Archive for the ‘Blog’ Category

Digital Imaging Institute

Jul 7th, 2010 - Filed under: Blog

Several years ago I thought that there was a need for an organization for photographers and imaging experts who worked in scientific and technical fields. That is, for who work within disciplines where the technical aspects of their work was more important than the aesthetic aspect of their work. These disciplines would include forensics, medicine, research, aerospace, historical documentation, academia, astronomy, biology, archaeology, etc.

Well, time passed and I didn’t do much except think about it. Then I received an e-mail one day from Mark Maio. He independently had the same idea, and formed The Digital Imaging Institute. He’s gathered a group of experts in a variety of technical disciplines to begin this organization. They have published issues of the excellent Digital Insight Magazine. They have formed DII Groups in specific disciplines as well as in specific technologies.

The organization is still new, but I anticipate that it will be the place where those of us who work in technical and scientific fields of imaging can share information with each other, learn from each other, and benefit from those in different disciplines who face similar challenges in finding the best imaging solutions.

Open Letter to Advanced Imaging Magazine

May 6th, 2010 - Filed under: Blog

The March, 2010 issue of Advanced Imaging magazine included an article on the use of H.264 compression in security camera systems. I thought the article was interesting, except for a couple of statements that distortion is somehow acceptable in security systems. I sent a letter to the author of the article (Barry Hochfelder) and the individual quoted in the article (Marc Damhaut of Euresys), and decided to also post it here:

I am a forensic image analyst and was initially pleased when I saw the article on surveillance / security video in the March 2010 article of Advanced Imaging magazine. But then I read the quote by Mr. Damhaut that, “In surveillance, you can compress it without [worrying about] distortion of the image. … If there’s a bit of distortion in the image, it’s not a problem.”

Well, if the video is of a homicide suspect and it’s important to make an identification based on facial features, tattoos, clothing, height, etc. to either identify the murderer, or exonerate an innocent individual, then that ‘bit of distortion’ may be essential! I can’t tell you how many times I’ve worked on cases where surveillance / security video systems have had just a bit too little resolution or just a bit too much compression to see the detail needed.

The problem is with manufacturers, installers and consumers. The manufacturers think that this application isn’t critical; the installer places the cameras in bad locations, doesn’t install lighting, bases his determination of the resolution on a live feed rather than the recorded and compressed video, etc.; and the consumer is looking for low cost, large capacity systems with an emphasis on catching employee theft. No one in this mix considers the potential of the video from these systems in serious crimes – or, at least, they don’t investigate the requirements of the forensic video/image analyst.

I am writing to call your attention to the misconception that the image requirements in these systems is somehow less important than in other applications. The truth is that these videos may help an innocent person prove their innocence, or help put a murderer behind bars.

Regards,

George Reis

Imaging Forensics
Forensic image analysis, digital imaging & photography.
Consulting, training & litigation support.

Testimony Reviews

Apr 28th, 2010 - Filed under: Blog, Expert Witness, Testimony

When I am scheduled to testify in court, I sometimes notify colleagues in the area and invite them to watch me with the hope that they can provide me with feedback. I’ve done this for a number of years, and have gotten feedback from a few colleagues including Jack Nadelle from the Los Angeles District Attorney’s Office and Steve Everest from the King County Sheriff’s Office. In my testimony on a recent homicide case, Steve wrote a page of notes that included things like the percentage of time I made eye contact with the jury during my testimony, how comfortable I appeared, the way I addressed technical issues, my demeanor during direct and cross examination, etc. The feedback I’ve gotten from colleagues like Jack and Steve have helped me to do my best when presenting evidence and my opinions in court. I recommend that anyone who testifies in court have others watch them and provide feedback. A key part of any experts work is to explain evidence and opinions formed about that evidence in court – getting feedback about our testimony helps us do this better.

