal Rules of Evidence (FRE), but the FRE – especially rule 702 – do assign the trial judge the task of ensuring that an expert’s testimony both rests on a reliable foundation and is relevant to the task at hand. Pertinent evidence based on scientifically valid principles will satisfy those demands..”

“If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise, if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.”
Not to beat the point to death, but Amped Software products more than meet this standard.

The thing that our customers love so much, is that the work that they do can be presented with such a rock-solid report, that gives them the confidence to present what they’ve done to the judge/jury. They don’t have to be a rocket scientist (though a few of our customers actually are). They just have to follow their training and confidently read from the report.

Q: I see that you’ve applied a Levels filter in step 4. Does that filter’s algorithm come from a peer-reviewed and published source.

A: Yes, indeed. It’s from Dr. Anil Jain’s 1989 textbook, Fundamentals of Digital Image Processing. You can find the algorithm’s discussion and description on page ...

It’s important to know that over 50% of the filters in Photoshop come from proprietary algorithms (internal, patented, secret). That number continues to grow as Adobe supports its main customers--professional photographers.

For those using freeware tools, where’s the references and support? It’s non-existent.

So here’s something to consider when working in law enforcement forensics where a mistake could either convict the innocent or free the guilty: don’t you want a rock-solid toolset that any court in the land would accept? Of course, you would.



For more information, or to request a quote, click here.

Note: the italicized text comes from Mark Stevens, LtCol USMC (Ret), Assistant Professor of Criminology, California State University Fresno, and his course on using multimedia evidence in trial.

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