There is also a benefit to watching someone else provide testimony. I’ve participated in a couple of cases where I was able to watch the opposing expert witness testify. But, recently, Grant Fredericks was giving testimony in my area and he invited me to watch his testimony. I was able to see how he explains what observations he made when analyzing video evidence, how he presents that evidence, and how he answers the questions put forth to him, etc. Grant does an excellent job at explaining his opinions and the video evidence – I was able to take away some ideas to use in future cases. All expert witnesses should take the opportunity to watch other experts testify.

If you are an expert presenting evidence and opinions in court, watching others testify and getting feedback from others on your testimony are very valuable.

Reflecting back on 2009

When I think about the past year, and cases I’ve worked, training I’ve received, training I’ve given, there are a few things that stand out.

In the arena of cases, I had two unique experiences – A Daubert Hearing in 12/08, and Grand Jury testimony in mid-2009.

The Daubert Hearing was on image authentication (are the images real, and do they represent real people and real events). That hearing was U.S. v. Frabizio in December of 2008, and was one of the few Daubert Hearings on photography, imaging, or image authentication. It was an interesting case, as it was going to its third trial. I was retained by defense counsel to analyze and interpret the government expert’s report and findings. I provided information to the defense attorney on this report, and attended the Daubert hearing, and answered her questions on his testimony. With the limited number of Frye and Daubert hearings on forensic photography, forensic image analysis, or image authentication, it was an interesting experience to participate in this hearing.

The Grand Jury testimony was also on an image authentication case. In this instance, I was an expert witness for the government. I have testified in cases since the early 1990s, but this was my first time to testify before a Grand Jury. It was quite interesting, as there is no judge, no defense attorney, and the accused is not present, nor is a case detective. It’s the prosecutor, a court reporter, the members of the grand jury, and the witness. In this case, I was impressed by the professionalism of the prosecutor and the members of the grand jury – I can imagine a situation in which a system without the formality or presence of a judge, defense attorney, etc. moving toward chaotic – I was pleased that this was far from the case.

As to training I received, it would be a toss up between two classes I took in the field of photogrammetry. One was on reverse projection photogrammetry that I posted about earlier. The other was a class in using Photomodeler (a software application for applying photogrammetry) for close range photogrammetry, presented by Dan Mills of DCM Technical Services. Photogrammetry is taking measurements from photos, and there are several approaches to this technology. Unfortunately, there are very few classes available in close range photogrammetry or in reverse projection photogrammetry. I was fortunate to get excellent training in each in 2009.

Regarding training that I provided – it’s difficult to isolate any one specific workshop. But, I did have the opportunity to give four workshops in digital photography to the San Francisco Police Department in 2009. That agency purchased Nikon D700 cameras for their crime scene investigators and wanted each member to be trained in the use of that camera for crime scene and evidence photography. I was proud to be the trainer they chose to provide this instruction. We held four, three-day sessions, with eight investigators in each session. It was a pleasure to work with this agency and to see their dedication to providing their front-line personnel with the tools and training to do their job.

Lastly, another highlight of 2009 was being appointed chair of the Forensic Photography and Imaging Certification Board of the International Association for Identification. It is an honor to have been chosen to fill this position, and our board is working hard on several projects.

The last year was successful in many ways – looking back at a few of the highlights helps see where we are today and prepare for the future. I’m looking forward to more interesting cases and great training opportunities in the coming year.

G

Photoshop Feature Requests

Nov 24th, 2009 - Filed under: Blog, Photoshop

When I present workshops, many people frequently ask for a handful of features. Two of the most popular are improvements to the History Log and getting back the LayerComps to PDF script. Two questions that are raised when these issues are brought up include, “Why is it this way?” and, “How do we let Adobe know we want this or that feature?”

The main reason why features don’t exist that you may think are obvious needs, is that Adobe doesn’t know that it’s a needed feature. If 100 people ask for a feature, then that gets their attention, but if only one person asks, it simply won’t carry the same weight of the frequently requested features.

I suggest that if there are features that you want, that you let Adobe know. You can do this by posting to the Adobe Photoshop Feature Request Forum. You’ll have to register to post, but it’s relatively painless.

What about finding solutions to problems you are having? Again, Adobe can’t fix a problem without knowing that it exists. They have a Photoshop Macintosh Forum, and a Photoshop Windows Forum.

Use these forums to let Adobe know what you’d like, what’s working and what’s not working. Another great resource is John Nack’s Blog. John is the Principal Product Manager for Photoshop at Adobe. He frequently asks readers of his blog for feedback on features. Keep an eye on his blog, and provide him with feedback when he asks for it in addition to posting on the forums listed above. If we don’t let Adobe know what we want, then we can only blame ourselves if we don’t get those features.

Reverse Projection Photogrammetry

Nov 22nd, 2009 - Filed under: Blog, Image Analysis, Photography, Video Analysis

The Law Enforcement and Emergency Services Video Association (LEVA) held it’s annual conference this week. I was fortunate to attend the two day pre-conference workshop on reverse projection photogrammetry presented by Richard Vorder Bruegge, Walter Bruehs, and Chris Iber, all from the FBI Forensic Audio, Video, and Imaging Analysis Unit.

Reverse Projection Photogrammetry is used to measure objects in a photograph or video. It can be used to determine if an individual could be excluded or included as a suspect based on height. In addition to using this method to determine the height of an individual in an image, I have used this technique to determine the position of objects in relation to their surroundings (after the objects were removed), the distance of safety barriers in construction scenes (after the construction was completed and the barriers removed), the size of cracks in a sidewalk (after the sidewalk was repaired), etc. from photos of those scenes.

The workshop covered issues related to the methodology and foundations of this technique. Any forensic image analyst or forensic video analyst who hasn’t yet had the opportunity to take this workshop should do so. It has been offered at the LEVA conference for two or three years, and also at the IAI Annual Conference.

Using Photoshop and Bridge for On-Screen Comparisons

Nov 9th, 2009 - Filed under: Blog, Fingerprints, Image Analysis, Photoshop, Video Analysis

Someone recently posted a question on the CLPEX website regarding on-screen comparisons. This question was specifically about fingerprint comparisons, but the method is the same whether comparing prints, footwear, vehicles, etc.

The first step is to determine which images to use (or eliminate). I frequently use Adobe Bridge for this. I set up Bridge in the Filmstrip workspace. If I need to compare two or three images to decide which I will use for the final comparison, I select multiple images and use the loupe tool to compare details. The loupe tool provides a 100, 200, 400, or 800 percent magnification of a portion of each image in the Preview panel. Just click on an image in this panel to activate the loupe, click and drag it to move it, click it again to close it. You can display one loupe on each image in the Preview panel, as shown here:

This image shows two images in Bridge with the loupe tool.

This image shows two images in Bridge with the loupe tool.

Once the images are selected, they can be opened into Photoshop for comparison.

If the images are of the same resolution and approximately the same cropping, then they can be synchronized for zooming and scrolling. Do this by choosing the “Zoom all Windows” and “Scroll all Windows” in the options for the Zoom and Hand tools. Now, if you tile the images side-by-side, and zoom, both images will zoom; scroll one, and the other will scroll as well.

A new blank layer can be added to each image and marks can be made on that blank layer to indicate various features. Multiple layers can be used to better separate different categories of features, etc. With the Extended version of Photoshop CS3 or CS4, the Count tool can be used to mark features.

G

An Introduction to the Blog

Oct 4th, 2009 - Filed under: Blog

I thought that the most appropriate first blog would be an introduction to who I am, and what my plans are for this blog. Something short and to the point.

I’m George Reis and I am the owner of Imaging Forensics, Inc. providing consulting services in forensic video analysis, forensic image analysis, and forensic photography to attorneys, police agencies, and insurance companies. I also provide training in these fields, primarily to law enforcement personnel.

What’s my plan? I hope to post weekly on issues relating my work – which means, image analysis, image authentication, forensic photography, expert witness work, the training I provide, etc. Tips and techniques that I find helpful in this work will likely be included as well. I’ll try to be brief and keep things interesting.

Since I’m new at this, I’d appreciate  your input on what you’d like to see here. Please post a comment, or drop me an e-mail.

G